Saturday, July 02, 2022

ECDC/EFSA : Avian Influenza Overview March – June 2022



Avian Epizootics In Europe Since 2016/17

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Prior to the 2016/17 avian H5N8 epizootic, the impact of HPAI H5 in Europe had been relatively small, usually involving anywhere from a handful to a few dozen widely scattered outbreaks in poultry each year. 

That pattern changed dramatically in the fall of 2016 when a recently reassorted clade 2.3.4.4b HPAI H5N8 virus emerged from either Russia or China, producing new, far more virulent virus (see EID Journal: Reassorted HPAI H5N8 Clade 2.3.4.4. - Germany 2016).

Although this 2016 epizootic was followed by two very quiet years (see chart above), clade 2.3.4.4b H5 virus was quietly reinventing itself - first reassorting into a relatively weak H5N6 virus - and eventually into a new, more problematic H5N1 virus which emerged in 2020.

This reassorted H5N1 not only spread more efficiently via migratory birds, it was more lethal to some wild avian species, resulting in huge die offs of birds across Europe. Instead of disappearing completely during the summer of 2021, the virus persisted at low levels, only to return with a vengeance last fall. 

The virus also managed to spread westward, across the Atlantic to North America where is has sparked another major epizootic, resulting in the loss of tens of millions of domesticated and wild birds. 

And both in Europe, and in North America, we continue to see signs that HPAI H5 is accruing mammalian adaptations (see here, here, here, and here) , which may help make it a bigger threat to human health in the future (see CDC HAN Advisory On Human H5 Infection In The United States).

Once again, we are seeing unusual persistence of avian flu (both in Europe and North America) well into summer, and last week we saw the first report of HPAI Detected In The Arctic (Svalbard), both of which may herald another wave returning in the fall. 

HPAI H5 is currently mostly a threat to wild birds, and the poultry industry, and its impact on human health has been minimal. That said, last May the CDC Added Zoonotic Avian A/H5N1 Clade 2.3.4.4b To IRAT List of influenza viruses with at least some pandemic potential.

Viral evolution is a double-edged sword, and we've seen several HPAI H5 viruses lose their virulence, and their threat recede, over the past 2 decades.  That's why we haven't heard about human H5N1  infections in former hotspots like Cambodia, Indonesia, and Egypt for years. 

Unfortunately, there is no guarantee we'll get as lucky with this iteration of HPAI H5.   

Because of this growing threat, the ECDC, along with EFSA, produce a quarterly, highly detailed, overview of avian flu both in Europe, and around the world.   Their latest edition runs 67-pages, and is chock full of both surveillance data and analysis. 

Due to its length, I've only posted the link and the abstract. I'll have a brief postscript after the break. 


European Food Safety Authority,
European Centre for Disease Prevention and Control,

European Union Reference Laboratory for Avian Influenza,

Cornelia Adlhoch, Alice Fusaro, José L Gonzales, Thijs Kuiken, Stefano Marangon, Éric Niqueux, Christoph Staubach, Calogero Terregino, Inma Aznar, Irene Muñoz Guajardo and Francesca Baldinelli

Abstract

The 2021–2022 highly pathogenic avian influenza (HPAI) epidemic season is the largest epidemic so far observed in Europe, with a total of 2,398 outbreaks in poultry, 46 million birds culled in the affected establishments, 168 detections in captive birds, and 2,733 HPAI events in wild birds in 36 European countries. 
Between 16 March and 10 June 2022, 1,182 HPAI virus detections were reported in 28 EU/EEA countries and United Kingdom in poultry (750), and in wild (410) and captive birds (22). During this reporting period, 86% of the poultry outbreaks were secondary due to between-farm spread of HPAI virus. France accounted for 68% of the overall poultry outbreaks, Hungary for 24% and all other affected countries for less than 2% each. Most detections in wild birds were reported by Germany (158), followed by the Netherlands (98) and the United Kingdom (48). 
The observed persistence of HPAI (H5) virus in wild birds since the 2020–2021 epidemic wave indicates that it may have become endemic in wild bird populations in Europe, implying that the health risk from HPAI A(H5) for poultry, humans, and wildlife in Europe remains present year-round, with the highest risk in the autumn and winter months. 
Response options to this new epidemiological situation include the definition and the rapid implementation of suitable and sustainable HPAI mitigation strategies such as appropriate biosecurity measures and surveillance strategies for early detection measures in the different poultry production systems. Medium to long-term strategies for reducing poultry density in high-risk areas should also be considered.
The results of the genetic analysis indicate that the viruses currently circulating in Europe belong to clade 2.3.4.4b. HPAI A(H5) viruses were also detected in wild mammal species in Canada, USA and Japan, and showed genetic markers of adaptation to replication in mammals.
Since the last report, four A(H5N6), two A(H9N2) and two A(H3N8) human infections were reported in China and one A(H5N1) in USA. The risk of infection is assessed as low for the general population in the EU/EEA, and low to medium for occupationally exposed people.


