Title: #Avian #Influenza A (#H7N9) Virus – #Situation as of March 6 2017.
Subject: Avian Influenza, H7N9 subtype, human cases and poultry epizootics in China.
Source: US Centers for Disease Control and Prevention (CDC), full page: (LINK).
Code: [ ]
Avian Influenza A (H7N9) Virus – Situation as of March 6 2017
H7N9 Outbreak Characterization
- H7N9 infections in people and poultry in China
- Sporadic infections in people; most with poultry exposure
- Rare limited person-to-person spread
- No sustained or community transmission
What's New & Updated
- H7N9: What should I do?
- CDC does not have any new or special recommendations for the U.S. public at this time regarding H7N9. CDC will keep you updated. Stay informed.
- Since H7N9 is not spreading easily from person to person at this time, CDC does not recommend that people delay or cancel trips to China.
- The World Health Organization also is watching this situation closely and does not recommend any travel restrictions.
- CDC advises travelers to China to take some common sense precautions, like not touching birds and washing hands often.
- Poultry and poultry products should be fully cooked. CDC will update its advice for travelers if the situation in China changes.
- This guidance is available at Avian Flu (H7N9) in China.
- Human infections with a new avian influenza A (H7N9) virus (“H7N9”) were first reported in China in March 2013.
- Annual epidemics of sporadic human infections with H7N9 viruses in China have been reported since that time.
- China is currently experiencing its 5th epidemic of H7N9 human infections.
- On February 27, 2017, the World Health Organization (WHO) announced that 460 human infections with H7N9 virus had been reported during the 5th epidemic,[1.3 MB, 15 Pages] making it the largest to date.
- This brings the total cumulative number of H7N9 cases reported by WHO to 1,258.
- During epidemics one through four, about 40 percent of people confirmed with H7N9 infection died.
- Most human infections with H7N9 virus have occurred after exposure to poultry; H7N9 viruses continue to circulate in poultry in China.
- Most reported patients with H7N9 virus infection have had severe respiratory illness (e.g., pneumonia); about 40% of patients have died.
- Rare instances of limited person-to-person spread of this virus have been identified in China, but there is no evidence of sustained person-to-person spread of H7N9 virus.
- Some cases of H7N9 have been reported outside of mainland China but most of these infections have occurred among people who had traveled to mainland China before becoming ill.
- H7N9 viruses have not been detected in people or birds in the United States.
CDC Risk Assessment
- While the current risk to the public’s health posed by H7N9 virus is low, the pandemic potential of this virus is concerning.
- Influenza viruses constantly change and it’s possible that this virus could gain the ability to spread easily and sustainably among people, triggering a global outbreak of disease (pandemic).
- In fact, of the influenza A viruses that are of special concern to public health, H7N9 virus is rated by the Influenza Risk Assessment Tool (IRAT), as having the greatest potential to cause a pandemic, as well as potentially posing the greatest risk to severely impact public health.
- It’s likely that sporadic human infections with H7N9 virus associated with poultry exposure will continue to occur in China.
- It's also possible that H7N9 virus may spread to poultry in neighboring countries and that human cases associated with poultry exposure may be detected in neighboring countries.
- It’s also possible that H7N9 cases may continue to be detected among travelers returning from H7N9 virus-affected countries, even possibly in the United States.
- However, as long as there is no evidence of ongoing, sustained person-to-person spread of H7N9 virus, the public health risk assessment would not change substantially.
- The U.S. Government supports international surveillance for H7N9 virus and other influenza A viruses with pandemic potential.
- CDC is following the H7N9 situation closely and coordinating with domestic and international partners.
- CDC takes routine preparedness actions whenever a new virus with pandemic potential is identified, including developing candidate vaccine viruses to use for vaccine production in case vaccine is needed.
- CDC has already developed 3 H7N9 candidate vaccine viruses (CVVs).
- These remained antigenically like H7N9 viruses that were circulating during the 4th epidemic.
- Genetic and antigenic analysis of viruses from the 5th epidemic is ongoing at CDC.
- This includes looking at viruses from the 5th epidemic to consider whether an updated candidate vaccine virus might be needed.
- CDC also will look at 5th epidemic viruses to see whether these remain susceptible to the antiviral drugs classified as neuraminidase inhibitors.
- CDC has issued guidance to clinicians and public health authorities in the United States, as well as provided information for people traveling to China.
- CDC will provide updated information as it becomes available.
|—H7N9 FAQ –|
|-- Health Care Guidance –|
|—H7N9 Images –|
- Increase in Human Infections with Avian Influenza A(H7N9) Virus During the Fifth Epidemic — China, October 2016–February 2017
- Antigenic and genetic characteristics of zoonotic influenza viruses and candidate vaccine viruses developed for potential use in human vaccines
- World Health Organization report: "Human infection with avian influenza A(H7N9) virus – China"
- World Health Organization report: ”Analysis of recent scientific information on avian influenza A(H7N9) virus”
- MMWR report: "Assessing Change in Avian Influenza A(H7N9) Virus Infections During the Fourth Epidemic — China, September 2015–August 2016
Keywords: USA; US CDC; Updates; China; H7N9; Avian Influenza; Human.