Africa CDC Convenes Emergency Meeting After Reports of a Large Outbreak of Non-Zaire Ebola In the DRC

 

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While details remain scant, overnight Africa CDC released an urgent statement overnight on what appears to be an unusually large outbreak of a non-Zaire Ebola virus in Ituri province, Democratic Republic of the Congo; centered primarily in the Mongwalu and Rwampara health zones. 

With the caveat that only 13 of 20 samples have tested positive - they report 246 suspected cases and 65 deaths - which (if correct) suggests this outbreak may have been ongoing for some time.

The preliminary finding of a `non-Zaire' Ebola strain is noteworthy. While a more complete genomic analysis expected within the next 24 hours, the two biggest contenders are the Sudan Ebolavirus (SEBOV) and Bundibugyo Ebolavirus (BEBOV).

Previously, 15 of the 16 confirmed Ebola outbreaks in the DRC since 1976 have been Ebola Zaire, with one outlier, an outbreak of the Bundibugyo Ebolavirus in 2012. 

A non-Zaire ebolavirus could complicate matters, since the current Ebola vaccine is designed specifically for ZEBOV, and it is not expected to provide significant cross protection against other strains. 

First, the statement from Africa CDC, after which I'll return with a bit more.

Africa CDC Calls Urgent Regional Coordination Meeting Following Ebola Virus Disease Outbreak in Ituri Province, DRC

Addis Ababa, Ethiopia / Kinshasa, DRC, 15 May 2026 — The Africa Centres for Disease Control and Prevention (Africa CDC) is closely monitoring the confirmed Ebola Virus Disease outbreak in Ituri province, Democratic Republic of the Congo, and is working with national authorities and partners to support a rapid, coordinated response.

Following consultations with the DRC’s Ministry of Health and National Public Health Institute, preliminary laboratory results from the Institut National de Recherche Biomédicale (INRB) have detected Ebola virus in 13 of 20 samples tested. The results suggest a non-Zaire ebolavirus, with sequencing ongoing to further characterise the strain. Results are expected within the next 24 hours with support from Africa CDC.

As of the latest update, about 246 suspected cases and 65 deaths have been reported, mainly in Mongwalu and Rwampara health zones. Four deaths have been reported among laboratory-confirmed cases. Suspected cases have also been reported in Bunia, pending confirmation.

Africa CDC is concerned about the risk of further spread due to the urban context of Bunia and Rwampara, intense population movement, mining-related mobility in Mongwalu, insecurity in affected areas, gaps in contact listing, infection prevention and control challenges, and the proximity of affected areas to Uganda and South Sudan.

In response, Africa CDC is convening an urgent high-level coordination meeting today, 15 May 2026, with health authorities from the DRC, Uganda and South Sudan, together with key partners including the World Health Organization, UNICEF, FAO, the United States CDC, the European CDC, China CDC, the Public Health Agency of Canada, Gilead Sciences, Merck & Co., Johnson & Johnson Innovative Medicine, Regeneron Pharmaceuticals, Roche, Abbott Laboratories, Cepheid, BioNTech, Moderna, Evotec Biologics, CEPI, Gavi, Médecins Sans Frontières, IFRC, the World Bank, the African Development Bank, Afreximbank, the Gates Foundation, the Wellcome Trust, and other partners.

The meeting will focus on immediate response priorities, cross-border coordination, surveillance, laboratory support, infection prevention and control, risk communication, safe and dignified burials, and resource mobilisation.

“Africa CDC stands in solidarity with the Government and people of the Democratic Republic of the Congo as they respond to this outbreak,” said H.E. Dr Jean Kaseya, Director General of Africa CDC. “Given the high population movement between affected areas and neighbouring countries, rapid regional coordination is essential. We are working with DRC, Uganda, South Sudan and partners to strengthen surveillance, preparedness and response, and to help contain the outbreak as quickly as possible.”

Africa CDC is preparing support across key response pillars, including coordination through emergency operations mechanisms, digital surveillance and data management, cross-border preparedness, laboratory coordination, infection prevention and control, risk communication and community engagement. In addition, Africa CDC will work with partners to assess the availability and appropriateness of medical countermeasures once sequencing results confirm the exact ebolavirus species.