Just as Europe's HPAI H5 has likely been ferried north to the high latitude roosting spots for migratory birds in Siberia and the arctic, it is a fair assumption that the virus has been carried by North American migratory birds to their summer roosting areas in the 19-million acre Arctic National Wildlife Refuge

The $64 question is what happens there

Does the virus die out over the summer, or does it persist, and potentially reassort (again) with other viruses or mutate, only to return next fall via the four North American Flyways (see below) that funnel millions of birds south each fall. 

As far as answers go, we probably won't know until October or November, when migratory birds begin to return to the lower 48 in quantity.  Until then, we'll be watching to see if HPAI H5  completely disappears over the next couple of months, or if it manages to maintain some presence in wild birds over the summer. 

Stay tuned.  

Friday, July 01, 2022

The Upcoming Hajj & The UKHSA MERS-CoV Risk Assessment


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Seven days from now (July 7th) Saudi Arabia will host the first Hajj since COVID emerged in early 2020 - and while it will be smaller than in past years, and limited to those under the age of 65 - it will draw as many as 1 million people from countries all around the globe. 

As we've discussed often, the Hajj - like many other mass gathering events - has the potential to amplify and disperse emerging and existing infectious diseases on a global scale (see J, Epi & Global Health: Al-Tawfiq & Memish On Hajj Health Concerns).

The biggest health concerns include mosquito borne illnesses (like Dengue, Chikungunya, Zika & Yellow Fever), tuberculosis, mumps, measles, chickenpox, norovirus and respiratory viruses like seasonal influenza & Rhinovirus - and since 2013 - MERS-CoV. .

In 2015's EID Journal: ARI’s In Travelers Returning From The Middle East, researchers found respiratory infections are the most commonly reported illness among religious pilgrims. This study also found that:
`Pneumonia is the leading cause of hospitalization at Hajj, accounting for approximately 20% of diagnoses on admission.’

But this year we also have the added concern of COVID, which is often indistinguishable from flu, MERS-CoV, and other respiratory viruses without testing.  

While reports of MERS-CoV cases have plummeted since early 2020, it is not clear how much of that can be attributed to lapses in surveillance and reporting, and how much to an actual decline in cases. 

Detecting MERS-CoV cases can be challenging, even when countries are actively looking for cases. A task has which has admittedly become even more difficult due to the COVID pandemic. 

Given its high case fatality rate, and the recent trend of coronaviruses adapting to humans (SARS and SARS-CoV-2), MERS-CoV remains a credible threat.  

Here is today's updated Risk Assessment from the UKHSA.

Guidance
UKHSA risk assessment of MERS-CoV

Updated 1 July 2022

Epidemiological update

As of 16 June 2022, 2,591 cases of Middle East Respiratory Syndrome (MERS-CoV) have been reported by WHO, with at least 894 related deaths. The majority of MERS-CoV cases have been reported from the Arabian Peninsula, with one large outbreak outside this region involving 186 cases in the Republic of Korea (RoK) in 2015. Cases have been exported to other countries outside of the Middle East, including cases being identified in the UK and South Korea in August and September 2018 respectively.

On 22 August 2018, Public Health England (PHE) reported a laboratory-confirmed case of MERS-CoV infection in a resident of the Middle East who had travelled from Saudi Arabia. In response to this, public health measures were implemented including identification of exposed contacts and provision of health advice. This was the third imported MERS case reported by the UK; the previous case was reported in 2013 was associated with 2 infections in close contact.

Excluding the 2015 outbreak in RoK, the majority of reported cases of MERS-CoV worldwide have been from the Kingdom of Saudi Arabia (KSA).

MERS-CoV in Saudi Arabia

In KSA, cases of MERS-CoV occur throughout the year; there is currently no evidence of sustained community transmission; human-to-human transmission is most likely to occur in healthcare facilities and household clusters. Large outbreaks linked to healthcare facilities are a feature of MERS-CoV and have occurred both within the Middle East and RoK. This underlines the significance of healthcare facilities as a risk factor for amplifying infection, but also the importance of effective and rapid implementation of infection prevention and control practices for possible cases to limit the potential for onward transmission to other patients and staff.

