NHC Monitoring Gulf Disturbance with 80% Chance of Development

 

#19,361

As a hurricane weary Floridian (see 2024's Hurricane Watches Raised For Most of Florida's West Coast), our El Niño dampened 2026 Atlantic Hurricane season has been a happy respite.  The last time there were no hurricanes this late into  October was 1914 (albeit, well before satellite coverage). 

There are still nearly 2 months left to the season (ends Nov 30th), so we may not get away completely unscathed.  

While conditions are only marginally conducive, the National Hurricane Center has given an area off the Mexican gulf coast an 80% chance of developing into a tropical system. 

If that happens, it will be named Isaias.

 

While it is too early to predict its strength or where it might head, residents along the northern Gulf coast should keep tabs on its development. The overnight forecast from the NWS NHC reads:

Tropical Weather Outlook

NWS National Hurricane Center Miami FL

200 AM EDT Tue Oct 6 2026

For the North Atlantic...Caribbean Sea and the Gulf of America:

1. Southwestern Gulf of America (AL92):

A trough of low pressure over the southwestern Gulf of America is

producing disorganized showers and thunderstorms. Although

environmental conditions appear only marginally conducive for

development, a tropical depression is likely to form within the next

couple of days. The system is expected to drift east-northeastward

through the middle portion of the week before turning northward. It

is too early to determine specific impacts to the northern Gulf

Coast, but interests there should closely monitor the progress of

this system.

* Formation chance through 48 hours...high...80 percent.

* Formation chance through 7 days...high...80 percent.

Our summer reprieve due to El Niño may be short-lived, as this phenomenon often brings wet and stormy winters to the gulf coast, and can batter California with repeated torrential rains (see California Declares State of Emergency to Bolster Statewide El Niño Preparedness).

As we discussed a month ago, in #NPM26: Preparing For An El Niño Winter, many parts of our country - and the world - may experience wild or unusual weather patterns over the next few months. 

Some areas may see floods, or ice storms, or blizzards, while others may see drought, or other weather anomalies.  While not everyone will be affected, this winter, it is a good idea to expect the unexpected. 

Follow-up on The Russian `Lab Leak' Story

 

#19,360

Two days ago, in About that Russian `Lab Leak' Story, we looked at admittedly sparse details on a purported lab accident at a Russian plague research institute in Irkutsk, Siberia which supposedly caused the death of a 28-year-old female lab worker. 

While this story has been making headlines around the world, nothing appears to have been confirmed. The WHO has been quoted as saying `it was aware of reports' and `it had offered support to Russia', but no cause of death had been determined.

The Interfax News Agency, which often reflects the Kremlin's position, reported on Sunday:

        (Translated)

Rospotrebnadzor reported a stable situation in the Irkutsk region. 

Moscow. October 4. INTERFAX.RU - Rospotrebnadzor reported that the sanitary and epidemiological situation in the Irkutsk region and the cities of Irkutsk and Shelekhov is stable.

"The sanitary and epidemiological situation in the Irkutsk region and the cities of Irkutsk and Shelekhov is stable. A special set of measures has been organized and implemented in response to the case of an employee of the Irkutsk Anti-Plague Institute of Siberia and the Far East who has been diagnosed with pneumonia of unknown etiology," the Rospotrebnadzor press service said in a statement on Sunday.

Based on the results of extensive testing, no microorganisms associated with the patient's professional activities were detected in the patient's sample, the department noted.

All my attempts to access the Rospotrebnadzor website (including via VPN) over the past few days have failed, and I'm seeing others are having similar difficulties.

 Today Taiwan's CDC addressed the reports in a statement on their website. 

In response to the suspected plague deaths reported in Russia, the Centers for Disease Control (CDC) has inquired about the incident through the International Health Regulations mechanism and is continuously monitoring the domestic and international epidemic situation and strengthening border quarantine measures.

        (Translated Excerpt)

The Centers for Disease Control (CDC) stated on October 6, 2026, regarding recent international media reports of a death from pneumonia of unknown cause reported on October 2, 2026, in Irkutsk Oblast, Siberia, Russia. The patient was a 28-year-old female laboratory technician at the Irkutsk Institute of Epidemiology and Microbiology, who died on October 2 after developing severe pneumonia.

