H5N1

Containing bird flu viruses a life and death battle in China

Via the South China Morning Post, a January 10 editorial: Containing bird flu viruses a life and death battle in China.

Bird flu sub-types affecting humans are named with science in mind, factually and without emotion. As innocuous as the four-character combinations of the letters H, N and numbers sound, though, there is every reason to be edgy about them. 

With H7N9 causing deaths around China, H9N2 re-emerging after a four-year hiatus and H5N1 a constant threat, a new killer variant, H10N8, has surfaced on the mainland. As with predecessors, health experts have warned that the jumping of the virus from poultry to people is enough cause for concern that it could lead to a pandemic. 

Such a development is especially worrisome for Hong Kong and countries that import poultry from the mainland. The sheer numbers of chickens - 14 billion at any one time - and the close proximity of people to animals and birds makes for ideal breeding conditions for cross-species flu viruses. Up to 80 per cent of chickens are raised in backyards and densely populated southern China has traditionally been an influenza hotspot. Guangdong was the source of the Sars epidemic in 2003 and it was from where H5N1 originated in 1997. 

Beijing's lack of transparency with Sars led to the virus' global spread. Serious deficiencies were exposed in the public health system and amid subsequent bird flu outbreaks, concerns raised about the manner in which poultry were bred and sold. 

The World Health Organisation lauds the changes in surveillance, monitoring and preparedness that have been put in place. But outsiders remain wary that there is the capacity to detect and contain outbreaks and the necessary transparency. 

The manner in which H10N8 has been revealed and reported is cause for confidence. Confirmation that a 73-year-old woman in Jiangxi had died of the virus on December 6 came promptly, as did the announcement that a 55-year-old was in hospital in a critical condition. New cases and deaths from H7N9 appear to have been fastidiously reported. Yet the huge role the nation plays in the global poultry industry, the weaknesses of the health care system and the challenges posed by bird-rearing methods make for a challenging mix. 

Early identification, transparency and containment are crucial in preventing pandemics. Education about the dangers of bird flu and investment in health care have to remain priorities, particularly in rural regions. Beijing has made great strides, but sustained strong political will at all levels of government is essential if outbreaks are to be kept in check.

China: A closer look at H10N8

Via The Lancet: Clinical and epidemiological characteristics of a fatal case of avian influenza A H10N8 virus infection: a descriptive study. The summary:

Background 

Human infections with different avian influenza viruses—eg, H5N1, H9N2, and H7N9—have raised concerns about pandemic potential worldwide. We report the first human infection with a novel reassortant avian influenza A H10N8 virus. 

Methods 

We obtained and analysed clinical, epidemiological, and virological data from a patient from Nanchang City, China. Tracheal aspirate specimens were tested for influenza virus and other possible pathogens by RT-PCR, viral culture, and sequence analyses. A maximum likelihood phylogenetic tree was constructed. 

Findings 

A woman aged 73 years presented with fever and was admitted to hospital on Nov 30, 2013. She developed multiple organ failure and died 9 days after illness onset. A novel reassortant avian influenza A H10N8 virus was isolated from the tracheal aspirate specimen obtained from the patient 7 days after onset of illness. 

Sequence analyses revealed that all the genes of the virus were of avian origin, with six internal genes from avian influenza A H9N2 viruses. The aminoacid motif GlnSerGly at residues 226—228 of the haemagglutinin protein indicated avian-like receptor binding preference. A mixture of glutamic acid and lysine at residue 627 in PB2 protein—which is associated with mammalian adaptation—was detected in the original tracheal aspirate samples. The virus was sensitive to neuraminidase inhibitors. Sputum and blood cultures and deep sequencing analysis indicated no co-infection with bacteria or fungi. Epidemiological investigation established that the patient had visited a live poultry market 4 days before illness onset. 

Interpretation 

The novel reassortant H10N8 virus obtained is distinct from previously reported H10N8 viruses. The virus caused human infection and could have been associated with the death of a patient.

Expect more bird flu viruses to jump to humans, warns health official in China

Via The Globe and Mail, a report by Nathan VanderKlippe: Expect more bird flu viruses to jump to humans, warns health official in China.

The lead World Health Organization official in China expects more bird flu viruses to jump to humans in the country after two new strains, H7N9 and H10N8, emerged fewer than 12 months apart. 

“We do expect to see more such strains pop up,” said Bernhard Schwartlander, the Beijing-based WHO China representative. Bird flu cases have tended to carry unusually high fatality rates, and the prospect of a novel strain taking root in human populations, and possibly jumping between people, is a continued source of anxiety for those monitoring global public health. 

