Experts suspect antigen variation of H1N1 virus

CHENNAI: Public health experts and doctors suspect that the H1N1 virus might have undergone an antigenic change to tide over herd immunity and survive hostile environment.
There are at least 5,000 admissions for fever across hospitals in TN every day including about 60 cases of H1N1 and 40 cases of dengue. An almost equal number of people are being treated at home.“We have been having high incidence of fever cases for a few weeks now. By now, most people must have acquired herd immunity. It has not happened. So there’s suspicion that the virus has adapted for survival,” said director of public health Dr K Kolandasamy.
Most number of cases is reported from Chennai, Tiruvallur and Kancheepuram. Isolated cases are seen in some areas of western and southern districts.
Doctors suspect small changes in the genes of H1N1. They share the same antigenic properties, but over time, these small genetic changes can be different, Kolandasamy said. “When this happens, the body’s immune system may not recognize the viruses. The antibody an infected person develops to fight against the disease may not work when the new virus enters the body. So people can get sick again,” he said.
There have been no studies done by the state so far, but the state will soon be working with virology labs to understand the change. Driector of King Institute of Preventive Medicine and Research Dr P Gunasekaran said the institute has sent samples of the virus to the National Institute of Virology (NIV) in Pune for further analysis.
As of now, doctors don’t see huge mutations to the virus as most people are responding well to treatment. “There is no need to panic. We have adequate stock of medicines, human resources and infrastructure to handle the flu. We are also holding health camps to pick up fever cases early. Patients have been asked to approach government hospitals for free treatment or meet qualified health professionals,” said health minister C Vijayabaskar.
Doctors say victims of fever, including ones with respiratory diseases, H1N1 and dengue, are children. Most hospitals including state-run Institue of Child Health in Egmore (ICH) have created additional wards and beds for children. “As long as they are well hydrated and diagnosed on time, there is no problem. In some children, pre-existing conditions such as heart disease can be fatal,” said ICH director Dr A T Arasar Seeralar.