According to an official statement issued by the Rospotrebnadzor (Russian official infectious disease management agency), as reported by local Russian media, expanded testing of the infected employee's samples revealed no special microorganisms related to her job duties. The country's biosafety expert committee also confirmed that no pathogen leakage occurred at the laboratory.

 

Furthermore, Russia has conducted extensive testing and hospitalized isolation observation on all contacts. Currently, only two cases of COVID-19 and two cases of rhinovirus infection have been detected, with no other special infectious disease pathogens found, and the relevant contacts have no abnormal symptoms. The incidence of respiratory diseases among the general population in the region remains within the normal seasonal range. Further information is still pending clarification. A WHO spokesperson stated that the public health risk posed by this event to the general public is low.

To monitor the situation, the Taiwan Centers for Disease Control (CDC) inquired with the International Health Regulations (IHR) window in Russia on October 5th for detailed information regarding the event to clarify the local epidemic situation and the risk of cross-border transmission. The CDC also sent a letter to the WHO today (October 6th) requesting information related to this case.

       (Continue . . . )

This press release appears to be mostly geared towards reassuring Taiwan's people that their CDC is aware of reports, and is making inquiries, but thus far there  appears to be no imminent threat. 

Exactly what happened - or may still be happening - in Irkutsk, Siberia remains unknown.  And frankly, there are no guarantees we'll ever get the full story.

Despite the reporting requirements of the IHR (International Health Regulations), many countries hold outbreak information close to their vest for political, societal, or economic reasons, since there are few downsides to doing so  (see From Here to Impunity).  

If there are any big developments I'll cover it, but if you want to keep up with the day-to-day developments, this FluTrackers thread should keep you well informed. 

 

AVMA: How can veterinary personnel recognize and protect themselves from domestic cats infected with HPAI A(H5N1) viruses?

 

#19,359

Last May, in MMWR: Serologic Evidence of HPAI A(H5N1) Virus Infection in a Veterinary Professional Exposed to an Infected Domestic Cat we looked at a probable cat-to-human transmission of HPAI H5N1. 

While long considered possible, actual evidence of cat-to-human transmission of avian flu viruses has been pretty sparse. Two notable exceptions being:

• In 2005, the CDC's EID Journal Probable Tiger-to-Tiger Transmission of Avian Influenza H5N1, reported that while no humans tested positive by RT-PCR, 2 close human contacts (3.5%) tested positive via serology (microneutralization) for the virus 4 weeks later.

• In 2018 we saw evidence suggesting several employers had been infected by LPAI H7N2 during an outbreak in 2016 (see J Infect Dis: Serological Evidence Of H7N2 Infection Among Animal Shelter Workers, NYC 2016).

In April of 2024, less than a month after the first detection of H5N1 in cattle, the CDC released Guidance for Veterinarians: Evaluating & Handling Cats Potentially Exposed to HPAI H5NI.  

After our summer lull, we are seeing an uptick in North American avian flu outbreaks in poultry, which typically increases when southbound migratory birds return from their high-latitude roosting areas.  

That suggests that the risks of domestic cats being infected are likely rising, and with that come exposure risks to their owners, veterinarians, and animal rescue staff.

Last week the AVMA (American Veterinary Medical Association) Journal published an updated - albeit, unofficial - best practices article penned by researchers at the CDC. 

Although this is a public domain article (produced by U.S. government employees) I've only posted extended excerpts.  Follow the link to read it in its entirety.  

I'll have a bit more after the break. 

How can veterinary personnel recognize and protect themselves from domestic cats infected with highly pathogenic avian influenza A(H5N1) viruses?

 

Lizette O. Durand, VMD, PhD1* ; Sonja J. Olsen, PhD1 ; Natalie M. Wendling, DVM, MPH2 ; Timothy M. Uyeki, MD, MPH, MPP1 ; Grazia Mirabito, PhD1 ; Tom T. Shimabukuro, MD, MPH, MBA1 ; Colin A. Basler, DVM, MPH2 

Abstract

Highly pathogenic avian influenza A(H5N1) viruses circulate globally in wild birds, causing poultry outbreaks and spillover infections in mammals and sporadic human infections. Recent detections in domestic cats highlight occupational risks for veterinarians handling cats in areas where A(H5N1) virus is circulating. Although the potential risk for cat-to-human A(H5N1) virus-transmission is currently low, vigilance is warranted. Veterinarians can use published recommendations to evaluate exposure risks, implement infection control practices, use recommended personal protective equipment, train staff, and coordinate with health officials. The One Health approach can help reduce risks of A(H5N1) virus infection to veterinary staff, cat owners, and other animals.
Keywords: avian influenza; cats; PPE; One Health; H5N1

Viewpoint articles represent the opinions of the authors and do not represent AVMA endorsement of such statements.