“We are nervous, because we know that things can change, and that may cause big problems,” said Dr. Schwartlander in an interview Wednesday. “We need to be very careful and be on alert. That’s very clear.” 

The discovery of H10N8, which killed a 73-year-old Chinese woman in December and sickened another, marks the fifth strain of avian influenza to jump from birds to humans in 17 years. It comes after H7N9 was discovered last February. That virus has since killed at least 70 world-wide. 

On Tuesday, Chinese researchers reported in the Lancet that the H10N8 shares much of its genetic base with H5N1, the bird flu strain that emerged in 2009 that has killed some 386 people, including an Alberta woman who died Jan. 3, in the first North American death. A genetic mutation allows H10N8 to better adapt to mammals, making it a particular cause for concern. 

And researchers have already identified other potentially dangerous viruses lurking in the shadows. Last August, scientists working with the H7N7 virus, which already exists in the Chinese poultry population, said it too was capable of jumping to mammals in lab tests. If it continues to circulate, “I am sure that human infection cases will occur,” University of Hong Kong researcher Guan Yi said then. 

Still, health officials have found no evidence of sustained human-to-human bird flu transmissions, including over the ongoing Chinese lunar new year season, when the risk of such transmission is particularly high as hundreds of millions of people jam into trains, buses and cars to visit home. 

“That’s the good news. The bad news, of course, is that may change, and that’s in the nature of the virus,” said Dr. Schwartlander. “The influenza virus has the ability to shift, to change over time.”

CIDRAP: H10N8 virus in first human case is novel strain

Via CIDRAP, Robert Roos writes: Study: H10N8 virus in first human case is novel strain. Click through for the full report and important links. Excerpt:

Chinese scientists reported today that the first human infection with an H10N8 avian influenza virus involved a new strain that carries genes from H9N2 viruses and has a mutation associated with adaptation to mammals. 

Writing in The Lancet, the scientists detailed the results of their genomic analysis of the virus, which was isolated from a 73-year-old Chinese woman who died Dec 6. Her illness was the first known human case involving that strain. 

A second human case in China was reported by the country's government news agency on Jan 27. "The pandemic potential of this novel virus should not be underestimated," the Lancet authors warn. 

The study says the genes for all six of the virus's internal proteins were derived from H9N2 viruses, which circulate in poultry and occasionally infect humans in China, usually causing a mild illness. 

The authors say H9N2 viruses also provided the internal protein genes for the H7N9 virus, which has caused scores of deaths in China since last spring, and the H5N1 virus, which has killed more than 380 people since 2003. 

A rapidly fatal illness 

The woman who had the first H10N8 infection lived in Nanchang, the capital of Jiangxi province (also the home of the second case-patient), and had hypertension, coronary heart disease, and myasthenia gravis, the report says. She fell ill with a cough on Nov 27 and became feverish 2 days later. 

On Nov 30 she was hospitalized with fever and severe pneumonia. Despite antibiotic and antiviral treatment, mechanical ventilation, and other measures, she died 9 days after her first symptoms. 

Using polymerase chain reaction and sequencing, the authors found that tracheal samples from the patient were positive for H10N8 and negative for seasonal flu viruses, H5N1, H7N9, and H9N2. They isolated the virus and dubbed it A/Jiangxi-Donghu/346/2013(H10N8), or JX346 for short. 

An epidemiologic investigation revealed that the patient had visited a live-poultry market 4 days before she got sick and had bought a chicken but did not handle it, the report says. She had no other contact with live poultry and no contact with sick people in the 2 weeks before her illness, nor had she traveled recently. The virus was not found in samples from the poultry market. 

Investigators identified 17 contacts of the patient, including 11 healthcare workers, 5 family members, and 1 caregiver, none of whom had any signs of flu-like illness in the 2 weeks after their exposures. Throat swabs from the healthcare workers tested negative for flu viruses, and serologic tests on the relatives were also negative.

Hong Kong: CHP on 6 new H7N9 cases and the new H10N8 case

The Centre for Health Protection has issued a news release: Six additional human cases of avian influenza A(H7N9) and one case of avian influenza A(H10N8) in Mainland closely monitored by DH. Excerpt:

According to the latest reports of the Mainland health authorities as at yesterday (January 25), six additional human cases of avian influenza A(H7N9) were confirmed in Guangdong (one case), Fujian (one case), Zhejiang (three cases) and Jiangsu (one case). The Centre for Health Protection (CHP) of the Department of Health (DH) is closely monitoring the situation.      

