Eleven more H7N9 infections have been reported from four Chinese provinces, according to official sources, and a World Health Organization (WHO) update provided an epidemiologic snapshot of a surge in infections, which includes two case clusters.
China is in its fifth wave of H7N9 activity, and earlier this month the fast pace of newly reported illnesses had already topped last season's total. According to a case list maintained by FluTrackers, an infectious disease news message board, 140 cases have already been reported this season. That number includes six cases exported from the mainland: four to Hong Kong and two to Macao.
High activity in Guangdong province
The newest cases from China include patients from four Chinese provinces: Hubei, Guizhou, Guangdong, and Hunan.
The cases from Hubei and Guizhou were noted in a Jan 16 statement from Hong Kong's Center for Health Protection (CHP), based on reports from provincial health officials. The patient from Hubei is a 38-year-old man from Wuhan with a history of poultry market exposure who is hospitalized in critical condition. Few details were noted about the Guizhou province patient, other than that he or she is age 79, is from Qiandongnan, and is hospitalized.
Notice of 11 cases, 8 of them previously unreported, from Guangdong province and a newly reported case from Hunan province came in a report today from the CHP that also warned travelers about high H7N9 activity in Guangdong province.
No details about the new Guangdong cases were reported, other than that the group of 11—all reported since Jan 1—hail from seven different cities and that two of them died from their illnesses. The CHP said the patient from Hunan province is a 36-year-old woman from Hengyang who had been exposed to poultry and is hospitalized in critical condition.
In the first week of January, 60 of 637 environmental samples from 21 live poultry markets in 15 Guangdong province cities yielded the H7 virus, for a positive rate of 9.42%, the CHP said.
Health officials warned the public to be on alert and take strict personal and environmental precautions, especially ahead of the upcoming Lunar New Year holidays.
The new cases push the global H7N9 total since the virus was first detected in humans in early 2013 to 948, according to a list kept by FluTrackers.
WHO update notes two clusters
The WHO today acknowledged an imported H7N9 case reported on Jan 5 by Hong Kong health officials, that of a 62-year-old man who got sick and was hospitalized during a trip to Guangdong province and died on Jan 6 after he returned to Hong Kong. It also said Chinese officials on Jan 9 reported 106 more lab-confirmed H7N9 cases, all of them involving patients who had illness onsets between Nov 22 and Dec 29.
Among the mainland cases, 36 were in females, the median age was 54 years, and patients were from seven different provinces, with most from Jiangsu, Zhejiang, Anhui, and Guangdong. Infections were fatal in 35 patients, and 57 have severe illnesses.
Eighty patients had been exposed to poultry or live poultry environments, the WHO said.
The group of cases includes two clusters for which human-to-human transmission can't be ruled out. They include a pair of patients from the city of Suzhou in Jiangsu province: a 66-year-old man and his 39-year-old daughter. The father had live poultry market exposure and died from his illness, and the daughter has severe pneumonia.
A second cluster includes a pair of men, ages 66 and 62, from the city of Hefei in Anhui province who were patients in the same hospital ward in the middle of December. The older of the two men had been exposed at a live poultry market and died on Dec 20. The other man is still hospitalized and is in severe condition.
The WHO said that increases in the number of human H7N9 cases in China in December and January have been similar to previous increases at this time of year but that close monitoring is needed to assess the risk and the need for any changes in control measures. Given that the virus continues to persist in poultry and their environments, more human cases are expected.
Though small H7N9 clusters have been reported in the past, there's still no evidence that the virus has gained the capacity for sustained transmission in people, the WHO said. In light of the new cases, it said China has stepped up its response measures to include increased surveillance, earlier clinical recognition and treatment, joint investigations between health and animal officials in the hardest hit areas, and poultry market closures or strengthened regulations in some areas.
Jan 16 CHP statement
Jan 17 CHP statement
FluTrackers H7N9 case list
Jan 17 WHO statement on H7N9 in China