Showing posts with label Testing. Show all posts
Showing posts with label Testing. Show all posts

Monday, November 17, 2014

Referral: Mackay On Early Negative Testing For Ebola

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Credit CDC PHIL

 

NOTE:  As I am posting this, NBC News is reporting the death of Dr. Martin Salia, who reportedly initially tested negative for the virus even after becoming symptomatic.

Ebola Patient Dr. Martin Salia Has Died in Nebraska: Officials

Dr. Martin Salia, an Ebola patient being treated in Nebraska, has died, medical officials said Monday.

Salia was diagnosed with Ebola in Sierra Leone and was airlifted to Nebraska on Saturday. He was the 10th Ebola patient to be treated on U.S. soil and the third treated at Nebraska Medical Center.

 

# 9337

 

We’ve often heard that Ebola tests aren’t conclusive until they are taken 48-72 hours after symptoms first appear, and based on recent media reports (see WaPo’s A doctor’s mistaken Ebola test: ‘We were celebrating. . . . Then everything fell apart’), that appears to have been the case with Dr. Martin Salia who died this morning.

 

Dr. Ian Mackay gives us some deep background on the testing for Ebola, and why a 48-72 hour window for testing was selected.

 

Ebola testing: 48-72 hours for a negative to turn positive

Currently, some fraction of the people who present very early after they may have been infected by Ebola virus for testing, return a negative result. This is probably a rare event because the majority of cases arrive for care with Ebola virus disease (EVD) already well underway.


The latest Centers for Disease Control and Prevention (CDC) guidance in these instances is to wait (48 to) 72 hours and see if the patient remains ill, or becomes more unwell. If they do either of these, a second test is performed.[1] If the suspect case recovers from illness, no repeated testing is indicated.


The test we rely on to confirm a clinically suspected EVD case is called a reverse transcriptase polymerase chain reaction (RT-PCR). RT-PCR is a technique designed to  seek out a tiny but very specific region of the Ebola virus's RNA genome, copy it into DNA then amplify those DNA copies a billion-fold by making more copies. Somewhere during that exponential amplification process, the technology of the day (currently fluorescence detection but formerly agarose gel detection, radiation and chemiluminescence) allows us to identify that the specific DNA we seek is appearing above an arbitrary threshold...we have a positive test result for Ebola virus.


(Continue . . . )

Thursday, October 23, 2014

NYC Health Dept Statement On Symptomatic HCW From Guinea

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UPDATED:  Added a statement from Doctors without Borders (MSF).  16:50 hrs EDT

 

# 9240

 

Normally I don’t report on suspected cases of Ebola since most will turn out to be false alarms, but since it is already all over the media, and the New York City Department of Health has issued a statement, I’ve reproduced it here.

 


Statement on Patient at Bellevue Hospital

October 23rd, 3:05 pm

Today, EMS HAZ TAC Units transferred to Bellevue Hospital a patient who presented a fever and gastrointestinal symptoms.  

The patient is a health care worker who returned to the U.S. within the past 21 days from one of the three countries currently facing the outbreak of this virus.

The patient was transported by a specially trained HAZ TAC unit wearing Personal Protective Equipment (PPE).  After consulting with the hospital and the CDC, DOHMH has decided to conduct a test for the Ebola virus because of this patient’s recent travel history, pattern of symptoms, and past work. DOHMH and HHC are also evaluating the patient for other causes of illness, as these symptoms can also be consistent with salmonella, malaria, or the stomach flu.

Preliminary test results are expected in the next 12 hours.

Bellevue Hospital is designated for the isolation, identification and treatment of potential Ebola patients by the City and State.  New York City is taking all necessary precautions to ensure the health and safety of all New Yorkers.

As a further precaution, beginning today, the Health Department’s team of disease detectives immediately began to actively trace all of the patient’s contacts to identify anyone who may be at potential risk. The Health Department staff has established protocols to identify, notify, and, if necessary, quarantine any contacts of Ebola cases.

The Health Department is also working closely with HHC leadership, Bellevue's clinical team and the New York State Department of Health to ensure that all staff caring for the patient do so while following the utmost safety guidelines and protocols.

The chances of the average New Yorker contracting Ebola are extremely slim. Ebola is spread by directly touching the bodily fluids of an infected person. You cannot be infected simply by being near someone who has Ebola.

 

Via Pathfinder on FluTrackers, we have the following brief statement from Doctors without Borders regarding this case:

 

Statement on Returned Field Worker

October 23, 2014

Doctors Without Borders/Médecins Sans Frontières (MSF) statement:

A person in New York City, who recently worked with Doctors Without Borders in one of the Ebola affected countries in West Africa, notified our office this morning to report having developed a fever.  As per the specific guidelines that Doctors Without Borders provides its staff on their return from Ebola assignments, the individual engaged in regular health monitoring and reported this development immediately.  While at this stage there is no confirmation that the individual has contracted Ebola, Doctors Without Borders, in the interest of public safety and in accordance with its protocols, immediately notified the New York City Department of Health & Mental Hygiene, which is directly managing the individual’s care. 

At this stage Doctors Without Borders will not be providing any further details about its colleague.

 

You’ll find that FluTrackers is maintaining an extensive thread on media reports here.

Tuesday, October 14, 2014

CDC Announces A Faster EV-D68 Lab Test

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# 9194

 

The number of confirmed Enterovirus D68 cases sits at 691 people from 46 states, but due to the complex and lengthy testing process, there has been a huge backlog of samples awaiting testing. Anecdotal reports from around the nation suggest the actual number of infections is many times higher, but patients with mild or moderate symptoms rarely get tested.


Today the CDC has announced their development of a faster, more streamlined lab test, which should help clear up the backlog of untested samples. 

 

This test is a is a “real-time” reverse transcription polymerase chain reaction, or rRT-PCR, and it reportedly identifies all currently circulating strains of EV-D68 in the United States.  It should quadruple the CDC’s lab capacity to turn around test results.

 

But at the same time, a faster test could artificially make the outbreak appear to be accelerating, so the CDC is taking great pains to assure that any sudden jumps in the number of confirmed cases in the coming days is more likely to be due to processing this backlog, than from a sudden spike in transmission.


This from the CDC’s press release:

 

CDC Develops a New, Faster Lab Test for Enterovirus D68

Confirmed cases will appear to rise as agency accelerates specimen testing; Changes in case counts due to faster testing will not represent a real-time influx of new cases

The Centers for Disease Control and Prevention (CDC) has developed and started using a new, faster lab test for detecting enterovirus D68 (EV-D68) in specimens from people in the United States with respiratory illness. This test will allow CDC to more rapidly test remaining specimens received from states since mid-September.

Every year, enteroviruses and rhinoviruses cause millions of respiratory illnesses in children. This year, EV-D68 has been the most common type of enterovirus identified, leading to increases in illnesses among children and affecting those with asthma most severely.  Other rhinoviruses and enteroviruses continue to be detected as well. 

