It was a virus few knew about at the time or understood. When in May, 2018, three of a family in Kerala died within hours of getting a high fever, headache and encephalitis, K K Shailaja, health minister of the state, knew terrible times were ahead. The Nipah virus attacks the brain system, causes the onset of encephalitis and therefore has a terrifying 70-100 per cent mortality rate. It manifests in fruit bats but can go to other domesticated animals and from there to human beings. Consuming fruit that might have been bitten by infected fruit bats or coming into contact with secretions of any infected creature can infect an individual. But the incubation period is five to 14 days so it takes a while for the patient to show the range of symptoms. The virus is highly contagious so contact tracing has to be extensive and slippages can be fatal.