Wednesday, May 22, 2024

CDC Statement On Michigan H5 Case

 

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The CDC emailed out the following statement on Michigan's 1st H5 influenza infection:



From:"Media (CDC)" <sohco@CDC.GOV>

To: <MMWR-MEDIA@LISTSERV.CDC.GOV>

Subject: CDC Reports Second Human Case of H5 Bird Flu Tied to Dairy Cow Outbreak

Date: May 22, 2024 3:30 PM​

Press Release

For Immediate Release
Wednesday, May 22, 2024


Contact: CDC Media Relations
(404) 639-3286          

CDC Reports Second Human Case of H5 Bird Flu Tied to Dairy Cow Outbreak

CDC’s Risk Assessment for the General Public Remains Low

May 22, 2024 -- A human case of highly pathogenic avian influenza (HPAI) A(H5) (“H5 bird flu”) virus infection in the United States has been identified in the state of Michigan. This is the second case associated with an ongoing multistate outbreak of A(H5N1) in dairy cows.[i] As with the case in Texas, the individual is a worker on a dairy farm where H5N1 virus has been identified in cows. While a nasal swab from the person tested negative for influenza in Michigan, an eye swab from the patient was shipped to CDC and tested positive for influenza A(H5) virus, indicating an eye infection. Similar to the Texas case, the patient only reported eye symptoms. CDC has been watching influenza surveillance systems closely, particularly in affected states, and there has been no sign of unusual influenza activity in people, including in syndromic surveillance.

Based on the information available, this infection does not change CDC’s current H5N1 bird flu human health risk assessment for the U.S. general public, which the agency considers to be low. However, this development underscores the importance of recommended precautions in people with exposure to infected or potentially infected animals. People with close or prolonged, unprotected exposures to infected birds or other animals (including livestock), or to environments contaminated by infected birds or other animals, are at greater risk of infection.

Case Background

A dairy worker who was being monitored because of their work exposure to H5N1-infected cattle reported symptoms to local health officials. Two specimens were collected from the patient. An upper respiratory tract specimen collected from the worker's nose was negative for influenza virus at the state health department laboratory. The eye specimen was sent to CDC for testing because it is one of a few labs where those specimens can be used with the CDC A(H5) test. The specimen was received by CDC and testing results confirmed A(H5) virus infection. The nasal specimen was retested at CDC and confirmed to be negative for influenza. The state was then notified of the results. The designation of the influenza virus neuraminidase (the N in the subtype) is pending genetic sequencing at CDC. Attempts to sequence the virus in the clinical specimen are underway and will be made available within 1-2 days if successful. Additional genetic analysis will look for any changes to the virus that could alter the agency’s risk assessment.

Conjunctivitis (eye infection) has been associated with previous human infections with avian influenza A viruses and is part of the current CDC case definition for A(H5N1) surveillance. While it’s not known exactly how eye infections result from avian influenza exposures, it may be from contamination of the eye(s), potentially with a splash of contaminated fluid, or touching the eye(s) with something contaminated with A(H5N1) virus, such as a hand. High levels of A(H5N1) virus have been found in unpasteurized milk from H5N1-infected cows.

CDC Activities

This case was detected through the state’s implementation of CDC’s recommended monitoring and testing strategies in exposed persons. In addition to enhanced and targeted surveillance, CDC also has:
  • Held numerous weekly engagements with state and local HDs around increasing their preparedness posture
  • Updated interim recommendations for worker protection to include those who work with dairy cows
  • Issued a Health Alert Notice (HAN) on identification of human infection and recommendations for investigations/response
  • Held a call with states asking them to move from preparedness to readiness
  • Updated interim recommendations for worker protection to include those who work in slaughterhouses
  • Conducted numerous calls with groups representing farmworkers
  • Asked states to furnish PPE for farmworkers
  • Announced incentives for workers who participate in public health research efforts into the outbreak
  • Asked states to work with clinical labs to increase submissions of positive influenza virus samples to public health labs for subtyping
Given the high levels of A(H5N1) virus in raw milk from infected cows, and the extent of the spread of this virus in dairy cows, similar additional human cases could be identified. Sporadic human infections with no ongoing spread will not change the CDC risk assessment for the U.S. general public, which CDC considers to be low.

