H5N1

CDC Confirms Human H5 Bird Flu Case in Missouri

Thanks to Greg Folkers for the link to this CDC news release: CDC Confirms Human H5 Bird Flu Case in Missouri. Excerpt:

September 6, 2024 -- CDC has confirmed a human case of avian influenza A(H5) ("H5 bird flu") reported by the state of Missouri. The case was identified through that state's seasonal flu surveillance system. The specimen was forwarded to CDC for confirmatory testing per usual protocols and confirmed yesterday. An investigation into the potential exposure is ongoing by the Missouri Department of Health and Senior Services (DHSS).  

Case Information  

Missouri DHSS reports that the patient, who was hospitalized, had underlying medical conditions, was treated with influenza antiviral medications, subsequently discharged, and has recovered. There is no immediate known animal exposure. No ongoing transmission among close contacts or otherwise has been identified.  

This is the 14th human case of H5 reported in the United States during 2024 and the first case of H5 without a known occupational exposure to sick or infected animals. H5 outbreaks in cattle have not been reported in Missouri, but outbreaks of H5 have been reported in commercial and backyard poultry flocks in 2024. H5N1 bird flu has been detected in wild birds in that state in the past.  

While other novel flu cases have been detected through the country's national flu surveillance system, this is the first time that system has detected a case of H5. Targeted H5-outbreak specific surveillance has been conducted as part of ongoing animal outbreaks and has identified all the other cases. In this case, the specimen from the patient originally tested positive for flu A, but negative for seasonal flu A virus subtypes. That finding triggers additional testing.

Hospital stays for respiratory illnesses increase among Canadian children

A news release from the Canadian Institute for Health Information: Hospital stays for respiratory illnesses increase among Canadian children.

February 22, 2024 —  The data confirms the anecdotal evidence from across the country last year: in 2022–2023, Canada’s hospitals saw a significant increase in stays due to respiratory illnesses among people younger than 18.  

In particular, data from the Canadian Institute for Health Information (CIHI) shows a rebound in hospitalizations for seasonal flu among children age 0 to 4 — the number of stays jumped to 2,444, a return to pre-pandemic volumes. The most common respiratory illnesses among children age 0 to 4 accounted for 32% of all hospitalizations in this group, increasing from 20% the previous year.   

In addition to seasonal influenza, hospitalizations for pneumonia tripled for Canadians age 0 to 17 and almost doubled for asthma. Among children age 0 to 4, hospitalizations doubled for lower respiratory infections, and stays for COVID-19 rose by 43%.  

“Having a baby or young child in hospital for any reason is tremendously difficult on families, and this increase in hospitalizations for respiratory illnesses among Canada’s youngest patients presented additional challenges for hospitals,” said Juliana Wu, Director, Acute and Ambulatory Care Information Services, CIHI. “We will continue to monitor and report on these trends to equip health system planners and decision-makers with the data required to continue to meet the needs of Canada’s pediatric population.”  

“Last year was unprecedented for all pediatric hospitals in this country and highlighted key gaps in our system. We know from experience that viral seasons will continue to affect our young patients, and this is why it is so important that we invest in our pediatric health system and adopt public health measures to help reduce the risks,” said Dr. Lindy Samson, Chief of Staff and Chief Medical Officer, Children’s Hospital of Eastern Ontario (CHEO), and pediatric infectious disease specialist.  

Quick facts  

• The respiratory illnesses that are in the top 10 reasons for hospitalizations accounted for 32% of all hospitalizations for Canadians age 0 to 4 in 2022–2023.  

• Hospitalizations for seasonal influenza among children age 0 to 4 increased to 2,444 in 2022–2023, similar to 2019–2020 volumes.  

• Large increases were also observed in this age group for other respiratory illnesses:  

* Hospital stays for lower respiratory infections such as acute bronchitis increased from 9,501 to 19,909.  

* Hospitalizations for pneumonia almost tripled, rising from 3,447 to 9,871.  

* Asthma hospital stays increased by 61%, from 3,474 to 5,607.  

* COVID-19 accounted for 3,310 hospitalizations, up 43% from the previous year.  

* Acute upper respiratory infections saw a 32% increase in hospitalizations, going from 2,114 to 2,797.