Africa CDC is urging communities in affected and at-risk areas to follow guidance from national health authorities, report symptoms promptly, avoid direct contact with suspected cases, and support response teams working to protect communities. Additional information will be provided as they become available and as sequencing results are finalised.

About Ebola Virus Disease

Ebola Virus Disease is a severe and often fatal illness. It spreads through direct contact with the bodily fluids of infected persons, contaminated materials, or persons who have died from the disease. Early detection, prompt isolation and care, contact tracing, infection prevention and control, community engagement, and safe and dignified burials are critical to stopping transmission. WHO describes Ebola as spreading through direct contact with bodily fluids and contaminated surfaces or materials.

There are 6 known types of Ebolaviruses, with the most recent (Bombali) discovered in 2018. 

• Ebola virus (species Zaire ebolavirus)
• Sudan virus (species Sudan ebolavirus)
• Taï Forest virus (species Taï Forest ebolavirus, formerly Côte d’Ivoire ebolavirus)
• Bundibugyo virus (species Bundibugyo ebolavirus)
• Reston virus (species Reston ebolavirus)
• Bombali virus (species Bombali ebolavirus)

Of these, only 4 are known to infect and sicken humans (Bombali and Reston have yet to do so). These viruses are endemic in bats, can infect non-human primates and other mammalian hosts, and occasionally spill over into humans.   

While most Ebola outbreaks are contained after a few dozen - or a few hundred - cases, the 2014-2016 West African outbreak spanned 3 countries, and claimed over 11,000 lives. 

Exported cases outside of Africa are rare, but have been reported (see here, here, and here).  

All of which means we'll be keeping a close eye on this emerging regional public health emergency.  

Preprint: Outbreak of H9N2 Avian Influenza Viruses in Lesser Rhea in Peru, June-July 2025

 

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Although we spend a good deal of time looking at the Asian-lineage of LPAI H9N2, which has become particularly well adapted to poultry and which continues to spill over into humans (particularly in China), we rarely hear about it in North or South America. 

In 2019's A Global Perspective on H9N2 Avian Influenza Virus, the authors summed up its impact on the Western Hemisphere:  

2.1.6. The Americas

H9N2 viruses have been isolated from poultry in the USA periodically throughout the second half of the twentieth Century, in fact the prototypic H9N2 isolate (A/turkey/Wisconsin/1/1966) was isolated in this period. All isolated viruses have been of the American lineage and appear to be spillover events from wild birds, possibly sea birds which carry genetically closely related viruses in this region. Since 2001, there has been no evidence of the virus in poultry in North America, despite routine surveillance and extensive evidence of other non-H9N2 viruses in poultry [64,65,66,67,68].

In South America, there is serological evidence from 2005 of H9N2 infections in Colombia, however, no virus was isolated and no further evidence has been reporter since [66]. 

As we've discussed often (see Cell: Early-warning Signals and the Role of H9N2 in the Spillover of Avian Influenza Viruses) LPAI H9N2 is famous for its ability to reassort with other influenza subtypes, often enhancing HPAI viruses with improved transmissibility or replication in mammals. 

And, in addition to birds, LPAI H9N2 has a track record of infecting humans, pigs, and even bats (see Preprint: The Bat-borne Influenza A Virus H9N2 Exhibits a Set of Unexpected Pre-pandemic Features).

All of which makes the following preprint - about a particularly virulent strain of (still LPAI) H9N2 spreading through a remote Rhea Conservation Center in Southern Peru - more than a little interesting.

I've only posted some excerpts from a much longer report. Follow the link to read it in its entirety.

Outbreak of H9N2 avian influenza viruses in lesser rhea in Peru, June-July 2025

Alejandra Garcia-Glaessner, Alvin Crespo-Bellido, Breno Muñoz-Saavedra, Diana Juarez, Patricia Barrera, Gabriela Salmon-Mulanovich, Shadam E. Checahuari-Jarata, Dany Cruz, Dennis X. Huisa-Balcon, Grover Idme, Martha L. Nelson, Jesus Lescano,  Mariana Leguia

doi: https://doi.org/10.64898/2026.05.08.723762

This article is a preprint and has not been certified by peer review  

 

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Abstract

Avian influenza viruses (AIVs) are endemic in the Americas and responsible for outbreaks in both domestic and wild birds that occasionally spill over into humans. We report the first known outbreak of AIV H9N2 in lesser rhea (Rhea pennata), also known as Darwin’s rhea, in the region of Puno-Peru. The animals in this study lived in an isolated conservation center located in remote highlands above 4,000 m.a.s.l.