Introduction

(SNIP)

Between March 2024 and March 2026, A(H5N1) viruses were detected in 137 domestic cats in the US.5 While detailed information is not available on all affected cats, they represent owned indoor only cats, owned indoor/outdoor cats, and feral domestic cats (including barn cats).

Detections were associated with exposure to sick or A(H5N1) virus–infected dairy cattle or contaminated fomites from dairy farms, contact with wild birds, eating raw meat, commercially produced raw pet food products and/or consuming raw milk contaminated with A(H5N1).6–10

Reported clinical signs of A(H5N1) illness in cats have included nonspecific signs, such as fever, lethargy, and loss of appetite; respiratory signs, including coughing, sneezing, labored breathing, nasal and ocular discharge; and neurologic manifestations, including abnormal gait, circling, tremors, seizures, and blindness.11 In documented fatal feline cases, cats deteriorated quickly, progressing from onset of clinical signs to death in a few days.9

During the same 2-year period, 71 human cases of influenza A(H5Nx) virus infection were confirmed in the US. Most cases occurred in people with occupational exposure to A(H5N1) virus-infected animals, including 41 in dairy farm workers and 24 in poultry depopulation workers. Three human cases were linked to backyard flocks and 3 had unknown exposures.12,13

While transmission of low pathogenic avian influenza A(H7N2) virus from domestic cats to humans has been documented,14–16 there have been no virologically confirmed human cases of A(H5N1) in the US transmitted from an infected cat. However, the recent report from Los Angeles County, California, provides serologic evidence of possible transmission of A(H5N1) virus from an infected cat to a veterinary professional who remained asymptomatic17. This newly identified possible source of A(H5N1) virus transmission from cats to humans is particularly relevant for veterinarians.

Although the overall risk of human A(H5N1) virus infection from cats or other companion animals is low, it is important for veterinarians to recognize and protect themselves and their staff from A(H5N1) virus transmission. When there is clinical suspicion for A(H5N1) virus infection in cats or other companion animals, a four-step One Health approach19 is available to protect veterinary personnel, pet owners, and other animals. 

Four-Step One Health Approach

Recognize cases

In most cases, domestic cats with A(H5N1) virus infection have presented with respiratory (eg, nasal discharge, tachypnea or breathing quickly, dyspnea or trouble breathing, sneezing, or coughing) or neurologic signs (eg, ataxia, circling, tremors, seizures, or blindness).4,9,17 Although other diseases, such as rabies, can present with respiratory and neurologic signs, in areas where A(H5N1) virus is circulating in animals,5 a detailed history can help narrow clinical suspicion for A(H5N1) virus infection. Before the appointment, clinic staff could consider conducting a prescreening interview to obtain a thorough exposure history.9,18 This history can include information about environmental exposures (eg, do owners work on a dairy farm or with domestic poultry, live on a farm, own a backyard flock) animal exposures (eg, unsupervised outdoor access, hunting wild birds or other animals, contact with farm animals), and dietary risk factors (consumption of raw meat, commercially produced raw pet food, or raw milk).

Protect clinic staff

If there is clinical suspicion for A(H5N1) in a sick cat, implementing infection prevention and control measures can help protect veterinary healthcare workers.18,20 These include, when possible, conducting exams in an isolation room to prevent contamination of other clinic areas and limiting the number of staff interacting with the cat. Personal protective equipment (PPE) use will depend on exposure level (high, medium, low). When interacting with or handling a potentially A(H5N1) virus–infected cat (high exposure), staff are advised to wear a National Institute for Occupational Safety and Health–approved particulate respirator (requires prior fit-testing), fluid resistant gowns (single-use disposable or reusable cloth gowns, or laboratory coats that are laundered after contact with the patient), eye protection, disposable gloves, shoe covers or dedicated footwear, and hair/head cover (Figure 1).18,20,21 It is recommended that clinical staff adhere to proper hand-washing protocols20–22 after touching a potentially infected cat, or contaminated equipment or surfaces18 and disinfect contaminated surfaces after use.20 Staff that do not have contact with potentially infected animals (low exposure) do not have to wear PPE.