Outside of hospital outbreaks and smaller household clusters, reported cases are sporadic and usually occur in individuals with a history of contact with camels or camel products such as consumption of raw camel milk. The UK Health Security Agency (UKHSA, previously Public Health England) will continue to monitor the situation in KSA.

Risk assessment

The previous sporadic imported cases to the UK highlight the continued risk of imported cases to the UK, reflecting the epidemiology of MERS-CoV infection in the Middle East. It is therefore imperative that health professionals remain vigilant for clinical presentations compatible with Middle East Respiratory Syndrome. Early identification and rapid implementation of appropriate infection control measures for possible cases, and reporting of these to local health protection teams is crucial.
The risk of infection with MERS-CoV to UK residents in the UK remains very low.
The risk of infection with MERS-CoV to UK residents travelling to the Middle East is very low, but may be higher in those with exposure to specific risk factors within the region, such as camels (or camel products) or the local healthcare system.

Testing for MERS-CoV is warranted for persons who meet the possible case definition together with rapid implementation of appropriate infection control measures while awaiting results of testing.

The majority of outbreaks of MERS-CoV in the Middle East have been linked to healthcare settings. A previous WHO mission to Saudi Arabia concluded that gaps in infection control measures have most likely contributed to these outbreaks; this reinforced the importance of strict adherence to recommended infection control measures in healthcare facilities.

Where UK infection control procedures have been followed, the probability of acute respiratory infection in a healthcare worker caring for a case of MERS-CoV, or a case of severe acute respiratory infection of unknown aetiology in the intensive care unit (ICU), is due to MERS-CoV is very low, but warrants testing. Any healthcare worker who develops an acute respiratory illness and has recently been in contact with a confirmed case of MERS-CoV would be tested for the virus. The risk will be higher for healthcare workers exposed to MERS-CoV who have not adhered to UK infection control procedures, such as the use of adequate personal protective equipment (PPE).

The risk to contacts of confirmed cases of MERS-CoV infection is low, but contacts should be followed up for 14 days following last exposure and any new febrile or respiratory illness investigated urgently for MERS-CoV.

Further information and guidance on MERS-CoV is available.

Travel advice

All travellers to the Middle East are advised to avoid contact with camels as much as possible:
  • travellers should practice good general hygiene measures, such as regular handwashing with soap and water at all times, but especially before and after visiting farms, barns or market areas
  • travellers are advised to avoid raw camel milk and/or camel products from the Middle East
  • travellers are also advised to avoid consumption of any type of raw milk, raw milk products and any food that may be contaminated with animal secretions unless peeled and cleaned and/or thoroughly cooked
  • travellers should follow the advice of local health authorities; there are currently no travel restrictions in place
  • travellers developing fever and cough within 14 days of travel from the Middle East should seek medical advice and must report their travel history so that appropriate clinical assessment, infection control measures and testing can be undertaken
  • people who are acutely ill with an infectious disease are advised not to travel but to seek health advice immediately
The Hajj and Umrah

International pilgrims will be allowed to undertake the Hajj in 2022.

The last Hajj where large numbers of international pilgrims could attend was in 2019. There was no reported increase in travel-related MERS-CoV cases for this latest or previous Hajj pilgrimages. However, cases of MERS-CoV have been imported to countries outside of Saudi Arabia following return from Umrah, a separate pilgrimage which can be performed throughout the year, as illustrated by the most recent Malaysian case.

UKHSA remains vigilant and closely monitors developments in the Middle East and in the rest of the world where new cases have emerged and continues to liaise with international colleagues to assess whether our recommendations need to change.

Infographics for people travelling to the Middle East or returning from the Middle East are available in a range of languages.

NaTHNaC has published travel health advice for Hajj and Umrah.

Further information for health professionals on the possible MERS case definition is available.


Past studies (see A Pandemic Risk Assessment Of MERS-CoV In Saudi Arabia) have suggested the MERS virus doesn't have all that far to evolve before it could pose a genuine global threat.

And while it remains mostly a theoretical concern, several studies have suggested that there it at least some potential for seeing a MERS-CoV/SARS-CoV-2 recombinant emerge someday. 