CDC expects, as with other enteroviruses, that EV-D68 infections will likely begin to decline by late fall.  The real-time lab results combined with data on hospital admissions will help us understand when and where the EV-D68 outbreak is ending.   CDC has received informal reports from some hospitals and states who are seeing signs of decreasing EV-D68 infections.  CDC is gathering more information from states and assessing whether this represents a national trend.

“CDC has received substantially more specimens for enterovirus lab testing than usual this year, due to the large outbreak of EV-D68 and related hospitalizations,” said Anne Schuchat, MD, assistant surgeon general and director of CDC’s National Center for Immunization and Respiratory Diseases. “When rare or uncommon viruses suddenly begin causing severe illness, CDC works quickly to develop diagnostic tests to enhance our response and investigations. This new lab test will reduce what would normally take several weeks to get results to a few days.”

Since the outbreak of EV-D68 began in August, CDC has tested 1163 specimens submitted by hospitals and from 45 states.  Of the specimens tested by the CDC lab from August 1 to October 10, about half have tested positive for EV-D68. About one third have tested positive for a rhinovirus or an enterovirus other than EV-D68. The new lab test will allow us to process the approximately one-thousand remaining specimens at a much faster rate.

Testing for EV-D68 is not used to determine treatment for a particular patient. Treatment for patients with EV-D68 is supportive therapy, such as oxygen therapy.  The outcome of the EV-D68 test is to collect surveillance data to help public health officials target our responses to the outbreak, not to determine the treatment plan for a specific patient.  CDC prioritized testing for the most severe cases since the outbreak began in August to get a better understanding of the disease.

(Continue . . . )

Wednesday, August 06, 2014

Mount Sinai Ebola `Suspect’ Tests Negative

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# 8924

 

As I wrote yesterday, about another `suspect’ case in Saudi Arabia - Most will likely turn out to have something less dire, like Dengue or malaria.  But the possibility of Ebola in travelers coming from West Africa cannot be ignored.

 

Tonight, not unexpectedly, we have confirmation that the `suspect case’ in isolation at Mount Sinai Hospital for the past two days in New York City has tested negative for the Ebola virus.  

 

Below is a screen shot of the announcement from the Mount Sinai Hospital Twitter account.

 

 

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Tuesday, August 05, 2014

Saudi MOH: Testing Possible Ebola Suspect

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# 8916

 

With the escalating Ebola crisis in Western Africa, and an increased awareness of the potential of seeing infected travelers land in other areas of the globe, we can expect to see a steady stream of reports like the one below announcing the testing of `suspected Ebola’ cases.

 

Most will likely turn out to have something less dire, like Dengue or malaria.  But the possibility of Ebola in travelers coming from West Africa cannot be ignored.

 

While I’m not inclined to post every suspected case being tested in this blog (they will get plenty of coverage elsewhere), today we’ve a report from the Saudi Ministry of Health regarding a suspected case recently arrived in Jeddah from Sierra Leone.


As Jeddah was ground zero for this year’s big MERS outbreak in Saudi Arabia, and is very near the Holy city of Mecca,  this one has enough crossover interest to be worthy of posting. 

 

As the MOH statement indicates, there are a lot of possibilities other than Ebola.

 

Saudi Arabia Testing Blood Samples of Suspected Ebola Case

05 August 2014

A Saudi man whose travel history includes a recent business trip to Sierra Leone presented with symptoms of viral hemorrhagic fever last night at a hospital in Jeddah.

The source of his infection could be one of several viruses, including Ebola virus because of his recent travel to a country in which there is an active outbreak of the disease.

The patient, 40, is in critical condition. He has been moved to a tertiary care center with advanced isolation and infection-control capabilities.

Preliminary testing at a specialized laboratory in Saudi Arabia was negative for Dengue virus.

Additional tests are underway to determine if the source of the infection is yellow fever, Alkhumra or another virus. MOH is also submitting samples for Ebola virus testing at an international reference lab at the recommendation of the World Health Organization.

Some viral hemorrhagic fevers are found in Saudi Arabia, however there has never been a case of Ebola virus in the Kingdom.

This case was detected by the Ministry’s surveillance system, which was established within the Command & Control Center and includes real-time monitoring and self-reporting by medical facilities across the Kingdom.

Saudi Arabia announced in April that it is not issuing visas for the 2014 Hajj and Umrah to pilgrims from Sierra Leone, Liberia and Guinea due to these countries suffering from an Ebola outbreak.

Medical workers are monitoring travelers at airports and seaports across the Kingdom.

Wednesday, June 25, 2014

Spain Testing Traveler For Possible Ebola Infection

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UPDATED 1350 HRS EDT:  Spanish Media: Negative Test Reported On Suspected Ebola Case

 

# 8779

 

While we don’t know yet if it will amount to anything, over the past 16 hours or so the Spanish press has been reverberating with reports of a suspected imported Ebola case, hospitalized and being tested, in Valencia (see FluTrackers thread). 

 

The patient, who apparently fell ill (shortness of breath, fever, nosebleed) on a flight from Morocco on Monday, is reportedly  `clinically stable’ in isolation at Hospital La Fe de Valencia, as test results are awaited.  

 

Given the ongoing Ebola outbreak in West Africa (see WHO Ebola Update – June 24th), and out of an abundance of caution, anyone with recent travel history to the region who displays signs of severe illness is likely to trigger a full scale public health response such as this. 

 

Typical of the media coverage of this event is the following from Teinteresa.es.

 

The possible case of Ebola evolves favorably isolated on Faith

  EFE , Castellón

The patient is isolated in the hospital La Fe suspected of having Ebola, of Guinean origin and landed in Valencia from Morocco, is progressing well from a clinical point of view while trying to determine if you have this pathology.

 

The Minister of Health, Manuel Llombart, has provided this information on statements to the media in Castellón, where today signed a collaboration agreement with the University Jaume I.

 

According Llombart, the patient, who has not offered more data, presented a series of symptoms during a flight from Morocco, as oxygen requirement and nasal bleeding, they did suspect the crew that could be infected by the Ebola virus.

(Continue . . .)

 

The prodromal symptoms of Ebola infection are nonspecific enough that they could be easily confused with a number of other viral (or malarial) illnesses, and so we’ll have to wait for test results before we know the score.  But even if this patient tests positive, the rapid isolation of the patient by local public health authorities is likely to prevent further spread.

 

Movies like 1995’s Outbreak with Dustin Hoffman, and books like Tom Clancy’s Executive Orders and The Hot Zone by Richard Preston, have helped to turn Ebola into the ultimate nightmare disease in the eyes of the public.

 

But the reality is, the spread of African Viral Hemorrhagic Fevers (VHFs which includes Ebola, Marburg & Lassa) have traditionally been geographically limited. The illness strikes quickly, with profound and debilitating symptoms, and that helps to limit human-to-human spread.

 

That isn’t to say it is inconceivable for one of these viruses to be exported outside of Africa. After all, over the past decade we’ve seen three cases of Lassa fever imported in the United States (see Minnesota: Rare Imported Case Of Lassa Fever). 

 

But for now, the risks of seeing Ebola get a foothold outside of Western and Central Africa is considered low. 

