2nd June 2018
Answer questions in NOT MORE than 200 words each. Content of the answer is more important than its length.
Links are provided for reference. You can also use the Internet fruitfully to further enhance and strengthen your answers.
GS III- S&T: HEALTH
Q1. Discuss the spread of the Nipah virus in Malaysia, Bangladesh and India.
- The Nipah virus made its first documented appearance in Malaysia in 1998. There, the virus is believed to have jumped from fruit bats of the Pteropus species to domestic pigs paddocked under the trees where such bats roost. From the pigs, the virus travelled to pig breeders, infecting and killing about 105 of them in an outbreak. Nipah next appeared in Bangladesh, triggering nearly 15 outbreaks in the 2000s. The pathogen had a different modus operandi in that country. It mainly infected people who had a taste for raw palm sap, which is frequently contaminated by bat urine and saliva. Once the virus spread to humans, it was transmitted from one person to another through respiratory droplets, a feature that wasn’t seen in Malaysia.
- Nipah killed nearly 70% of those it infected in Bangladesh, compared to 40% in Malaysia. During the epidemic years in Bangladesh, the virus also crossed the border to enter West Bengal — twice. The outbreaks occurred in 2001 and 2007 in the districts of Siliguri and Nadia, killing 70 people. Other states affected by Nipah that border Bangladesh were- Assam and Tripura. Diagnostic test called Real Time Polymerase Chain Reaction (RT-PCR), detects viral genetic material.
- Nipah spreads mainly through respiratory droplets, and sicker patients secrete more virus. Unlike other viruses like measles in the Paramyxovirus family to which Nipah belongs, Nipah does not spread efficiently and moves only to people within a metre of very sick patients. This pattern of transmission is typical of how Nipah spread in Bangladesh and West Bengal. In the 2001 Siliguri outbreak, the first wave occurred in the Siliguri District Hospital, where patient zero infected nine others, including five staff members.
- The Nipah virus can incubate in the body for up to 21 days, health officials cannot take it easy for a while. Only when 42 days, or two incubation periods, pass after the last confirmed case will the State be declared Nipah-free.
- The spread of the virus in Kerala remains a mystery, given that the only other Indian outbreaks have happened in West Bengal. But the strongest suspects now are Kozhikode’s large fruit bat populations. The species were found to be carriers of the Nipah virus in both Malaysia and Bangladesh.
- Experiments have shown that the Nipah virus circulates within bats for brief periods of time, during which the likelihood of transmission to humans, or a “spillover” event, increases. In a 2011 study published in the American Journal of Tropical Hygiene and Medicine , virologists experimentally infected fruit bats from Malaysia and Australia with the Nipah virus, and the closely related Hendra virus. When they tried to isolate the pathogen from the bats only a few days later, they were unable to do so in most cases.
- India has a poor record of outbreak investigations. About 10,000 people develop encephalitis-like symptoms each year but never get a diagnosis. Some regions, such as Uttar Pradesh’s Gorakhpur and Bihar’s Muzaffarpur, saw thousands of deaths in repeated annual outbreaks before the causes were established. Against this background, the discovery of an exotic pathogen in the very second patient hit by an outbreak, as was the case in Kozhikode, has few precedents.Under the 2005 International Health Regulations, India is obligated to report outbreaks of emerging infectious diseases to the World Health Organisation.
- Officer trained in Ebola outbreak protocols instructed the doctors in infection-control measures — isolating patients, using surgical masks and decontaminating surfaces. It was an extraordinarily swift response by any measure.