In a research study that will boost efforts to develop a vaccine for chikungunya, a group of city scientists has found that the chikungunya virus, responsible for recurring outbreaks in South India except Kerala and coastal Karnataka since the 2006 epidemic, has undergone a mutation.
The virus appears to have adapted to the local vector (mosquito) diversity for wider spread. Even though there is no evidence to suggest that it has become more virulent, the mutation in the gene (E1-K211E) appears to be an “adaptive mutation” of the virus to suit the local mosquito, the Aedes Aegypti. Dr K. Sumathy and Dr Krishna M. Ella, of the Bharat Biotech International Ltd, Hyderabad, studied the genetic make-up of the Chikungunya virus. “We tried to understand the molecular epidemiology of the virus in the country and globally because of our on-going efforts for developing a novel vaccine for prophylaxis of chikungunya infection,” Dr Sumathy said.
The chikungunya virus now spreading in AP and the neighbouring states is a variant. “There appears to be no distinct serotypes of the virus that have evolved over the past few decades,” Dr Sumathy added. The virus strain that has caused the massive 2006 epidemic in India is the same that appears to cause recurring outbreaks in Tamil Nadu, AP, and Karnataka except its coastal parts. The epidemic strain of the virus appears to have adapted to the vector diversity in the country for a wider growth.
However, there are no medical implications because the genetic diversity of the virus has not resulted in a distinct antigenic diversity or serotypes. “Understanding the genetic diversity of the virus is important for effective public health measures, such as control of vector population,” Dr Sumathy explained. The mutation appears to aid the adaptation of the virus to the mosquito for its propagation and dissemination.