 

In the most recent ECDC Rapid Risk Assessment on Ebola (June 9th), experts worked out several scenarios where the Ebola virus might travel to the European Union, including a scenario similar to the one that is currently under investigation. 

 

As you will see, the recommendations are quite specific, and not as draconian as many might suppose:

 

Scenario 3: Passenger with symptoms compatible with EVD on board an airplane

Cabin crew that identify a sick passenger on board and suspect an infectious disease, and ground staff receiving the passenger at the destination, should strictly follow the IATA guidelines for suspected communicable diseases.

These guidelines provide information on how to handle a sick passenger during the flight, how to reduce the risk of transmission on board the aircraft, how to communicate the event to the destination airport, and how to record  contact details on passenger locator cards for the passengers in the two rows around the case. Public health authorities and emergency medical services at the airport of destination should be informed in advance of arrival.

On arrival, the sick passenger should be put in a separate room awaiting medical assessment. The assessment of possible exposure to ebolavirus and of the compatibility of the symptoms with Ebola virus disease is outside the  scope of the airline crew’s actions and should be performed by medically trained ground staff.


The population incidence of Ebola virus infection is low, even during an outbreak, and it is considered highly
unlikely that a passenger infected with Ebola virus boards an airplane. In addition, the prodromal presentation of the disease is not characteristic enough to distinguish an Ebola virus infection from many other viral diseases. The public health response to a sick passenger on an aircraft should be based on a thorough assessment of the patient’s possible exposure to ebolavirus rather than on the clinical presentation. The evaluation of the exposure should check if, within the past three weeks, the passenger has:


•  visited a country where ebolavirus disease has been confirmed (for the current outbreak: Guinea, Sierra Leone and Liberia); AND
•  been in contact with a sick or dead wild animal (particularly bats) while there;

OR

•  cared for and touched a severely ill or dead person.

A ‘yes’ to question 1 and to either question 2 or 3 would signify that the ill passenger has been potentially exposed to Ebola virus in an affected country in the past three weeks. If the investigation does not conclude a  significant  risk of exposure to ebolavirus (no specific exposure for the sick traveller, no symptoms during the flight), contact tracing is not indicated. If the passenger is at risk of having been exposed to Ebola virus, the following epidemiological measures based upon proximity to the index patient should be considered (ECDC RAGIDA guidelines):


•  Passengers and crew with reported direct contact


Co-travellers and crew members who had reported direct body contact with the index case should be tracedback. To gather this information, any records of significant events on the flight should be obtained from the airline.

•  Passengers seated one seat away from the index patient

As direct contact is the main route of transmission for Ebola virus, only passengers who were seated one seat
away from the index case in all directions should be included in the trace-back. If the index case occupied an
aisle seat, the three passengers seated directly across the aisle from the index case should also be traced-back.

•  Crew members of plane section

Crew members who provided in-flight service in the section of the aircraft where the index case was seated
should be included in the trace-back, as well as other crew members who had direct contact with the patient.

•  Cleaning staff of plane section

The staff that cleaned the section seat where the index case was seated and the toilet facilities (if used by the
index case) should be traced-back.

Traced-back passengers, crew members and cleaning staff who have been identified should be assessed for their specific level of exposure. The risk for transmission is considered low if no direct contact with the passenger or with material potentially contaminated by the passenger’s bodily fluids has occurred. Self-monitoring of temperature should be considered for 21 days for all contacts. The same measures should be considered when a patient reports symptoms during a flight but fails to alert the crew.


There is no reason to quarantine the airplane upon arrival when a passenger presents with symptoms during the flight.

 


It should be noted that we don’t know if the suspect case meets the criteria (had recent contact with sick or dead wild animals or cared for or touched a severely ill or dead person), only that he supposedly hails from Guinea and fell ill on the flight. 

 

Hopefully we’ll get test results later today to either confirm or rule out Ebola. 

 

But either way those tests come out the risks to his fellow airline passengers, the general public in Spain (and the rest of Europe), remain low.

Thursday, June 12, 2014

Mackay On MERS-CoV PCR Serum Testing

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Coronavirus – Credit CDC PHIL

 

# 8731

 

Earlier this week the CDC’s EID Journal published a dispatch on a 2013 family cluster of MERS-CoV infection that began in Qatar and migrated to Tunisia (see WHO Coronavirus (nCoV) Update On Tunisian Cases). This cluster consisted of a 66 year old father, and his two adult children, although initially the father tested negative for the virus.

 

Volume 20, Number 9—September 2014
Dispatch

Family Cluster of Middle East Respiratory Syndrome Coronavirus Infections, Tunisia, 2013

Fekri Abroug , Amine Slim, Lamia Ouanes-Besbes, Mohamed-Ali Hadj Kacem, Fahmi Dachraoui, Islem Ouanes, Xiaoyan Lu, Ying Tao, Clinton Paden, Hayat Caidi, Congrong Miao, Mohammed Mohammed Al-Hajri, Mokhtar Zorraga, Wissem Ghaouar, Afif BenSalah, Susan I. Gerber, and World Health Organization Global Outbreak Alert and Response Network Middle East Respiratory Syndrome Coronavirus International Investigation Team

AIn 2013 in Tunisia, 3 persons in 1 family were infected with Middle East respiratory syndrome coronavirus (MERS-CoV). The index case-patient’s respiratory tract samples were negative for MERS-CoV by reverse transcription PCR, but diagnosis was retrospectively confirmed by PCR of serum. Sequences clustered with those from Saudi Arabia and United Arab Emirates.

(Continue . . .)

 

Most readers of this blog are aware that respiratory samples (sputum, swabs, etc.) are normally tested for evidence of viral shedding (usually by rRT-PCR) when active MERS-CoV infection is suspected, and sometimes convalescent serum is collected and checked for antibodies several weeks after infection. 

 

Although primarily thought of as a `respiratory’ disease, MERS-CoV infection is also known to produce severe systemic illness, with the virus showing a decided affinity for the kidneys.

 

Which opens up a third avenue for MERS-CoV testing; using PCR testing of blood serum to look for signs of viremia (or `viraemia’), aka - replication of the virus in the bloodstream. 

 

As you might expect, all of this gets a bit technical, so who better to take us through the process than Dr. Ian Mackay? 

Follow the link to read:

 

Thursday, 12 June 2014

MERS-CoV in the blood....

The Middle East respiratory syndrome coronavirus (MERS-CoV) is, at its core, a respiratory virus. Well, as far as we know it is anyway. But, like other respiratory viruses (see an earlier post on rhinoviruses), MERS-CoV can be detected in the blood....a so-called "viraemia". In some cases this is identified in other virus infections in parallel with the viral load being generally high, perhaps indicating that virus is replicating beyond the body's ability to contain and control it at the site of initial replication.


Perhaps, and MERS-CoV may be a good example of this, so-called extra-respiratory spread of a respiratory virus occurs when it has a penchant for blood vessel cells (they present its receptor or have something in their cellular machinery that aids virus replication) or some other ability to specifically get beyond the respiratory tract.

