A youth from Ernakulam district in Kerala has tested positive for the Nipah virus infection, a year after a similar outbreak in the state had claimed 17 lives. The infected patient this year has survived for more than 10 days now, and health authorities are hopeful that this latest outbreak would be contained soon. The infected patient has been isolated, and everyone he had potential contact with in the last few days is being screened.

The virus
Nipah virus causes a so far incurable infection in human beings, which can sometimes be fatal. The infection is generally transmitted from animals to human beings, mainly from bats and pigs. Human-to-human transmission is also possible, and so is transmission from contaminated food.

The natural host of the virus are fruit bats of the Pteropodidae family and Pteropous genus, widely found in South and South East Asia. However, the actual source of the current infection is not yet known. 

First identified in 1999 in Malaysia, Nipah virus infections have been detected quite frequently in Bangladesh. There have been a few incidents of infection in India earlier, apart from last year’s outbreak in Kerala.

Patients either show no symptoms of the infection, thereby making it difficult to detect, or develop acute respiratory problems, or encephalitis that often becomes fatal.

The World Health Organization (WHO) says the infection has been found to be fatal in 40% to 75% of the infected patients. There is no treatment available as of now, either for humans or animals, nor any vaccine.

The previous outbreak
Last year’s outbreak was confined to two districts, Kozhikode and Malappuram.   Nipah virus has been found in other parts of India earlier. The first outbreak was in 2001 in Siliguri, where more than 30 people were hospitalised with suspected infection. Another outbreak happened in 2007 in Nadia of West Bengal. Again, over 30 cases of fever with acute respiratory distress and/or neurological symptoms were reported, five of which turned out to be fatal. Last year, after the outbreak in Kerala, doctors tested samples from suspected cases in Karnataka, Telangana and Maharashtra. All of them tested negative.

Can it spread?
As of now, scientists feel the current outbreak is likely localised, like last year’s. So far only one suspected sample has tested positive. More people showing symptoms are being screened and so are people in physical contact with them.

People who have had close contact with a patient are considered to be at potential risk. These include people who have slept in the same household , have had direct physical contact either with the patient or a deceased who had an infection, or have touched the blood or other body fluids (saliva, urine, sputum) of the patient during illness.