H5N1

Avian influenza A viruses among occupationally exposed populations, China, 2014–2016

Via Emerging Infectious Diseases: Avian Influenza A Viruses among Occupationally Exposed Populations, China, 2014–2016. The abstract:

To determine the seroprevalence and seroconversion of avian influenza virus (AIV) antibodies in poultry workers, we conducted a seroepidemiologic study in 7 areas of China during December 2014–April 2016. We used viral isolation and reverse transcription PCR to detect AIVs in specimens from live poultry markets. 

We analyzed 2,124 serum samples obtained from 1,407 poultry workers by using hemagglutination inhibition and microneutralization assays. We noted seroprevalence of AIV antibodies for subtypes H9N2, H7N9, H6N1, H5N1-SC29, H5N6, H5N1-SH199, and H6N6. In serum from participants with longitudinal samples, we noted seroconversion, with >4-fold rise in titers, for H9N2, H7N9, H6N1, H5N1-SC29, H6N6, H5N6, and H5N1-SH199 subtypes. We found no evidence of H10N8 subtype. 

The distribution of AIV antibodies provided evidence of asymptomatic infection. We found that AIV antibody prevalence in live poultry markets correlated with increased risk for H7N9 and H9N2 infection among poultry workers.

New discovery could spell end to seasonal flu

Via Deutsche Welle: New discovery could spell end to seasonal flu. Excerpt:

A potential breakthrough discovery of new antibodies could lead to a universal vaccine. If successful, it could protect against all types of deadly influenza viruses and even prevent pandemics, a study shows. 

 Immunologist Ali Ellebedy was working on a study analyzing the immune response to flu infection in humans. During his research, he spotted a new type of powerful antibody in a blood sample from a patient infected with human influenza virus.   

Ellebedy then sent samples of the antibody to Florian Krammer — a microbiologist who proved the effectiveness of the antibodies by testing them against extensive samples of virus proteins dating back to the 1970s. These proteins, called neuraminidase, enable the virus to spread through the human body. 

The study, which was jointly conducted by Scripps Research, Washington University's School of Medicine in St. Louis and the Icahn School of Medicine in New York, was published in the October 25 issue of Science.  

Future vaccine could survive antiviral resistance  

Krammer told DW that the beauty of this new antibody, called 10G1, is that it binds to the parts of the virus that never change. This means that even if new strains of influenza viruses are detected, a potential vaccine containing new antibodies would still be effective. 

Moreover, the antibody has a powerful potential to attack both A and B subtypes of influenza viruses, making it an even better candidate for a universal vaccine that would combat human, swine, and bird strains, as well as other rarer strains of lethal flu viruses.

Pneumonic plague is diagnosed in China

The New York Times takes note: Pneumonic Plague Is Diagnosed in China. Excerpt and then a comment:

BEIJING — Two people in China were diagnosed with plague, setting off a panic on Tuesday about the potential spread of the highly infectious and fatal disease and prompting China’s government to warn citizens to take precautions to protect themselves.  

Beijing officials said the two infected people came from Inner Mongolia, a sparsely populated region of northern China. They sought treatment on Tuesday in a hospital in Beijing’s Chaoyang District, where they were diagnosed with pneumonic plague, according to the government office of the district.  

The Chinese Center for Disease Control and Prevention said on Weibo, the microblogging site, that there was no need for Beijing residents to panic and that the risks of further transmission are “extremely low.” The authorities quickly isolated the patients, conducted epidemiological investigations on the people who could have been exposed and disinfected all the relevant sites, the CDC said. They have also strengthened monitoring of patients with fever, it added. 

Pneumonic plague is one of three types of infectious disease known as plague caused by the same bacterium, Yersinia pestis. Patients diagnosed with pneumonic plague, which causes high fevers and shortness of breath, sometimes first contract the closely related and more well-known disease, bubonic plague.

Fears are mounting in China over a possible outbreak of the disease, once known as the Black Death, which killed tens of millions of people in medieval Europe, and spread through Asia and Africa. 

Last month, the authorities in China said they would strengthen quarantine measures to prevent plague from entering the country after Madagascar was struck by a fast-spreading outbreak of the disease. It is unclear when the cases were first detected in China but residents are asking why the authorities took so long to diagnose and disclose the problem. 

