Chinese health authorities are urging calm as the circle of people infected with an elusive influenza virus widens.
Over the past two days, Zhejiang province reported its first three cases — a 67-year-old retiree from Hangzhou, a 64-year-old man from Huzhou and a 38-year-old chef. The 38-year-old chef worked in neighboring Jiangsu province, where four cases had already been reported, and died on 27 March. As of 4 April, ten people, all in the Shanghai region, have been infected. Three have died, and the rest are listed in critical condition.
Health authorities are working under the assumption that poultry is to blame, and the government has warned people not to slaughter chickens. The warning is timely: some families in southern China sacrifice chickens as part of a ritual during tomb-sweeping holidays, which start today.
But the source of the virus is still a mystery. A few of those infected had direct contact with poultry, but others did not. According to official state media, tests have failed to find the virus in poultry or pigs. Shanghai tested 34 of the some 16,000 carcasses recently found floating nearby in the Huangpu River following concern that they could have carried the disease. So far, no infections in animals have been confirmed.
If it is birds that are carrying the virus, they do not seem to suffer symptoms. This makes it difficult to implement what has been the most effective tool against H5N1 and other avian flu viruses — culling of sick birds.
Although the virus clearly can be pathogenic in humans, it does not seem to be passing easily from human to human. Among hundreds of people who have been in contact with those who fell sick, none have been found to be infected.
At present, there is no vaccine. ‘Candidate’ vaccines against other H7 viruses are available, but none target the various strains of H7N9.
Chinese central and local governments seem to be acting relatively quickly to track new cases and prepare health centres to deal with them. The health ministry distributed reagents for detecting H7N9 to the country’s 31 administrative districts. Jiangsu province, which accounts for four of the nine cases, has implemented emergency measures including strengthening of networks to report unexplained cases of pneumonia and communication with agriculture departments to expand epidemiological studies.
But health authorities have still come under criticism for delays in reporting cases and apprising families of the extent of the problem. The uncle of one victim said he thought that his son had died from pneumonia until he saw the news about H7N9 on television. He says that the hospital failed to recognize the seriousness of his nephew’s condition.