China's H7N9 avian flu cases continue to climb
With novel H7N9 avian influenza cases in China this month already topping an early, steep surge seen in December, two provinces reported four more cases, according to official sources, as US officials posted a travel alert because of the spike in infections.
China is in its fifth wave of H7N9 activity and is just days away from the Lunar New Year holiday, a time of increased poultry trade and consumption, as well as travel. The United Nations Food and Agriculture Organization (FAO) yesterday posted an update on human illnesses and poultry developments, which included an epidemiologic curve showing cases this month running ahead of December. The FAO said 109 new human cases have been reported since its last update on Jan 10, boosting the global overall total since the virus emerged in 2013 to 1,040 cases, 368 of them fatal.
The FAO report also said provincial and agriculture ministry sampling has turned up the virus in markets, a farm, and a slaughterhouse, with a 9.42% positive rate in Guangdong province market samples. A serology study of poultry in several Chinese provinces (Gansu, Jiangsu, Qinghai, Shanxi, and Liaoning) found 349 positive H7 samples. More cities in Guangdong, Zhejiang, and Anhui province have temporarily suspended poultry trade.
Meanwhile, in the newest developments with human cases, Hong Kong's Centre for Health Protection (CHP) said two more H7N9 cases have been reported in Henan, both involvnig men, ages 59 and 36, who died from their infections. And Hubei province yesterday reported two new infections, in a 65-year-old man who had poultry market exposure, and a 78-year-old woman, according to a provincial health department statement translated and posted by FluTrackers, an infectious disease news message board.
The US Centers for Disease Control and Prevention (CDC), meanwhile, published an H7N9-related travel alert for visitors to China, Hong Kong, and Macau, all of which have reported cases this year. The alert is for the lowest level of the three possible: "watch," which means that travelers should practice "usual precautions."
Jan 24 FAO H7N9 update
Jan 25 CHP statement
Jan 25 FluTrackers thread
Jan 25 CDC travel alert
Flu numbers rise in most of Northern Hemisphere
Influenza cases continue to rise in North America, while an early start to the flu season in Asia and Europe has led to a steady stream of cases in those regions, according to the World Health Organization's (WHO's) weekly flu update yesterday.
According to the update, the H3N2 strain is predominating in North America. In the United States, influenza-like illnesslevels were above the seasonal thresholds and respiratory syncytial virus activity was still being reported. So far, most influenza samples tested in North America have been antigenically matched to the reference viruses used in the 2016-17 flu vaccine.
H3N2 is also the most prominent subtype circulating in Europe and East Asia. The WHO said several Eastern European countries reported a steep rise in cases in early 2017.
Worldwide, 96.4% of tested samples collected between Dec 26 and Jan 8 were typed as influenza A and 3.6% as influenza B. Only West Africa is reporting more influenza B activity than influenza A. Of the "A" viruses subtyped, 97.4% were H3N2.
Jan 24 WHO flu update