H7N9 is a serotype of the species Influenzavirus A (avian influenza virus or bird flu virus). H7 normally circulates amongst avian populations with some variants known to occasionally infect humans. An H7N9 virus was first reported to have infected humans in 2013.
According to World Health Organization, symptoms include fever, cough, and shortness of breath, which progressed to severe pneumonia.WHO also notes that information is limited.
On April 4, 2013, China's agricultural authorities reported that the H7N9 virus had been detected from pigeon samples collected at a marketplace in Shanghai. It should be noted that pigeons are not defined or meet the definition of poultry, which are the most likely to transmit the virus. Previously, The Guardian reported that unnamed experts believed the virus may infect poultry without making them sick, making it more difficult to track.
The World Health Organization still said it was "unlikely" to become a pandemic.The World Health Organization stated that there was no evidence of ongoing human-to-human transmission.The close contacts of those infected with H7N9 are being monitored, but have shown no signs of infection.
The fact that no evidence of ongoing human-to-human transmission for the current H7N9 outbreak has yet been found suggests that the virus is undergoing “stuttering transmission” in which a virus that normally circulates in an animal reservoir infects a person, but further human-to-human transmission does not occur. In general, viruses capable of stuttering transmission have acquired novel sequence variations that allow them to infect humans, but have yet to acquire sequence variations that allow them to sustain efficient transmission between humans. Comparative genomics analysis is now being performed at the Influenza Research Database to identify candidate sequence variations that might be involved in human adaptation.
Treatment
Currently, no vaccine exists for H7N9, but antigenic and genome sequencing suggests that H7N9 is sensitive to neuraminidase inhibitors, such as oseltamivir and zanamivir. Oseltamivir is also known under its trade name Tamiflu.
The Centers for Disease Control and Prevention (CDC) has begun sequencing and development of a vaccine as routine procedure for any new transgenic virus. The CDC and vaccine manufacturers are developing a candidate virus to be used in vaccine manufacturing if there is widespread transmission.
In response to a request from the United States Centers for Disease Control and Prevention (CDC) and Biomedical Advanced Research and Development Authority (BARDA), and after the H7N9 flu virus gene sequences were made available through the Global Initiative on Sharing Avian Influenza Data (GISAID), the J. Craig Venter Institute (JCVI) and Synthetic Genomics Vaccines, Inc (SGVI) began working with Novartis to synthesize the genes of the new viral strain and supplied these synthesized genes to the CDC.