The Recombination Potential between SARS-CoV-2 and MERS-CoV from Cross-Species Spill-over Infections

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Middle East Respiratory Syndrome Coronavirus (MERS-CoV) coinfection: A unique case series

Good reasons why we need improve surveillance and testing of cases, and the reporting of them promptly to WHO  Otherwise, we risk being blindsided by the next global health threat.

FDA Recommends Adding BA.4/5 Spike Protein To Create A Bivalent COVID Booster Shot


Credit ACIP/CDC  

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The COVID and primary and booster vaccines currently being used were introduced over 18 months ago (Dec 2020), and were based on the first European (D614G) (correction: original Wuhan D614) strain of the coronavirus.  Since then, SARS-CoV-2 has undergone major evolutionary changes (Alpha, Delta, and several iterations of Omicron), rendering the original vaccine less effective over time. 

While it has been apparent for some time that a new vaccine formulation was needed, with new variants appearing and rising to dominance every couple of months, deciding on a formulation has been difficult.  

Earlier this year BA.1 was favored as the heir apparent, and work began on incorporating that variant into a new candidate vaccine, but BA.1 is now nearly extinct.  BA.2, which supplanted BA.1, is fading fast and the new rising stars are BA.4 and BA.5.

But how long they will reign is anyone's guess. 

Yesterday the FDA decided that manufacturers should proceed with incorporating BA.4/5 into a booster shot - which hopefully can be made available by the fall - but the primary shot will remain `as is' for now.  

Getting an updated booster developed, tested, and deployed by fall is a tall order, and a bit of a gamble as well, given the speed at which SARS-CoV-2 has been evolving.  

But continuing to use the original booster is expected to provide decreasing benefits over time.  The statement from the FDA follows:


Coronavirus (COVID-19) Update: FDA Recommends Inclusion of Omicron BA.4/5 Component for COVID-19 Vaccine Booster Doses

 The following is attributed Peter Marks, M.D., Ph.D., director of the FDA’s Center for Biologics Evaluation and Research

 
For Immediate Release:June 30, 2022 
Statement From:Peter Marks, M.D., PhD.

Director - Center for Biologics Evaluation and Research (CBER)

On Tuesday, the U.S. Food and Drug Administration’s independent experts on the Vaccines and Related Biological Products Advisory Committee met to publicly discuss whether a change to the current vaccine strain composition of COVID-19 vaccines for booster doses is necessary for the 2022 fall and winter seasons.

The COVID-19 vaccines that the FDA has approved and authorized for emergency use have made a tremendous difference to public health and have saved countless lives in the U.S. and globally. However, SARS-CoV-2, the virus that causes COVID-19, has evolved significantly, with recent surges around the world associated with the rapid spread of highly transmissible variants such as omicron.

Currently available vaccines have helped reduce the most serious outcomes (hospitalization and death) caused by COVID-19, but results from post-authorization observational studies have shown that effectiveness of primary vaccination wanes over time against certain variants, including omicron. And while initial booster doses have helped restore protection against severe disease and hospitalization associated with omicron, studies have also indicated waning effectiveness of first booster doses over time.

The American public can be assured that any COVID-19 vaccine authorized or approved by the FDA meets our standards for safety and effectiveness. We encourage those who are currently eligible for a booster to get one.

As we move into the fall and winter, it is critical that we have safe and effective vaccine boosters that can provide protection against circulating and emerging variants to prevent the most severe consequences of COVID-19. Following a thorough discussion on June 28, 2022, an overwhelming majority of the advisory committee voted in favor of including a SARS-CoV-2 omicron component in COVID-19 vaccines that would be used for boosters in the U.S. beginning in fall 2022.

Following the vote, and striving to use the best available scientific evidence, we have advised manufacturers seeking to update their COVID-19 vaccines that they should develop modified vaccines that add an omicron BA.4/5 spike protein component to the current vaccine composition to create a two component (bivalent) booster vaccine, so that the modified vaccines can potentially be used starting in early to mid-fall 2022.

As we expect this coming year to be a transitional period when this modified booster vaccine may be introduced, we have not advised manufacturers to change the vaccine for primary vaccination, since a primary series with the FDA-authorized and approved COVID-19 vaccines provides a base of protection against serious outcomes of COVID-19 caused by circulating strains of SARS-CoV-2.

Vaccine manufacturers have already reported data from clinical trials with modified vaccines containing an omicron BA.1 component and we have advised them that they should submit these data to the FDA for our evaluation prior to any potential authorization of a modified vaccine containing an omicron BA.4/5 component. Manufacturers will also be asked to begin clinical trials with modified vaccines containing an omicron BA.4/5 component, as these data will be of use as the pandemic further evolves.