Li Jifeng, a doctor at Beijing Chaoyang Hospital where the two people sought treatment, wrote on WeChat, a social media platform, that the patients sought treatment on Nov. 3. That post, which has since been deleted, was published by CN-Healthcare, a website that covers health care news in China. Dr. Li could not be reached for comment and Beijing Chaoyang Hospital declined to comment.  

Dr. Li wrote that the patient she saw was a middle-aged man, who had a fever and complained of breathing difficulties for 10 days. He sought treatment at a hospital in Inner Mongolia but his condition did not improve. His wife also developed a fever and respiratory problems.  

“After so many years of specialist training, I’m familiar with the diagnosis and treatment of most respiratory diseases,” wrote Dr. Li. “But this time, I looked and looked at it. I couldn’t guess what pathogen caused this pneumonia. I only knew it was rare.”

On why the authorities took so long to make the announcement, Dr. Li wrote that signs of any infectious disease need to be repeatedly verified and investigated, and such announcements cannot be “transmitted casually.”  

The police quarantined the emergency room in the Chaoyang Hospital on Monday night, the news outlet Caixin reported, citing residents.  

On Tuesday, Chinese censors instructed online news aggregators in China to “block and control” online discussion related to news about the plague, according to a directive seen by The New York Times. 

Skeptical Chinese internet users have charged the government with being slow to disclose news about the disease, which is transmitted between humans and kills even faster than the more-common bubonic form. China has a history of covering up and being slow to announce infectious outbreaks, prompting many people to call for transparency this time. 

“The plague is not the most terrifying part,” one user wrote on Weibo. “What’s even scarier is the information not being made public.”

China took a deserved kicking for its suppression of SARS news, and when H7N9 avian flu suddenly appeared in Shanghai and spread across the country, the authorities almost drowned us with information—not only news reports, but research articles that made Saudi MERS studies look as pathetic as they were.

Somehow those reports dried up not long after the accession of Xi Jinping, and health problems in a nation of over 1 billion mysteriously solve themselves these days.

 

Pneumonic plague, serious as it is for the unlucky person who contracts it, is a very small problem in a large and prosperous country. (It's been endemic in US Southwest since the San Francisco plague outbreak of 1900. And antibiotics routinely beat it.) Plague in China deserves coverage as a one-off, and the Chinese authorities would look a lot better if they'd reported these cases as an interesting oddity: "in other news..."

The re-emergence of HPAI H7N9 viruses in humans in mainland China, 2019

Via Eurosurveillance: The re-emergence of highly pathogenic avian influenza H7N9 viruses in humans in mainland China, 2019. The abstract:

After no reported human cases of highly pathogenic avian influenza (HPAI) H7N9 for over a year, a case with severe disease occurred in late March 2019. Among HPAI H7N9 viral sequences, those recovered from the case and from environmental samples of a poultry slaughtering stall near their home formed a distinct clade from 2017 viral sequences. Several mutations possibly associated to antigenic drift occurred in the haemagglutinin gene, potentially warranting update of H7N9 vaccine strains.

ECDC: CDTR, week 17

ECDC has published Communicable Disease Threats Report, 21–27 April 2019, week 17. The summary:

The ECDC Communicable Disease Threats Report (CDTR) is a weekly bulletin for epidemiologists and health professionals on active public health threats. This issue covers the period from 21–27 April 2019 and includes updates on influenza A(H7N9), chikungunya and dengue, dengue, Ebola virus disease, influenza, Rift Valley fever and risks of communicable diseases related to Cyclone Idai.

Branswell: What happened to bird flu?

Via STAT, Helen Branswell brings back memories: What happened to bird flu? How a threat to human health faded from view. Excerpt from a very good article:

Just over a dozen years ago, a bird flu virus known as H5N1 was charting a destructive course through Asia, North Africa, and the Middle East, ravaging poultry in apocryphal numbers and killing 6 in 10 humans known to have contracted it. 

The overall human death toll was low — in the hundreds — but scientists and government officials feared that the virus could ignite a human pandemic reminiscent of the catastrophic 1918 Spanish flu. Emergency plans were drafted, experimental H5N1 vaccines were created and tested, antiviral drugs were stockpiled. 