Between June and July 2025, a total of 46/92 animals were recorded sick, with symptoms including greenish diarrhea (100%), hyporexia (24%), dyspnea (76%), nasal discharge (42%), drowsiness (18%) and isolation from the flock (73%), and 94% later died. Gross pathology exams revealed septicemia characterized by severe hepatitis, pneumonia, tracheitis, enteritis, and encephalitis. Swab and necropsy samples tested positive for Influenza A by PCR and were later identified as H9N2 through whole genome sequencing.

We generated complete H9N2 genomes for two individuals. No additional pathogens were found. Phylogenetic analysis across all eight segments revealed that the viruses were low pathogenicity H9N2 AIV strains of North American origin, which indicated this outbreak was a new introduction of the virus into South America.

We also performed a comparative mutational analysis and identified multiple mutations previously associated with mammalian host adaptation, increased virulence, increased pathogenicity, and increased virus binding to α2-6 receptors, which may explain the high mortality rates observed despite the supposedly low pathogenicity of the strain. We also identified novel mutations specific to rhea viruses that will need to be experimentally validated.

This is the first report of a natural H9N2 systemic infection in an avian host, highlighting a need for increased surveillance efforts for zoonotic influenza viruses with pandemic potential.

(SNIP)

A larger concern is the potential for H9N2 AIVs to create reassortants with locally circulating strains that could make them especially well adapted to mammals [76]. H9N2 has been reported in bats during routine surveillance efforts in Egypt and South Africa [77,78], further highlighting the host range of this subtype.

The introduction of a new strain of H9N2 is therefore of particular concern, as it is a well-recognized donor of internal gene segments that have contributed to the emergence of other influenza strains through reassortment [79].

The limited availability of H9N2 sequences from South America remains a significant challenge for interpreting regional viral evolution. This is the first reported outbreak of LPAI H9N2 in lesser rheas and provides genomic evidence of a distinct introduction of this subtype of AIV into South America. 

Our findings expand our current knowledge of H9N2 host range in a high altitude environment and provide evidence that low pathogenicity strains can result in high mortality rates, perhaps linked to specific viral mutations.

Surveillance programs need to be strengthened to incorporate broad monitoring for circulating AIVs in both poultry and wild birds to enable early detection and close monitoring of regional virus circulation, cross-species transmission, viral evolution, genetic adaptation and future risk assessment.

       (Continue . . . )

LPAI H9N2 was first identified in Wisconsin poultry in 1966. In the 1990s it swept across much of Eurasia, becoming `hyperendemic' in many affected countries (see 2019's Viruses: A Global Perspective on H9N2 Avian Influenza Virus).

Range Of Endemic H9N2 Viruses

Although some attempts have been made at controlling the H9N2 virus (including using largely ineffective vaccines) - since it produces relatively mild illness in poultry - it is often tolerated or ignored.

While H9N2 remains far from our biggest pandemic concern, the CDC has designated 2 different lineages (A(H9N2) G1 and A(H9N2) Y280) as having at least some pandemic potential (see CDC IRAT SCORE), and several candidate vaccines have been developed.

And many will be surprised to see that, in terms of risk of emergence, the H9N2 Y280 lineage is ranked higher than H5N1, while the G1 lineage is ranked only slightly lower.

All of which makes LPAI H9N2 - either as a standalone threat or as a co-conspirator - worthy of our attention and respect.  

NERC Issues Level 3 Alert As Grid Faces `Unprecedented Challenges' Due to Surge In Large Power Consumers

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Twenty years ago (2006) NERC, or the North American Electric Reliability Corporation, was tasked with "ensuring the reliability of the North American bulk power system" following the 2003 Northeast blackout which affected more than 50 million people in the United States and Ontario, Canada.

