Deconstructing the 90% Of Camels Have MERS Meme

Credit FAO

 

# 9757

 

Earlier this week a big story hit the Arabic press – and has caused heavy (and very concerned)  traffic on Arabic Twitter – stating that 90% of Saudi Camels have the MERS virus.  I mentioned it briefly two days ago in Postcards From The MERS Twitterverse, but have been unable to find any paper, or study to back up this assertion. 

 

First a media report on this story, after which I’ll be back with reasons why I think this report is off base.

 

Almost all Gulf camels have MERS, warns Saudi health official

By Courtney Trenwith

Wednesday, 25 February 2015 1:50 PM

Almost all camels in the Gulf are infected with the Middle East Respiratory Syndrome (MERS), a Saudi Health Ministry official has been reported as saying.

The fatal virus, which already has infected more than 1000 and killed at least 376 patients, is believed to have spread from camels to humans.

The high rate of camel infection – 90 percent, according to Saudi Arabia’s undersecretary for preventative health Abdullah Asiri – raises a serious issue for the Gulf, where camels are a deep part of daily life for many locals.

Asiri said exterminating the animals was not an acceptable solution and instead research on a vaccine needed to be accelerated, Arab News reported.

(Continue . . . )

Obviously, if 90% of Saudi Camels are actively infected, this would pose major infectious disease risk. 

 

But it is makes far more sense that 90% of Saudi Camels have been infected with the MERS coronavirus (i.e. have serum antibodies) sometime in the past. Not that 90% are currently infected (and capable of spreading the disease) as intimated by this report.

It is a small, but important difference.

 

The idea that camels are a repository for the MERS coronavirus gained traction in August of 2013 when we saw a study in the  Lancet: Camels Found With Antibodies To MERS-CoV-Like Virus, which found specific antibodies to the MERS coronavirus in all 50 (100%) of the dromedary camel samples gathered (from multiple locations) in Oman.

 

Much lower levels of antibodies were detected in 14% of camels from two dromedary herds tested from the Canary Islands.

 

The following January (2014) in EID Journal: MERS-Like Antibodies In Camels, UAE 2003-2013, we saw a report showing  97% of  dromedary camel serum samples collected in 2003 and 2013 in the United Arab Emirates (UAE) showed specific antibodies for the MERS coronavirus.

 

Again in August, in EID Journal: Three Decades Of MERS-CoV Antibodies In Camels, we saw serological evidence showing an infection rate of 81%  going back over 30 years.

 

But none of these studies were designed to show that these camels were actively infected and shedding the virus.

 

While we’ve limited reports from the field on active infection with MERS virus in camels, we’ve one study that found 10 of 35 (27%) camels tested during the 2013–14 calving season (see EID Journal: MERS Coronavirus In A Saudi Dromedary Herd) actively shedding the virus. From the report:

 

At farm A, we detected MERS-CoV in 1 of 4 dromedaries sampled on November 30, none of 11 sampled on December 4, nine of 11 sampled on December 30, and none of 9 sampled on February 14 (Table 1). Of the 10 dromedaries that tested positive for MERS-CoV, 9 had parallel nasal and fecal specimens tested, with virus detected in the nasal swab specimens from 8 and the fecal specimen from 1.

At the December 30 sampling, 7 of 8 calves and 2 of 3 adults tested positive for MERS-CoV, indicating that when MERS-CoV circulates on a farm, both calves and adults can be infected (Technical Appendix[PDF - 81 KB - 3 pages] Table). Because all 12 adults with serum collected before December 30 were seropositive (titers >320), it is likely, though not certain, that the MERS-CoV infections in the 2 adults (nos. 21, 19Dam) sampled on December 30 were reinfections, as has been reported for other CoVs.

 

And last year (see EID Journal: MERS Coronaviruses in Dromedary Camels, Egypt) we saw a sampling from Egypt that found  4 (3.6%) of nasal swabs (out of 110 tested) were positive for the MERS-CoV virus (via RT-PCR testing). A positive PCR test is indicative of a current infection, with active viral shedding.

 

Obviously nowhere near the 90% range.

 

Perhaps even more on point, in EID Journal: Replication & Shedding Of MERS-CoV In Inoculated Camels we saw a study showing that camels intentionally inoculated with the human MERS strain shed copious amounts of the virus via nasal discharge for at least a week.

 

While there is some evidence that a camel can become re-infected with the MERS coronavirus, we don’t know how often that really happens.  But whether the first infection, or a subsequent one, the `window’ of opportunity for passing on the virus to humans (or other camels) appears limited to a week or two. 

As young camels have the least exposure to the virus, they appear the most susceptible to infection. And that has been postulated as a factor in the spring surge of MERS infections across the Middle East.

Camels appear to be an important conduit for the virus to move into the human population, but we’ve seen estimates that only 3% of cases are caused by direct zoonotic infection (see Dr. Tariq Madani: 97% Of MERS Cases From Human-to-Human Transmission).

If camel-to-human transmission could be eliminated, it might stop the reseeding of the virus into the human population. 

 

And until a camel vaccine can be developed, and deployed, exercising caution and good infection control practices around camels is certainly advisable.

But as far as the claim that 90% of camels have MERS, that appears to be more than a little overstated.

Postcards From The MERS Twitterverse

# 9748

 

Between the rising case counts of the past couple of weeks, yesterday’s WHO Mission statement which cited critical lapses in our understanding of how the MERS coronavirus transmits, a new report that suggests 90% of camels in the region may be infected, and a new statement by the Saudi MOH on diagnosing the virus – Arabic twitter traffic  (hashtag  كورونا  aka `Corona’) is really humming this morning.

I’m currently seeing 30 to 40 tweets a minute, with the camel story making up the bulk of the activity. 

 

While zoonotic transmission of the coronavirus has been suspected for at least 18 months (see Aug 2013’s  Lancet: Camels Found With Antibodies To MERS-CoV-Like Virus), and the evidence has mounted since then (see CIDRAP: More Evidence for Camel-to-Human MERS-CoV Transmission), the general public has been slow to accept the idea that the beloved symbol of their nation could harbor a deadly disease.

 

A concept made even harder to accept due to the widespread belief in the healthful effects of camel’s milk and urine in the treatment of disease.

