Tracing evolution of chicken flu virus yields insight into origins of deadly H7N9 strain

Date:

December 29, 2014

Source:

St. Jude Children's Research Hospital

Summary:

An international research team has shown how changes in a flu virus that has plagued Chinese poultry farms for decades helped create the novel avian H7N9 influenza A virus that has sickened more than 375 people since 2013.

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Coming soon — a treatment for bird flu!

Editorial Team July 22, 2014 at 7:03 pm

In a novel discovery, scientists have identified six potential therapeutics to treat the deadly H7N9 avian influenza.’The seriousness of the disease often results from the strength of immune response, rather than with the virus itself. Turning down that response, rather than attacking the virus, might be a better way to reduce that severity,’ explained Juliet Morrison from University of Washington, Seattle.

The viruses that cause severe illness like H7N9 trigger gene expression signatures that are different from the signatures seen in milder infections. ‘Importantly, we can exploit these signatures for antiviral drug discovery,’ Morrison added. The investigators used a computational approach to identify potentially therapeutic drugs. They searched databases containing gene expression profiles of cultured human cells that had been treated with different drugs. These drugs could potentially dampen the harmful host response. (Read:Potential treatment for drug-resistant H7N9 influenza virus comes closer to reality)

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Study fingers chickens, quail in spread of H7N9 influenza virus

Date:

March 18, 2014

Source:

American Society for Microbiology

Summary:

Among the copious species of poultry in China, quail and chickens are the likely sources of infection of H7N9 influenza virus to humans, according to a paper. The H7N9 avian influenza virus was first reported in humans in March 2013 in China. Since then over 375 human cases have been confirmed and over 100 have died. Only 1 case has been reported outside of China: A woman from Guangdong Province who was traveling in Malaysia and is presumed to have contracted the virus in China. According to the World Health Organization, most known human infections have resulted from direct or indirect contact with poultry.

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New Details About H7N9 Influenza Infections That Suddenly Appeared in China

June 19, 2013 — Researchers with the Network Dynamics and Simulation Science Laboratory at the Virginia Bioinformatics Institute have revealed new information about the latest strain of type A influenza, known as H7N9, in a report in the journal PLOS Currents: Outbreaks.

Since June 7, 132 confirmed cases of human infection with H7N9 have been reported in China and 37 people have died, according to the World Health Organization. It is the first time human infection with the avian influenza H7N9 subtype has been detected, and researchers fear that this strain may have pandemic potential.

The possibility of an animal source of the infection is being investigated, as is the possibility of person-to-person transmission.

However, most people who contracted the disease reported having contact with live birds in a bird market prior to infection. Researchers at the Network Dynamics and Simulation Science Laboratory found that younger women generally have the most contact with poultry, but it is older men who are experiencing the most infections.

The findings suggest that there is something unique about older men that makes them particularly susceptible to H7N9. Their greater risk of infection is not just because they tend to spend more time exposed to an avian source.

Researchers quickly compiled the data using a variety of available sources to discover risk factors, which could aid in containing the spread of H7N9.

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Risks of H7N9 Infection Mapped

May 3, 2013 — A map of avian influenza (H7N9) risk is presented in Biomed Central's open access journal Infectious Diseases of Poverty today. The map is composed of bird migration patterns, and adding in estimations of poultry production and consumption, which are used to infer future risk and to advise on ways to prevent infection.

As of today, there have been 127 confirmed cases of H7N9 in mainland China with 27 deaths. A lack of information about the virus and its mode of transmission has led to public concerns that H7N9 could be a pandemic waiting to happen.

A map of avian influenza (H7N9) risk is presented in Biomed Central's open access journal Infectious Diseases of Poverty today. (Credit: Benyun Shi, Shang Xia, Guo-Jing Yang, Xiao-Nong Zhou, Jiming Liu. Inferring the potential risks of H7N9 infection by spatiotemporally characterizing bird migration and poultry distribution in eastern China. Infectious Diseases of Poverty, 2013; 2 (1): 8 DOI: 10.1186/2049-9957-2-8)

To quantify the risk of this happening scientists from the Hong Kong Baptist University and Chinese University of Hong Kong have generated a map of H7N9 risk in eastern China. The map is based on the northwards migratory patterns of birds (from the 4th February to the end of April) using environmental and meteorological data over the same 12 weeks -- from Zhejiang, Shanghai, and Jiangsu, to Liaoning, Jilin, and Heilongjiang.

The distribution of potentially infected poultry was also included in the model. The majority of early cases of H7N9 were found in Shanghai, but Shanghai is not a big poultry exporter so the model shows limited transmission via this route. In contrast, Jiangsu distributes poultry to Shanghai, Zhejiang, and beyond.

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2 in China are first-known deaths from H7N9 bird flu

7:41a.m. EDT March 31, 2013

H7N9 is considered a low pathogen strain that is not easily contracted by people

China says the World Health Organization has been notified of the case

A third person, a woman in Anhui province, also was infected and is in critical condition

BEIJING (AP) — Two Shanghai men have died from a little-known type of bird flu in the first known human deaths from the strain. Chinese authorities said Sunday that it wasn't clear how the men were infected, but that there was no evidence of human-to-human transmission.

A third person, a woman in the nearby province of Anhui, also contracted the H7N9 strain of bird flu and was in critical condition, China's National Health and Family Planning Commission said in a report on its website.

There was no sign that any of the three had contracted the disease from each other, and no sign of infection in the 88 people who had closest contact with them, the medical agency said.

H7N9 bird flu is considered a low pathogenic strain that cannot easily be contracted by humans. The overwhelming majority of human deaths from bird flu have been caused by the H5N1 strain.

http://www.usatoday.com/story/news/world/2013/03/31/bird-flu-deaths-china/2039551/