(Continue . . .)

 

Wednesday, May 14, 2014

Mackay: Putting Respiratory Viruses In Perspective

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Credit VDU BlogDr Ian Mackay

 

#8618

 

While wait for the test results from the MERS exposed HCWs in Orlando (and announcement later this morning from the World Health Organization’s IHR Emergency Committee Meeting on MERS), Dr. Ian Mackay has a wonderful `explainer’ on the wide world of respiratory viruses, which include far more `players’  than most people imagine.

 

Follow the link to read:

 

Keep calm and call the lab...without it, you know less than you think you do

This morning there are 2 symptomatic healthcare workers (HCWs) in the United States (of America; I'm just going to use the "US" from from here on) who came into contact with the recently diagnosed MERS-CoV positive 44M (age and sex confirmed yet?) imported case.

The news has driven something of a twitter storm in the #MERS channel. Not unexpected I guess. The implication is that these 2 have acquired MERS-CoV from contact with the imported MERS-CoV-positive person. 

But that link is still far from proven yet.

(Continue . . . )

 

Saturday, December 21, 2013

Hong Kong: Dr. Ko Wing-man On H7N9 Testing Of Poultry

 

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Photo Credit – FAO

 

 

# 8098

 

 

With increasing, albeit incomplete evidence of the H7N9 virus circulating in poultry in Mainland China, it is understandable that Hong Kong would like to prevent the virus from entering their territory, and infecting their poultry – or worse – people.

 

As the 7 million+ residents of Hong Kong consume more poultry than can be produced locally, every week a large quantity of live poultry is imported from neighboring Guangdong Province.  The same province that has reported 5 human H7N9 infections in the past few weeks.

 

Negotiations over virus testing procedures have been underway for several weeks between mainland authorities and Hong Kong’s SFH (Secretary for Food & Health) Dr. Ko Wing-man.  At issue is expanding the use of serum –or serological – testing for the virus. 

 

Unlike PCR testing, which can detect the virus if the bird is shedding virus when the samples are taken, serology tests can tell us if the bird has ever been exposed to the virus.  And that could tell us a great deal about how widespread the virus is in the poultry population.  It does not, however, tell us whether the tested subject is currently infectious (it may, or may not be).

 

And therein lies the rub.  

 

The powerful Chinese Ministry of Agriculture – which in the past has taken every opportunity to deny they have a `bird flu problem’  - would take a dim view of culling (or banning`possibly not currently infected’  poultry based on a test only indicative of  prior exposure.

 


Today, Dr. Ko Wing-man made the following comments regarding the negotiations with the mainland.

 

SFH on avian influenza A(H7N9)

Following is the transcript of remarks made by the Secretary for Food and Health, Dr Ko Wing-man, before attending a public function this afternoon (December 21):


Secretary for Food and Health: We are still discussing with the Mainland authorities regarding the introduction of serological test for avian influenza A(H7N9) among the imported poultry. I hope that it is at the final stage. But there are implications of introducing such a test which we have to deal with before the implementation.

For example, I have repeatedly explained that although the rapid PCR test for avian influenza A(H7N9), which is currently in use, is already quite a big improvement in terms of our overall risk management, some experts feel that it is not 100% safe. The serological test will perhaps give us a clearer picture of how widespread the avian influenza A(H7N9) virus is among the poultry population, but the test itself cannot directly imply that the batch of poultry concerned is infectious. (A positive result) from a serological test does not strictly mean that the poultry batch (concerned) is infectious.

 

Therefore, how to dispose of the particular batch of imported poultry which is tested positive in serology investigation is a question, and it is something that we really need to have an agreement beforehand. I believe the Mainland authorities are now considering this aspect. I will give it a little bit more time.


(Please also refer to the Chinese portion of the transcript.)

Ends/Saturday, December 21, 2013
Issued at HKT 19:01

 

 

In China, food insecurity breeds unrest, and so anything that threatens the national food supply is treated as a serious national security risk.  For many Chinese, poultry is their only affordable source of meat protein.

 

With the H5N1 virus, the choice to cull was relatively easy.  It killed a high percentage of the birds it infected.   If you didn’t cull your flock, the virus would do it for you.  And continue to spread, to boot.

 

But with H7N9, the virus produces little or no discernable illness in poultry. To the poultry farmer, culling means killing  – by all outward appearances – perfectly healthy birds. 

 

While the small number of human infections with the H7N9 virus would seem ample incentive to eradicate infected birds, to date, the evidence implicating poultry as the primary vector of the disease is pretty much circumstantial.  We’ve no `smoking chicken’.


And so an agreement between Hong Kong and Mainland China on poultry testing has yet to be agreed upon.

 

Leaving us with more questions than answers regarding  the rate of infection, and geographic spread, of the H7N9 virus in Chinese poultry.

Thursday, December 19, 2013

Dealing With `The Fog Of Flu’

 

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Photo Credit CDC

 

# 8090

 

Although influenza is a hot topic right now (avian, human seasonal, even `mystery’), not every influenza-like-illness (ILI) out there is caused by an influenza virus. In fact, of the more than 6,200 specimens tested by U.S., WHO and NREVSS collaborating labs last week, only about 13% were positive for influenza. 

 

And this among samples highly suspected of being influenza.

 

The truth is, it is very difficult to differentiate between influenza infections, RSV (respiratory syncytial virus), respiratory adenoviruses, parainfluenza viruses, rhinoviruses, coronaviruses, metapneumovirus, (and others) without using sophisticated lab tests. 

 

While commonly viewed as `lesser’ respiratory viruses, the rogue’s gallery of non-influenza viruses above are all perfectly capable of causing severe illness, and even death.  Particularly in the very young, very old, or those with comorbid medical conditions.

 

In a clinical setting - most influenza-like-illnesses go unidentified. Viral respiratory infections are generally self-limiting illnesses, treatment is pretty much the same regardless of etiology, and so there is little point in trying to identify the cause of every illness.

 

When doctors do test for influenza, they generally use an RIDT (Rapid Influenza Detection Tests), but as we’ve seen reported often over the years (see MMWR: Evaluating RIDTs) these tests often suffer from a lack of sensitivity (and to a lesser extent) specificity.  Less often, samples will be sent for more detailed PCR testing.

 

Researchers – with better tools available today – are indentifying `new’ viruses all of the time. A few well distributed viruses that until recently, were unknown, include:

 

  • The human metapneumovirus (HMPV) was identified in Dutch children with bronchiolitis about a dozen years ago.  Since then, it has been found to be ubiquitous around the world, and responsible for a significant percentage of childhood respiratory infections . . . yet until 2001, no one knew it existed.
  • Human Bocavirus-infection (HBoV) wasn’t identified until 2005, when it was detected in 48 (9.1%) of 527 children with gastroenteritis in Spain (cite).  It has since been found around the globe using PCR testing.

 

And the list grows longer every year.