Despite the increased warnings (see Saudi Ministry Of Agriculture Issued Warnings On Camels) urging breeders and owners to limit their contact with camels, and to use PPEs (masks, gloves, protective clothing) when in close contact with their animals, we continue to see occasional stories in the Saudi Press `exonerating camels’ as a source of the disease.

All of which makes today’s report, claiming that Saudi Health: 90% of Ebel Gulf infected with Corona a major twitter topic.   Note : `Ebel’, `Apple’, and `Beauty’ are all common translations from the Arabic for `camel’.

 

WASHINGTON: US Undersecretary of the Saudi Ministry of Health for Preventive Health Dr. Abdullah Asiri "that 90% of Ebel Gulf countries infected with Corona."

He pointed out that 50% of the beauty in Al-Ahsa region east of the kingdom carrying "Corona" in the respiratory secretions, stressing that the person who infected mixer beauty colds, exhibition of transmitting the virus to a family member without showing symptoms

(Continue . . . )

Despite the growing body of evidence, the recent PSA videos from the MOH (see below), and continued warnings to avoid contact and to wear PPEs around `beauty’,  public acceptance of the notion remains slow in coming.

 

Also trending are comments about, and links to, a statement posted by the Saudi MOH today on laboratory testing, and the need for isolation of, MERS cases.

 

 

 

D.nsrin Sherbini: symptoms of respiratory viruses and virus (Corona) are similar

05 May 1436

Advisory infectious diseases and epidemics, Dr. Nasrin Sherbini confirmed that the only way to make sure the infection (Corona) is through a laboratory test, and that there are no symptoms that can differentiate between respiratory viruses such as influenza virus (Corona); all of them are similar.

She added that the virus (Corona) is transmitted through droplets of a cough or sneeze of an infected for Mkhaltin person has a direct and close to, or touch the membranes of the eyes, nose and mouth after touching places them spray the patient; therefore must contacts monitoring after the patient isolate them, and hasten the detection and screening at the emergence of symptoms such as high fever or symptoms of flu or pneumonia Kdik of breath and chest pain and the like.

This came during the hosting of the National Center for Media and Health Education of the Ministry of Health within the activities of the awareness campaign to introduce the virus (Corona) that causes respiratory syndrome Middle East (MERS.COV).

She noted that many studies supports that beauty is one of the sources (Corona), and that the transmission of the virus is through the respiratory tract, the spray camels and their secretions often and not by drinking milk, but preferably limited to drinking milk and dairy products, pasteurized only, and when having to drink milk directly from the camels and other livestock must be well boiled. They must take the necessary contacts of a camel wearing protective face precautions (nose and eyes), especially when approaching them directly and exposure to secretions and Rmazha or righteousness.

Attributed the high rate of infection among people with chronic diseases in cases recorded since the emergence of the virus to the general health situation of people with chronic diseases and weak immunity; making them more susceptible to infection than others.

It is worth mentioning that the National Center for Media and health education will continue to host a group of doctors and specialists from all health sectors until 06/05/1436 AH, via toll-free telephone Center 8,002,494,444 and the calculation of the ministry on Twitter saudimoh;  to respond to queries from callers and answer their questions about HIV (Corona ), where it will be on Wednesday hosted d. Future newborn, consultant infectious diseases, from 1:00 pm until 3:00 pm

 

While much of the Arabic twitter traffic appears `coordinated’  (tons of re-tweets of `official’ messages, or `safe’ news stories) occasionally accusatory tweets show up, such as the pair below laying blame on the previous MOH.

 

After seeing big declines in twitter traffic regarding MERS in the last half of 2014, the past few days have seen a sizable reawakening of public interest.

 

A trend that is likely to only increase as the expected spring wave accelerates over the next several months.

WHO MERS Update – Saudi Arabia

Credit FAO

 

 

# 9206

 

While are understandably focused on Ebola, there are other emerging viral infections out there that could – if they they began to spread efficiently among humans – pose an even bigger global threat than Ebola.  Among those are the various flavors of avian flu (H5N1, H7N9, H5N6, etc.) and the MERS coronavirus.

Although the number of MERS cases has dropped over the summer, we continue to see a small trickle of cases in Saudi Arabia.  The latest World Health Organization update lists 7 new cases, 4 of whom report frequent contact with camels or camel products.

The exact role of camels in the transmission of MERS to humans has yet to be established, but increasingly camels are being viewed as a  likely zoonotic source of the virus (see EID Journal: Replication & Shedding Of MERS-CoV In Inoculated Camels).

 

Last September we saw the KSA MOH Reiterates Camel Warnings On MERS.

 

 

 

Middle East respiratory syndrome coronavirus (MERS-CoV) – Saudi Arabia

Disease outbreak news
16 October 2014

The National IHR Focal Point of Saudi Arabia (SAU) has reported additional laboratory-confirmed cases of infection with Middle East respiratory syndrome coronavirus (MERS-CoV) to WHO.

Epidemiological update

Between 29 September and 11 October 2014, 7 additional cases of MERS-CoV infection were reported, including 1 death, with details as follows:

• A 69 year old male from Taif City who developed symptoms on 17 September 2014. The patient has comorbidities and his possible contact with animals and consumption of raw camel products is currently under investigation.
• A 65 year old male from Jubail City who developed symptoms on 24 September 2014. The patient has comorbidities, frequent contact with camels and frequently consumes raw camel milk.
• A 70 year old male from Alhenakiah City who developed symptoms on 24 September 2014. The patient has comorbidities, frequent contact with camels and frequently consumes raw camel milk.
• A 60 year old male from Geiya city who developed symptoms on 1 October 2014. The patient has comorbidities, frequent contact with camels and frequently consumes raw camel milk.
• A 51 year old male from Haradh City who developed symptoms on 30 September 2014. The case died on 05 October 2014. The patient had comorbidities, frequent contact with camels and frequently consumed raw camel milk.
• A 77 year old male from Taif City who developed symptoms on 3 October 2014. The patient has comorbidities and became infected while hospitalized.
• A 50 year old non-national male from Najran City who developed symptoms on 3 October 2014. He reported no history of contact with animals, but resides in an area with heavy presence of camel farms.

The tracing of household contacts is ongoing for these cases.

In addition, the deaths of 4 previously reported MERS-CoV cases from Saudi Arabia were also reported.