WHO: Influenza A(H1N2)v-United States of America

A WHO DON: Influenza A(H1N2)v-United States of America. Excerpt:

Situation at a glance:  

On 4 August 2023, the United States International Health Regulations (IHR) National Focal Point informed PAHO/WHO of a human infection with a novel influenza A(H1N2) variant virus identified in the State of Michigan. This was confirmed by Reverse Transcription Polymerase Chain Reaction at the United States (US) Centers for Disease Control and Prevention (CDC) on August 2.  

The case was not hospitalized and is recovering from the illness. Investigations by local public health officials identified swine exposure by the patient at an agricultural fair.  

Additional public health response efforts including enhanced surveillance for cases is undergoing. Given the potential impact on public health, human infections with these viruses need to be monitored closely. In this event, there was no reported evidence of sustained human-to-human transmission, the illness was mild and no further influenza variant virus transmission in the community has been identified.  

Description of the case:  

On 4 August 2023, the United States IHR National Focal Point informed PAHO/WHO of a human infection with a novel influenza A(H1N2) variant virus identified in the State of Michigan and confirmed by the US CDC.   

According to the report, the case is under 18 years old, with no comorbidities, resident in the State of Michigan, who developed respiratory illness on 29 July 2023. The case presented with fever, cough, sore throat, muscle aches, headache, shortness of breath, diarrhea, nausea, dizziness, and lethargy. On 29 July, the case sought medical care at an emergency department, and an upper respiratory tract specimen was collected on 30 July. The specimen tested positive for influenza A virus on the same day. On 1 August, the patient received influenza antiviral treatment (Oseltamivir).  

On 31 July, the specimen was tested at the Michigan Department of Health and Human Services (MDHHS), and RT-PCR results were positive for influenza A virus but lacked reactivity with diagnostic tests for contemporary human influenza viruses representing either (H1) pdm09 or (H3) subtypes. The specimen was then sent to the US CDC for further testing and received on 2 August. On the same day, RT-PCR analysis of the specimen indicated an influenza A(H1N2) variant (v) virus. The virus was isolated and subsequent analysis including genetic sequencing is underway.  

The case was not hospitalized. Investigation by local public health officials identified swine exposure by the patient at an agricultural fair, that took place between 23 and 29 July, within 10 days prior to illness onset. Additional investigation did not identify respiratory illness in any of the patient’s close contacts or household contacts. No additional cases were identified related to this agriculture fair. No person-to-person transmission of influenza A(H1N2)v virus associated with this case has been identified. No additional cases of human infection with A(H1N2)v virus have been identified as of 10 August 2023.  

This is the first influenza A(H1N2)v virus infection identified in the United States this year. Since 2005, there have been 512 influenza A variant virus infections (all subtypes), including 37 (human infections with influenza A (H1N2)v viruses reported in the United States.

Pandemics disable people — the history lesson that policymakers ignore

Via Nature, an excellent article by Laura Spinney: Pandemics disable people — the history lesson that policymakers ignore. Excerpt:

When Ashley Shew turned up for an appointment at a medical centre in spring 2020, a member of staff told her she could remove her mask because only people with pre-existing conditions were vulnerable to COVID-19. Shew was surprised. “A hard-of-hearing amputee battered by chemotherapy and more”, as she describes herself, she is a regular at the centre — the appointment that day concerned her prosthetic leg. Who, she wondered, did the staff member think counted as a person with pre-existing conditions?  

The invisibility of disability is not new, says Shew, a 38-year-old philosopher who explores the intersection of technology and disability at Virginia Polytechnic Institute and State University in Blacksburg. “But it is particularly deadly that we don’t frame COVID-19 as a disability issue,” she says. “Even linguistically we’re pointed away from it. ‘Pre-existing conditions’ is a way of not saying ‘disability’.”  

From the beginning of this pandemic, people with disabilities understood that the disease would target them and would swell their ranks. Disability historians knew that there was a penumbra of ill health to previous mass-death events. Health economists warned that, as with tuberculosis, HIV and other diseases, morbidity would stalk mortality. Too many others have clung stubbornly to a belief that COVID-19 is something from which a minority of people die, and that most bounce back quickly and intact, with only their immune system updated. The longer the pandemic drags on, the harder it is to maintain that fiction.  