Since there is limited information on the potential transmission of A(H5N1) viruses from cats to humans, it is suggested that sick cats be isolated from people and other animals until a negative real-time reverse transcription–PCR test result for influenza A(H5N1) is returned or until resolution of clinical signs.18 During this time, it is important for clinical staff to understand how to properly don and doff PPE, which may require refresher training.20,21

Contact public health and animal health officials

When there is clinical suspicion of A(H5N1) in a cat, veterinarians should contact their state or local public health officials or state public health veterinarian.18 While the decision to isolate a cat potentially infected with A(H5N1) virus at home or at a veterinary clinic should be made by the veterinarian and cat owner, local public health and animal health officials may have additional protocols for isolating, testing, and managing of A(H5N1) virus–infected animals as well as monitoring of exposed persons.

Guidance from the CDC recommends that all persons exposed to an animal infected with A(H5N1) viruses self-monitor their health for signs and symptoms of A(H5N1) virus infection up to 10 days after the last known exposure.23 They can contact their health-care provider and designated state or local public health official if they develop any clinical signs or symptoms (eg, acute respiratory illness and/or conjunctivitis)23 to discuss testing and treatment options for people exposed to confirmed A(H5N1) virus–infected animals. The CDC currently recommends antiviral treatment with oseltamivir for symptomatic persons who are confirmed, probable, or suspected cases of novel influenza A virus infection associated with severe human disease such as A(H5N1) virus infection.24 Oseltamivir for post-exposure prophylaxis using treatment dosing (twice daily for 5 days) as soon as possible can be considered for persons exposed to sick cats confirmed or suspected with A(H5N1) virus infection.25 Additionally, persons who are symptomatic should stay home and limit contact with others until the test results are known.23

Educate owners

Veterinarians may consider educating cat owners about the potential exposure risks for A(H5N1) viruses. Strategies such as keeping cats indoors and discouraging consumption of raw milk, raw meats, and commercially produced raw pet foods, can reduce risk.18 When A(H5N1) virus infection is suspected, veterinarians should consider providing information on safe handling of cats and suggest that owners contact their public health department for more information on self-monitoring of their symptoms.18

Implementing the One Health19 approach in veterinary clinics can protect both humans and animals. The CDC provides recommendations to protect veterinary staff managing cats exposed to A(H5N1) virus, emphasizing the importance of considering influenza A(H5N1) virus infection in the differential diagnosis, implementing infection prevention and control protocols, and using proper PPE by veterinarians and clinic staff.18 Given the potential transmission risk, veterinarians should remain cautious when interacting with cats potentially infected with A(H5N1) viruses.

Acknowledgments

The authors would like to thank Reid Harvey and Alice Shumate for their thoughtful discussions around worker safety within a veterinary practice.

Disclosures

The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the CDC.

 

Since its arrival in late 2021, the amount of HPAI H5 virus in the environment has sharply increased during the fall and winter, making now a good time to think about how you will protect your companion animals (dogs and cats) during the months ahead.

The CDC offers the following advice to pet owners on how they may keep their animals safe from avian flu, and what to do if they suspect infection.

While cat-to-human transmission of influenza viruses has only rarely been documented, HPAI H5 continues to exceed our expectations, and we should treat it as an evolving threat.  

About that Russian `Lab Leak' Story

#19,358

Over the past 72 hours there has been a media frenzy over a reported plague death, supposedly in a Russian laboratory worker, and the subsequent quarantining of roughly 200 contacts. 

While headlines have often been bombastic, official information has been sparse.  My attempts to access Russia's Rospotrebnadzor - their National Health Agency's website - even using a VPN, have been unsuccessful. 

Complicating matters, the Russian media has presented several conflicting stories.  Given the `tabloid' nature of many Russian news outlets - and the lack of official information - it is difficult to separate the fact from the fiction. 