Cases identified in SAU following a retrospective review

Following a retrospective review of laboratory records in non-Ministry of Health hospitals, the National IHR Focal Point of SAU has also reported 19 additional cases of MERS-CoV infection, including 11 deaths. Of the additional cases, 1 occurred in August 2013, 2 occurred in March 2014, 10 occurred in April 2014 and 6 occurred in May 2014.

Of the additional cases reported by SAU, 79% (15 people) are Saudi nationals. Sixteen of the reported cases resided in Jeddah, 2 in Kharj and 1 in Dhahran. The median age is 56 years (ranging from 27 to 89), 68% (13/19) were men, and 11% (2/19) of the reported cases were health care workers.

The retrospective identification of these 19 cases does not alter the pattern and dynamic of the epidemic and the global risk assessment remains unchanged.

In addition, SAU notified WHO of 1 false positive case reported in a cohort of cases that occurred between 11 April - 9 June 2014. SAU also reported that 1 case had been reported twice and was therefore a duplicate case.

Globally, 877 laboratory-confirmed cases of infection with MERS-CoV including at least 317 related deaths have been reported to WHO. The total case count removes the false positive case and the duplicate case reported above.

EID Journal: Replication & Shedding Of MERS-CoV In Inoculated Camels

Credit FAO

 

# 9011

 

The case for camels being a likely route of MERS-CoV to humans has become a bit stronger with yesterday’s publication of an EID journal study showing that camels intentionally inoculated with the human MERS strain shed copious amounts of the virus via nasal discharge for at least a week.

This isn’t the first time camels have been implicated as an intermediate host (bats are still eyed as the likely primary reservoir of the MERS virus), but this study does show a plausible route of both camel-to-camel and camel-to-human transmission.

 

Earlier this summer, in mBio: Airborne Fragments Of MERS-CoV Detected In Saudi Camel Barn, we saw some limited evidence that MERS could be an airborne virus.   But other modes of transmission – such as droplet, direct contact, or contaminated fomites – are thought to be bigger factors.

 

Over the past 6 months we’ve seen a steady stream of new information implicating camels as a host for the virus, and a  possible conduit to the human population.

 

FAO: `Stepped Up’ Investigations Into Role Of Camels In MERS-CoV

Mackay’s Compendium Of Camel-MERS Studies

CIDRAP: More Evidence for Camel-to-Human MERS-CoV Transmission

Kuwait Tests Camels - Finds 6% Positive For MERS-CoV

 

A couple of weeks ago, the KSA MOH Reiterated Camel Warnings On MERS, urging breeders and owners to limit their contact with camels, and to use PPEs (masks, gloves, protective clothing) when in close contact with their animals. 

 

Today’s study not only shows that infected camels can shed massive amounts of the MERS coronavirus from their nasal discharges, that they can do so without showing other signs of serious illness.

 

Replication and Shedding of MERS-CoV in Upper Respiratory Tract of Inoculated Dromedary Camels

Danielle R. Adney, Neeltje van Doremalen, Vienna R. Brown, Trenton Bushmaker, Dana Scott, Emmie de Wit, Richard A. Bowen¹ , and Vincent J. Munster¹

Author affiliations: Colorado State University, Fort Collins, Colorado, USA; (D.R. Adney, V.R. Brown, R.A. Bowen); National Institutes of Health, Hamilton, Montana, USA (N. van Doremalen, T. Bushmaker, D. Scott, E. de Wit, V.J. Munster) 

Abstract

In 2012, a novel coronavirus associated with severe respiratory disease in humans emerged in the Middle East. Epidemiologic investigations identified dromedary camels as the likely source of zoonotic transmission of Middle East respiratory syndrome coronavirus (MERS-CoV). Here we provide experimental support for camels as a reservoir for MERS-CoV. We inoculated 3 adult camels with a human isolate of MERS-CoV and a transient, primarily upper respiratory tract infection developed in each of the 3 animals.

Clinical signs of the MERS-CoV infection were benign, but each of the camels shed large quantities of virus from the upper respiratory tract. We detected infectious virus in nasal secretions through 7 days postinoculation, and viral RNA up to 35 days postinoculation. The pattern of shedding and propensity for the upper respiratory tract infection in dromedary camels may help explain the lack of systemic illness among naturally infected camels and the means of efficient camel-to-camel and camel-to-human transmission.

<SNIP>

This is actually some pretty impressive work, and helps fill in some major gaps in our knowledge of the ecology of the MERS virus among camels.  While based on just three test subjects, no virus shedding was observed in camel urine of feces. 

Possible infection via consumption of camel milk or camel meat was not investigated, and remains an open question (see Eurosurveillance: MERS-CoV Antibodies & RNA In Camel’s Milk – Qatar).

Some excerpts from the discussion follow, but download the entire study for more on methods and materials.

Discussion

(excerpt)

The large quantities of MERS-CoV shed in nasal secretions by each of the 3 camels suggest that camel-to-camel and camel-to-human transmission may occur readily through direct contact and large droplet, or possibly fomite transmission. Histopathologic examination revealed that the URT, specifically the respiratory epithelium in the nasal turbinates, is the predominant site of MERS-CoV replication in camels.

Neutralizing antibodies were detected from 14 dpi onward, reaching a maximum neutralizing titer of 640 after 35 days. Serologic studies in camels in the field have reported MERS-CoV neutralizing titers as high as 5,120 (14,16), potentially indicative of repeated exposure and re-infection.

The study reported here was done on the basis of inoculation of 3 male animals with a human isolate of MERS-CoV, and the study design we used imposed several limitations on how these data inform what occurs in natural infections. The camels we inoculated were exposed to a high dose of virus by 3 simultaneous routes of inoculation.

In retrospect, the inoculation dose does not seem excessive, based on the large quantity of virus shed nasally in all 3 animals (Figure 2). The total dose inoculated was relatively equivalent to the amount of virus present in a single nasal swab sample taken during the first days postinoculation, and it seems probable that a camel shedding this quantity of virus would readily infect other camels or humans with which it had direct contact. The fact that we inoculated the camels with the virus by 3 routes precludes drawing conclusions regarding efficiency of transmission by a particular route, which is a topic that should be addressed in future studies.