 

Adding to our misery, it is not all that  uncommon to be infected by more than one virus (or a viral/bacterial combination) at the same time. In 2008 a study (see Frequent detection of viral coinfection in children hospitalized with acute respiratory tract infection using a real-time polymerase chain reaction) looked at clinical samples taken from 254 children treated in Germany over a 10 month period, finding:

 

Respiratory syncytial virus (RSV) was the most frequently detected pathogen in 112 samples (44.1%), followed by human bocavirus (hBoV) in 49 (19.3%), and rhinovirus in 17 samples (6.7%).

 

Viral coinfection was detected in 41 (16.1%) samples with RSV and hBoV being the most dominating combination (27 cases, 10.6%). Viral coinfection was found in 10 cases (17%) of children with bronchitis (n = 58) and in 7 cases (23%) of bronchiolitis (n = 30). In patients with pneumonia (n = 51), 17 cases (33%) were positive for 2 or more viral pathogens.

 

This plethora of pathogens helps to explain – in part - why so many people who get the flu shot every year complain they still caught `the flu’.  

 

Often, they’ve caught one of these ubiquitous `flu-like illnesses’ that are not covered by the shot.

 

And it also helps to explain why, in Montgomery, Texas, public health officials have not yet been able to determine the cause of a handful of unusually severe respiratory infections (see Montgomery County, Tx Influenza-Like Illness Investigation Update – Dec 18th.  There are literally dozens of possibilities to be explored and ruled out.

 

Dr. Ian Mackay weighs in this morning on the discovery process in:

 

Texan flu step: flu-like illness outbreak in Montgomnery County [UPDATED]

 

In places like Hong Kong, China, Indonesia, Saudi Arabia, and Egypt, the elimination process becomes even more difficult.  There they not only have the above complement of seasonal flu and non-flu viruses, they have multiple strains of novel influenza (H5N1, H7N9, H9N2) to contend with, and in the Middle East, an emerging coronavirus as well (MERS-CoV).

 

All of which can present with more or less the same symptoms . .. at least at the start of the infection.

 

Testing is both imperfect and time consuming, and getting accurate results depends on more than just the laboratory diagnostics employed.  Patient samples have to be taken at the right time (when the patient is shedding virus), from the right place (with respiratory viruses, deeper into the respiratory system is usually better), and packaged and transported properly to give the best chance of detection.

 

All of which means that we are often left to deal with the `fog of flu’.   Incomplete, or sometimes erroneous reports, from around the world. 

 

After nearly 9 years of doing this blog, I can only recommend patience and a healthy dose of skepticism when we see news reports of something `unusual’ or perhaps, even `alarming’  somewhere in the world.  Early media reports are often misleading, and are designed more to drive web traffic or sell newspapers than they are to inform the public.

 

None of which is to suggest that we shouldn’t watch these reports with interest.  We should, since one of these days, one of them could certainly herald the arrival of a serious threat.

 

But, as I wrote last year in  Novel Viruses & Chekhov’s Gun, most of these threats will  turn out to be less dangerous than they first appear.

 

As for that rare virus that genuinely poses a serious public health threat?

 

Well, that’s why we urge people to follow good flu hygiene year-round, stay informed, and have a good pandemic (and all threat’s disaster) preparedness plan in place (see Pandemic Preparedness: Taking Our Cue From The Experts.)

 

Because - regardless of what may come down the pike tomorrow - the advantage always goes to those who prepared today.

Saturday, November 09, 2013

Poultry Samples Around Dongguan H7N9 Case Test Negative

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Credit Wikipedia

 

# 7955

 

Last Tuesday (see CHP: Notification of confirmed human case of H7N9 in Guangdong Province) we learned of a 3-year-old boy in the city of Dongguan, Guangdong Province, who was hospitalized with the H7N9 virus.  While the route of infection was unknown, the assumption is that most people contract this virus through contact with infected poultry.

 

Yesterday we learned that attempts by Dr. Ko Wing-man – SFH of Hong Kong – to prevent importation of poultry from farms close to Dongguan City were blocked (see Hong Kong: No Deal On Poultry Import Restrictions From Areas With Human H7N9 Cases) as the virus had not yet been detected in poultry there – only in humans.

 

One of the the many mysteries surrounding this avian virus is that despite roughly 140 human cases scattered across China since last February, the virus has only rarely been detected in poultry. This has led  to speculation that there might be another – intermediate – host involved in its transmission to humans. 

 

But thus far, despite a good deal of investigation and testing, no other likely host has been identified.

 

Today we’ve a report from Yangcheng Evening News (published in  Guangzhou City, Guangdong, China) indicating that out of 175 recent samples tested by their agricultural department, no positive results were found in Dongguan City poultry.  The (machine translated) version is linked below:

 

Poultry samples found no H7N9 virus

Yangcheng Evening News reporter Qin Xiaohui reports: the evening of 8, Dongguan City Bureau of Agriculture informed that, recently, Dongguan City Bureau of Agriculture animal disease prevention and control center for the major poultry markets Changping sample testing of 175 samples were collected from poultry, the City level veterinary laboratory testing found no H7N9 bird flu positive.

 

The evening of 8, Dongguan City, Guangdong Dongguan Bureau of Agriculture released a children (living in Dongguan Changping) confirmed H7N9 avian influenza infection in the latest issue of the Bulletin. Informed that since April this year detected H7N9 bird markets Dongcheng three positive samples after Dongguan City Bureau of Agriculture animal H7N9 avian influenza projects into the routine monitoring of the project, in accordance with provincial deployment requirements to carry out sampling and monitoring, has been operating in the city of poultry, aquaculture sectors cumulative sampled more than 20,000 copies, of which 1550 were from Changping samples were not detected H7N9 bird flu positive.

 

Dongguan City Bureau of Agriculture said it would closely monitor the progress of events, and strictly implement work measures. First, continue to proactively with the provincial and municipal departments communication and collaboration, mutual exchange reported; second is to continue to step up inspections to monitor and increase focus on the area of ​​the frequency of workplace inspections; third is to continue to strengthen quarantine supervision, requiring all three birds wholesale market in Field quarantine quarantine personnel strictly control market; fourth is to continue to strengthen publicity and urge employees to do personal protection.

 

Given the likelihood that poultry are the vector, one has to wonder if the sensitivity (or perhaps the sample collection method) of these  tests being used to detect this virus in poultry is somehow lacking.

 

Genetic analysis clearly shows that the H7N9 virus has an avian origin. 

 

In May, the CDC posted the following graphic that shows the evolutionary (reassortant) steps they believe led to the creation of the new H7N9 virus in China.

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The eight genes of the H7N9 virus are closely related to avian influenza viruses found in domestic ducks, wild birds and domestic poultry in Asia. The virus likely emerged from “reassortment,” a process in which two or more influenza viruses co-infect a single host and exchange genes.

This can result in the creation of a new influenza virus. Experts think multiple reassortment events led to the creation of the H7N9 virus. These events may have occurred in habitats shared by wild and domestic birds and/or in live bird/poultry markets, where different species of birds are bought and sold for food.

As the above diagram shows, the H7N9 virus likely obtained its HA (hemagglutinin) gene from domestic ducks, its NA (neuraminidase) gene from wild birds, and its six remaining genes from multiple related H9N2 influenza viruses in domestic poultry.