The FDA has been planning for the possibility that vaccines would need to be modified to address circulating variants and previously provided guidance to industry on how to do so efficiently. As has been the case with all COVID-19 vaccines throughout the pandemic, the agency will evaluate all relevant data to inform the safety, effectiveness and manufacturing quality of modified vaccines under consideration for authorization or approval to ensure that they meet the FDA’s standards.

In keeping with our commitment to transparency, the FDA will communicate future plans pertaining to the potential authorization or approval of COVID-19 vaccine booster doses with an omicron component.

CDC Director Endorses ACIP Recommendation On High-Dose/Adjuvanted Flu Vaccines For Seniors

ACIP Presentation

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Just over a week ago ACIP Voted (15-0) To Preferentially Recommend High-Dose/Adjuvanted Flu Vaccines For Seniors and sent their recommendations to the CDC.  Although it took a week, yesterday the CDC's Director Rochelle P. Walensky, M.D., M.P.H. issued the following endorsement. 

First the statement from the CDC, after which I'll have a bit more.

CDC Director Adopts Preference for Specific Flu Vaccines for Seniors
Media Statement

For Immediate Release: Thursday, June 30, 2022
Contact: Media Relations
(404) 639-3286

CDC Director Rochelle P. Walensky, M.D., M.P.H., adopted the Advisory Committee on Immunization Practices’ (ACIP) recommendation to preferentially recommend the use of specific flu vaccines for adults 65 years and older, including higher dose and adjuvanted flu vaccines. The preference applies to Fluzone High-Dose Quadrivalent, Flublok Quadrivalent and Fluad Quadrivalent flu vaccines.

While flu seasons vary in severity, during most seasons, people 65 years and older bear the greatest burden of severe flu disease, accounting for the majority of flu-related hospitalizations and deaths. Additionally, changes in the immune system with age mean that older adults often do not have as strong an immune response to vaccination as younger, healthy people. “Given their increased risk of flu-associated severe illness, hospitalization, and death, it’s important to use these potentially more effective vaccines in people 65 years and older,” said José R. Romero, M.D., Director of CDC’s National Center for Immunization and Respiratory Diseases. Additionally, data has shown that racial and ethnic health disparities exist in populations that receive a high-dose flu vaccine compared with standard-dose flu vaccines. “This recommendation could help reduce health disparities by making these vaccines more available to racial and ethnic minority groups,” said Dr. Romero.

Last Thursday, ACIP voted to preferentially recommend the use of higher dose flu or adjuvanted flu vaccines over standard-dose unadjuvanted flu vaccines for people 65 years and older. This recommendation was based on a review of available studies which suggests that, in this age group, these vaccines are potentially more effective than standard dose unadjuvanted flu vaccines. Dr. Walensky’s adoption of the ACIP recommendation makes this recommendation official CDC policy, which will be further detailed in an upcoming Morbidity and Mortality Weekly Recommendation Report later this summer.

In recent years, CDC has not recommended any one flu vaccine over another for any age group, and there is still no preferential recommendation for people younger than 65. People 65 and older should try to get one of the three preferentially recommended vaccines, however, if one of these vaccines is not available at the time of administration, people in this age group should get a standard-dose flu vaccine instead.


Influenza has always been unpredictable, but following the emergence of COVID and two year's of pandemic mitigation efforts, it has demonstrated increasingly unusual behavior.  

There are also genuine concerns over the health impacts of dual (COVID and flu) infection (see The Lancet: SARS-CoV-2 Co-infection With Influenza Viruses, RSV, or Adenoviruses), although nobody is quite sure how common that might be. 

While the seasonal flu vaccine generally provides a moderate (40%-60%) level of protection against flu, last year it only prevented about 35% of infections.  Better than originally reported, but still disappointing. 

But most of this protection went to those under the age of 50 (see chart below), with those over 50 - a cohort that generally has a less robust immune response to vaccines -  seeing statistically little protection. 


While it is uncertain how much more protection these newer high-dose/adjuvanted vaccines will afford seniors in any given flu season, it is expected to be better than the standard dose vaccine. 

And with an uncertain flu/COVID season ahead, we can use any advantage we can get. 