The influence of camel age on susceptibility and dynamics of virus shedding is another notable parameter that requires further study. It seems likely that productive infection and shedding of virus in natural settings occurs predominantly in juvenile camels (28). This could be the result of an intrinsic difference in age-related susceptibility, but is more likely related to the immunologically naïve status of the animals in the context of a high force of infection after decay of passively acquired antibodies. The animals we infected were young adults, but were seronegative and therefore probably as susceptible as juveniles from MERS-CoV–endemic regions.

Another aspect of pathogenesis not addressed here is whether virus is present in milk or meat from infected camels and thereby poses another potential route of exposure to humans who consume such products. Despite these limitations, the magnitude and pattern of virus shedding was essentially identical in all 3 animals and supports the available epidemiologic data indicating that camels are likely a major reservoir host for MERS-CoV. Additional experimental and field studies are clearly required to address the duration of shedding of infectious MERS-CoV from infected camels, to determine whether infection results in protective immunity, and to clarify the burden of illness among humans resulting from transmission from camels.

KSA MOH Reiterates Camel Warnings On MERS

Image Credit: A Saudi farmer kisses a young she-camel - Credit: Al Sharq

 

# 9073

 

Although it has been a bit slow in coming, the acceptance that there is a strong connection between exposure to camels and contracting the MERS coronavirus seems to have finally taken hold in Saudi Arabia. Six months ago the Ministry of Agriculture was in full denial (see Saudi MOA Spokesman: Camel Link Unproven), and camel kissing briefly surged as an act of defiance.

 

For many Saudis, the idea that camels – a beloved national symbol that literally made settlement of that arid region possible – could carry a disease deadly to humans,  is simply unthinkable.   A concept made even harder to accept due to the widespread belief in the healthful effects of camel’s milk and urine in the treatment of disease.

 

In the face of mounting evidence, finally last May the Saudi Ministry Of Agriculture Issued Warnings On Camels, urging breeders and owners to limit their contact with camels, and to use PPEs (masks, gloves, protective clothing) when in close contact with their animals.

Since then we’ve seen a steady stream of new information implicating camels as an intermediate host for the virus, and a likely conduit to the human population.

 

FAO: `Stepped Up’ Investigations Into Role Of Camels In MERS-CoV

Mackay’s Compendium Of Camel-MERS Studies

CIDRAP: More Evidence for Camel-to-Human MERS-CoV Transmission

Kuwait Tests Camels - Finds 6% Positive For MERS-CoV

 

Although the number of MERS cases has dwindled over the summer, yesterday two new cases were reported, and with the Hajj just three weeks away, the Ministry of Health apparently feels it is time for a reminder.  Today they have posted a notice on the Saudi MOH site, their Facebook page, and on twitter.

Translation of KSA MOH Tweet

 

A hat tip goes to Sharon Sanders on FluTrackers for the following link.  For those unused to these machine translations: Apple=camel  and muzzle and/or gag curtain=face mask.

 

 

For transfer of coronavirus into human health Ministry warns against dealing with camels unprotected

18 October 1435

Renewed Health Ministry warning to all citizens and residents to take necessary precautions in dealing with Apple. The Ministry showed that despite the decline in disease and thankfully, the expected individual cases of disease caused by direct exposure to secretions of camels without wearing a muzzle and gloves and cover the body. The Ministry said that these individual cases may be a source of transmission of the virus to others health workers at hospitals or close contacts at home.

The Ministry showed that research conducted by scholars of the Saudis last November proved without doubt the role of camels to transport human coronavirus to which scientific studies have shown the presence of the virus in the mucus and saliva of camels particularly affected by symptoms such as runny nose and fever. The Medical Council has issued an advisory of the Ministry of health warnings and stressed the need for taking precautions within the camel barns during direct dealing with, as well as within the slaughterhouses. These precautions include wearing protective gloves and gag curtain of flesh. And calls upon the Ministry of health of the citizens and residents of the need to follow those precautions and not lax in maintaining their health and the health of those around them.

 

EID Journal: Three Decades Of MERS-CoV Antibodies In Camels

Credit FAO

 

 

# 8957

 

 

Although it certainly seems longer, it has been just over a year since we saw the first real evidence linking camels to the MERS-CoV virus (see Lancet: Camels Found With Antibodies To MERS-CoV-Like Virus).  Since then, as testing procedures have matured and been deployed, we’ve seen a steady stream of studies showing that many Middle Eastern dromedaries either carry the live virus, or antibodies indicating prior infection.

 

mBio: Airborne Fragments Of MERS-CoV Detected In Saudi Camel Barn

Eurosurveillance: MERS-CoV Antibodies & RNA In Camel’s Milk – Qatar

Kuwait Tests Camels - Finds 6% Positive For MERS-CoV

mBio: MERS-CoV Carriage By Dromedaries

 

While bats are still a prime suspect as the reservoir host for this emerging coronavirus, camels increasingly are viewed as an important intermediate host, and possible bridge to infecting humans (see WHO Update On MERS-CoV Transmission Risks From Animals To Humans & FAO: `Stepped Up’ Investigations Into Role Of Camels In MERS-CoV).

 

While human cases have only originated on the Arabian peninsula, that region imports tens of thousands of camels each year from the Horn of Africa, leading some to suspect the actual `source’ of the MERS coronavirus might come from the East African nations of Somalia, Kenya, or Sudan. 

 

Last May, in  EID Journal: MERS Antibodies In Camels – Kenya 1992-2013, we saw a study using archived camel blood samples going back 20 years that found MERS antibodies were circulating in Kenya as early as 1992.  Today, we’ve a new study that pushes back the clock at least another 10 years.

Volume 20, Number 12—December 2014

Dispatch

MERS Coronavirus Neutralizing Antibodies in Camels, Eastern Africa, 1983–1997

Marcel A. Müller¹ , Victor Max Corman¹, Joerg Jores, Benjamin Meyer, Mario Younan, Anne Liljander, Berend-Jan Bosch, Erik Lattwein, Mosaad Hilali, Bakri E. Musa, Set Bornstein, and Christian Drosten

Abstract

To analyze the distribution of Middle East respiratory syndrome coronavirus (MERS-CoV)–seropositive dromedary camels in eastern Africa, we tested 189 archived serum samples accumulated during the past 30 years. We identified MERS-CoV neutralizing antibodies in 81.0% of samples from the main camel-exporting countries, Sudan and Somalia, suggesting long-term virus circulation in these animals.

(Continue . . .)