The Moscow Times' - which is one of the more reliable sources for Russian news - reported on Friday: 

Nearly 200 People Under Observation After Irkutsk Lab Worker Dies From Plague

Citing `other news reports' and a statement on the social media platform VKontakte by Alexei Tsydenov, head of the neighboring republic of Buryatia - they reported:

`Health authorities in Siberia’s Irkutsk region have placed nearly 200 people under medical observation after a laboratory worker died from plague.'

According to exiled news outlet Lyudi Baikala (People of Baikal) and pro-Kremlin broadcaster REN TV, the lab worker was a 27 or 28 year-old female, who reported that she had accidentally broken a test tube containing live bacteria.  

They go on to say she was hospitalized on Tuesday with severe pneumonia, was placed on a ventilator, and died on Thursday.  

While this reads like the opening to a Michael Crichton novel, we've seen lab leaks and handling `mishaps' before (see here, here, here, here, and here), so it is plausible.  It would seem, however, that a number of important BSL biosecurity measures would have to be breached. 

A Latvian-based media outlet (https://meduza.io/) reported several alternate scenarios involving recent field trips where exposure might have occurred. 

Local governments have posted, then removed, warnings (see original and translation below) from social media sites. 

Perhaps most credible are reports of a high-level meeting between local and federal officials (including Anna Popova, Chief State Sanitary Physician of the Russian Federation). This (translated) post from Irkutsk regional governor Igor Kobzev was posted on Oct 2nd.

An extraordinary meeting of the regional sanitary and anti-epidemic commission was held with the participation of Anna Yuryevna Popova, Chief State Sanitary Doctor of the Russian Federation. The reason for the meeting was information about a suspected case of a particularly dangerous infection in a resident of the region.

In this regard, Rospotrebnadzor has organized and is implementing a full range of anti-epidemic measures. At the SPEC meeting, an operational action plan was approved and instructed to strictly implement all its sections and provisions.

I would like to inform you that all identified contacts have been placed under medical observation. Currently, these contacts show no signs of illness, and laboratory test results are negative.

The situation is under strict monitoring by Rospotrebnadzor and the Irkutsk Regional Government. I ask everyone to rely solely on official information.

My channel on MAX | VK | OK | Zen

t.me/kobzevii/17919

58.9K edited Oct 2 at 01:08

The best round-up of news reports, and analysis, I've found is from the BEACON biothreats surveillance platform, housed by Boston University Center on Emerging Infectious Diseases (CEID).

RFI: Fatal laboratory-acquired infection in Irkutsk Region, Russia; possible pneumonic plague; 197 contacts hospitalized for observation
Sat 03 Oct 2026

While I would hope we'll get more details soon, the willingness of many countries to share sensitive infectious disease information has eroded over the past few years (see No News Is . . . Now Commonplace).

Assuming this involves a `plain vanilla' Yersinia pestis - and treatment is begun promptly - it should respond to antibiotics.  We've seen outbreaks of pneumonic plague before in Madagascar,  Mongolia, and even the United States, and all were eventually brought under control. 

Plague can present in three forms: bubonic, septicemic and pneumonic. If untreated, bubonic plague can evolve to a more transmissible pneumonic plague.

• Bubonic Plague (Yersinia pestis) - carried by rats, squirrels, and other small rodents, and transmitted by fleas - sets up in the lymphatic system, resulting in the tell-tale buboes, or swollen lymph glands in the the groin, armpits, and neck.

• Less commonly pneumonic plague may develop, when the infected individual develops a severe pneumonia, with coughing and hemoptysis (expectoration of blood), which may spread the disease by droplets from human-to-human.

In 2019's CDC: The 8 Zoonotic Diseases Of Most Concern In The United States, we looked at a joint CDC, USDA, DOI report on the top (n=56) zoonotic diseases of national concern for the United States. 

While Zoonotic Influenzas (avian, swine, etc.) were at the top of the list, Plague ranked 4th, and novel coronaviruses (MERS, SARS, etc.) ranked 5th.

I confess to having a particular interest in Plague, which stems from my brief stint working as a paramedic in Phoenix, Arizona where plague cases are still occasionally found. 

I also read, around the age of 11 – James Leasor’s The Plague and The Fire -which recounts two incredible years in London’s history (1665-1666), which began with the Great plague, and ended with the Fire of London.