Two years in, the debilitating tail of the pandemic has revealed itself in the form of tens of millions of people living with long COVID1. It is high time to ask whether attitudes to disability will change as a result. Will society grasp that the body can be altered for a long period — even permanently — by infectious disease, just as it seems to have accepted that the body politic will never be the same again? And will it make the necessary accommodations?  

These questions have been asked before.  

Long influenza  

Consider the ‘mother of all pandemics’ — the 1918 Spanish influenza outbreak. Even in the 1920s, scientists understood that this flu had neurological and other effects. The most notorious and debated of those — still — is the overlapping pandemic of encephalitis lethargica (EL) or ‘sleepy sickness’. Eighty per cent of EL survivors went on to develop a Parkinson’s-like disease. According to cell biologist Richard Smeyne at the Jefferson Hospital for Neuroscience in Philadelphia, Pennsylvania, it has never been proved biologically that flu caused both EL and this post-encephalitic parkinsonism — at least not in the sense of catching the virus in flagrante in the brain tissue of people who had died. Yet the statistical case for it seems strong. 

The neurological tails of two subsequent flu pandemics, in 1957 and 1968, were less pronounced, but both were followed by rises in cases of encephalitis (brain inflammation), among other conditions. Once again, researchers failed to demonstrate a clear causal link with an earlier flu infection, but it has since been established that the flu virus can infect the brain and trigger inflammation there and elsewhere in the body. Clinicians see this after every flu season, in a wave of strokes and heart attacks predominantly among older people. And flu can cause encephalitis in children. It’s rare, but it can kill, and those who survive can be left with long-term brain damage.

Circulation of influenza, RSV, and SARS-CoV-2: an uncertain season ahead

Via The Lancet Respiratory Medicine: Circulation of influenza, RSV, and SARS-CoV-2: an uncertain season ahead.

A new report by the Academy of Medical Sciences has warned that the UK could face exceptionally large outbreaks of respiratory syncytial virus (RSV) and influenza during the autumn and winter of 2021–22. The surge in infections could overlap with the spike in cases of COVID-19 that is expected to follow the lifting of lockdown restrictions across the country. “It is clear that the health-care system must plan for a high burden of respiratory diseases”, wrote the authors of the new report. They urged the government to rollout point-of-care joint testing for influenza, SARS-CoV-2, and RSV, and to ensure that the influenza vaccine is widely taken-up by eligible populations. 

The warning partly reflects the success of the precautions that have been deployed against SARS-CoV-2. Mask-wearing, social distancing, and sharply constrained population movements have dramatically reduced transmission of respiratory pathogens such as RSV and influenza. Hospitals in Italy and France reported drops of more than 80% in the number of paediatric patients treated for acute bronchiolitis during the 2020–21 season, compared with previous years. Australia, Chile, and South Africa registered just 51 cases of influenza between them over the entire 2020 southern hemisphere winter. In the USA, the 2020–21 influenza season was the mildest since at least 1997, the earliest year for which records are available. 

 The vast majority of children contract RSV before the age of 2 years. “We now have a whole bunch of children who have not been exposed to the virus for 18 months to 2 years”, points out Charlotte Summers, reader in intensive care medicine at the University of Cambridge, UK, and member of the expert advisory group for the Academy of Medical Sciences report. The larger the susceptible population, the greater the risk of a sizeable outbreak once a virus starts circulating. 

England discontinued nearly all of its lockdown restrictions on July 19, 2021. Scotland and Wales are scheduled to do the same by mid-August. Even though there are several weeks of summer remaining, cases of RSV are on the rise (the USA is also seeing an out-of-season increase in RSV detections). Whether this will translate to increased hospitalisations remains to be seen. The Academy of Medical Sciences report recommended that children's wards and paediatric intensive care units should be ready for a potential influx of patients with RSV, otherwise they could find themselves overwhelmed. Modelling studies undertaken for the report suggested that a reasonable worst-case scenario for RSV would entail an outbreak somewhere in the region of 1·5–2 times greater than during a typical year, assuming the UK stays out of lockdown. 

The results for the modelling studies for influenza were similar. “There has probably been a waning of immunity to influenza, plus we have not had enough cases elsewhere in the world to offer a strong idea of what needs to go into the vaccine”, said Summers. The mildness of the 2019–20 influenza season in the UK might have further reduced population immunity. 

