Two confirmed cases of Nipah virus infection have triggered anxiety in West Bengal, with many drawing parallels between the development and the early stages of Covid-19 pandemic. But similarities between the two diseases largely end at the word ‘virus’, say infectious disease experts, highlighting the major differences between Nipah and Covid.
How Nipah spreads and why it is not Covid-like
“Nipah is fundamentally different from Covid,” said Dr Dip Narayan Mukherjee, consultant in microbiology and head of infection control at Woodlands Hospital. “Covid was a new virus with a very high secondary attack rate. It spread easily through respiratory droplets and air, leading to epidemics and eventually a pandemic.”
Nipah virus, by contrast, does not spread through casual respiratory contact. Transmission occurs through direct contact with infected body fluids such as saliva, blood, cerebrospinal fluid or urine. “The secondary attack rate of Nipah is much lower, maybe one-fifth of Covid or even less,” Mukherjee explained. This is why Nipah causes localised outbreaks rather than widespread community transmission.
However, he warned that lower infectivity does not mean lower danger. “The mortality rate of Nipah can be as high as 50 to 70 per cent, compared to Covid’s 2 to 3 per cent,” he said.
Who is at risk and who is not
Unlike Covid, where age and comorbidities determine vulnerability, Nipah risk is driven by exposure. “The vulnerable group is not the general public or people in crowded areas. It is those who have come into direct contact with an infected person or contaminated body fluids,” said Mukherjee.
Healthcare workers, caregivers and close contacts are therefore monitored through contact tracing. “Diabetes or other illnesses do not decide who gets infected. Contact duration and type of exposure matter,” he added.
Dr Joydeep Ghosh, consultant in internal medicine at Fortis Hospital, Anandapur, echoed the caution. “If you are from an affected area or have been exposed to someone later diagnosed with Nipah, you need to be alert and isolate yourself if symptoms appear,” he said.
Symptoms that need urgent attention
Doctors stress that early Nipah symptoms can resemble common flu, but the progression is more severe. Neurological signs such as repeated vomiting, seizures, altered mental status or coma are key red flags.
Ghosh added, “If someone develops fever, headache, convulsions or altered consciousness after possible exposure, they should seek medical help immediately.”
Face mask not must for general public
Wearing face masks is not essential for the general public, doctors say, since Nipah is not airborne. Hand hygiene, safe food practices and avoiding partially eaten fruits are critical. “Do not consume raw fruits without washing them properly,” said Mukherjee. Avoid areas with known bat or pig exposure during an outbreak.
“This is not a situation for panic. But awareness, isolation when needed and timely medical care are crucial,” Ghosh said.