CDC Recommendations
  • People should avoid close, long, or unprotected exposures to sick or dead animals, including wild birds, poultry, other domesticated birds, and other wild or domesticated animals (including cows).
  • People should also avoid unprotected exposures to animal poop, bedding (litter), unpasteurized (“raw”) milk, or materials that have been touched by, or close to, birds or other animals with suspected or confirmed A(H5N1) virus.
  • CDC has interim recommendations for prevention, monitoring, and public health investigations of A(H5N1) virus infections in people. CDC also has updated recommendations for worker protection and use of personal protective equipment (PPE).
  • Following these recommendations is central to reducing a person’s risk and containing the overall public health risk.
More information is available on the CDC website at https://www.cdc.gov/flu/avianflu/avian-flu-summary.htm.

[1] first human case of A(H5N1) bird flu in the United States linked to an outbreak in dairy cows was also the first likely case of human infection with A(H5N1) from a cow globally. This was reported on April 1, 2024. The person reported eye redness as their only symptom, consistent with conjunctivitis, and recovered. Learn more about this case in a letter published in the New England Journal of Medicine titled Highly Pathogenic Avian Influenza A(H5N1) Virus Infection in a Dairy Farm Worker. The April 1 case was actually the second human case of A(H5N1) reported in the United States. The first human case of A(H5N1) bird flu in the United States was reported in 2022 in a person in Colorado who had direct exposure to poultry and who was involved in depopulating poultry with presumptive A(H5N1) bird flu. The 2022 human case was not related to dairy cattle. The person only reported fatigue without any other symptoms and recovered. Learn more at U.S. Case of Human Avian Influenza A(H5) Virus Reported.

Michigan Announces Their 1st Human H5 Infection (Mild & Now Recovered)

Recommended PPE For Farmers 



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Michigan, whose dairy farms have been particularly hard hit by H5N1, today is reporting their first human H5 infection, in a farmer who has had extensive contact with cattle.  The farm worker reportedly had mild symptoms and has since recovered. 

Details are scant in today's announcement, although I would expect to hear a more detailed report from the CDC in the days ahead. 







 

Readout of CDC Call with State Public Health Partners on H5N1 Influenza Monitoring

 

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Although there were plans in place to reduce the reporting requirements of hospitals (see above) starting May 1st, given the multi-state infection of dairy herds with HPAI H5N1 - along with anecdotal reports of farm workers suffering from `flu-like illnesses' - the CDC has been forced to find alternatives (see CDC Update: New Influenza A Dashboard & Reporting Changes For Hospitals).

Last week, the CDC asked:

Despite this change in mandatory reporting, CDC and CMS are encouraging hospitals to continue submitting data voluntarily to NHSN. CDC has begun sharing the voluntarily reported data on its website with weekly updates. Full details on NHSN hospital data reporting guidance are available on the NHSN website.

At the same time also seen media reports - and official acknowledgements - that some states where H5N1 has been detected in dairy cattle have not been exactly welcoming of federal investigators (see here, and here), and without an invitation, the CDC has no jurisdiction. 

Turf wars between local and federal officials are nothing new, although until fairly recently the CDC appeared immune. The deep political divide over the agency's COVID response appears to have changed that dynamic.

Yesterday the CDC held a telephone meeting with State Public Health partners, asking them to step up their surveillance efforts over the summer.  I'll have a bit more after the break. 
Readout of CDC Call with State Public Health Partners on H5N1 Influenza Monitoring
Media Alert

For Immediate Release: Tuesday, May 21, 2024
Contact: Media Relations
(404) 639-3286
media@cdc.gov

May 21, 2024 – Today, in a meeting with public health partners, CDC Principal Deputy Director Nirav D. Shah laid out the agency’s recommendations that influenza surveillance systems continue operating at enhanced levels during the summer and to increase the number of positive influenza A virus samples submitted for subtyping to help detect even rare cases of human H5N1 virus infection in the community.

CDC Influenza Division Director Vivien Dugan joined leaders and members from the Association of State and Territorial Health Officials (ASTHO), the Association of Public Health Laboratories (APHL), Big Cities Health Coalition (BCHC), the Council of State and Territorial Epidemiologists (CSTE), and the National Association of County and City Health Officials (NACCHO) on the call.

