- The resurgence of Nipah infection in Kerala, which has resulted in two confirmed deaths and two people being treated, has aroused concerns about this lethal viral disease.
- Nipah, while not as contagious as COVID-19, is far more lethal, with case fatality rates ranging from 40% to 75%.
What exactly is Nipah Virus Infection?
- Nipah is a zoonotic illness, which means it is spread to people by diseased animals or contaminated food.
- Direct person-to-person transmission is also feasible through close contact with an infected individual.
- Fever, headache, cough, sore throat, difficulty breathing, and vomiting are some of the symptoms.
- Nipah infection can cause disorientation, drowsiness, seizures, and encephalitis (brain swelling) in severe cases, eventually leading to coma and death.
Historical Outbreaks of the Nipah Virus:
- The Nipah virus was initially detected in Malaysia (1998) and Singapore (1999), taking its name from the Malaysian hamlet where it was isolated. The ingestion of infected food is the primary mechanism of transmission from animals to humans. This can happen if you eat raw date palm sap or fruit that has been contaminated with the saliva or urine of diseased bats.
- Animal Host Reservoir: The virus’s recognised hosts are fruit bats, also known as flying foxes. It is passed on to other animals such as pigs, dogs, cats, goats, horses, and sheep. Human infection is mainly caused by direct contact with these animals or by eating food contaminated with their saliva or urine. Human-to-human transmission has also been observed, especially in families and healthcare settings.
Nipah Virus Spread and Mortality
- Unlike SARS-CoV-2, which spreads quickly, the Nipah virus spreads slowly. However, its high mortality rate is a major source of concern.
- Nipah has a significant fatality rate during epidemics, ranging from 68-75%. In the 2001 Siliguri outbreak, for example, 45 of the 66 affected people died from the virus. Similarly, 17 of the 18 confirmed cases died during the 2018 Kerala incident.
- Localised epidemics: It is worth noting that Nipah epidemics have stayed localised and have been suppressed rather swiftly. The virus’s low infectiousness and poor human-to-human transfer help to keep it contained.
- Reproductive Number (R0): Studies show that R0 for Nipah epidemics is around 0.48, indicating a sluggish rate of transmission within the community. An R0 value less than one indicates that an infected person does not infect more than one additional person, resulting in a relatively quick end to the outbreak.
- High Death Rates: The virus’s high death rates also play a role in limiting its propagation.
Source: https://timesofindia.indiatimes.com/india/kerala-reports-two-nipah-virus-deaths-expert-team-dispatched-by-centre/photostory/103632505.cms#:~:text=Till%20date%2C%20Kozhikode%2C%20Kerala%20has,old%20boy%20from%20Chathamangalam%20died.