China over the past few days reported 82 new H7N9 avian influenza cases, including several previously unreported cases between late November and the end of December, already topping the number seen during the entire fourth wave of infections last season.
So far as many as 125 cases have been reported from the mainland, with Hong Kong confirming 3 imported cases. In December, Chinese researchers in an analysis of the fourth wave of H7N9 activity said 118 illnesses occurred, the fewest in the waves so far. The high mark for illnesses was during the second wave, which in 2014 totaled 304 cases.
At least 35 deaths have been reported this season, according to a case list kept by FluTrackers, an infectious disease news message board.
At this point it's not clear why activity is surging this season, but the Chinese researchers said the virus continued to be detected in poultry, mainly at live-bird markets.
Hong Kong notes earlier cases, 2 new infections
Hong Kong's Centre for Health Protection (CHP) today said mainland health officials notified it of 83 cases—25 of them fatal—from four provinces that involved illness onsets from Nov 22 to Dec 29. Provincial health department had already announced 11 of the infections covered in the CHP report, 2 of them fatal, according to earlier government statements translated and posted by FluTrackers.
Of the 83 illnesses covered in the CHP report, affected provinces include Jiangsu (52), Zhejiang (21), Anhui (9), and Fujian (1). The gender breakdown was 54 men and 29 women. Exposure to poultry or poultry markets was reported for 58 of the patients, with the virus sources still under investigation for 17 people.
The CHP report also noted two more recent case-patients, a 55-year-old woman from the Jiangxi province city of Yichun who is in critical condition at a Nanchang hospital and a 49-year-old female poultry seller from the Guizhou province city of Sandu who is also hospitalized in critical condition.
A CHP spokesman said mainland health authorities have recorded 125 H7N9 cases so far this season.
Because H7N9 continues to persist in animals and the environment in the mainland, more human cases are expected there and in neighboring areas, including Hong Kong.
"Therefore, we strongly urge the public to avoid touching birds, poultry, or their droppings and visiting poultry markets or farms during travel, particularly in the upcoming Lunar New Year holidays," the CHP said. "If feeling unwell, such as having a fever or cough, wear a mask and seek medical advice at once."
Cases in Jiangxi, Hunan, Guizhou, Shanghai
In related developments, provincial and local health departments, plus state media, reported eight more cases in the past few days.
Jiangxi province detected four more H7N9 cases, with all the patients in critical condition, according to government reports translated and posted by FluTrackers. Patients are a 72-year-old woman hospitalized in Nanchang, a 83-year-old woman and a 48-year-old man hospitalized in Jiujiang, and a 55-year-old woman hospitalized in Yichun.
Elsewhere, Shanghai health officials reported an H7N9 infection in a 58-year-old man, according to a translation of a government statement. The illness is the third reported from Shanghai during the current wave of activity. It's not clear if the patients were exposed to the virus in Shanghai or elsewhere; the two earlier infections detected in the city involved patients with connections to Jiangsu and Sichuan province.
Shandong province reported its second recent case, which involves a 53-year-old man from the city of Laiwu, according to a translation of a local health commission statement posted by FluTrackers. Hunan province also reported an H7N9 illness in a 35-year-old man who had close contact with poultry. He is listed in critical condition, according to the translated provincial health department notice.
Guizhou province reported yet another case, that of a 52-year-old man from Qiannan who works as a poultry vendor, Xinhua, China's state news agency. The man is being treated in the hospital.
Dec 16, 2016, Morbidity and Mortality Weekly Report study on fourth H7N9 epidemic in China
FluTrackers H7N9 case list
Jan 9 CHP statement
Jan 7 FluTrackers thread on 3 cases from Jiangxi province
Jan 8 FluTrackers thread on 1 case from Jiangxi province
Jan 7 FluTrackers thread on Shanghai case
Jan 7 FluTrackers thread on Shandong province case
Jan 7 FluTrackers thread on Hunan province case
Jan 9 Xinhua story on additional Guizhou province case