Shah emphasized the importance of remaining vigilant and outlined a nationwide influenza virus monitoring plan for the summer season, which is a time when influenza activity and testing typically decline. The goal of this plan is to maintain heightened awareness of circulating influenza viruses given the ongoing outbreak of H5N1 among poultry and U.S. dairy cattle.

Specifically, Shah asked jurisdictions to work with clinical laboratories to increase submissions of positive influenza virus samples to public health laboratories for subtyping. Subtyping is a process that determines whether the influenza A sample is a common, seasonal influenza virus or a novel virus like H5N1.

CDC is committed to supporting state and local public health officials and will continue to provide information to support their H5N1 influenza response efforts.


While all of this seems reasonable and prudent, it isn't clear how aggressively individual jurisdictions will respond.  

From a strict public health perspective, it makes sense to pull out all the stops while you still can.  To try to mitigate the H5N1 threat before it evolves into a `humanized' strain.   

But there are other considerations.  While they involve `cold calculations', they deserve mention. 

  • The best case scenario is that H5N1 is incapable of sparking a pandemic. We've been watching it for nearly 3 decades, and it hasn't managed yet.  Although it would be a huge gamble, those who doubt its pandemic potential may find any proposed `cures' to be far worse than the disease. 
  • A more cynical view would be that yes, H5N1 has genuine pandemic potential.  But stopping it (at great pain and expense) in any one state or by any one industry won't prevent it from taking off in another state, a different country, or via a different host species next week or next month.
While I'm not a fan of either approach, I understand the lure of each. Both grant us permission to `do nothing' while we wait to see what happens. Very much the way we've decided to deal with climate change.

But I digress. 

There is a 3rd option, but few people seem willing to embrace it.  To prepare for the next pandemic as if it were both inevitable and imminent.  

But that would require `doing something', which probably takes it out of consideration. 

Australia: Victoria Reports Imported H5N1 Case (ex India)

 
Victoria :  Credit Wikipedia

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The plot, as they say, thickens

Overnight (here) the government of Victoria State in Australia announced (h/t FluTrackers) the detection of an imported case (of a child) infected with H5N1 from India, which apparently occurred in March of this year.  

Details are disappointingly vague (no specific dates are provided), but it is revealed the child has recovered and contact tracing has uncovered no additional infections. 

This begs a lot of questions.  But first, the gist of the announcement from Victoria's Chief Health Officer.



What is the issue?
A case of avian influenza A (H5N1) infection, also known as “bird flu”, has been reported in Victoria. This is the first human case of H5N1 avian influenza in Australia. The case occurred in a child, who acquired the infection in India and was unwell in March 2024. The avian influenza virus was detected through further testing of positive influenza samples that takes place to detect novel or concerning flu virus strains, as part of Victoria’s enhanced surveillance system. Contact tracing has not identified any further cases of avian influenza connected to this case.
There are lots of different subtypes (strains) of avian influenza. Most of them don’t infect humans. Some subtypes, including H5N1, are more likely to cause disease and death in poultry. These are known as highly pathogenic avian influenza (HPAI) viruses. Significant outbreaks of HPAI viruses are being reported in poultry and non-poultry birds and mammals overseas. The United States of America is currently experiencing outbreaks of HPAI (H5N1) in dairy cows, with one recent human case in a dairy worker. Whilst the Victorian case is HPAI (H5N1), it is not the same as the strains that have caused these outbreaks in the United States of America.

          (Continue . . . )

The rest is boilerplate and/or standard health advice. That said, there are are so many unanswered questions/problems with this report, I scarcely know where to begin.  

  • The absence of any dates at all make it impossible to know whether this case was only very recently discovered (through retrospective testing), or if they've known about this case for some time (weeks? ) and are just announcing it now.
    • We discussed previously how difficult it can be to detect individual human infections, even in countries that are actively looking for cases (see UK Novel Flu Surveillance: Quantifying TTD). In Australia, which is one of the last regions of the world without H5N1, it would be understandably pretty far down the suspect list. 
  • The assurance that this `strain' is not the same as the strain in American cattle may well be true, but it doesn't tell us much. The clade is not given (presumably 2.3.4.4b, although from Asia others are possible), and there are no genomic details provided. 
  • There is no mention of the possible exposure of this case back in India, or even where in India this case came from.  When was the Indian government notified?  When was WHO? 
  • The child was described as experiencing a  `severe infection', but no details of symptoms, treatment, or time to recover are provided. 
  • Contact tracing is mentioned, but no numbers or context is provided.  Depending upon the time delay in diagnosing the index case, their tracing options could have been quite limited.