Over the past dozen years we've looked at a number of their reliability assessments (see here, here, and here) amid growing governmental concerns over the reliability of the electrical grid (see NIAC: Surviving A Catastrophic Power Outage).

Until relatively recently, the biggest threats to the grid were thought to be natural disasters (hurricanes, ice storms, severe space weather, etc.), `bad actors' (cyber-threats, sabotage, etc.), or aging infrastructure (see ASCE report card on America’s infrastructure).

But over the past couple of years the rapidly increasing power demands from A.I. data centers, bitcoin harvesting, and cloud computing have added yet another potential failure point.

Last summer the U.S. Department of Energy published a 73-page report that warned that if current schedules for retirement of reliable power generation (especially baseload) continue, without enough firm replacement, the risk of blackouts in 2030 could increase by 100× over current levels.

Four months ago, in NERC: Long-Term Reliability Assessment (Jan 2026), we looked at a 181-page NERC Long-Term Reliability Report which similarly warned that our power grid is facing a growing risk of electrical shortfalls over the next decade.

From their press release:

January 29, 2026

WASHINGTON, D.C. – NERC’s 2025 Long-Term Reliability Assessment (LTRA) and infographic spotlight intensifying resource adequacy risks throughout the North American bulk power system (BPS) over the next 10 years. Summer peak demand is forecast to grow by 224 GW, a more than 69% increase over the 2024 LTRA forecast with new data centers for artificial intelligence and the digital economy accounting for most of the projected increase.

Winter demand growth continues to outpace summer demand growth with 246 GW of growth forecast over the next 10 years, reflecting the evolution of electricity usage. Uncertainty and lag in the pace of new resource additions are driving heightened concerns that industry will not be able to keep up with rapidly increasing demand.

Up until recently, the biggest concern has been limited generating capacity along with increasing demand, but last September NERC issued a Level 2 Alert which warned of a new threat; that the power draw from these massive computing centers can be erratic, with sudden drop offs and surges, that can destabilize the grid. 

They wrote: 

NERC, Regional Entities, and NERC registered entities have analyzed a series of disturbances that occurred on the bulk power system (BPS) resulting in widespread and unexpected customer-initiated load reduction of large loads. These disturbances involved multiple events during which 1,000+ MW of unexpected Large Loads output reduction occurred, with most events occurring in 2024 or 2025. The increase of Large Loads-related events coincides with an increase in Large Load penetration across the BPS.

Since then, it has become apparent that:

the risks are increasing faster than expected,

real-world events are already occurring,

and industry response to the earlier alert has been insufficient

All of which forced NERC to raise the ante last week. 

NERC Issues Level 3 Alert, Reliability Guideline Focused on Large Load Challenges
May 04, 2026
 
WASHINGTON, D.C. – As the grid faces unprecedented challenges from a surge in large power consumers, NERC is taking significant steps to ensure the reliability of the bulk power system (BPS). NERC released a Level 3 Essential Action Alert, Computational Load Modeling, Studies, Instrumentation, Commissioning, Operations, Protection, and Control, outlining seven actions registered entities must implement to address immediate risks posed by computational loads interfacing with the BPS.

The Level 3 Alert was issued as NERC observed customer-initiated large load reductions and significant oscillations that occur in seconds, leaving little or no room for real-time responses, threatening BPS reliability. The deadline for registered entities to submit their responses is August 3, 2026.

In another move to address emerging large loads, NERC released new voluntary guidelines to safeguard grid reliability. The Reliability Guideline: Risk Mitigation for Emerging Large Loads, recommends actions for traditional utilities and grid operators, and the companies behind these large loads including equipment manufacturers. The goal is to ensure that as more industrial-scale consumers connect to the grid, they actively participate in practices that protect grid stability. These steps highlight that proactive planning and participation can enable even more of these facilities to come online reliably and quickly. The guideline also acts as a reliability bridge while NERC updates its formal Reliability Standards to address these new challenges.

Registered entities subject to the Level 3 Alert are encouraged to act now by reading the alert and submitting responses by the August deadline. And, although non-binding, NERC strongly urges all relevant entities, from transmission operators to equipment makers, to adopt the recommended risk mitigation strategies outlined in the Reliability Guideline.