 

While infected poultry remain the most likely culprit, the definitive answer to exactly how the H7N9 virus is spreading in China, and occasionally manages to infect humans, remains frustratingly elusive.

Thursday, November 07, 2013

MERS Surveillance & Testing Pearls

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Photo Credit WHO

 

# 7945

 

The World Health Organization, CDC, and the ECDC have all recommended heightened surveillance and testing for the MERS coronavirus – with particular attention to be paid to recent travelers to the Middle East. The Mantra, published by WHO with every MERS notification over the past few months, reads:

 

Based on the current situation and available information, WHO encourages all Member States to continue their surveillance for severe acute respiratory infections (SARI) and to carefully review any unusual patterns.

 

Health care providers are advised to maintain vigilance. Recent travellers returning from the Middle East who develop SARI should be tested for MERS-CoV as advised in the current surveillance recommendations.

 

Patients diagnosed and reported to date have had respiratory disease as their primary illness. Diarrhoea is commonly reported among the patients and severe complications include renal failure and acute respiratory distress syndrome (ARDS) with shock. It is possible that severely immunocompromised patients can present with atypical signs and symptoms.

 

Health care facilities are reminded of the importance of systematic implementation of infection prevention and control (IPC). Health care facilities that provide care for patients suspected or confirmed with MERS-CoV infection should take appropriate measures to decrease the risk of transmission of the virus to other patients, health care workers and visitors.

 

All Member States are reminded to promptly assess and notify WHO of any new case of infection with MERS-CoV, along with information about potential exposures that may have resulted in infection and a description of the clinical course. Investigation into the source of exposure should promptly be initiated to identify the mode of exposure, so that further transmission of the virus can be prevented.

 

Despite these appeals, somehow the case identified yesterday in Spain (see ECDC: Rapid Risk Assessment On MERS-CoV) managed to present at a hospital in Mecca on October 28/29th- be diagnosed with pneumonia - but was not isolated, or identified as having the MERS virus.  As a consequence, she was able to fly back to Spain two days later, potentially exposing others.

 

All of which makes the following UMEM Educational Pearl, posted by the University of Maryland School of Medicine, particularly timely. Titled: Isolation criteria for MERS-CoV, it discusses a `hypothetical’ case history, and whether or not MERS testing and isolation are indicated.

 

Title: Isolation criteria for MERS-CoV

Keywords: MERS-CoV, Viral Illness, Respiratory (PubMed Search)

Posted: 11/6/2013 by Andrea Tenner, MD
Click here to contact Andrea Tenner, MD

Case Presentation:

A 56y/o man with diabetes presents with fever, cough, and diarrhea x 2 days.

V/S: T:38.7 BP:165/88 P: 105 R:24 O2 sat:91% on room air

CXR: left lower lobe infiltrate.

On further history you learn he has just returned from visiting family in Saudi Arabia 7 days ago.  While there, he visited a cousin that was ill.

Clinical Question:

Should this patient be isolated for Middle Eastern Respiratory Syndrome – Corona Virus (MERS-CoV)?

Answer:

Yes, there are 150 cases to date and 64 have died.  None confirmed in the US yet but 6 confirmed in Europe.

Patients who should be isolated in an airborne iso room with N95 mask use (similar to TB) are:

Patients with fever + pneumonia/ARDS AND one of the following:

  • Travel to the Arabian Peninsula within 14 days of symptom onset
  • Close contact with a person with fever and respiratory illness within 14 days of travel to the Arabian Peninsula
  • Member of a cluster of patients with severe ARI being evaluated for MERS-CoV

Bottom Line:

In patients with febrile respiratory illness requiring hospitalization and recent travel to the Arabian Peninsula: isolate for MERS-CoV and contact the health department.

(Continue . . . )

 

In September, the CDC updated their guidance on the surveillance for, and testing of suspected MERS cases, in their MMWR report:

 

Updated Information on the Epidemiology of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Infection and Guidance for the Public, Clinicians, and Public Health Authorities, 2012–2013

(EXCERPT)

Evaluating patients. CDC has changed its guidance to indicate that testing for MERS-CoV and other respiratory pathogens* can be conducted simultaneously and that positive results for another respiratory pathogen should not necessarily preclude testing for MERS-CoV. Health-care providers in the United States should continue to evaluate patients for MERS-CoV infection if they develop fever and pneumonia or acute respiratory distress syndrome (ARDS) within 14 days after traveling from countries in or near the Arabian Peninsula.† Providers also should evaluate patients for MERS-CoV infection if they have ARDS or fever and pneumonia, and have had close contact§ with a recent traveler from this area who has fever and acute respiratory illness.

CDC continues to recommend that clusters¶ of patients with severe acute respiratory illness (e.g., fever and pneumonia requiring hospitalization) be evaluated for common respiratory pathogens and reported to local and state public health departments. If the illnesses remain unexplained, particularly if the cluster includes health-care providers, testing for MERS-CoV should be considered, in consultation with state and local health departments. In this situation, testing should be considered even for patients without travel-related exposure. Additional information about CDC's interim guidance regarding who should be evaluated for MERS-CoV infection is available at http://www.cdc.gov/coronavirus/mers/interim-guidance.html.

 

 

Dr. Ian Mackay on his Virology Down Under blog has some choice comments regarding the failure to detect this case while still in Saudi Arabia, as well.  Follow the link to read:

 

MERS-CoV case in Spain, imported from Saudi Arabia during visit for Hajj pilgrimage [UPDATED]

Sunday, November 03, 2013

The Price Of Vigilance

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Photo Credit WHO

UPDATED :   Not unexpectedly, the suspected cases in France referenced below have reportedly tested negative for the MERS coronavirus, and will be released from the hospital.  A h/t to Pathfinder on FluTrackers for the update.

# 7931

 

The inevitable result of the emergence of a pair of novel viruses (H7N9 & MERS-CoV) - and the call by the World Health Organization for all member nations to `continue their surveillance for severe acute respiratory infections (SARI) and to carefully review any unusual patterns’  - is that anyone with a recent travel history to the Middle East or to China, and who presents to a hospital with fever and/or flu-like symptoms, is going to probably be tested, and isolated, until these viruses can be ruled out.


Over the past several months, we’ve seen Hong Kong’s CHP announce the isolation, and testing, of more than a dozen cases recently arrived from the Middle East – none of whom tested positive for the virus. 

Last week we saw similar negative tests announced by both France and Egypt (see France: MOH Statement On Negative MERS-CoV Case &  Egypt Testing Suspected MERS-CoV Case).

Similarly, Hong Kong reported a number of negative H7N9 tests over the summer.

 

As we’ve seen with suspected cases of H5N1 over the years, many are tested, but very few actually prove positive for the virus.

 

And the reason is fairly simple:  The early symptoms for MERS-CoV, H5N1, H7N9 ; Fever, malaise, respiratory symptoms, even pneumonia . . . are virtually identical to a host of other (far more common) viral infections like influenza and rhinoviruses.

