GUWAHATI, Sept 9 � In the present decade, an increasing trend of Japanese Encephalitis (JE) is observed in Assam. It has been reporting the second highest number of JE cases in the country for the past five years, including the current year. The State is reporting JE cases for the past about 34 years since 1976.
On top of all these, the State has been reporting a large number of cases of acute encephalopathy syndrome (AES) in the recent times. The AES is the stage of the disease, which resembles the symptoms of JE, but remains to be confirmed.
This is stated by sources in the Dibrugarh-based Regional Medical Research Centre (RMRC), of the Indian Council for Medical Research (ICMR). The jurisdiction of the RMRC is spread all over the North East region.
Available literature showed that in the last decade, there has been a major upsurge of AES in 135 epidemic districts in the states of Assam, Andhra Pradesh, Bihar, Goa, Karnataka, Manipur, Maharashtra, Madhya Pradesh, Tamil Nadu, UP, Pondicherry and West Bengal where an estimated 378 million population are facing the risk of JE.
Among these states, Uttar Pradesh and Assam have been reporting maximum JE cases. Mortality due to JE has been estimated to range between 20 per cent and 30 per cent. Gorakhpur in Uttar Pradesh is heading the list of JE- affected areas in the country, said the sources.
It is observed that the peak period of outbreak of the disease coincides with monsoon and continues till the post-monsoon period, that is� from July to September. Open fields with stagnated water, high density of mosquito vector population and presence of reservoirs or amplifying hosts (as for example, pigs, ardeid birds, etc) provide favourable conditions for transmission of JE.
Non-immunized population living in endemic areas is vulnerable to the disease. Available data shows that mostly children in the pediatric age group in the JE endemic areas are vulnerable. But in recent years some age shift has been observed in Assam.
The RMRC has collected the list of districts now reporting AES cases. Micro- stratification of the list will need further work. It has also been conducting studies pertaining to various aspects of Japanese encephalitis, like diagnosis, epidemiology and vector biology since around 1985.
It took up a study entitled �Development of an early warning system for the outbreak of Japanese encephalitis with the help of remote sensing and GIS in conjunction with the epidemiological studies in Assam� in collaboration with the North East Space Application Centre (NESAC), Umiam from Oct 2002 to April 2006. Based on high endemicity of JE, the Dibrugarh district was selected as the study area.
In keeping with the findings of the study, village level map of the district was generated and JE-prone areas were identified. The identified villages were spotted on the map showing the high risk, medium risk and low risk villages separately and a list was also provided along with it. Gradations of forecast of outbreaks were made at village level as high risk, medium risk and low risk.
Details of the early warning for JE pertaining to Dibrugarh district was being communicated to the National Vector-Borne Disease Control Programme (NVBDCP), New Delhi with copies to NVBDCP, Assam and its district unit since 2008. But the RMRC does not monitor the responses to such early warnings directly. All these practices are continuing since 2008, said the sources.
The RMRC and NESAC studies can be extended to other districts of the State depending on fund availability and operational feasibility, and, of course, the interest of the end users, said the sources.