Much is uncertain. “We do not know what the influenza virus is going to look like when it returns”, said Rachel Baker, associate research scholar in the department of ecology and evolutionary biology at Princeton University, USA, “How much did the virus evolve during the period of low case numbers? Will we see a strain that people have been exposed to or vaccinated against in the past?” It is unclear how the British will respond to the easing of the lockdown restrictions. “Without national mandates for things like mask-wearing and distancing, a lot will come down to individual behaviour, and no-one really knows how people's behaviour will change”, said Summers. Baker suggested that vulnerable populations should continue wearing masks in crowded public places. 

Hospitals will have to quickly identify which patients have influenza and which ones have COVID-19, and ensure the two sets of patients are kept separate from each other and from vulnerable patients who do not have any respiratory symptoms. No small task, particularly if the viruses are surging at the same time.

However, risk for all-cause dementia was reduced for those who engaged in low (odds ratio [OR], 0.30; 95% CI, 0.25 – 0.36) and moderate to high (OR, 0.13; 95% CI, 0.10 – 0.16) levels of physical activity compared with their inactive peers.

Feter said it is particularly noteworthy that adults aged 80 and older who engaged in moderate to high levels of physical activity were at lower risk for dementia than inactive adults aged 50 to 69 years.

"In our opinion, this is the study's main finding," he said.

Although aging is the strongest risk factor for dementia, "we showed that moderate-intensity physical activity once per week can attenuate, or even eliminate, the risk of dementia associated with aging," Feter noted. "In fact, older adults engaging in regular physical activity have a lower risk of dementia than adults aged up to 30 years younger."

However, he noted several study limitations, including the way that physical activity and dementia were assessed and that reverse causality and residual confounding "might not be ruled out from our findings."

Los Angeles: Our century-old mask wars

Via The Los Angeles Times: Coronavirus Today: Our century-old mask wars. Excerpt:

Good evening. I’m Amina Khan, and it’s Tuesday, Dec. 29. Here’s what’s happening with the coronavirus in California and beyond. 

The pitched political battle over masks may feel like a quintessentially 2020 kind of conflict. But as it turns out, the anti-mask movement is more than a century old. Columnist Gustavo Arellano takes us back to 1919, when the world was facing another devastating global outbreak: the so-called Spanish flu, which is estimated to have infected a third of the world’s population and killed at least 50 million.  

Back then, more than 700 concerned citizens and doctors signed a petition asking the Los Angeles City Council to enact a mask mandate to combat the pandemic, or “the disease will come back again, and will exact a heavier toll than ever.” 

But councilmembers wouldn’t budge. One said the masks left the wearer “breathing in the foul air which they exhale.” Another snarked that he might have been more sympathetic “if the doctors would come through and agree on some one thing, or if any of them could agree at all.” A third said he would “not propose to take the advice of a lot of outsiders.”  

L.A. weathered the flu pandemic better than most major American cities, largely thanks to City Health Commissioner Dr. Luther Powers, who shut down businesses and schools early on, even when others did not. But Powers had a chance to save even more lives by implementing a mask ordinance — and he didn’t. 

If Powers had required everyone to wear masks in public, that “would’ve had an impact,” said J. Alexander Navarro, a medical historian at the University of Michigan.

Widespread mask use in L.A. seemed imminent when the Spanish flu hit California in the fall of 1918, Arellano writes. San Francisco issued an order for people to wear them outside their homes, and San Diego required them for anyone serving the public. Gov. William D. Stephens urged Californians to wear masks, saying they offered “but little discomfort and means a service rendered to our fellow-men and to our country.” 

These messages appear to have had an effect: The Times reported on Oct. 23 that masks in L.A. “were quite common in large offices ... where the general public is coming and going all day in numbers.” 

Mayor Frederick Woodman even brought a resolution to the City Council to enforce mask wearing, but Powers balked and the enforcement measure failed. Instead, the council passed a measure advising the public to wear masks, but not requiring it.  

The window of opportunity, it seemed, had closed. The council soon became hostile to a mask mandate. This paper openly called masks “muzzles” and published editorial cartoons mocking their advocates. In a Dec. 1, 1918, editorial titled “Adios ‘Flu’ Scare!” the paper’s editorial board wrote that “the real sufferers are the men and women whose incomes have been stopped, whose businesses have been all but ruined.” Sound familiar? 