A quick check of the CSIRO site and the WHO DON list show no updates on this event. While the immediate risk from this imported case has likely passed, this absence of specific data does little to inspire confidence. 

Hopefully more detailed information will be released sooner rather than later. 

Tuesday, May 21, 2024

EnvSciTech: Detection Of H5 HA In Municipal Wastewater Solids With Increases in Influenza A in Spring, 2024



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Not quite two weeks ago we saw a preprint reporting the detection of avian H5N1 in wastewater from 9 (unnamed) Texas cities - starting last March - whose rate exceeded that of seasonal influenza viruses by April. 

While the origins of these viruses are still thought to be primarily from avian or bovine sources, some contributions from humans cannot be excluded.

A week ago the CDC unveiled - and last Friday updated - their own wastewater surveillance dashboard; one that samples up to 674 facilities, but only measures influenza A activity.  In other words, it does not identify individual subtypes like H5. 

The CDC's latest update, however, does show an unexpected increase in influenza A virus detection (see maps below) in a small number of cities.  


With HPAI H5N1 spreading in cattle across multiple states, and the potential for spillovers to other mammals (including humans), what is desperately needed is a nationwide wastewater surveillance system that can discriminate between seasonal influenza and novel subtypes. 

While that still might not tell us the source of the virus, it would tell us a lot more about the scope of the the problem, and that could tell public health officials where they should be concentrating their testing resources. 

Yesterday the journal Environmental Science & Technology Letters published a report from the research team at @WastewaterSCAN which found additional evidence of H5 in wastewater solids in 4 facilities  in communities (in Texas and North Carolina) reporting H5N1. 

As a control, they also tested wastewater on the island of Hawaii - where H5N1 has not been reported in cattle - and those results were negative. 

First an overview, from their twitter feed


The full report is lengthy, but well worth reading. I've only posted some excerpts, so follow the link to read it in its entirety.  I'll have a brief postscript after the break. 
Detection of Hemagglutinin H5 Influenza A Virus Sequence in Municipal Wastewater Solids at Wastewater Treatment Plants with Increases in Influenza A in Spring, 2024
Marlene K. Wolfe, Dorothea Duong , Bridgette Shelden, Elana M. G. Chan, Vikram Chan-Herur,Stephen Hilton, Abigail Harvey Paulos,Xiang-Ru S. Xu, Alessandro Zulli, Bradley J. White , and Alexandria B. Boehm*
Cite this: Environ. Sci. Technol. Lett. 2024, XXXX, XXX, XXX-XXX
Publication Date:May 20, 2024
https://doi.org/10.1021/acs.estlett.4c00331

© 2024 The Authors. Published by American Chemical Society. This publication is licensed under CC-BY-NC-ND 4.0.
Abstract

Prospective influenza A (IAV) RNA monitoring at 190 wastewater treatment plants (WWTPs) across the US identified increases in IAV RNA concentrations at 59 plants in spring 2024, after the typical seasonal influenza period, coincident with the identification of highly pathogenic avian influenza (subtype H5N1) circulating in dairy cattle in the US. We developed and validated a hydrolysis-probe RT-PCR assay for quantification of the H5 hemagglutinin gene. We applied it retrospectively to samples from four WWTPs where springtime increases were identified and one WWTP where they were not.
The H5 marker was detected at all four WWTPs coinciding with the increases and not detected in the WWTP without an increase. Positive WWTPs are located in states with confirmed outbreaks of highly pathogenic avian influenza, H5N1 clade 2.3.4.4b, in dairy cattle. Concentrations of the H5 gene approached overall influenza A virus gene concentrations, suggesting a large fraction of influenza virus inputs were H5 subtypes. At all four H5 positive WWTPs, industrial discharges containing animal waste, including milk byproducts, were permitted to discharge into sewers.
Our findings demonstrate that wastewater monitoring can detect animal-associated influenza contributions and highlight the need to consider industrial and agricultural inputs into wastewater. This work illustrates wastewater monitoring’s value for comprehensive influenza surveillance, including for influenzas that currently are thought to be primarily found in animals with important implications for animal and human health.