 

You’ll want to read the entire paper for methods, materials, and their detailed findings.  In the conclusion, the authors write:

 

MERS-CoV sequences from camels in Saudi Arabia and Qatar were closely related to sequences found in humans and did not show major genetic variability that would support long-term evolution of MERS-CoV in camels (10,11). The MERS-CoV sequence from a camel in Egypt was phylogenetically most distantly related to all other known camel-associated MERS-CoVs but closely related to the early human MERS-CoV isolates (10). An urgent task would be to characterize the diversity of MERS-related CoV in other camels in Africa to elucidate whether the current epidemic MERS-CoV strains have evolved toward more efficient human transmissibility.

The existence of unrecognized human infections in African or Arabian countries in the past cannot be ruled out. Resource-limited African countries that have been exposed to civil unrest, such as Somalia and Sudan, are not likely to diagnose and report diagnostically challenging infections resembling other diseases. The lack of MERS-CoV antibodies in a small cohort serosurvey in Saudi Arabia did not suggest the long-term circulation of MERS-CoV in humans on the Arabian Peninsula (15).

Large serosurveys in countries where camels are bred and traded, especially in eastern Africa, are needed to explore the general MERS-CoV seroprevalence in camels and humans, particularly humans who have close contact with camels. Such serosurveys could provide the data needed to ascertain whether MERS-CoV has been introduced into, but unrecognized in, the human population on the African continent.

Debating A Controversial MERS Paper

Coronavirus – Credit CDC PHIL

 

# 8891

 

Last week, Professor Raina MacIntyre, Head of the School of Public Health and Community Medicine and Professor of Infectious Disease Epidemiology at UNSW, published a paper called The discrepant epidemiology of Middle East respiratory syndrome coronavirus (MERS-CoV), where she suggested that the unusual patterns of the MERS coronavirus outbreaks  might  indicate deliberate human release.

 

Professor MacIntyre went on to explain why a bio terror source ought to be at least considered in  MERS coronavirus: animal source or deliberate release?, published last week in The Conversation.

 

While best known for her work in respiratory virus transmission studies, over the past year we’ve looked at research from Dr. MacIntyre looking at whether the Flu Vaccine May Reduce Heart Attack Risk and just last month she and co-author Lauren M Gardner looked at some of the paradoxes presented by the MERS coronavirus. (see BMC Research Notes: Unanswered Questions About MERS-CoV.)

 

Dr. MacIntyre’s  latest paper, however, has been greeted with a good deal of skepticism, particularly among researchers and virologists, both on twitter, and in the media (see CIDRAP News Report).  

 

Today, a sextet of scientists and researchers – including well known infectious disease bloggers Dr. Ian Mackay and Maia Majumder - provide a rebuttal to Professor MacIntyre’s controversial hypothesis. Joining them are Dr.  Lisa Murillo from Los Alamos, Dr.  Katherine Arden from the University of Queensland, Dr. Nicholas G. Evans and Stephen Goldstein, both from the University of Pennsylvania.

 

Follow the link below to read their rationale, as published in The Conversation,  in its entirety.

 

 

30 July 2014, 5.40am BST

Middle East respiratory virus came from camels, not terrorists

When you hear hooves, shout camel, not bioterrorist. Delpixel/Flickr

The Middle East respiratory syndrome coronavirus (MERS-CoV) is a tiny, spiky package of fat, proteins and genes that was first found in a dying man in the Kingdom of Saudi Arabia in 2012.

 

Since then, we have learnt a little more about the virus. We know that nearly 90% of infections have originated in the Kingdom of Saudi Arabia. It is lethal in about a third of known cases, most of whom are older males, often with one or more pre-existing diseases of the heart, lung or kidney. So far it has claimed nearly 300 lives.

 

Camels have emerged as the most likely source of human MERS-CoV infections. In fact, blood samples collected between 1992 and 2013 show camels have been fighting MERS-CoV for at least 20 years.

 

But, in an unusual twist, research published last week calls on us to seriously consider, or at least acknowledge, that bioterrorism might explain the emergence of MERS-CoV in people. Raina MacIntyre, Professor of Infectious Disease Epidemiology at UNSW Australia, suggests that “deliberate release” may explain the paradoxical pattern of ongoing MERS-CoV infections.

(Continue . . .)

 

Although one can never totally eliminate the possibility that there is a human hand behind the spread of MERS, I confess that after reading Dr. MacIntyre’s paper last week,  I came away far less than convinced.  

 

While I briefly considered blogging the story, I saw that it had already been covered by CIDRAP News, and was being heartily debated on Twitter, and decided there was little of substance I could add.

A decision I’m glad of now, since others (far more qualified than myself) have now weighed in on the issue.   

mBio: Airborne Fragments Of MERS-CoV Detected In Saudi Camel Barn

Credit FAO

 

*** UPDATED with mBIO Link ***

 

# 8855

 

 

A little later today the open access journal mBio will publish a new paper, prepared by researchers from King Abdulaziz University in Saudi Arabia, on  RT-PCR testing of air samples taken from a camel barn during the time of a well studied probable camel-to-human transmission event last November (see CIDRAP: More Evidence for Camel-to-Human MERS-CoV Transmission).

 

mBio usually posts new articles mid-morning East Coast time every Tuesday, so I’ll update this blog with a link when they do.

 

Detection of the Middle East Respiratory Syndrome Coronavirus Genome in an Air Sample Originating from a Camel Barn Owned by an Infected Patient

Esam I. Azhar, Anwar M. Hashem, Sherif A. El-Kafrawy, Sayed Sartaj Sohrab, Asad S. Aburizaiza, Suha A. Farraj, Ahmed M. Hassan, Muneera S. Al-Saeed, Ghazi A. Jamjoom and Tariq A. Madani

doi:10.1128/mBio.01450-14

 

Until that time, we’ve got a press release from the American Society for Microbiology (excerpts below). 

 

The discovery of fragments of MERS-COV virus in an air sample collected in a camel barn - while an important piece of the the MERS transmission puzzle - is neither totally unexpected nor proof of airborne transmission of the virus.  It only demonstrates a potential route of infection.

First the press release, then I’ll return with more.