Thursday, June 30, 2022

Eurosurveillance: Surface Contamination in Hospital Rooms Occupied by Patients Infected with Monkeypox

 

Monkeypox Virus - Credit CDC PHIL  

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Three weeks ago the CDC - while admitting there were still some unknowns - adjusted their guidance on the transmission of Monkeypox (see CDC Statement On Monkeypox Transmission), relaxing some of their their recommendations on isolation and hospital infection control procedures. 

This new guidance now only called for a private room (no special air handling required) and de-emphasized the potential airborne spread of Monkeypox. They provided some examples of how Monkeypox can and can't spread: 

    • No: Casual conversations. Walking by someone with monkeypox in a grocery store. Touching items like doorknobs.
    • Yes: Direct skin-skin contact with rash lesions. Sexual/intimate contact. Kissing while a person is infected.
    • Yes: Living in a house and sharing a bed with someone. Sharing towels or unwashed clothing.
    • Yes: Respiratory secretions through face-to-face interactions (the type that mainly happen when living with someone or caring for someone who has monkeypox).
    • Maybe/Still learning: Contact with semen or vaginal fluids.
    • Unknown/Still learning: Contact with people who are infected with monkeypox but have no symptoms (We think people with symptoms are most likely associated with spread, but some people may have very mild illness and not know they are infected).
Other than the caution over sharing linens, towels, or a bed, very little mention is made about the potential for transmission via contaminated surfaces or fomites.  

In fact, their example (abovespecifically rules out transmission by touching objects like doorknobs. 

Which brings us to a new study, published today in Eurosurveillance, on evidence of surface contamination in and around hospital rooms inhabited by Monkeypox patients in Germany, including places not touched by the patient and in the adjacent anteroom where HCWs donned and doffed their PPE. 

Among the most contaminated surfaces they found were door knobs, cabinet door handles, faucets, and light switches.  

Viral DNA may be detected, of course, even when the virus is no longer viable, or in concentrations too low to be infectious.  But these researchers were able to successfully isolate viable virus from 3 of the samples, suggesting transmission of the Monkeypox virus by fomite is at least possible

How likely that is to occur, and whether additional infection controls are needed, isn't known yet. But we have a history of underestimating the ability of viruses to get around. 

This is a lengthy and detailed report, and you'll want to read it in its entirety.  I've only posted some brief excerpts. 


Evidence of surface contamination in hospital rooms occupied by patients infected with monkeypox, Germany, June 2022 




Since 4 May 2022, the largest west-African-clade-monkeypox outbreak to date in countries with non-endemic occurrences has been described [1]. The outbreak involves transmission among people in close physical contact with symptomatic cases [1,2], in contrast to previous outbreaks, where zoonotic transmission was reported as the main mechanism of spread [3]. Nevertheless, events of person-to-person transmission have been previously described [3,4]. Additionally, transmission to personnel taking care of patients was reported on rare occasions [5,6]. 
Indirect transmission via contaminated objects is also discussed in the literature [6,7]. However, there are insufficient data on the environmental contamination of surfaces with monkeypox virus. We systematically examined surfaces of two hospital rooms occupied by monkeypox patients and the adjacent anterooms, which are used for donning and doffing personal protective equipment (PPE), for monkeypox virus contamination using PCR. In addition, we assessed the infectivity on cell culture of the collected samples by virus isolation.

          (SNIP)

Discussion 

Besides zoonotic transmission, monkeypox virus infections have been reported after person-to-person transmission [3]. To our knowledge, the highest rate of secondary cases described to date was in a central African outbreak in 1996–1997, where 65 (73%) of 89 case-patients with available data had had contact to another case-patient within 7–21 days before their onset of illness [4]. Person-to-person transmission with nosocomial transmission from a patient to three healthcare workers was reported in another African outbreak [5]. One nurse who evaluated the patient, and who later became ill, had removed the patient’s clothing, taken the patient’s temperature, and drawn blood without adequate PPE. Nosocomial transmission was also reported related to an imported case from Nigeria to the United Kingdom [6]. In this case, the infected healthcare worker changed potentially contaminated bed linen without adequate PPE.

There are no definite data on the required infectious dose with monkeypox virus in humans. However, in contrast to variola virus [9], a significantly higher dose is assumed to be required to trigger infection [10]. In non-human primates, infection could be initiated by intrabronchial application of 5×104 plaque-forming units (PFU) [11]. Orthopoxviruses are reported to remain infectious under dry conditions and different temperatures [12]. Dried vaccinia virus is stable up to 35 weeks (at 4 °C) without loss of infectivity [12]. In this study monkeypox virus was successfully isolated from three different samples, each with a total of at least 106 virus copies. Thus, contaminated surfaces with such viral loads or higher, could potentially be infectious and it cannot be ruled out that their contact with especially damaged skin or mucous membranes, could result in transmission.

