H7N9 Bird Flu and Antiviral Efficacy Testing

Microbac Laboratories, Inc. offers regulatory-compliant virucidal efficacy and drug efficacy (IC50) testing against Avian Influenza A Virus H7N9, under BSL-3. Disinfectants should be tested following ASTM E1053-11 for U.S. EPA or Canada submission; and EN14476 for European submission. Antiseptics should be tested following ASTM E1052-11 or EN14476. The tests may be performed under GLP, cGMP, non-GLP.

Initially emerged in 2013, the avian influenza A virus subtype H7N9 seems to be active again in China. The U.S. Centers for Disease Control and Prevention (CDC) has recently issued a new travel warning about bird flu in China advising people traveling to China staying away from chickens and poultry markets. There have been at least 120 confirmed new human cases of avian influenza A (H7N9) since September 2016, with 37 deaths1. This article gives a brief overview of the bird flu H7N9, its treatment and prevention strategies, and the testing methodologies.

Officials are watching H7N9 because it has the potential to cause a human pandemic. Although H7N9 doesn’t seem to infect people easily, influenza viruses can mutate and swap genetic material and become more contagious and dangerous. Most human infections with H7N9 have occurred after exposure to poultry. Early symptoms are similar to those of seasonal flu and may include fever, cough, sore throat, muscle aches and fatigue, loss of appetite, and runny or stuffy nose. Most reported H7N9 patients have had severe respiratory illness; about one-third of patients have died. Person-to-person spread of this virus has been rare but was previously identified2.

The Influenza A subtype H7N9 virion is spherical, roughly 80 – 120 nm in size. Its genome consists of 8 segments of negative-sense RNA with each segment encoding either 1 or 2 proteins3.

Prevention of flu is done mostly through vaccination. The flu vaccine can take many forms, but is mostly commonly delivered through an intramuscular shot. A clinical diagnosis of flu is often difficult with symptoms of flu overlapping with many other viral and bacterial infections. A laboratory diagnosis is critical in establishing flu. A nasopharyngeal swab is taken and used for determination of flu through cell culture, antibody staining, or PCR depending on availability and required turn-around time for results4.

1. http://www.nbcnews.com/health/health-news/cdc-issues-h7n9-bird-flu-travel-warning-n712541
2. https://www.cdc.gov/flu/avianflu/h7n9-virus.htm
3. Bouvier, N., Palese, P. (2011). “The Biology of Influenza Viruses”. Vaccine 26 (Suppl 4): D49-D53.
4. Leland, et al. 2007. “Approved respiratory specimens vary among FDA cleared influenza assays”. Clinical Microbiology (20): 49-78.

January 30, 2017