 

 

Middle East Respiratory Syndrome coronavirus detected in the air of a Saudi Arabian camel barn

Saudi Arabian researchers have detected genetic fragments of Middle East Respiratory Syndrome coronavirus (MERS-CoV) in the air of a barn holding a camel infected with the virus. The work, published this week in mBio®, the online open-access journal of the American Society for Microbiology, indicates that further studies are needed to see if the disease can be transmitted through the air.

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For the study, researchers on three consecutive days last November collected three air samples from a camel barn owned by a 43-year-old male MERS patient who lived south of the town of Jeddah, who later died from the condition. Four of the man's nine camels had shown signs of nasal discharge the week before the patient became ill; he had applied a topical medicine in the nose of one of the ill camels seven days before experiencing symptoms.

Using a laboratory technique called reverse transcription polymerase chain reaction (RT-PCR) to detect gene expression, they found that the first air sample, collected on November 7, contained genetic fragments of MERS-CoV. This was the same day that one of the patient's camels tested positive for the disease. The other samples did not test positive for MERS-CoV, suggesting short or intermittent shedding of the virus into the air surrounding the camels, said lead study author Esam Azhar, PhD, head of the Special Infectious Agents Unit at King Fahd Medical Research Center and associate professor of medical virology at King Abdulaziz University in Jeddah.

Additional experiments confirmed the presence of MERS-CoV-specific genetic sequences in the first air sample and found that these fragments were exactly identical to fragments detected in the camel and its sick owner.

"The clear message here is that detection of airborne MERS-CoV molecules, which were 100% identical with the viral genomic sequence detected from a camel actively shedding the virus in the same barn on the same day, warrants further investigations and measures to prevent possible airborne transmission of this deadly virus," Azhar said.

"This study also underscores the importance of obtaining a detailed clinical history with particular emphasis on any animal exposure for any MERS-CoV case, especially because recent reports suggest higher risk of MERS-CoV infections among people working with camels," he added.

Meanwhile, he said, mounting evidence for camel-to-human transmission of MERS-CoV warrants taking precautionary measures: People who care for camels or who work for slaughterhouses should wear face masks, gloves and protective clothing, and wash their hands frequently. It is also important to avoid contact with animals that are sick or have tested positive for MERS-CoV. Those who visit camel barns, farms or markets should wash hands before and after contact with animals. In addition, pasteurization of camel milk and proper cooking of camel meat are strongly recommended.

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Airborne (aerosolized or large droplet) transmission of MERS-CoV in humans is assumed to occur - hence the CDC’s stringent Interim Guidance for Health Professionals   on the use of PPEs – but other routes may be equally important players. 

 

Last May, in MERS: A Focus On Fomites?  we looked at investigations focusing on the potential  role of inanimate objects and environmental surfaces in the transmission of the virus.

 

How the virus jumps to man – presumably from camels – and how camels acquire, and spread the virus, is less well mapped out. As Dr. Ian Mackay graphically illustrated last may, there are a lot of options.

 

Camels at the centre, aerosol all around...

An airborne-centric view of how the camel could be a source of sporadic human infection by MERS-CoV, a virus that is genetically very similar whether found in camels or humans.

The inner ring (orange) is more about droplets and aerosols-if you must differentiate on size. 

These are potential routes by which a human in contact with, or near to, camels might acquire virus from them, when those camels are actively infected.

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The detection of fragments of MERS-CoV – using RT-PCR testing – in air samples in a camel barn doesn’t tell us if those fragments were viable, and capable of infecting anyone or anything. 

 

But this study does show that the opportunity for the virus to spread from camels through the air exists, and thus invites additional research into this plausible route of transmission.

 

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mBio: Debating The Dromedary - MERS Coronavirus Connection

Credit FAO

 

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For nearly a year we’ve watched the evidence mount up that camels play a major role in the hosting, and probable spread, of the MERS coronavirus which was first discovered two years ago in the Middle East.  Dromedaries aren’t viewed as being the only possible animal reservoir of the virus, nor are they believed responsible for he majority of human cases.

 

But the virus (or antibodies to the virus) have certainly been found in camels (see Kuwait Tests Camels - Finds 6% Positive For MERS-CoV), and we’ve seen a few instances where camel-to-human transmission is strongly suspected (see CIDRAP: More Evidence for Camel-to-Human MERS-CoV Transmission).

 

Last month,  in Eurosurveillance: MERS-CoV Antibodies & RNA In Camel’s Milk – Qatar we looked at research supporting the notion that consumption of unpasteurized camel’s milk might be a route to infection.

Some of the most compelling research has been associated with Dr. Ian Lipkin, including a study published last February (see mBio: MERS-CoV In Saudi Arabian Camels) that established MERS-CoV to be a common, likely mild or asymptomatic, infection in young camels in Saudi Arabia and that suggested that they may well be the source of at least some portion of the human infections we’ve seen over the past two years.

 

Another study, again involving Dr. Lipkin, was published the end of April (see mBio: MERS-CoV Carriage By Dromedaries) that recovered the MERS-CoV from nasal swabs of camels, and demonstrated that whole-genome consensus sequences were indistinguishable from MERS coronaviruses recovered from humans.

 

An accompanying press release, Columbia University's Mailman School of Public Health, states:

"The finding of infectious virus strengthens the argument that dromedary camels are reservoirs for MERS-CoV," says first author Thomas Briese, PhD, associate director of the Center for Infection and Immunity and associate professor of Epidemiology at the Mailman School. "The narrow range of MERS viruses in humans and a very broad range in camels may explain in part the why human disease is uncommon: because only a few genotypes are capable of cross species transmission," adds Dr. Briese.

 

Despite the preponderance of evidence, not everyone is ready to accept these findings as `proof’ of the role of camels in the spread of the MERS coronavirus (see Saudi MOA Spokesman: Camel Link Unproven).

Today the open access journal mBio has published a long letter, written by Emad M. Samara Ph.D and Professor Khalid A. Abdoun, both of the Department of Animal Production at King Saud University  that call into question the findings of the two previously mentioned studies involving Dr. Lipkin. 

 

After listing a number of the findings in these previous studies, the authors argue that they cannot be taken as `conclusive evidence’  that dromedary camels carry the infectious form of MERS-CoV or have ever infected humans. 

 

They suggest it is equally plausible (albeit, unproven) that humans are the ones who have infected camels.

 

It’s a long letter – far too long to reproduce here – and so in fairness to their argument,  I would invite my readers to follow the link to read it in its entirety.    When you return, I’ll have a link to a reply from Dr. Lipkin et al.