 Those interested in reading the full 15-page document can find it at: 

 
Although the risk mitigation strategies mentioned above are currently non-binding, it seems likely this is a prelude to a major policy shift, as they call them `. . . a reliability bridge while NERC updates its formal Reliability Standards to address these new challenges.'

While it remains to be seen how much of an impact these massive data centers will have on day-to-day delivery of electricity to the nation, it seems likely that utility costs will continue to increase, and that localized brownouts/blackouts will become more common. 

With hurricane season approaching, those interested in small solar power options to soften the impact of power outages may wish to revisit the following blogs.

The Gift of Preparedness - Winter 2023 Edition

 #NatlPrep: Prolonged Grid Down Preparedness

How Not To Swelter In Place

Preprint: Variable Transmission Efficiency of Mammalian Origin HPAI D1.1 H5N1 Strains in Ferrets

 

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When we talk about the dangers of the H5Nx virus, it is with the understanding that there are currently several genetically distinct subclades of the virus circulating around the globe (2.3.4.4b, 2.3.2.1a, 2.3.2.1e, etc.), spanning numerous subtypes (H5N1, H5N2, H5N5, H5N6, H5N8, etc.) and literally hundreds of genotypes.

Fortunately, these HPAI viruses are not all created equal. Most only infect birds, while some have evolved enough to spillover into mammals, while fewer still have shown the ability to infect humans. 

Human infections may be mild - as we've typically seen with the North American  `Bovine' B.13 genotype of H5N1 (clade 2.3.4.4b) -  or more severe - as we've seen with the clade 2.3.2.1e H5N1 viruses (40% CFR) found in Cambodia.

Even when you compare nearly identical viruses (same subclade, same subtype, and same genotype) some have proved more virulent, or more transmissible, than its close relatives. 

Which is why we often find ourselves focusing on tiny amino acid changes in the influenza genome - including PB2 mutations like E627K, D701N, Q591K, and M631L and HA mutations like Q226L and E190D - which may favor mammalian adaptation. 

But new ones (see Sci. Adv.: PB2 and NP of North American H5N1 Virus Drive Immune Cell Replication and Systemic Infections) continue to be discovered.

The impact of these mutations can vary between virus strains, and can be enhanced or attenuated by other amino acid changes (some known, others yet to be discovered) that may occur elsewhere in the genome. 

For years, researchers have looked at the PB2-E627K mutation as possibly being the most important, but we've a preprint today that finds - at least in one specific H5N1 D1.1 strain -  that the PB2 D701N mutation appears to drive virus transmissibility in ferrets. 

First the link, abstract, and the discussion from the preprint.  I'll have a bit more after the break. 

Variable transmission efficiency of mammalian origin HPAI D1.1 H5N1 strains in ferrets

Grace E. Quirk,  Michelle N. Vu,  Valerie Le Sage,  Kaitlyn Bushfield-Thomason,  Hanh Dung Nguyen,  Seema S. Lakdawala
doi: https://doi.org/10.64898/2026.05.07.722809
This article is a preprint and has not been certified by peer review 
 
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Abstract

Highly pathogenic avian influenza H5N1 2.3.4.4b genotype D1.1 lineage continues to predominate in the United States wild bird population and has spilled over into dairy cattle three independent times. To assess the transmission risk of this sublineage, we performed direct-contact transmission experiments for three distinct D1.1 strains in ferrets. 

Two of these strains were isolated from humans and one from a lethal cat infection. We found that only one human isolate (A/NV/10/2025) was able to transmit efficiently between ferrets. Compared to the other strains, this isolate harbored the mammalian adaptive PB2 D701N mutation, suggesting this mutation may be critical for D1.1 transmission as opposed to the PB2 E627K substitution present in the lethal cat isolate. 

Based on these data we conclude that the transmission fitness of D1.1 strains is modest but that special attention should be paid to emergence of adaptation at the PB2 701 position.

(SNIP) 

Discussion

In this study we describe transmission fitness of three D1.1 genotype 2.3.4.4b clade H5N196 viruses. Two of the three strains, A/WA/255/2024 and A/Cat/TX/009022-007/2025, had low to no spread to cohoused ferrets. Reports by the CDC using a related D1.1 strain A/WA/239/202498 reported low transmission efficiency by direct contact to 1/3 recipient ferrets [9].