Detection of up to 1.1×106 viral copies on gloves is consistent with the detection of viral DNA on surfaces typically handled only by medical staff such as the door handles of the anteroom. The detection of the virus at very low concentrations even outside the isolation unit indicates that containment protocols may not have been fully adhered to.

The findings in this report are subject to some limitations. As DNA is an environmentally stable molecule, detection of viral DNA by PCR cannot be equated with infectious virus. Despite high contamination with up to 105 cp/cm2 as well as the successful recovery of monkeypox virus from samples with a total of > 106 copies, our findings do not prove that infection can occur from contact with these surfaces. No secondary case in the context of clinical care of the two patients in our study has been observed so far. The study was performed only for two cases and might not be generalised to other cases. In particular, in certain cases, depending on the skin regions mainly affected and the number of lesions, the levels of contamination of different surfaces may vary.

Overall, these data underscore the importance to remind hospital personnel of the need to follow recommended protection measures for monkeypox. Sufficient time and attention must be given to the careful doffing of PPE and personnel must be properly trained in these procedures. Regular disinfection of frequent hand and skin contact points during the care processes additional to regular room cleaning and surface disinfection using products with at least virucidal activity against enveloped viruses can reduce infectious virus on surfaces and thereby risk of nosocomial transmission [13]. 

Suitable strategies for preventing the spread of the virus outside the patient's room must be individually adapted to the situation of the respective medical facility. The application of the double-gloving method [14] with discarding of the outer glove layer or disinfection of the gloved hand [15,16] before entering an anteroom can contribute to this. After the final doffing of the PPE, proper hand hygiene must be performed immediately. Pre-exposure vaccination for healthcare workers [17,18] as well as early post-exposure vaccination in the case of probable or confirmed contamination in the absence of or incorrectly applied protective equipment [18,19] may be considered.

Those living in the same households of affected individuals should be advised that, in addition to avoiding close physical contact, disinfection of shared skin- and hand-contact surfaces might be useful to prevent transmission [20,21]. At the present time, the viral load on inanimate surfaces required for disease transmission is unknown. Therefore, future studies should also investigate the dose dependent infectivity of such surfaces.


New Zealand Revises Testing Guidance For Suspected COVID Reinfection

 

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Early in the pandemic conventional wisdom held that once you have been infected with COVID, you were protected against reinfection - probably for years - and potentially forever.  While there were reasons to question this `best case scenario' (see COVID-19: From Here To Immunity), many people believed we could `infect ourselves out of this pandemic'. 

By the summer of 2020, reinfections - while rare - were beginning to appear, and their numbers only increased with the arrival of Alpha in late 2020, and Delta in the spring of 2021.  

Vaccines, which were also expected to provide `durable' protection, were showing decreased longevity with the arrival of each new variant.  `Breakthrough' infections, particularly after the emergence of Omicron, took off (see MMWR: Waning 2-Dose and 3-Dose Effectiveness of mRNA Vaccines Against COVID-19).

But even with this changing viral landscape many countries have set an arbitrary 60, 90, or even 180 day `window' following infection (or vaccination) where they assume a person is `protected', and re-testing for COVID is not generally recommended. 

Last week, in EID Journal: Early SARS-CoV-2 Reinfections within 60 Days and Implications for Retesting Policies, we looked at multiple documented cases of reinfection (by different lab-confirmed variants) well within the 60-day window, and a call to re-evaluate these arbitrary (and optimistic) assumptions about the duration of immunity. 

In light of these recent findings, yesterday New Zealand's Ministry of Health lowered their threshold for re-testing following COVID infection from 90 days to just 30 days

I'll return with a postscript after the break. 


Getting reinfected with COVID-19

The latest evidence shows that getting reinfected with COVID-19 can occur within a short period of time. Reinfection will become more likely as new variants spread among the community

Last updated: 30 June 2022

We have updated our advice on getting infected again with COVID-19 after a previous COVID-19 infection and when people should take a rapid antigen test (RAT).  

If a person develops new symptoms consistent with COVID-19, and it’s 29 days or more since a previous infection, it’s possible they have a reinfection with COVID-19 and they should test using a RAT.