 

Concerns about Misinterpretation of Recent Scientific Data Implicating Dromedary Camels in Epidemiology of Middle East Respiratory Syndrome (MERS)

Emad M. Samara, Khalid A. Abdoun 

LETTER

This letter addresses some concerns about two recent articles published by the same authors in mBio (1, 2), specifically many uncertainties regarding the potential applicability of their epidemiological data, which were obtained from dromedary camels (DCs) infected with Middle East respiratory syndrome coronavirus (MERS-CoV), to human public health.

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The reply to this critique is fairly brief - where the authors stand by their work - can be read at the following link:

 

Reply to “Concerns About Misinterpretation of Recent Scientific Data Implicating Dromedary Camels in Epidemiology of Middle East Respiratory Syndrome (MERS)”

Abdulaziz N. Alagaili^a, Thomas Briese^b, William B. Karesh^c, Peter Daszak^c, W. Ian Lipkin^b

 

It is absolutely true that one can rarely say `case closed, time to etch our findings in stone’  with any field of scientific research. `Conclusive evidence’  is a very high, sometimes unobtainable, standard of proof. 

 

And few would argue that more work doesn’t need to be done on the virology, ecology, and epidemiology of the MERS coronavirus. 

 

But until that can happen, we pretty much have to go by the preponderance of evidence. And for now, despite the misgivings of these authors from King Saud University, that evidence strongly suggests camels play an important role in the hosting, and spread of MERS-CoV.  

EID Journal: Equine H3N8 In Mongolian Bactrian Camel

 

Bactrian Camel – Credit Wikipedia

 

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Mongolia is home to recurring epizootic outbreaks of Equine H3N8 – an avian influenza that jumped to horses about a half century ago, and to dogs a decade ago -  among their horse populations (see Isolation and characterization of H3N8 equine influenza A virus associated with the 2011 epizootic in Mongolia). 

 

These outbreaks, which occur roughly once a decade, not only impact the lives and economy of nomadic Mongolians, it has the potential of exposing other mammals to the virus.

 

While not as plentiful as horses, the Bactrian (two humped) camel is an important domesticated beast of burden for Mongolians, and as such is frequently exposed to both humans and horses.  It is also on the critically endangered list, and may even be extinct in the wild.

 

In the fall of 1979 a severe epizootic influenza broke out among Mongolian camels, which turned out to be a reassortant of the recently re-emerged (1977) H1N1 (aka `Russian flu’) virus, showing that this species of camels was susceptible to at least some strains of influenza.

 

Virology. 1993 Dec;197(2):558-63.

A reassortant H1N1 influenza A virus caused fatal epizootics among camels in Mongolia.

Yamnikova SS¹, Mandler J, Bekh-Ochir ZH, Dachtzeren P, Ludwig S, Lvov DK, Scholtissek C. 

Abstract

In the autumn of 1979 a severe influenza epizootic started among camels in Mongolia (Lvov et al., 1982; Viprosi Virusol. 27, 401-405.) Between 1980 and 1983 13 independent isolates of H1N1 viruses were obtained from diseased camels, which were virtually indistinguishable from the human A/USSR/90/77 strain by serological means. Two hundred and seventy-one samples of camel sera collected between 1978 and 1983 contained antibodies against the human A/USSR/90/77 isolate. After experimental infection of camels with some of these isolates, the animals developed similar symptoms as those found during natural infection: coughing, bronchitis, fever, discharge from nose and eyes. A genetic sequence analysis revealed that among the eight segments (genes) the PB1, HA, and NA genes were almost identical with allelic genes of the USSR/77 strain, and the PB2, PA, NP, M, and NS genes were almost identical with those of the A/PR/8/34 strain.

 

Today the EID Journal carries a report on the detection of the Equine H3N8 influenza virus in a Mongolian Bactrian camel, likely acquired through exposure to infected horses.  First the link and some excerpts from the study, after which I’ll have a bit more:

 

Volume 20, Number 12—December 2014

Dispatch

Equine Influenza A(H3N8) Virus Isolated from Bactrian Camel, Mongolia

Myagmarsukh Yondon, Batsukh Zayat, Martha I. Nelson, Gary L. Heil, Benjamin D. Anderson, Xudong Lin, Rebecca A. Halpin, Pamela P. McKenzie, Sarah K. White, David E. Wentworth, and Gregory C. Gray

ABSTRACT

Because little is known about the ecology of influenza viruses in camels, 460 nasal swab specimens were collected from healthy (no overt illness) Bactrian camels in Mongolia during 2012. One specimen was positive for influenza A virus (A/camel/Mongolia/335/2012[H3N8]), which is phylogenetically related to equine influenza A(H3N8) viruses and probably represents natural horse-to-camel transmission.

CONCLUSIONS

The phylogeny indicates that A/camel/Mongolia/335/2012 probably represents a relatively recent horse-to-camel transmission event. Without additional isolates from camels or corresponding epidemiologic data, and given the close genetic relationship between A/camel/Mongolia/335/2012 and related equine viruses, it is impossible to determine at this time whether the virus has been successfully transmitted from camel to camel.

In recent years, enhanced surveillance has detected influenza A viruses across a wider range of mammalian hosts, including horses, swine, dogs (14), seals (15), cats, and now camels, providing a more complete picture of the ecology of influenza A viruses beyond their presence in birds. How influenza A viruses successfully jump from 1 host species to another, and what the constraints on interspecies transmission are, remain key questions about influenza virus ecology and assessments of pandemic threats. Our findings highlight the need to further elucidate the ecology of influenza viruses and other pathogens in free-ranging camel populations.

 

As noted before, anytime an influenza virus jumps to a new host, we tend to take notice.  Influenza viruses as a rule are promiscuous, but until 2003 when it jumped to dogs, the H3N8 virus had only impacted birds and horses.

 

Last week, in Study: Dogs As Potential `Mixing Vessels’ For Influenza, we looked at a study that examined the susceptibility of canine tracheal cells to infection by canine, equine, and human influenza strains – including equine H3N8.

 

Any species that is susceptible to multiple, and diverse, flu strains has at least the potential to serve as a `mixing’ vessel for viral reassortment. Dogs, given their massive numbers and close contact with humans, are a far greater concern in this regard than Mongolian camels.

