Recent Upsurge of A(H7N9) Cases in China

This image shows the distribution of A(H7N9) human cases in China over the five epidemic waves, week 7/2013 to 4/2017. Courtesy of European Centre for Disease Prevention and Control
 
A steep increase of human cases of avian influenza A(H7N9) has been reported from China since the beginning of December 2016. During this wave, the number of human cases is already higher than during the last two waves in 2014-15 and 2015-16. The majority of recently reported human cases are associated with exposure to infected live poultry or contaminated environments, including markets where live poultry are sold. Influenza A(H7N9) viruses continue to be detected in poultry and their environments in the areas where human cases are occurring. In addition, the human cases are more geographically widespread and cases are also reported from rural areas, unlike in previous epidemics.

At present, the most immediate threat to EU citizens is to those living or visiting influenza A(H7N9)-affected areas in China concludes the updated rapid risk assessment by the European Centre for Disease Control (ECDC). Caution should be taken by people travelling to China to avoid direct exposure to poultry, live poultry markets or backyard farms.

The recent upsurge of human cases indicates the possibility of imported cases to Europe. However, the risk of the disease spreading within Europe between humans remains low as the virus does not appear to transmit easily from human to human: investigations do not support sustained human-to-human transmission.

Travelers that visited affected areas and develop respiratory symptoms and fever within up to 10 days after their return should consult a physician and inform him/her about their recent travel history to facilitate early diagnosis and treatment.

People in the EU presenting with severe respiratory or influenza-like infection and a history of travel to the affected areas in China -- with potential exposure to poultry or live bird markets -- will require careful investigation, management and infection control. Adequate samples for influenza tests should be rapidly taken and processed from patients with relevant exposure history within 10 days preceding symptom onset. Early or presumptive treatment with neuraminidase inhibitors should be considered for suspect or confirmed cases, in line with relevant national and international recommendations. Contacts of confirmed cases should be followed-up and tested. Offering post-exposure prophylaxis should be considered.

Source: European Centre for Disease Prevention and Control (ECDC)