This reflects a change from our earlier advice which was that people would not need to re-test if they had tested positive for COVID-19 within the past 90 days.  

It is unclear how common it is to be reinfected with COVID-19. We are constantly monitoring international and national data and updating our reinfection guidance as new evidence becomes available.

Anyone reinfected with COVID-19 will have access to the same advice, help and support as they would receive for a new COVID-19 infection.

Advice for people who have had COVID-19 before and get new symptoms 28 days or less since your last infection

If COVID-19 symptoms return and it is 28 days or less since your last COVID-19 infection:there is no need to take a rapid antigen test (RAT) you should stay home and recover until 24 hours after you no longer have symptoms.

Some people recovering from COVID-19 may have symptoms that come and go for some time afterwards or they may be caused by other infections like the common cold, flu or a chest infection.

If you have an underlying health condition or your symptoms are getting worse, seek advice from a health practitioner or call Healthline on 0800 358 5453.

COVID-19 symptoms

29 days or more since your last infection

If you develop new COVID-19 symptoms and it is 29 days or more since your last COVID-19 infection:it is possible that you have COVID-19 again and you should take a RAT. if you test positive, this will be considered a reinfection and you should follow the standard COVID-19 isolation guidelines.

COVID-19 symptoms

Self-isolation requirements if you have COVID-19

Your household contacts will also need to isolate, unless they have either:had COVID-19 in the last 90 days and are recovered been a household contact in the last 10 days.

Isolation requirements for household contacts.

If your result is negative

If your result is negative, your symptoms could be another infection, such as the flu or another virus. If your symptoms continue you should repeat a RAT 48 hours later. If this is still negative, then stay at home until at least 24 hours after your symptoms resolve.

If you have an underlying health condition or symptoms that are getting worse, you should call Healthline on 0800 358 5453 or your local healthcare provider.

Reinfection with COVID-19 – what we know so far

Reinfection refers to the detection of a second or subsequent COVID-19 infection, regardless of the variant involved.

You are more likely to become reinfected as your immune response from the vaccine, or your previous COVID-19 infection, decreases over time.

It is still unclear how common reinfections are but they’re likely to become more common as new variants and subvariants spread across New Zealand.

For most people illness caused by reinfection is likely to be no more severe than a previous infection, but they can experience different symptoms.

Changing from 90 days to 29 days or more

Early in the COVID-19 pandemic, many countries chose to advise not to test within a 90-day period of an initial infection, when reinfection was thought to be unlikely and difficult to diagnose with PCR.

Evidence now shows that reinfection can occur within 90 days, particularly with new variants.

In recognition of this evidence our advice is now to test from day 29, if you experience new COVID-19 symptoms following a previous infection.

Within 29 days of a previous infection it is very difficult to diagnose reinfection because symptoms, viral levels and test positivity can continue to vary for some weeks following an infection with COVID-19.

Evidence on reinfections is evolving rapidly. We will continue to monitor emerging information on reinfection and update this advice as new evidence becomes available.

COVID-19 infection and immunity

Monitoring reinfection in the community

When someone uploads a positive RAT into My Covid Record, if it is 29 days or more since their last infection, they will be categorised as a reinfection and given the same advice and support as for a new infection.

Using this data from My Covid Record we can now monitor the number of people with a reinfection with COVID-19. Information on the number of reinfections will be included in the daily COVID-19 updates published on our website.

Latest COVID-19 current cases in New Zealand.

Guidance for clinicians

We have updated our clinical guidance for healthcare providers about how to manage patients who present with symptoms consistent with COVID-19, or a positive COVID-19 RAT, after a previous COVID-19 infection.

Guidance on reinfection for clinicians.

Downloads
Clinical guidance on testing for possible covid-19 reinfection (docx, 409 KB)
Clinical guidance on testing for possible covid-19 reinfection (pdf, 231 KB)

Everything we know about the BA.4/BA.5 Omicron variants (see NEJM: Neutralization Escape by SARS-CoV-2 Omicron Subvariants BA.2.12.1, BA.4, and BA.5) suggests they have an even greater ability to evade prior immunity, making `breakthrough infections' and reinfections even more likely in the months ahead. 

The SARS-CoV-2 virus has shown a remarkable ability to adapt to humans (and other hosts), and as it has evolved its abilities have changed. 

As the COVID threat changes, we need to be nimble enough in our response to pivot when needed, if we are to bring this pandemic under control.  

Hopefully more countries will follow New Zealand's lead.