 

While the discovery of a single equine H3N8 virus among Bactrian camels may seem like an obscure, perhaps even insignificant bit of research, it reveals another piece of the influenza puzzle.

 

Learning how influenza viruses jump and adapt to new species – even among relatively small population of animals in a remote areas of the world – may very well lead to a better understanding of how the next pandemic (or epizootic) virus will emerge.

WHO Update On MERS-CoV Transmission Risks From Animals To Humans

Credit FAO

 

 

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Over the past nine months we’ve seen a steady procession of research papers, and cautionary public health statements, implicating camels as one potential source of human infection with the MERS Coronavirus.  

 

The virus has certainly been found in camels see Kuwait Tests Camels - Finds 6% Positive For MERS-CoV), and  we’ve seen a few instances where camel-to-human transmission is strongly suspected (see CIDRAP: More Evidence for Camel-to-Human MERS-CoV Transmission).

Yesterday, in Eurosurveillance: MERS-CoV Antibodies & RNA In Camel’s Milk – Qatar research supporting the notion that consumption of unpasteurized camel’s milk might be a route to infection. 

 

Acceptance of this MERS-camel connection in Saudi Arabia and the Middle East has been slow in coming. We’ve seen tepid warnings about avoiding raw camel products, along side statements from officials that there is no actual `proof’ that camels can transmit the virus to humans (see Saudi MOA Spokesman: Camel Link Unproven).

 

For many Saudis, the idea that camels – a beloved national symbol that literally made settlement of that arid region possible – could carry a disease deadly to humans,  is simply unthinkable. 

 

Nevertheless, the evidence is mounting, and today the World Health Organization released the following interim statement on the risks of camel-to-human transmission of the virus.

 

 

 

 

Middle East respiratory syndrome coronavirus (MERS‐CoV)

13 June 2014

Update on MERS‐CoV transmission from animals to humans, and interim recommendations for at‐risk groups

Over the past year, several investigations into the animal source of MERS‐CoV have been conducted. MERS‐CoV genetic sequences from humans and camels in Egypt, Oman, Qatar and Saudi Arabia demonstrate a close link between the virus found in camels and that found in people in the same geographic area. These and other studies have found MERS‐CoV antibodies in camels in Africa and the Middle East. 

Preliminary results from an ongoing investigation in Qatar show that people working closely with camels (e.g. farm workers, slaughterhouse workers and veterinarians) may be at higher risk of MERS‐CoV infection than people who do not have regular close contacts with camels. In Qatar and several other countries, animals, including goats, cows, sheep, water buffalo, swine and wild birds, have been tested for antibodies to MERS‐CoV, with no positive results.

The absence of antibodies in these animals indicates that the likelihood of other animals having a substantial role in transmission of MERS‐CoV is very low. These studies provide evidence that camels are a likely primary source of the MERS‐CoV that is infecting humans.  The current pattern of disease appears to be the result of repeated introductions of the virus from camels to people, resulting in limited human‐to‐human transmission, but not in sustained transmission.

Therefore, discovery of the routes of transmission, whether direct or indirect, between camels and people, is critical to stopping transmission of the virus.  WHO is working with partner agencies with expertise in animal health and food safety, including FAO, OIE and national authorities, to facilitate ongoing investigations. 

Investigation protocols and guidelines for dealing with new cases are available on the WHO website (http://www.who.int/csr/disease/coronavirus_infections/en/). 

General recommendations

As a general precaution, anyone visiting farms, markets, barns or other places where camels are present should practice general hygiene measures, including regular hand washing after touching animals, avoiding touching eyes, nose or mouth with hands, and avoiding contact with sick animals. People may also consider wearing protective gowns and gloves while handling animals. 

The consumption of raw or undercooked animal products, including milk and meat, carries a high risk of infection from a variety of organisms that might cause disease in humans. Animal products processed appropriately through proper cooking or pasteurization are safe for consumption but should also be handled with care, to avoid cross‐contamination with uncooked foods.

Recent studies in Qatar show that MERS‐CoV can be detected in raw milk from infected camels. Whether camels excrete MERS‐CoV in milk or the virus gets into the milk through cross‐contamination during milking is unclear. However, if MERS‐CoV is present, it will be destroyed by pasteurization or cooking. Camel meat and camel milk are nutritious products that can continue to be consumed after cooking, pasteurization, or other heat treatments. Safe alternatives should be developed to the tradition of sales of raw camel milk for direct consumption, along roadsides and farm gates.

Recommendations for at‐risk groups

Until more is understood about MERS, people with diabetes, renal failure, chronic lung disease, and immunocompromised persons are considered at high risk of severe disease from MERS‐CoV infection. Therefore, these people should avoid contact with camels, should not drink raw camel milk or camel urine, and should not eat meat that has not been properly cooked. Such recommendations should also be disseminated to travellers, tourists and pilgrims with above mentioned underlying conditions coming to the region from around the world.

Preliminary results from recent studies in Qatar indicate that people handling or working with camels are at increased risk of infection with MERS‐CoV compared with people who do not have contact with camels. Until more evidence is gathered, it is prudent for camel farm workers, slaughterhouse workers, market workers, veterinarians and those handling camels at racing facilities to practice good personal hygiene, including frequent hand washing after touching animals.

They should wear facial protection where feasible and protective clothing, which should be removed after work and washed daily.  Workers should also avoid exposing family members to soiled work clothing, shoes, or other items that may have come into contact with camel excretions. It is therefore recommended that these clothes and items remain at the workplace for daily washing and that workers have access to and use shower facilities at their workplaces before leaving the premises.

Camels infected with MERS‐CoV may not show any signs of infection. It is therefore not possible to know whether an animal in a farm, market, race track or slaughterhouse is excreting MERS‐CoV that can potentially infect humans. However, infected animals may shed MERS‐CoV through nasal and eye discharge, faeces, and potentially in their milk and urine. The virus may also be found in the organs and meat of an infected animal. Therefore, until more is known about infection in animals, the best protection is to practice good hygiene and avoid direct contact with all of these. Obviously sick animals should never be slaughtered for consumption; dead animals should be safely buried or destroyed. 

People who are not wearing protective gear should avoid contact with any animal that has been confirmed positive for MERS‐CoV until subsequent tests have confirmed that the animal is free of the virus.