A fascinating read (if you can find a copy) for both history and epidemic aficionados.   

Antiviral Research: N70S/Y155H Combined Mutation of Neuraminidase of Avian Influenza H9N2 Virus confers oseltamivir and zanamivir resistance and pathogenicity to Mice

Range Of Endemic H9N2 Viruses

#19,357

LPAI H9N2 has gained a reputation for spreading uncontrollably in Asian and African poultry, for frequently reassorting with other viruses, and for increasingly spilling over into humans. 

Nature: Genetic diversity of H9N2 avian influenza viruses in poultry across China and implications for zoonotic transmission

J. Inf.: Zoonotic Threat of Novel H6N2 Avian Influenza Virus with Internal Genes Exclusively Derived from H9N2, China, 2025

Emerg. Microbes & Inf.: Novel emerging reassortant H6 avian influenza viruses with internal genes from G57 genotype of H9N2 pose potential zoonotic risk

WHO WPRO Reports 2 Recent H9N2 Cases From Chinese Mainland

While H9N2 is rarely thought of as being in the same league as H5N1, the CDC lists two lineages (A(H9N2) G1 and A(H9N2) Y280) as having modest pandemic potential, and several candidate vaccines have been developed.

As a standalone virus, H9N2 appears to pose a moderate threat, but it has frequently aided and abetted more formidable novel flu viruses (e.g. H5N1, H5N6, H7N9, H10Nx) by providing some or all of their internal genes (see PNAS: Evolution Of H9N2 And It’s Effect On The Genesis Of H7N9).

Last month, we looked at report of 6 H6Nx reassortants - all carrying the internal genes from H9N2 - and 5 with its NA from H5N1, and 1 NA from H9N2. Of note, the H6N2 isolate showed dual receptor binding to both avian and human-like receptor cells.

This promiscuous nature magnifies any changes that might increase LPAI H9N2's zoonotic threat, since they could potentially be `shared' with other novel influenza A viruses. 

Which brings us to a paper published this week reporting reduced in vitro susceptibility to oseltamivir and zanamivir among H9N2 viruses carrying dual N70S/Y155H neuraminidase mutations—a combination the authors suggest has become common among recently circulating viruses in China.

The authors report as much as a 42-fold reduction in viral inhibition in one isolate tested, and a 23-fold reduction in another.  

Neither is enough to render oseltamivir or zanamivir useless, but it could reduce their effectiveness, particularly in cases of delayed treatment or severe infections. 

This is a fairly technical paper, so I've only posted a few excerpts. Those wishing a deeper dive will want to follow the link and read the paper in its entirety.  I'll have a brief postscript after the break.

N70S/Y155H Combined Mutation of Neuraminidase of Avian Influenza H9N2 Virus confers oseltamivir and zanamivir resistance and pathogenicity to Mice

Shenyu Ma a 1, Yuting Chen a 1, Jianwen Zhu a 1, Yuhan Zong b c, Keyu Cai b c, Zhonglong Yang b c, Wenlei Wang a, Yunfei Guo b c, Yan Guo a, Xinyue Duan a, Ziyan Fang a, Nan Zhu a, Sujuan Chen b c, Pinghu Zhang a c

10.1016/j.antiviral.2026.106540

Highlights

• H9N2 viruses recently circulating in China harbors novel N70S/Y155H dual mutations in N2;

• H9N2 viruses with N70S/Y155H mutations exhibit high pathogenicity to BALB/c mice.

• N70S/Y155H linked mutations in N2 confer resistance to oseltamivir and zanamivir, rather than peramivir.

• Neuraminidase inhibitors exhibited limited efficacy on H9N2 virus with novel N70S /Y155H dual mutations.

Abstract

Recently, H9N2 avian influenza virus (AIV) poses a significant threat to both the poultry industry and public health. Therefore, investigating the impact of its neuraminidase mutations on susceptibility to neuraminidase inhibitors (NAIs) is of great importance for clinically preventing potential cross-species transmission of H9N2. 

In this study, our results revealed that NAI resistance-related mutations of most H9N2 viruses isolated from China during 1998 to 2024 mainly occurred at positions N70S, E119A/D/G/V, Q133K, Q136A, D151E, Y155H, I222V, R224K, E276D, R292K, N294S, and R371K. 