And then … nothing happened.

The virus continued to kill chickens and to occasionally infect and sometimes kill people. But as the years passed, the number of human H5N1 cases subsided. There has not been a single H5N1 human infection detected since February 2017.  

This is the good news. The bad news is that the situation could change in an instant. Related: How live animal markets create a perfect storm for bird flu 

“We don’t know how the story’s going to end,” warned Nancy Cox, who retired from the Centers for Disease Control and Prevention in late 2014 after leading its influenza operations for more than two decades. 

It’s not just H5N1 that has dissipated. The virus’s nearly-as-scary cousin, H7N9, emerged in China in 2013 and sickened more than 1,500 people in China over five years, killing roughly 40 percent of them. 

But after an extraordinary surge of cases — 766 — in early 2017, there were a mere three infections recorded in 2018. So far in 2019 there have been none.  

Although there are ways to make sense of H7N9’s decline, no one knows precisely why H5N1 has faded from view.  

“There are things that occur with influenza that don’t quite add up completely,” Cox admitted.  

Scientists do know the H5N1 viruses have mutated in ways that may be important to their ability to interact with people. Several years ago, these viruses effectively splintered, with some dumping their N1 neuraminidase — a gene that produces a key protein found on the surface of flu viruses — and replacing it with another. The process is called reassortment, and, in this case, it resulted in the emergence of a lot of new pairings over a fairly short period of time.  

The most common and most dangerous viruses to emerge — for birds at least — have been H5N6 and H5N8 viruses. Both are highly pathogenic, meaning they kill domestic poultry. 

“The H5N1 virus has not gone away. It’s just changed into different versions of itself,” explained influenza expert Malik Peiris, a professor of virology at the University of Hong Kong. “We don’t know how the story’s going to end.”  

Peiris suggested it might be a mistake to see the evolution of the virus as nothing but a positive development.  

“It is good news, the fact that overall the H5N1 problems have reduced,” he said. “But you know, you can look at it the other way around. So now we have two high pathogenic [H5] viruses kicking around.”

New Year's Eve, 2008

Just out of curiosity, I've checked what I'd been blogging about here on December 31, 2008...ten short years ago.

It was mostly bird flu; the H1N1 "swine flu" pandemic was almost six months in the future, and I hadn't yet realized that bird flu could not be considered apart from an enormous range of global-health issue. (Also in the future: Haiti's cholera, MERS, H7N9, Zika, and urban Ebola.)

So I was reporting on a two-month-old baby in Shenzhen who was recovering from H9N2. The case provoked authorities in Guangdong to tighten inspection of poultry markets.

Indian doctors in Manipur were working "round the clock" to prevent the spread of H5N1 to their city after an outbreak in Assam state.   

In Nigeria, the Bauchi state ministry of health was on the alert for H5N1 as well; it was about that time, I seem to recall, that Nigeria had one human case of H5N1, which had been fatal.

Here in Canada, Ontario was finally making public the rates of hospital-acquired infections from superbugs like C. diff and MRSA.

On New Year's Day, I was reporting a health scare about possible H5N1 in an Indonesian village. And I posted links to the old Flu Wiki Forum (no longer online) and Mike Coston at Avian Flu Diary (still very much online).

Ten years later we're watching a slightly different mix of bacteria and viruses, but the war goes on. It has been my good fortune to follow the war from a safe vantage point, while gaining ever deeper respect for the men and women fighting it from the villages of Asia and Africa and Latin America to the hospitals of Europe and North America. I hope my posts have accurately reported their extraordinary efforts.

Influenza H5/H7 virus vaccination in poultry and reduction of zoonotic infections, Guangdong province, China, 2017–18

Via Emerging Infectious Diseases, a quiet bombshell: Ahead of Print - Influenza H5/H7 Virus Vaccination in Poultry and Reduction of Zoonotic Infections, Guangdong Province, China, 2017–18. The abstract and then a comment:

We compared the detection frequency of avian influenza H7 subtypes at live poultry markets in Guangdong Province, China, before and after the introduction of a bivalent H5/H7 vaccine in poultry. The vaccine was associated with a 92% reduction in H7 positivity rates among poultry and a 98% reduction in human H7N9 cases.

