What really happened was that the health authorities in Kerala were prepared for an outbreak because Kerala has had a history of past outbreaks and a health system with very well trained doctors and health professionals to handle it. See the 2018 Nipah virus outbreak in Kerala that was handled really well, there was even a popular movie about it (Virus) that came out the year after.

It's the same story in east Asian countries where they had the SARS outbreak in early 2000s and so they were prepared for new outbreaks.