The case in Guangdong involves an 82-year-old man who lives in Shenzhen. He is currently under treatment in a local hospital.      The case in Fujian involves a 46-year-old woman who is still hospitalised for treatment.      

The three cases in Zhejiang involve a man aged 49, and two women aged 48 and 60. All of them are currently hospitalised for treatment 

The case in Jiangsu involves a 57-year-old man who is still hospitalised for treatment.      

As of January 25, a total of 237 human cases of avian influenza A(H7N9) have been confirmed on the Mainland, including Zhejiang (98 cases), Shanghai (41 cases), Jiangsu (32 cases), Guangdong (30 cases), Fujian (13 cases), Jiangxi (six cases), Anhui (four cases), Henan (four cases), Beijing (three cases), Hunan (two cases), Shandong (two cases), Hebei (one case) and Guizhou (one case, imported from Zhejiang).      

Additionally, the CHP received notification of an additional human case of avian influenza A(H10N8) in Jiangxi from the National Health and Family Planning Commission. The patient is a 55-year-old woman who visited a poultry market on January 4. She became ill on January 8 and is currently hospitalised for treatment.

China: A second case of H10N8 reported

Via China News: Jiangxi H10N8 found one case of human infection with avian influenza confirmed cases. Excerpt from a Google translation:

According to Jiangxi Provincial Health and Family Planning Commission informed the evening of January 25, recently, Nanchang, monitoring found one case of severe pneumonia, January 25, 2014, by the National Family Planning Health Organization expert consultation, diagnosis in this case human infection H10N8 confirmed cases of avian influenza. 　　

Patient Zhang, female, 55 years old, who lives in Nanchang Hi-tech Development Zone. The patient appeared in the January 8, sore throat, dizziness, fatigue and other symptoms, January 15 hospitalized patients currently in critical condition. The epidemiological investigation, the patient had a history of exposure bazaars. All close contacts through medical observation does not appear abnormal.

A little perspective on H7N9

The above map from The Economist is a useful guide to understanding the sheer size of China's population. We should always think about this in assessing the threat of a disease like H7N9. For any given individual, the odds of contracting H7N9 are truly minuscule.

Let's look at the four provinces with the most cases. Zhejiang's population is about 54.7 million (equivalent to Myanmar). The province has so far recorded 83 cases, which means that one in 659,000 residents has contracted the disease. Shanghai has 23.7 million people, (equivalent to Cameroon) and 40 cases, or one per 592,000 residents.

Jiangsu's 78.6 million are equivalent to Iran, and its 31 cases mean those patients have contracted H7N9 against odds of 2.5 million to one. And Guangdong, with 105.9 million, is equivalent to the Philippines. Each of its 26 cases is one in 4 million.

So why are China and the rest of us paying so much attention to this almost non-existent disease when, since January 1, over 60,000 worldwide have died of malaria? And 103,587 have died of HIV/AIDS? And 468,382 children under 5 have died (most from diarrhea)? And 800,000 have died of various communicable diseases?

Perhaps we've tuned out on those death tolls, made them background noise, out of sheer self-preservation. Click through that malaria link to Worldometers and you can watch the numbers growing before your eyes. (Click on "this year" and see how many have died so far today.) 

We pay attention to the novel infections, I suspect, precisely because they're novel. We've already factored in (that is, learned to ignore) the routine diseases. But H5N1, H7N9, and H10N8 are new, mysterious, and therefore potentially as bad as malaria or diarrhea. So we jump every time another unlucky chicken vendor falls ill on the far side of the world. 

We also remember when H1N1 came out of nowhere four years ago and spread around the world as fast as jetliners could carry it. If it had developed a case fatality rate like that of H5N1, we'd still be speaking of it in hushed tones, instead of shrugging it off as WHO losing its bureaucratic cool. But we sense just such a fatal pandemic in every new flu strain. 

So we study each strain like military intelligence officers, as if its genome carried an enemy's plans for invasion and conquest. In the process, we learn more about the influenzas in general, so what H5N1 or H7N9 reveals could be used in a counterattack against other strains.

The same could be true of MERS, if we could ever figure out how the hell people catch it except from other people. (Just to be on the safe side, I have totally abstained from kissing camels and bats.)

So the attention we pay to these fringe viruses is certainly worth the effort. I just wish it were politically possible to attack the routine diseases as well—and do it so successfully that governments have to start worrying about jobs for all those toddlers who will now grow up into healthy young adults instead of dying before age 5.