Among them, the combined N70S and Y155H mutations are common characteristics of H9N2 viruses circulating in recent years. In vivo experiments demonstrated that these H9N2 viruses harboring the combined N70S and Y155H mutations exhibit high pathogenicity to BALB/c mice without prior adaption.

In vitro neuraminidase inhibition assays confirmed that these H9N2 viruses bearing the N70S/Y155H mutations exhibited greater reduced inhibition than their counterparts bearing the N70S or Y155H single mutation to oseltamivir and zanamivir, but remained highly sensitive to peramivir. 

Notably, the in vivo protective effect of NAIs against H9N2 virus with combined N70S and Y155H mutations is limited, possibly due to the restricted ability of these drugs to ameliorate the excessive inflammatory responses. Therefore, there is an urgency to strengthen research on epidemiological surveillance and prevention strategies for avian influenza H9N2 harboring these mutations.

       (SNIP)

Discussion

In this study, we performed phylogenetic and comparative sequence analyses of the neuraminidase (NA) genes from 125 H9N2 avian influenza viruses isolated from poultry between 1998 and 2024. Our results showed that early H9N2 viruses circulating in China mainly belonged to the G1-like lineage, whereas more recent strains were predominantly classified within the Y280-like lineage.

Sequence analysis further revealed that most of H9N2 viruses harbored multiple mutations associated with reduced susceptibility to neuraminidase inhibitors (NAIs), including substitutions at catalytic or framework residues (E119A/D/G/V, R292K, N294S, and R371K), as well as N70S, D151E, Y155H, R224K, and E276D mutations, which may affect enzyme conformation or the substrate-binding microenvironment[25]. 

These findings suggest that H9N2 viruses may have gradually accumulated a genetic background associated with altered antiviral susceptibility during long-term evolution.

(SNIP)

Collectively, our findings provide new experimental evidence for understanding the relationship between the combined N70S and Y155H mutations in N2 and altered susceptibility to NAIs in avian influenza H9N2 viruses. This study expands current understanding of the susceptibility of H9N2 to NAIs and highlights the need for continued surveillance of emerging neuraminidase mutations of H9N2 viruses circulating in poultry.

       (Continue  . . . )

While none of this necessarily elevates the public health threat of LPAI H9N2, this general trend of LPAI H9N2 to accrue resistance mutations bears watching, particularly when you consider the numerous other warnings we've seen of its zoonotic potential. 

EM&I: Genetic evolution, phylodynamics, geographic spread of H9N2 avian influenza viruses in China from 2014 to 2025: an increasing potential zoonotic risk

Viruses: Epidemiological and Virological Characteristics of H9N2 Avian Influenza Virus in Jiangsu Province, China, 2024

EM&I: Enhanced Replication of a Contemporary Avian Influenza A H9N2 Virus in Human Respiratory Organoids

 

Communications Medicine: Pathogen-specific ripple effects of COVID-19 nonpharmaceutical interventions in reshaping endemic disease dynamics

Heatmap of respiratory infections in Tokyo 2016-2026

#19,356

We've a new report in Nature today which looks at the reported incidence of 32 different infectious diseases in Tokyo, Japan over a nearly 10-year span (2016-2025), that  shows the changes that occurred during and after the height of the COVID/NPI era.

While some people still have doubts over the effectiveness of NPIs, the incidence of common respiratory infections (influenza, RSV, pertussis, even chickenpox) plummeted during 2020-2021 (see above graphic). 

But after the NPI mandates ended, most of these viral scourges returned; some with seemingly even greater intensity than before the lockdown. We followed many similar increases around the world.

CDC HAN #0484: Increase in Pediatric Invasive Group A Streptococcal Infections

Denmark SSI Declares A Mycoplasma Pneumonia Epidemic

WHO Statement (DON) On Respiratory Illness Surge Reported In Northern China

CDC HAN #00498: Increased Respiratory Syncytial Virus (RSV) Activity in Parts of the Southeastern United States

Others, like influenza, eventually returned to near pre-pandemic levels, although the influenza B/Yamagata lineage is now considered missing-in-action, with its last sighting in March of 2020. 

Notably, the incidence of tuberculosis reported in Tokyo dropped roughly 40% after the lockdown ended. 