Little did they know that the city was about to be overwhelmed by a second wave of influenza. In January, Powers finally wrote up a mask mandate but ultimately did not back its passage.

Comparison of the characteristics, morbidity, and mortality of COVID-19 and seasonal influenza: A nationwide, population-based retrospective cohort study

Via The Lancet Respiratory Medicine: Comparison of the characteristics, morbidity, and mortality of COVID-19 and seasonal influenza: a nationwide, population-based retrospective cohort study. The summary:

Background 

To date, influenza epidemics have been considered suitable for use as a model for the COVID-19 epidemic, given that they are respiratory diseases with similar modes of transmission. However, data directly comparing the two diseases are scarce. 

Methods 

We did a nationwide retrospective cohort study using the French national administrative database (PMSI), which includes discharge summaries for all hospital admissions in France. All patients hospitalised for COVID-19 from March 1 to April 30, 2020, and all patients hospitalised for influenza between Dec 1, 2018, and Feb 28, 2019, were included. The diagnosis of COVID-19 (International Classification of Diseases [10th edition] codes U07.10, U07.11, U07.12, U07.14, or U07.15) or influenza (J09, J10, or J11) comprised primary, related, or associated diagnosis. Comparisons of risk factors, clinical characteristics, and outcomes between patients hospitalised for COVID-19 and influenza were done, with data also stratified by age group. 

Findings 

89 530 patients with COVID-19 and 45 819 patients with influenza were hospitalised in France during the respective study periods. The median age of patients was 68 years (IQR 52–82) for COVID-19 and 71 years (34–84) for influenza. Patients with COVID-19 were more frequently obese or overweight, and more frequently had diabetes, hypertension, and dyslipidaemia than patients with influenza, whereas those with influenza more frequently had heart failure, chronic respiratory disease, cirrhosis, and deficiency anaemia. 

Patients admitted to hospital with COVID-19 more frequently developed acute respiratory failure, pulmonary embolism, septic shock, or haemorrhagic stroke than patients with influenza, but less frequently developed myocardial infarction or atrial fibrillation. In-hospital mortality was higher in patients with COVID-19 than in patients with influenza (15 104 [16·9%] of 89 530 vs 2640 [5·8%] of 45 819), with a relative risk of death of 2·9 (95% CI 2·8–3·0) and an age-standardised mortality ratio of 2·82. 

Of the patients hospitalised, the proportion of paediatric patients (<18 years) was smaller for COVID-19 than for influenza (1227 [1·4%] vs 8942 [19·5%]), but a larger proportion of patients younger than 5 years needed intensive care support for COVID-19 than for influenza (14 [2·3%] of 613 vs 65 [0·9%] of 6973). In adolescents (11–17 years), the in-hospital mortality was ten-times higher for COVID-19 than for influenza (five [1·1% of 458 vs one [0·1%] of 804), and patients with COVID-19 were more frequently obese or overweight. 

Interpretation 

The presentation of patients with COVID-19 and seasonal influenza requiring hospitalisation differs considerably. Severe acute respiratory syndrome coronavirus 2 is likely to have a higher potential for respiratory pathogenicity, leading to more respiratory complications and to higher mortality. In children, although the rate of hospitalisation for COVID-19 appears to be lower than for influenza, in-hospital mortality is higher; however, low patient numbers limit this finding. These findings highlight the importance of appropriate preventive measures for COVID-19, as well as the need for a specific vaccine and treatment.

Analysis: Could COVID-19 knock out flu in Europe this winter?

Via Reuters: Analysis: Could COVID knock out flu in Europe this winter? Excerpt:

PARIS (Reuters) - As Europeans brace for a grim winter with the threat of rising COVID-19 infections, minimal numbers of flu cases recorded so far point to a possible silver lining.

Data available for Europe since the beginning of October, when flu case numbers usually start to ramp up, mirror shallow figures seen in the Southern Hemisphere earlier this year. 

Some doctors say a combination of lockdowns, mask wearing and handwashing appear to have hampered transmission of the flu, while warning that the data should be treated with caution because the peak of the season is weeks or even months away.  

According to Flu News Europe, a joint monitoring platform of the European Centre for Disease Prevention and Control and the World Health Organization which collects samples in 54 European regions, only one person was diagnosed with flu out of 4,433 sentinel tests during Sept. 28-Nov. 22.  

