TEZPUR, July 30 � Japanese Encephalitis(JE) has become a serious threat for the common masses here as it has already taken the lives of four people from different parts of the district. It is to be mentioned here that with the advent of the monsoon, some parts of the district, particularly the northern part along the Assam-Arunachal border areas alongwith Dhekiajuli, Balipara, North Jamuguri, Biswanath Chariali, Gohpur, Bihaguri, Behali, North Jamuguri, and Rangapara etc., have this year become vulnerable to the outbreak of the disease.
The district officer of the National Vector Borne Disease Control Programme here said that till date a total of 83 doubtful JE patients were diagnosed out of which JE was confirmed in 31 patients and among these 10 were deaths were due to AES (Acute Encephalitis Syndrome) death and four were deaths due to JE.
On the otherhand Dr. Durlav Saikia, who has been carrying out an extensive study on JE interacting with this reporter stated that Japanese Encephalitis, also known as �brain fever� 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. He also said that intensification and expansion of irrigated rice production systems in South and South-East Asia over the past 20 years have had a vital impact on the spread of Japanese encephalitis, where irrigation expands into semi-arid areas, the flooding of the fields at the start of each cropping cycle leads to an explosive build-up of the mosquito population. This may cause the circulation of the virus to spill over from their usual hosts (birds and pigs) into the human population.
�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 1 in 200 infections results in severe disease characterised by rapid onset of high fever, headache, neck stiffness, disorientation, coma, seizures, spastic paralysis and death. The fatality rate can be as high as 60% among those with disease symptoms; 30% 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.� Dr Saikia said adding the virus causing Japanese encephalitis is transmitted by mosquitoes belonging to the Culex tritaeniorhynchus and Culex vishnui species, which breed particularly in flooded rice fields. The virus circulates in ardeid birds (herons and egrets). Pigs are amplifying hosts, in that the virus reproduces in pigs and infects mosquitoes that take blood meals, but does not cause disease. The virus tends to spill over into human populations when infected mosquito populations build up explosively and the human biting rate increases (these culicines are normally zoophilic, i.e., they prefer to take blood meals from animals).
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. JE distribution is very significantly linked to irrigated rice production combined with pig rearing. It is a patchy disease and important outbreaks have occurred in a number of places in the past 15 years, including South India (Arcot district in Tamil Nadu) and in Sri Lanka (Mahaweli System H) alongwith the north-eastern region of the country, he said.
Pointing out the way to combat the deadly disease Dr Durlav Saikia said that an effective vaccine is available for Japanese encephalitis, but it is expensive and requires one primary vaccination followed by two boosters. This is an adequate intervention for travellers, but has limited public health value in areas where health services are limited. An inexpensive live-attenuated vaccine is used in China, but is not available elsewhere. Chemical vector control is not a solution, as the breeding sites (irrigated rice fields) are extensive. In some rice production systems faced with water shortages, however, certain water management measures (alternate wetting and drying) may be applied that reduce vector populations. Personal protection (using repellents and/or mosquito nets) will be effective under certain conditions. Eliminating the pig population is often a measure taken in the wake of outbreaks. Certainly, the introduction of pig rearing as a secondary source of income for rice-growing farmers in receptive areas must never be encouraged. He also said that as necessary measures, various NGOs and the Health department here with the cooperation of the district administration have been conducting various programmes from time to time, including awareness campaigns, vaccination, free health camps etc.
Moreover, the District Malaria Officer informed that the fogging drive has been conducted in vulnerable areas like Karibil Nepali, Rajabari and Dubia under Gohpur PHC, Ulubari under Bihaguri PHC, Medhichuburi under Dhekiajuli PHC, Bhuyanpara SC village, Khanaguri under North Jamuguri PHC, Ward No-5 and 9 under Dhekiajuli PHC, Lehugaon and Tengabari under Biswanath Chariali PHC, district jail, Sonitpur under Bihaguri PHC, Tolokabari, Kusukmtola (Milanpur), Uttar Balijuri (Forest Village) under North Jamuguri PHC, Dikoraijan, Napam, Baligaon and Ameribari SC and Lalbasti under Balipara PHC, Ratua under Behali PHC as pre-cautionary measure.
On the otherhand, the District Immunisation Officer, Dr Biman Sarma informed that during this monsoon, over 30,000 people have been vaccinated in the district. When contacted, DC Sonitpur Lalit Gogoi said that in this regard, the district administration has alerted the Health department, so that no patient dies following any kind of deficiency.