Published Date: 2012-07-12 20:01:46
Subject: PRO/AH/EDR> Japanese encephalitis & other - India (10): (AS)
Archive Number: 20120712.1199565
JAPANESE ENCEPHALITIS AND OTHER - INDIA (10): (ASSAM)
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Thu 12 Jul 2012
Source: Outbreak News [edited]
According to an India Blooms report, last week at least 22 people died of Japanese encephalitis in Assam's Sivasagar district. As many as 28 people are currently undergoing treatment at different block Public Health Centres (PHCs) in the district. "So far, 22 people have died of Japanese encephalitis in the district; 28 are undergoing treatment," said Additional Deputy Commissioner (Health) Sivasagar I Rahman.
According to reports, several cases of acute Japanese encephalitis syndrome (AES) emerged from different areas of the district. Several areas under the 8 block PHCs of Khelua, Geleki, Morabajar, Patsaku, Kalugaon, Dimow, Sapekhati and Metora have witnessed fast spread of the disease.
According to the World Health Organization (WHO), Japanese encephalitis is a viral disease that infects animals and humans. It is transmitted by mosquitoes and in humans causes inflammation of the membranes around the brain. Intensification and expansion of irrigated rice production systems in South and Southeast Asia over the past 20 years have had an important impact on the disease burden caused by Japanese encephalitis [virus infections].
Japanese encephalitis (JE) is a disease caused by a flavivirus that affects the membranes around the brain. Most JE virus infections are mild (fever and headache) or without apparent symptoms, but approximately one in 200 infections results in severe disease characterized by rapid onset of high fever, headache, neck stiffness, disorientation, coma, seizures, spastic paralysis and death. The case fatality rate can be as high as 60 per cent among those with disease symptoms; 30 per cent of those who survive suffer from lasting damage to the central nervous system. In areas where the JE virus is common, encephalitis occurs mainly in young children because older children and adults have already been infected and are immune.
The virus causing Japanese encephalitis is transmitted by mosquitoes belonging to the _Culex tritaeniorhynchus_ and _Culex vishnui_ groups, which breed particularly in flooded rice fields.
Japanese encephalitis is a leading cause of viral encephalitis in Asia with 30 000 - 50 000 clinical cases reported annually. It occurs from the islands of the Western Pacific in the east to the Pakistani border in the west, and from Korea in the north to Papua New Guinea in the south. Because of the critical role of pigs, its presence in Muslim countries is negligible. JE distribution is very significantly linked to irrigated rice production combined with pig rearing.
[Byline: Robert Herriman]
ProMED-mail from HealthMap Alerts
[A 1 Jul 2012 report indicated that there were 20 deaths due to Japanese encephalitis virus (JEV) infections in Assam state (See ProMED-mail archive no. 20120701.1186667). Now there are 22. Assam has had recent outbreaks of JEV infections. One presumes that the above cases are laboratory confirmed as (JEV) infections. Other reports from northeast India mention AES but with JEV discarded or responsible for a minority of cases. In the above report, no mention is made of recent JEV vaccination campaigns in this area. Pigs can be amplifying hosts because they have a viremia of relatively long duration and a high enough titer to serve as a source of infectious blood meals for _Culex_ mosquitoes. Wading birds, such as herons, serve as reservoir hosts.
A HealthMap/ProMED-mail interactive map showing the location of Assam state can be accessed at http://healthmap.org/r/00J-. - Mod.TY]