In contrast, A/NV/10/2025 spread to all three cohoused animals. Additionally, recipient ferrets naturally infected with A/NV/10/2025 reached humane endpoint criteria prior to the scheduled end of the study, suggesting that not only is this virus transmissible, but it can result in severe natural infection. 

The viruses in this study were chosen because of their mammalian origin and their unique PB2 mammalian adaptive residues. A/NV/10/2025 has a classical PB2 mammalian adaptive mutation at position 701, in contrast to the 627 residue present in the A/Cat/TX/009022-007/2025106 strain.

While we cannot exclude the impact of other mutations in present in A/NV/10/2025 (Table107S2) compared to A/Cat/TX/009022-007/2025 and A/WA/255/2024, it is highly likely that mammalian adaptation of residue 701 is playing a role in the forward transmission potential of this strain. 

Interestingly, only 1% of all D1.1 strains curated by Nextstrain [10] contain a PB2110 D701N mutation, but 7% of spillovers into mammalian species contain this mutation [3]. While PB2 E627K mutation is more prevalent in mammalian spillover viruses at 35%, this mammalian adaptation in D1.1 has not been related to forward transmission of the virus in ferrets in our study or others [9]. 

Our findings suggest that while less common in initial mammalian spillover events, PB2 D701N may increase the risk of onward transmission. Targeted surveillance of D1.1 strains for the acquisition of PB2 D701N in animals at the human-animal interface may identify priority variants for pandemic risk assessment. 

       (Continue . . .)

We've looked at the impact of the PB2-D701N mutation often in the past, and while considered to be an important mammalian-adaptation marker in both H5 and H7 subtypes, it has not been a reliable predictor of transmissibility or virulence across the board. 

But for the H5N1 D1.1 virus (and perhaps others), the presence of the PB2-D701N mutation may be a useful early warning sign. 

I would note that just two days ago, in Sci Adv: Mammary and Respiratory Infection of Sheep with H5Nx clade 2.3.4.4b Viruses with Milk-mediated Transmission to Lambs, that one of the mutations seen in H5N1 infected sheep was PB2-D701N. 

Deep sequencing of milk samples from mammary glands, oral swabs, and lung tissues revealed the emergence of viral variants distinct from the consensus sequence generated from the challenge D1.1 virus.

Notably, the left mammary gland of a D1.1-infected sheep appeared to select for the variant PB2-701N, while the right gland retained mixed residues of PB2-627 (E/K) and PB2-701 (D/N). 

Another indication that while the emergence of a pandemic strain of H5N1 may be a long shot, Nature's laboratory is open 24/7, and it continues to tinker. 

At Least One Evacuated American Passenger From m/v Hondius Tests Positive for Hantavirus

 

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Overnight the HHS announced that - of the 17 evacuated Americans from the m/v Hondius - 1 (currently asymptomatic) individual has tested positive for Hantavirus, and a second individual has shown `mild symptoms'.  

While the mantra has been that testing of asymptomatic individuals was unlikely to yield positive results, this is a reminder that there are very few absolutes when it comes to viruses and human physiology. 

We discussed the possibility of asymptomatic spread of the Andes Virus a week ago, and while evidence is sparse, studies have suggested (see Serological Evidence of Hantavirus Infection in Apparently Healthy People from Rural and Slum Communities in Southern Chile) that at least some infections may be mild or asymptomatic.

A more recent 2025 study (see Virological characterization of a new isolated strain of Andes virus . . .), published in PloS NTD reported:

In this work, we described the isolation of the strain responsible for the largest ANDV PTP transmission outbreak, which occurred in the small town of Epuyén and began on November 2, 2018. This strain, ARG-Epuyén, exhibited a high capacity for PTP transmission, necessitating the implementation of quarantine measures to curtail further spread [8].

The median reproductive number (the mean number of secondary cases caused by an infected person) was 2.12 before control measures were implemented and subsequently dropped to below 1.0 by late January.