(SNIP)

Discussion

H5 influenza RNA was readily detected in wastewater solids at sites in TX and NC with atypical increases in influenza A M gene concentrations in March and April 2024 during a period of a known H5N1 outbreak in the US. The presence of H5 in municipal wastewater indicates that contributions into the wastewater system include excretions or byproducts containing influenza viral RNA with an H5 subtype, but do not indicate the species that may be shedding an H5 influenza. During March and April 2024, increases in IAV M gene concentrations at the TX and NC WWTPs were not coincident with increases in human influenza activity (personal communication, local health officers, and documented by state positivity rate data). However, both the increases in M gene concentrations and H5 detection occurred immediately prior to and during reported outbreaks of H5N1 in dairy cattle in the regions. (16) These results suggest that wastewater monitoring is a viable method of monitoring certain animal pathogens, and can provide a leading edge of detection that is of particular importance for diseases with zoonotic potential like HPAI.

Hypothesized Sources of H5

H5N1 outbreaks in dairy cattle were reported on 3/25/24 in the Texas panhandle, (32) which contains the City of Amarillo and on 4/9/24 in North Carolina. (16) There was also a human case of H5N1 reported in Amarillo in an individual who worked at a commercial dairy cattle farm and reported close proximity to dairy cows. (7) Amarillo, Dallas County, and Forsyth County WWTPs receive discharges from industries handling Animal by-products, including dairies that receive milk from across the region and beef processing plants (personal communication from local staff). Dairy cattle have been reported to shed H5N1, as well as other viruses, in milk in high quantities. (33,34) During the current outbreak, H5N1 nucleic-acids have been detected in both raw and pasteurized milk. (35) Pasteurization is expected to inactivate the virus, although it may still be detectable as noninfectious genetic material can persist past pasteurization. (36) Regardless of whether milk or milk products entering the sewer system have undergone pasteurization or pretreatment before they are discharged, our methods detect viral nucleic acids, although importantly their detection does not imply viability - this was not within the remit of the current study. Note that since these WWTPs are separate sanitary sewer systems, inputs of agricultural runoff or farm waste are not expected.

Given the outbreaks in dairy milking cattle in the region, (16) reports of H5N1 shedding in cow milk and detection in milk products on the shelf, and animal industry contributions into wastewater at the four WWTPs, we hypothesize that dairy processing discharge into the sewage system is driving the detection of H5 identified in wastewater solids. The lack of detection of the H5 marker in Hawai’i where there are no documented HPAI infections in animals, no dairy processing discharge, and no evidence of springtime increases in the IAV M gene supports this hypothesis. 

It is important to note that, even if true, this does not eliminate the possibility of contributions from other animals, including humans. If dairy industry activities in sewersheds are a primary source of H5 in wastewater, this suggests that there may be additional, unidentified outbreaks among cattle with milk sent to these facilities since milk from infected animals is required to be diverted from food supply. Select lift station and industrial discharge sampling in the Amarillo sewersheds identified H5 marker in discharge from a dairy processing plant, but also at lift stations that contained wastewater from primarily residential and retail areas (see SI, Figure S5). While we note that these samples are not directly aligned with samples from the corresponding utilities, this evidence supports the hypothesis of significant dairy contributions, as well as the likelihood of multiple sources to the WWTPs.

         (Continue . . . ) 

Wastewaterscan.org is based at Stanford University, in partnership with Emory University, and their public dashboard (see below) currently provides recent and historical information on the detection of 12 different pathogens. 



While not every state is being monitored, hopefully in the weeks ahead their surveillance system will give us with a much better idea of the spread of H5 across the nation. 

Stay tuned. 

Monday, May 20, 2024

The Lancet: Proactive Surveillance for Avian Influenza H5N1 and Other Priority Pathogens at Mass Gathering Events

image

Credit Wikipedia

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Even though we are not currently in the midst of a COVID pandemic, mass gathering and travel events like Carnival in Rio, the Super Bowl, Mardi Gras, Chunyun (aka the Chinese New Year), the Summer & Winter Olympics, Umrah and the Hajj pose unique public health challenges not only for the host country, but for the world at large.