The chart on vector-borne and/or sexually transmitted diseases is equally fascinating, as syphilis and HIV/AIDS reporting suggested only a small reduction during lockdown, and the incidence of syphilis sharply increased after the lockdown ended. 

In fairness, during the height of the pandemic, a lot of testing capacity was diverted to COVID, meaning rising or falling trends during that time period may not have been fully captured, which could account for some of the abrupt shifts seen after the lockdown ended. 

Admittedly, some of these post-pandemic shifts may be incidental findings, and not directly related to the lockdown. The authors warn:

Our cross correlation analyses quantify the temporal alignment between changes in reported incidence and NPI-related indicators (Fig. 2b, c), although these associations should not be interpreted as evidence of the independent causal effect of individual NPIs.

I've only reproduced a small excerpt from the study. Follow the link to read it in its entirety.  I'll have a brief postscript after the break.  

Pathogen-specific ripple effects of COVID-19 nonpharmaceutical interventions in reshaping endemic disease dynamics

Daipeng Chen, Seyed M. Moghadas & Gergely Röst
Communications Medicine (2026) Cite this article
 
We’re sharing this article early to provide faster access to peer-reviewed, accepted research. It is citable and carries a permanent DOI. This version is subject to further edits and will be replaced automatically by the final Version of Record. All legal disclaimers apply.

Abstract

Background

Nonpharmaceutical interventions (NPIs) implemented during COVID-19 disrupted the transmission of many endemic infectious diseases, but their broader, system-wide effects across multiple pathogens remain incompletely understood.

Methods

Using nearly a decade of weekly surveillance data for 32 infectious diseases in Tokyo, we combined time-series analyses, mechanistic modelling, and epidemic-trajectory reconstruction to investigate pathogen-specific changes associated with NPIs.

Results

High-incidence respiratory and intestinal infections decline most sharply in 2020, with reductions closely aligned with NPI stringency. Post-NPI rebounds vary substantially: respiratory syncytial virus and group A streptococcus peak several times above historical baselines, whereas influenza, hand, foot, and mouth disease, and herpangina return to pre-NPI levels. Model-based simulations suggest that differences in rebound magnitude and timing may depend on pathogen-specific epidemiological parameters related to immunity duration and susceptible replenishment. Beyond short-term resurgences, we also identify longer-lasting shifts in reported incidence trajectories, including reduced tuberculosis incidence, increased syphilis incidence, and a biennial phase shift in hand, foot, and mouth disease.

Conclusions

COVID-19 NPIs produce profound but highly pathogen-specific changes in other infectious disease dynamics. These effects extend beyond temporary suppression and rebound, with several pathogens exhibiting persistent deviations in reported incidence trajectories after the NPI period. These findings highlight how pathogen-specific epidemiological characteristics may contribute to heterogeneous post-NPI trajectories, which could inform tailored control strategies.

Plain language summary

Measures such as mask wearing, school closures, and reduced social contact were widely used during the COVID-19 pandemic to limit the spread of SARS-CoV-2. These nonpharmaceutical interventions also affected many other infectious diseases, but their broader consequences have not been fully understood. In this study, we analysed nearly 10 years of weekly surveillance data for 32 infectious diseases in Tokyo.

We found that many respiratory and intestinal infections fell sharply during 2020, but their resurgence after restrictions were lifted differed greatly between diseases. Some infections, such as respiratory syncytial virus infection and group A streptococcus infection, rebounded to unusually high levels, whereas others returned to patterns closer to those seen before the pandemic. We also found longer-term changes, including fewer tuberculosis cases, more syphilis cases, and a shift in the two-year cycle of hand, foot, and mouth disease. These results show that different infections may respond differently to large-scale public health measures, which may help improve disease surveillance and future control planning.

       (Continue . . . )

For logistical and political reasons, the world stopped reporting and counting COVID deaths quite early in the pandemic, but a 2022 Lancet report estimated 18.2 million excess deaths during the first 2 years. 

How many have died since then is unknown, as is how many deaths were prevented by the COVID vaccines, social distancing, and NPIs. It is probably fair to say all are measured in the millions. 

But every action (or inaction) has unintended consequences . . some good, some bad.  Some we may be able to predict, others not so much.  

Pandemics, like life, can only be understood by looking backwards. 

But with enough honest introspection, we might better understand - and handle - the next one.