Early intervention allowed for the collection of samples leading to the isolation of this new ANDV strain from an asymptomatic case. An early passage of this strain was sequenced, revealing only one amino acid difference from the virus recovered from the patient. Like the Andes/ARG strain, this strain was able to grow in a new host without needing adaptation [26].

So while rare, there is precedent for positive test results from asymptomatic individuals.  

What isn't well understood is whether - or how effectively - asymptomatic (or presymptomatic) individuals may be able to transmit the virus. The ECDC's Threat Assessment Brief, published on May 6th, had this to say:

Do asymptomatic individuals have a role in transmission?

Current very limited evidence does not support a significant role for asymptomatic individuals in hantavirus transmission, supporting active symptom monitoring of asymptomatic exposed individuals. Infectivity is highest on the first day of symptom onset, which indicates a high likelihood of some infectiousness one-two days before onset of symptoms.

 
While a lot of governments, eager to reassure the public, are quick to equate asymptomatic with `healthy', the reality is far more nuanced. Given its lengthy incubation period, an exposed individual's status can change in a matter of hours. 

Which is why - while not wanting to use the dreaded `Q' word - exposed individuals around the world are being segregated and monitored for symptoms. 

While I remain far from convinced that this Andes virus outbreak will turn into a global public health emergency, there are enough unknowns here to command our respect and attention. 

And even if the current strain of ANDV is incapable of bigger things, evolution is a thing. 

Meaning that anything we say today about the virus may not hold true tomorrow. 

WHO WPRO: 1 (fatal) Human Infection with H5N6 Reported By China

 

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After an impressive run of cases between 2021-2023 (see ECDC chart below), we've gone nearly 2 years (July 2024) since the last human H5N6 case was reported by of China.

While it is certainly possible that there have been cases that were either not detected by local surveillance - or were simply not reported - we've continued to see studies coming out of China cautioning on the the evolution of this subtype.

Emerg. Microbes & Inf: Unique Phenomenon of H5 HPAI Virus in China: Co-circulation of Clade 2.3.4.4b H5N1 and H5N6 results in diversity of H5 Virus

Transboundary & Emerging Dis.: The H5N6 Virus Containing Internal Genes From H9N2 Exhibits Enhanced Pathogenicity and Transmissibility

China CDC Weekly: Infection Tracing and Virus Genomic Analysis of Two Cases of Human Infection with Avian Influenza A(H5N6) — Fujian Province, China

So it is not completely surprising that the WHO reported, in their most recent  Avian Influenza Weekly Update # 1044 SitRep, on China's 93rd human infection (since 2014) with H5N6.  

Human infection with avian influenza A(H5N6) virus

From 1 to 7 May 2026, one new case of human infection with avian influenza A(H5N6) virus was reported to WHO in the Western Pacific Region. The case is a 55-year-old female from Chongqing Municipality,China, with symptom onset on 16 April 2026. She developed severe pneumonia, was hospitalised on 23 April, and died on 3 May. 

She had purchased, slaughtered, and consumed poultry. Samples collected from a cutting board tested positive for influenza A (H5). All close contacts tested negative and developed no symptoms. Since 2014, a total of 93 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 58 deaths (CFR 62.4%) have been reported to WHO in the Western Pacific Region.

Once again, this case appears to be linked to the purchase of live market poultry.

As we've discussed previously (see Mixed Messaging On HPAI Food Safety), there is some degree of risk in the slaughtering of live birds and preparation of raw poultry; especially from birds raised at home or purchased from live markets.

In 2024 the WHO published  Interim Guidance to Reduce the Risk of Infection in People Exposed to Avian Influenza Viruses, which lists a number of `risk factors', including:

• keep live poultry in their backyards or homes, or who purchase live birds at markets;

• slaughter, de-feather and/or butcher poultry or other animals at home;

• handle and prepare raw poultry for further cooking and consumption;

Although far more common in Asia and the Middle East, dozens of outbreaks of HPAI H5 in poultry markets here in the United States have been reported (see USDA Report 9 More Live Bird Markets Infected With HPAI H5).

While reports of human H5N6 infection in China have receded sharply over the past couple of years, novel influenza A viruses have a nasty habit of reinventing themselves (often via reassortment), before making dramatic returns.

Which is why we never like to say `never' when it comes to novel flu.