In all of these events - hundreds of thousands, sometimes millions - of people travel from all over the world to spend a few days or a week in a common, usually crowded, location where they can easily exchange viral and bacterial pathogens - both common and exotic - before returning home. 
 
Since many infectious diseases have relatively long incubation periods (7-10+ days), or may present mildly or even asymptomatically in some people, carriers - traveling both to and from the venue - may not be obvious.  

In a little over 3 weeks Saudi Arabia will host the Hajj, with upwards of 2 million devout expected to make the pilgrimage during the second week of June. Like many other mass gathering events, the Hajj 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).

While COVIDMERS-CoV, and Avian Flu are often the first threats that come to mind, most infectious illnesses acquired during these mass gathering/migration events are far more common; seasonal flupneumoniavector borne infections (Zika, CHKV, Dengue, Malaria, Yellow Fever, etc.), norovirus, etc (see CDC's Traveler's Health Saudi Arabia).

While these events (and over the weeks that follow) can be periods of enhanced risk, last week in The Lancet Dr. Ziad Memish et al. argued that they can also offer unique opportunities to identify, and quantify new or emerging disease risks, including HPAI H5N1. 

First the commentary, after which I'll have a brief postscript.

Proactive surveillance for avian influenza H5N1 and other priority pathogens at mass gathering events

Recurring mass gatherings at religious, sporting, or festival events have historically been the focus and sources of infectious disease transmissions1 since they serve as hubs for international spread. Advanced planning, risk assessment, and updates on guidance to countries hosting the event, and to those from which the attendees arise, are crucial for reducing risk, prevention, surveillance, and outbreak response.in2,3 Preventing outbreaks of influenza has always been on the radar of WHO 4 and of countries hosting mass gathering events.5,6,7 

In 2004, the emergence of the novel Highly Pathogenic Avian Influenza (HPAI) virus, A(H5N1), had focused attention of Saudi Arabia's government and of WHO because of the nearly 1·6 million pilgrims from across the world expected for the annual Hajj pilgrimage at the time.5 Fortunately, there have been no major outbreaks from any mass gathering events.

Most of the human avian influenza cases reported worldwide to date, have been avian influenza A(H7N9), A(H5N1), and A(H5N6) viruses.48 Although these viruses do not currently transmit easily from person to person, the recent (April, 2024) reports of mild or asymptomatic human cases of A(H5N1)8,9,10 infections detected in the USA, China, Viet Nam, and Europe should be taken seriously by countries preparing to host mass gatherings at religious, festival, and sporting events. The first human case of influenza A(H5N1) in the USA was reported in 2022 in a person in Colorado who had direct exposure to poultry.9 In England, UK, there have been 298 cases reported since October, 2021, with four cases since October, 2023.10 

The widespread circulation of HPAI viruses in millions of birds has been driving rapid diversification with emergence of different genotypes and reassortment events. Although circulating avian influenza viruses continue to prefer avian-type receptors, sporadic mutations are being detected in infected wild birds and domestic poultry, associated with onward transmission to mammals.11

Public health preparedness and careful planning and surveillance before and during mass gathering events remain important for preventing major outbreaks, interruption of the events, or onward transmission globally after the event. Evidence of this preparedness comes from no adverse outcomes of mass gatherings at religious events held over the past decade during WHO's public health emergency of international concern of Zika virus disease, Ebola virus disease, and COVID-19 for Hajj (2015–23) and Kumbh Mela (2015, 2017, 2023). Similarly, during mass gathering sporting events, such as the Tokyo 2022–2023 Olympics, during the COVID-19 pandemic; the 2015 Africa Cup of Nations Football tournament in Equatorial Guinea during the outbreak of Ebola virus disease; and the Rio 2016 Olympics during the Zika virus outbreak.

