H7N9 Bird Flu Cases Rise in Winter
Credit: Chickens via Shutterstock

Cases of H7N9 bird flu have spiked in China recent weeks with the arrival of flu season.

Between Jan. 16 and Jan. 20, there were 23 new cases of H7N9 reported in China, according to the World Health Organization. In addition, there were 32 other cases reporting during the first half of January. 

The outbreak first began last March, although there was a decline in cases during the summer months. The recent rise in cases is likely related to flu season, according to Reuters. Flu activity is highest in the winter months.

In total, nearly 200 people are known to have been sickened with the H7N9 virus, including 52 people who have died. There is still no evidence of sustained human-to-human transmission, WHO said.

WHO has not recommended any travel or trade restrictions.