H7N9 activity intensifies in China with 16 more cases

The number of new human H7N9 avian flu cases in China increased sharply today, with 16 reported, including 15 on the mainland—most of them in Guangdong province—and another imported infection reported by Hong Kong.

Could latest wave top last season's?

China and Hong Kong have now reported 38 cases in the fifth wave of H7N9 activity, which began in October, far more than the 10 cases reported at this point in the season last year.

Disease activity could also mark a turnabout from the fourth wave last year, which at 118 cases had the lowest total of any of the first waves. In a Dec 16 report in Morbidity and Mortality Weekly Report (MMWR) on last season's H7N9 wave, Chinese researchers said it lasted longer than the others, from September 2015 to August 2016, with a greater percentage of cases affecting people in rural areas. When compared with previous waves, a greater percentage of people last season were admitted to intensive care units and were diagnosed as having pneumonia, though the team said no antigenic changes in the virus were seen.

Increasing H7N9 activity comes amid the lead-up to the Lunar New Year holiday, which comes with a travel surge and an increase in live-poultry transport and sales. Lunar New Year falls on Jan 28, and 2017 is the year of the rooster.

H7N9 is endemic in Chinese poultry, and the MMWR report said tests on poultry samples by China's agriculture ministry since April 2013 have found 233 positive samples from 16 provinces, all but 1 from live-poultry markets.

Live-market closures were one of the key steps that slowed H7N9's earlier waves, and three cities in Jiangsu province—Suzhou, Wuxi, and Changzhou—recently suspended live-poultry sales.

New cases in 3 provinces

Guangdong province health officials said in a monthly communicable disease report that 14 H7N9 cases were detected in December, 7 of them fatal, according to a report translated and posted by FluTrackers, an infectious disease news message board. The report didn't give any epidemiologic details, but 1 of the cases is thought to be an illness first reported in early December.

The south China province has been a hotbed of human H7N9 cases, especially during the second and biggest H7N9 wave that occurred in the winter of 2013-14.

Elsewhere, Shandong province in eastern China today announced its first H7N9 case of the current season, according to a provincial government statement translated by FluTrackers. The patient is a 77-year-old man from Rizhao.

Jiangxi province in the southeastern part of the country reported its second case of the fifth wave, in a 48-year-old man, according to a translated government statement posted today by FluTrackers.

Hong Kong reports third imported case

In a related development, Hong Kong's Centre for Health Protection (CHP) today reported its third imported H7N9 case of the season, involving a 62-year-old man with underlying health conditions who was got sick while traveling in Guangdong province on Jan 1, where he was initially hospitalized.

According to a CHP statement, the man left the hospital in the city of Dongguan against medical advice on Jan 3 and returned to Hong Kong, where he was hospitalized yesterday. His condition worsened and he is now in the intensive care unit in critical condition. Tests at the Hong Kong hospital today confirmed the man's H7N9 illness.

The man denied any exposure to poultry or live-bird markets, the CHP said, adding that it is monitoring the man's close contacts and tracing other contacts in Hong Kong. The CHP is also working with mainland officials to explore how and where the man was exposed to the virus.

All three of Hong Kong's recent H7N9 cases have connections to Guangdong province, and the CHP said it is monitoring the 14 recently reported December cases from the province, which span seven different cities: Guangzhou (3), Jiangmen (3), Jieyang (2), Shenzhen (2), Zhaoqing (2), Dongguan (1) and Zhongshan (1).

The new H7N9 cases lift the overall global total to 845, according to a case list maintained by FluTrackers.

See also:

Dec 16 MMWR report on China's fourth H7N9 wave

Jan 5 FluTrackers thread on Guangdong province cases

Jan 5 FluTrackers thread on Shandong province case

Jan 5 FluTrackers thread on Jiangxi province case

Jan 5 CHP statement

FluTrackers H7N9 case list

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