Proactive detection and surveillance programmes need to be incorporated using the latest diagnostic platforms for the whole range of viral and bacterial pathogens (panel). The shared risk for preventing spread of zoonotic pathogens and antimicrobial resistance should be addressed jointly through a One Health approach by countries hosting mass gathering events in liaison with the quadripartite alliance of the UN Food and Agriculture Organization, the UN Environment Programme, WHO, and the World Organisation for Animal Health.Panel

Growing list of viral and bacterial pathogens with epidemic potential of concern at 2024 mass gathering events

Viral pathogens

WHO Blueprint Priority pathogens list
  • Crimean–Congo haemorrhagic fever virus
  • Ebola virus
  • Marburg virus
  • Lassa fever virus
  • MERS-CoV
  • SARS-CoV
  • SARS-CoV-2
  • Nipah virus and henipaviruses
  • Rift Valley fever virus
  • Zika virus
  • Monkeypox virus
Other re-emerging viruses of concern
  • Highly pathogenic avian Influenza virus (H5N1)
  • HIV (antiretroviral resistant strains)
  • Non-polio enteroviruses (EV-71, EV-68)
  • Influenza A and variants
  • Dengue virus
  • Yellow fever virus
  • Rabies virus
  • Equine encephalitis virus
  • Other
Bacterial pathogens
WHO priority AMR pathogens list
Critical priority

  • Acinetobacter baumannii (carbapenem-resistant)
  • Pseudomonas aeruginosa (carbapenem-resistant)
  • Enterobacteriaceae (carbapenem-resistant, ESBL-producing)
  • Mycobacterium tuberculosis (multidrug-resistant, extensively drug-resistant, and totally drug-resistant)
High priority
  • Enterococcus faecium (vancomycin-resistant)
  • Staphylococcus aureus (meticillin-resistant, vancomycin-intermediate, and vancomycin-resistant)
  • Helicobacter pylori (clarithromycin-resistant)
  • Campylobacter spp (fluoroquinolone-resistant)
  • Salmonellae spp (Typhi and non-typhoidal; fluoroquinolone-resistant)
  • Neisseria gonorrhoeae (penicillin-resistant, cephalosporin-resistant, and fluoroquinolone-resistant)
Medium priority
  • Streptococcus pneumoniae (penicillin non-susceptible)
  • Haemophilus influenzae (ampicillin-resistant, azithromycin-resistant, ceftriaxone-resistant)
  • Shigella spp (fluoroquinolone-resistant)
  • Bordetella pertussis (macrolide-resistant)
  • Vibrio cholerae (resistant to ampicillin, nalidixic, chloramphenicol, and tetracycline)

Mass gathering events provide several opportunities to identify current risks and mitigate the transmission of HPAI H5N1. The actual burden of HPAI in the animal and human populations globally is unknown due to a lack of active surveillance. The mode of transmission of HPAI H5N1 from different animal groups and risk to humans is not fully understood.
Several knowledge gaps on H5N1 need to be filled and mass gathering events provide opportunities to address them. Because many animal products are consumed at mass gathering events and some religious rituals require live animal sacrifice, extensive screening and testing for HPAI H5N1 of poultry, the meat industry, and sacrificial animals, both local and imported, should be mandated and monitored. 

Currently, not enough testing is being done by countries across the globe. Standardised protocols need to be put in place for wastewater surveillance for detection of HPAI at any mass gathering events. Animals used at religious mass gathering events for sacrifice or consumption need to randomly be sampled and tested. Imported animals should be screened at the source or on arrival, and quarantined if tested positive to prevent spread to humans and other animals. Ultimately, the development, advancement, and scaling up of the production of a vaccine for human A(H5N1) and its variants will be crucial for preventing spread at mass gathering events.

Mass gatherings offers an opportunity to collect evidence on H5N1. Any findings could be eye-opening, particularly if H5N1 is widely present in animals given the apparently lack of human infection.

We declare no competing interests. AZ acknowledges support from the Pan-African Network For Rapid Research, Response, Relief and Preparedness for Infectious Disease Epidemics funded by the EU-EDCTP2–EU Horizon 2020 Framework Program; is in receipt of a UK National Institute for Health and Care Research Senior Investigator Award; and is a Mahathir Science Award and EU-EDCTP Pascoal Mocumbi Prize Laureate.

These are exactly the sort of things we should be doing for mass gathering events, even if H5N1 weren't in the wings.  

But, in our current climate of `Don't Test, Don't Tell' - where 90% of global COVID hospitalizations and deaths are no longer reported, where avian flu infections are often only belatedly announced (if at all), and even testing of cattle and dairy workers for H5N1 in the United States has met stiff resistance, it isn't at all clear whether the resources, or the political will, currently exists to get it done. 

But with a little less hubris, I suppose it could come in handy for the pandemic-after-next.