NIPAH ENCEPHALITIS, HUMAN - BANGLADESH (02)
Posted on 07TH APR 2015
tagged Nipah Encephalitis, Bangladesh
Date: Sun 5 Apr 2015
Source: Outbreak News Today [edited]
The Bangladesh Institute of Epidemiology, Disease Control and Research (IEDCR) has reported a total of 9 human Nipah virus cases this year as of February 2015. Of the 9 cases, health officials report 6 fatalities, or a 67 per cent case-fatality rate.
These cases are from 6 different districts: Nilphamari, Ponchoghor, Faridpur, Magura, Naugaon, Rajbari. Median age of the Nipah cases is 13 years (Range: 2 - 45 years). 5 (56 per cent) were male.
One cluster identified in Naugaon consists of 3 Nipah encephalitis cases, according to the IEDCR. Of these 2 are laboratory-confirmed cases. Numbers of isolated cases are 6.
According to the World Health Organization (WHO), in the Bangladesh and India outbreaks, consumption of fruits or fruit products (e.g., raw date palm juice) contaminated with urine or saliva from infected fruitbats was the most likely source of infection. Fruit bats of the family Pteropodidae -- particularly species belonging to the _Pteropus_ genus -- are the natural hosts for Nipah virus. There is no apparent disease in fruit bats.
In more recent outbreaks of the disease, person-to-person transmission has been seen in Bangladesh and India.
Related: What is Nipah virus?
The disease in humans can range from asymptomatic infection to fatal encephalitis. Encephalitis and seizures occur in severe cases, progressing to coma within 24-48 hours.
The case fatality rate is estimated at 40-75 per cent; however, this rate can vary by outbreak depending on local capabilities for surveillance investigations, according to the WHO. Those who survive acute encephalitis make a full recovery, but around 20 per cent are left with residual neurological consequences such as persistent convulsions and personality changes.
There is no treatment or vaccine available for either people or animals.
Nipah virus was 1st detected in Malaysia in 1998 but at present Bangladesh, a hotspot for infectious diseases, is the only country in the world that reports the disease.
[Byline: Robert Herriman]
ProMED-mil from HealthMap Alerts
[As noted in the previous comment (ProMED-mail archive no. 20150204.3143251) "Giant fruit bats or flying foxes (_Pteropus_ of several species) are reservoirs of Nipah virus and, as the above report indicates, they contaminate date palm sap or the fruit. This is the season for cases of Nipah virus infection to occur. The transmission season is usually January to April. As mentioned in comments in a previous post (ProMED-mail archive no. 20140113.2168940), local residents scarify the upper areas of palm trees to collect sap in large jars. The bats come to drink the sap, and defecate and urinate in the sap. If the bats are shedding Nipah virus, it contaminates the sap. If the sap is consumed uncooked, humans that drink it can become infected. Local people say that cooking the sap adversely alters the flavor. However, skirts made of local bamboo can serve as a barrier preventing bats' access to the sap collecting sites."
"It is unfortunate that the public awareness efforts have not prevented these cases from occurring. Perhaps because cases are sporadic and geographically scattered, there is little public perception of risk of infection and serious disease. Until effective public education to prevent infection is implemented, sporadic cases will continue to occur."
An image of a _Pteropus_ fruit bat can be found at http://upload.wikimedia.org/wikipedia/commons/3/3d/Pteropus_giganteus_fg....
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