This sentinel-source data -- case figures collated by national health authorities based on samples taken by a range of community doctors -- translates into a positivity rate of 0.02%, well below a 10% threshold that the WHO considers to be “epidemic” when it comes to flu. 

At the same time last year, this percentage stood at 15%. 

While scientists caution that the coronavirus pandemic has constrained testing for flu, the low sentinel rate so far will provide some relief to governments and health authorities, which had feared a potentially lethal “twindemic” of COVID-19 and flu that could overwhelm hospitals during the winter. 

“In any given typical year, we should be witnessing hundreds of influenza cases at this stage in Europe and beyond,” Bruno Lina, a senior virologist with Hospices Civils de Lyon, which runs 13 hospitals in France’s third-largest city, told Reuters. 

“Steps adopted to prevent transmission of COVID-19 are very efficient against influenza and other respiratory viruses.”

Virological surveillance of influenza viruses in the WHO European Region in 2019/20 – impact of the COVID-19 pandemic

Via Eurosurveillance: Virological surveillance of influenza viruses in the WHO European Region in 2019/20 – impact of the COVID-19 pandemic. The abstract:

The COVID-19 pandemic negatively impacted the 2019/20 WHO European Region influenza surveillance. Compared with previous 4-year averages, antigenic and genetic characterisations decreased by 17% (3,140 vs 2,601) and 24% (4,474 vs 3,403). Of subtyped influenza A viruses, 56% (26,477/47,357) were A(H1)pdm09, 44% (20,880/47,357) A(H3). Of characterised B viruses, 98% (4,585/4,679) were B/Victoria. Considerable numbers of viruses antigenically differed from northern hemisphere vaccine components. In 2020/21, maintaining influenza virological surveillance, while supporting SARS-CoV-2 surveillance, is crucial.

Double threat of COVID-19 and influenza

A news item in The Lancet Respiratory Medicine: Double threat of COVID-19 and influenza. Excerpt:

At the time of publication, it looks like the second wave of COVID-19 is well underway in Europe. The weekly tally of new cases has been steadily rising for more than 2 months, but the past few weeks have seen accelerated transmission. Cases have also been trending upwards in the USA. Oct 14, 2020, saw the nation register the highest number of new cases of COVID-19 since Aug 7. In general, countries are much better prepared than they were when severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first exploded onto the scene. But October also marks the beginning of the flu season in the northern hemisphere. If both viruses surge simultaneously, even the best resourced health-care systems would be hard pressed to cope. 

The southern hemisphere avoided such an eventuality. Their recently concluded flu season was exceptionally mild. It is possible that behind the apparently low caseload lay thousands of undetected patients. Perhaps influenza testing fell away as countries concentrated their resources on COVID-19. Large numbers of people might have struggled through bouts of influenza at home, hidden from the statisticians. In a briefing to the media on June 15, 2020, WHO director-general Tedros Adhanom Ghebreyesus noted that “influenza surveillance has either been suspended or is declining in many countries, and there has been a sharp decline in sharing of influenza information and viruses because of the COVID-19 pandemic”. He added that “compared with the last 3 years, we've seen a dramatic decrease in the number of specimens tested for influenza globally”. 

Nonetheless, it is hard to imagine that the precautions against SARS-CoV-2 did not prove even more effective against influenza, a less contagious virus. By this time last year, Australia had confirmed 298 120 cases of influenza and 812 deaths. Thus far this year, the country has registered 21 156 cases and just 36 deaths. “While influenza testing in Australia and New Zealand is maintained or even increased, very few influenza viruses were detected”, stated WHO, in their most recent influenza update. 

But whether this will translate to an equivalently mild flu season in the northern hemisphere, where the public is becoming increasingly tired of control measures, remains to be seen. The UK, for example, is unlikely to replicate the kind of lockdown it enacted in the early part of the pandemic. 

“I think we are probably going to see a great deal more COVID-19 in the USA over the next few months, as people move indoors and we continue without any concerted approach to containment”, said Daniel Salmon, director of Johns Hopkins Institute for Vaccine Safety (Baltimore, USA). 

“But we should expect the social distancing and other measures to have some effect on influenza transmission, even if they are not followed across the board.”