Emergence of H10N8: single intrusion or looming epidemic?

Thanks to Greg Folkers for sending the link to this report in Journal of Infection: Emergence of avian influenza A(H10N8) in human after A(H5,6,7,9,10 and N1,2,3,7,9): single intrusion or looming epidemic? The summary:

In December 2013, China reported the first human case of avian influenza A(H10N8). A 73-year-old female with chronic diseases who had visited a live poultry market succumbed with community-acquired pneumonia. 

While human infections with avian influenza viruses are usually associated with subtypes prevalent in poultries, A(H10N8) isolates were mostly found in migratory birds and only recently in poultries. Although not possible to predict whether this single intrusion by A(H10N8) is an accident or the start of another epidemic like the preceding A(H7N9) and A(H5N1), several features suggest that A(H10N8) is a potential threat to humans. 

Recombinant H10 could attach to human respiratory epithelium, and A(H10N4) virus could cause severe infections in minks and chickens. A(H10N8) viruses contain genetic markers for mammalian adaptation and virulence in the haemagglutinin (A135T, S138A[H3 numbering]), M1(N30D, T215A), NS1(P42S) and PB2(E627K) protein. 

Studies on this human A(H10N8) isolate will reveal its adaptability to humans. Clinicians should alert the laboratory to test for A(H5,6,7,9,10) viruses in patients with epidemiological exposure in endemic geographical areas especially when human influenza A(H1,3) and B are negative. 

Vigilant virological and serological surveillance for A(H10N8) in human, poultry and wild bird is important for following the trajectory of this emerging influenza virus.

Hong Kong: Man, 86, may have picked up H9N2 bird flu at Shenzhen market

Via the South China Morning Post: Man, 86, may have picked up H9N2 bird flu at Shenzhen market. Excerpt:

Mainland health officials believe the Shenzhen-based Hong Kong man infected with H9N2 bird flu is likely to have contracted the virus at a market that he visited every day. 

But the live poultry stall at the wet market near where the 86-year-old patient lived was open again yesterday after briefly closing for disinfection. 

He Hianfeng of the Centre for Disease Control and Prevention of Guangdong said yesterday that the man visited the market every day although he did not come into contact with live poultry. 

The man was in a stable condition yesterday under isolation in Princess Margaret Hospital. 

An infectious diseases expert warned, meanwhile, that without more stringent controls on mainland chickens, more Hongkongers were likely to be infected with the H9N2, H7N9 and H10N8 bird flu strains. 

"Three different strains of bird flu appear to be spreading from birds to humans this year. It shows that the virus has been very active," University of Hong Kong microbiologist Professor Yuen Kwok-yung said. 

"Since there is a large number of live poultry on the mainland, the chance of cross-infection will increase too, and there may be a higher chance of it spreading to humans."

China: H5N2 outbreak ‘under control’

Via Shanghai Daily: Chicken farm flu outbreak ‘under control’. Excerpt:

The Chinese mainland’s first outbreak of H5N2 bird flu, which killed 4,000 birds at a chicken farm, is under control, authorities in a northern province said yesterday. 

The chickens died at the Hufeng farm in Baoding City in Hebei Province last Tuesday, the local government said. 

A total of 125,700 chickens were culled on Thursday and safely disposed of and surrounding areas have been sterilized, it said. Areas within 3 kilometers of the farm have been cordoned off. 

Eleven people found to have been in contact with the poultry have been isolated but none has been confirmed as infected with the virus, officials said. 

On Thursday night, more than 1,000 paramilitary and police officers were sent to the farm to cull the birds. On Saturday, the state lab for bird flu confirmed it was the H5N2 strain that had caused the initial deaths. 

The privately run Hufeng chicken farm was established in 1992. The chickens that had died from the H5N2 virus were bought in late November. 

The outbreak was the first of its kind on the Chinese mainland. Taiwan reported infections of H5N2 in chickens in March 2012, triggering a cull of 58,000 poultry. 

In other bird flu cases, Jiangxi Province in east China confirmed a human case of the H10N8 strain last Wednesday. 

136 people infected 

And earlier last week, four new human cases of H7N9 bird flu were confirmed in south China’s Guangdong Province. 

China reported the world’s first human case of H7N9 bird flu infection in March. 

As of Friday, a total of 136 people have been confirmed as infected with the virus, the National Health and Family Planning Commission said. 

Of those infected, 45 had died, representing a fatality rate of 33.1 percent. No cases have been reported in other countries so far.