That would presumably explain the lack of reported human H7N9 cases in the last year or so. The new vaccine was introduced in July 2017 and, the report says, coverage was 97.9% (282 million birds) by November. That's a remarkable feat of logistics.

This is not a China-wide success, evidently. Flu in China reports a November outbreak of avian H5N6 in Jiangsu province that's resulted in the deaths over 30,000 birds.

Hong Kong to remain vigilant over H7N9 bird flu threat, health chief Sophia Chan vows

My Google Alert for H7N9 has turned up nothing for months but business stories about various H7N9 vaccines. But the South China Morning Post has this: Hong Kong to remain vigilant over bird flu threat, health chief Sophia Chan vows, as Japanese research confirms H7N9 virus can be transmitted via respiratory droplets. Excerpt:

Hong Kong’s health minister promised the government would stay alert over any possible outbreak of bird flu in the city as new research in Japan confirmed the H7N9 virus could be transmitted via respiratory droplets.

Secretary for Food and Health Sophia Chan Siu-chee on Sunday said the government had done a lot in the prevention and surveillance of bird flu at local farms and markets selling live poultry. 

“We will continue to communicate with international organisations and health organisations to understand more about avian flu and the risks,” she said. 

Her remarks followed a report that University of Tokyo researchers had confirmed the H7N9 bird flu virus could be transmitted via respiratory droplets. 

Researchers placed a healthy ferret and one infected with the virus in separate cages 7cm apart. Four days later, they found the healthy ferret was infected. Droplets containing the virus were found 80cm from the sick animal. 

H7N9 is a subtype of the influenza virus which has been detected in birds in the past. It was first seen in people in 2013 in China. Most patients infected become severely ill. 

Most of those infected had reported recent exposure to live poultry or potentially contaminated environments, especially markets where live birds were sold, the World Health Organisation (WHO) said. 

The virus does not appear to transmit easily from person to person, and sustained human-to-human transmission has not been reported.

For more on the study behind this report, see this Avian Flu Diary post by Mike Coston.

Vietnam reports no new cases of bird flu in humans since 2014

Via Viet Nam News: VN reports no new cases of bird flu in humans since 2014. Excerpt:

Việt Nam has reported no new cases of human infection with avian influenza viruses since the second half of 2014, an agriculture official said. 

Deputy Minister of Agriculture and Rural Development Hà Công Tuấn said Việt Nam successfully prevented the epidemic from spreading on a large scale. The infection was mainly local and only affected a small portion of poultry. 

“The number of human infections and deaths from bird flu in the country has markedly decreased year after year,” Tuấn told a conference on the National Avian Flu Control Plan for 2014-18 and 2019-25 in Hà Nội on Tuesday. 

“No new cases have been found since the final months of 2014.” 

In the ten years between 2004 and the first half of 2014, 64 people died of the A/H5N1 strain of bird flu in Việt Nam. 

The deaths made up 50.4 per cent of the 127 cases of A/H5N1 bird flu infections, said Deputy Head of the Ministry of Agriculture and Rural Development’s Department of Animal Health Đàm Xuân Thành 

Thành said the A/H5N1 bird flu was first detected in the country at the end of 2003.  

“Việt Nam was among the first countries to announce a bird flu outbreak,” Thành said. “The incident caused big losses in poultry with some 45 million animals slaughtered between 2003 and 2006.” 

Thành added that hundreds of thousands of infected poultry had been culled annually in the years since.  

In a report presented to the conference, Thành said the achievements of the National Avian Flu Control Plan for 2014-18 included basic control of avian flu among animals, having no human infections, successful prevention of the spread of A/H7N9 bird flu into the country and safe export of poultry products. 

The animal husbandry sector had recovered and maintained stable growth with 330 million animals nationwide. Pollution due to the slaughter of infected poultry had been mitigated. 

Nevertheless, he warned that the risk of other strains of avian influenza viruses entering Việt Nam was still high, especially in provinces bordering other countries. The A/H5N1 and A/H5N6 strains were relatively prevalent, some 5 per cent on average.