If MERS or Avian flu is even a possibility, then prudence dictates immediate isolation and testing – at least until the cause of the illness can be identified, and novel viral infections ruled out.  And since these viruses pose a potential larger public health  threat - testing for them is newsworthy – even though most of these tests will prove negative.

 

Yesterday, reports began to emerge (see FluTrackers Thread) of a family in Toulouse, France – with recent travel history to Saudi Arabia - who are being tested for the MERS coronavirus. This morning, an update from Le Parisien

Despite the headline, we still don’t know if any of these people have the MERS virus.

 

Coronavirus: three people hospitalized in Toulouse

Published on 03.11.2013, 12:13 PM | Updated: 12:58

Seven people, including six of the same family were hospitalized Friday in Toulouse (Haute-Garonne) for a hint of coronavirus MERS. This Sunday, three of them are still under observation at the Purpan Hospital. | (DR)

Seven people, including six of the same family were hospitalized Friday in Toulouse (Haute-Garonne) for a hint of coronavirus. This Sunday, three of them are still under observation at the Purpan Hospital. Two had flu-like symptoms after a trip to the Middle East.

These are the grandparents who showed signs of difficulty breathing and fever over 38 degrees, tells France 3 Midi-Pyrenees .

Both were returned on October 28, a trip to Saudi Arabia and suffered samples to identify a potential novel coronavirus MERS-CoV. Their children and grandchildren have had to meet the same tests but showed no signs of the disease. Most have also been released from the hospital on Saturday but were forced into isolation at the moment. Only the son of the two travelers, the father of two children, remained in hospital. In parallel, a seventh person, a septuagenarian, was hospitalized after a pilgrimage to Mecca but emerged immediately.

(Continue . . . )

 

Mild infections have sometimes required more than one test to obtain a positive result, but we should have a better idea on whether this family Toulouse, France have the virus in the next 24 hours or so.    

 

With cold & flu season upon us, it is going to be even harder for clinicians to differentiate between common respiratory viruses and the more dangerous, but far rarer, MERS-COV and H7N9 avian flu viruses. So we can expect to see a steady stream of news items, like this one, alerting us to cases being tested.

 

All of which highlights the need for an accurate and rapid test for both of these viruses (see Referral: Dr. Mackay On MERS-CoV Testing).  Something that is being worked on, but that so far, remains elusive.

Wednesday, October 30, 2013

Referral: Dr. Mackay On MERS-CoV Testing

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Coronavirus – Credit CDC PHIL

 


# 7921

 

 

Dr. Ian Mackay has a informative post this morning on his Virology Down Under blog on the recently announced rapid blood test for MERS-CoV.   As readers who follow this blog already know, lab tests are not always definitive.   First  a link to Ian’s piece, then I’ll be back with a bit more.

 

New MERS-CoV laboratory test: takes 10-minutes but what can it tell you?

 

The two main measures of the accuracy of any diagnostic test are sensitivity and specificity.

  • Sensitivity is defined as the ability of a test to correctly identify individuals who have a given disease or condition.
  • Specificity is defined as the ability of a test to exclude someone from having a disease or illness.

 

While a rapid MERS-CoV test would be a great boon to surveillance, our experience with Rapid Influenza test kits (see MMWR: Evaluating RIDTs) has not been all that encouraging.

 

According to the CDC:

The rapid tests vary in terms of sensitivity and specificity when compared with viral culture or RT-PCR. Product insert information and research publications indicate that:

  • Sensitivities are approximately 50-70%
  • Specificities are approximately 90-95%

 

But of course, this is a different test, a different collection method, and a different virus.  As Dr. Mackay points out, we need to see some real-world data on how well this new test works in the field.

 

We also know a lab test can have excellent sensitivity and specificity under laboratory conditions – but if the sample collected from the patient doesn’t contain enough virus (or is improperly stored or transported) – then the best test in the world won’t be accurate.


Testing for MERS has often relied on taking throat swabs - which can be sub-optimal when trying to detect deep lung infections. As we’ve seen with H5N1, H7N9, and MERS-CoV -  false negatives can result.

 

The World Health Organization issued the following testing recommendations for MERS last summer (see WHO: Revised MERS-CoV Case Definitions), for precisely this reason.

 

Inconclusive testing: Patients with an inconclusive initial testing should undergo additional virologic and serologic testing to determine if the patient can be classified as a confirmed MERS-CoV case. It is strongly advised that lower respiratory specimens such as sputum, endotracheal aspirate, or bronchoalveolar lavage fluid be used when possible. If patients do not have signs or symptoms of lower respiratory tract infection and lower track specimens are not available or clinically indicated, both nasopharyngeal and oropharyngeal swab specimens should be collected.

If initial testing of a nasopharyngeal swab is negative in a patient who is strongly suspected to have MERS-CoV infection, patients should be retested using a lower respiratory specimen tract or a repeat nasopharyngeal specimen with additional oropharyngeal specimen if lower respiratory tract specimens are not possible, and paired acute and convalescent sera.

 

A reminder, that at least with lab tests,  `No’ doesn’t always mean `no’.

Monday, August 26, 2013

Nepal: Human H5N1 Testing (Or Lack Thereof)

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# 7601

 

 

At the risk of sounding like a broken record, we really don’t know the true number of H5N1 (or MERS-CoV, H7N9, et al.) infections around the world. The quality, availability, and consistency of lab testing varies considerably between (and indeed, even within) countries.

 

Many nations must send samples to a reference lab outside their borders in order to test for exotic viruses.

 

As of the 23rd of August, the official World Health Organization  count puts the number of H5N1 cases at 637, with 378 fatalities (CFR 59.3%). 

 

But over the years we’ve seen a number of `suspected cases’ around the world that were either never tested, or whose negative test results were suspect.

 

In many places people succumb to diseases without ever seeing the inside of a hospital, much less having lab tests run.  Which may - at least partially - explain why some places report H5N1 in poultry, but have yet to report a human case.

 

As Dr. Ian Mackay already stated in his blog this morning:

 

Don't test, don't find. Know nothing.

 

Today we’ve a report out of Nepal  (h/t Gert van der Hoek on FluTrackers) – a nation which is currently embroiled in a major outbreak of H5N1 in its poultry - that suggests they may have recently missed two recent H5N1 fatalities.

 

But since they didn’t test (or even collect samples), we will probably never know.  A third case is being tested, and we should have results in a week.

 

First the report from the Himalayan Times, then I’ll return with more.

 

Bird flu suspected in two deaths‚ no test conducted

2013-08-26 2:27

SURYA PS.KANDEL

No bird-to-human bird flu transmission has been reported so far in Nepal.

 

NARAYANGADH: Bird flu has been suspected in the deaths of two women, who suffered from common cold and fever, at the Teaching Hospital of College of Medical Sciences in Bharatpur.

 

The hospital has written a letter to the District Public Health Office (DPHO) after the twin deaths on Saturday, suspecting that the victims were infected with the avian influenza virus (H5N1). However, no sample was collected from the deceased for further laboratory test.

 

Another patient suffering from common cold, cough and fever is receiving treatment at the ICU of the same hospital. She is given Tamiflu, the antiviral medicine used to treat bird flu.

 

According to Public Health Inspector Ram K.C., nasal and throat swabs collected from her have been sent to the National Public Health Laboratory in Kathmandu for the confirmation of suspected virus.

(Continue . . . )

 

It is a bit difficult to understand why samples weren’t collected - even post-mortem - but this story indicates they were not.  An opportunity lost. 

 

To be fair - it doesn’t matter where in the world you are, or what disease you are interested in – we really can only guess at its true incidence. Our own CDC can only roughly estimate the number of cases of diseases we have each year.

 

surveillance

As the pyramid chart above indicates, only a tiny fraction of infectious disease cases  are actually reported to health authorities. - Credit CDC

 

It was just a week ago, in CDC: Estimate Of Yearly Lyme Disease Diagnoses In The United States, that we learned the true burden of Lyme disease in this country may be as much as 10 times greater than are reported.

 

And just about 2 months ago, in CID Journal: Estimates Of Human Infection From H3N2v (Jul 2011-Apr 2012), we saw a study that estimated that in 2011 – a year where there were only 12 cases of H3N2v reported – the real number of cases was probably in excess of 2000.

 

While it is clearly impossible to test everyone for everything, the more testing that we can do, the better will be our understanding of the burden of, and threat posed by, these emerging viruses.

 

 

For more on the difficulties in assessing the incidence (and mortality/morbidity rates) of emerging diseases, you may wish to revisit:

 

Lancet: Clinical Severity Of Human H7N9 Infection
H7N9: CFR Considerations

The Great CFR Divide 

Revisiting The H5N1 CFR Debate

Monday, August 12, 2013

CDC HAN Update On MERS-CoV

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# 7566

 

Of interest primarily to clinicians and public health officials across the country, the CDC this afternoon has issued a HEALTH ALERT NETWORK (HAN) update on the MERS coronavirus. 

 

Today’s HAN update contains technical changes from the last MERS-CoV HAN update issued on June 7th (see CDC HAN: Updated Guidelines For Evaluation Of MERS-CoV).

 

These changes primarily involve new guidance on who should be evaluated for MERS-CoV infection, a clarification on the CDC’s definition of a `probable case’, and more detailed instructions on how and when specimens should be collected for testing.

 

While the medical community has been on the lookout for cases for several months, to date, no MERS-CoV cases have been reported in the United States.

 

Notice to Healthcare Providers and Public Health Officials: Updated Guidance for the Evaluation of Severe Respiratory Illness Associated with Middle East Respiratory Syndrome Coronavirus (MERS-CoV)

Summary: The Centers for Disease Control and Prevention (CDC) continues to work closely with the World Health Organization (WHO) and other partners to better understand the public health risks posed by Middle East Respiratory Syndrome Coronavirus (MERS-CoV). To date, no cases have been reported in the United States. The purpose of this health update is 1) to provide updated guidance to healthcare providers and state and local health departments regarding who should be tested for MERS-CoV infection, 2) to make them aware of changes to CDC’s “probable case” definition, and 3) to clarify what specimens should be obtained when testing for MERS-CoV. Please disseminate this information to infectious disease specialists, intensive care physicians, primary care physicians, and infection preventionists, as well as to emergency departments and microbiology laboratories.

Background

MERS-CoV, formerly called novel coronavirus, is a beta coronavirus that was first described in September 2012. As of August 12, 2013, 94 laboratory-confirmed cases have been reported to WHO. Of those cases, 49% (46) were fatal. All diagnosed cases were among people who resided in or traveled from four countries (Kingdom of Saudi Arabia, United Arab Emirates, Qatar, or Jordan) within 14 days of their symptom onset, or who had close contact with people who resided in or traveled from those countries. Cases with a history of travel from these countries or contact with travelers from these countries have been identified in residents of France, the United Kingdom, Tunisia, and Italy. To date, no cases have been reported in the United States. The most up-to-date details about the number of MERS-CoV cases and deaths by country of residence are on CDC’s MERS website (http://www.cdc.gov/coronavirus/mers/index.html).

Updates to Interim Guidance and Case Definitions

Interim Guidance for Health Professionals: Patients in the U.S. Who Should Be Evaluated

CDC has changed its criteria for who should be evaluated for MERS-CoV. In the previous guidance (HAN 348, dated June 7, 2013), CDC did not recommend MERS-CoV testing for people whose illness could be explained by another etiology. The new guidance states that, in patients who meet certain clinical and epidemiologic criteria, testing for MERS-CoV and other respiratory pathogens can be done simultaneously and that positive results for another respiratory pathogen should not necessarily preclude testing for MERS-CoV.

 

The new guidance also clarifies recommendations for investigating clusters of severe acute respiratory illness when there is not an apparent link to a MERS-CoV case. Clusters* of patients with severe acute respiratory illness (e.g., fever and pneumonia requiring hospitalization) should be evaluated for common respiratory pathogens and reported to local and state health departments. If the illnesses remain unexplained, testing for MERS-CoV should be considered, in consultation with state and local health departments.

 

For CDC’s updated interim guidance for healthcare professionals, see (http://www.cdc.gov/coronavirus/mers/interim-guidance.html).

Case Definitions

CDC has not changed the case definition of a confirmed case, but the criteria for laboratory confirmation have been clarified. CDC has changed its definition of a probable case so that identification of another etiology does not exclude someone from being classified as a “probable case.”

For CDC’s updated case definitions, see (http://www.cdc.gov/coronavirus/mers/case-def.html).

CDC may change its guidance about who should be evaluated and considered a case as we learn more about the epidemiology of MERS-CoV infection and risk of transmission.

Interim Guidance about Testing of Clinical Specimens

CDC recommends collecting multiple specimens from different sites at different times after symptom onset. Lower respiratory specimens are preferred, but collecting nasopharyngeal and oropharyngeal (NP/OP) specimens, as well as stool and serum, are strongly recommended. This will increase the likelihood of detecting MERS-CoV infection. For more information, see CDC’s Interim Guidelines for Collecting, Handling, and Testing Clinical Specimens (http://www.cdc.gov/coronavirus/mers/guidelines-clinical-specimens.html). Many state health department laboratories are approved for MERS-CoV testing using the CDC rRT-PCR assay. Contact your state health department to notify them of people who should be evaluated for MERS-CoV and to request MERS-CoV testing. If your state health department is not able to test, contact CDC’s EOC at 770-488-7100.

*In accordance with the WHO’s guidance for MERS-CoV, a cluster is defined as two or more persons with onset of symptoms within the same 14-day period, and who are associated with a specific setting such as a classroom, workplace, household, extended family, hospital, other residential institution, military barracks, or recreational camp. See WHO’s Interim Surveillance Recommendations for Human Infection with Middle East Respiratory Syndrome Coronavirus (http://www.who.int/csr/disease/coronavirus_infections/InterimRevisedSurveillanceRecommendations_nCoVinfection_27Jun13.pdf Learn more about Adobe Acrobat Reader ).