There were 23 probable positive cases of Nipah virus infection reported in Kerala in the two outbreaks in May 2018 and June 2019. Of this, 17 died after confirmation of the disease and 3 survived. Adding another other 3 pre-confirmation deaths in a single family exposed to the virus, the death toll could be 20. The symptoms were respiratory and/or neurological issues. Since there were no treatment protocols existed, ribavirin was the drug used as symptomatic medication. There exists no clinical proof to establish survival due to this. In the 2018 outbreak, the first detection was probably late, after a series of deaths in a single family. It was the intuition of a team of doctors who attended to the index case at a private hospital that led to the identification of infection, later confirmed by the virology research unit of Manipal Hospital in Karnataka and the National Virology Institute of Pune. But it was a major task for the state machinery, including the civil and hospital administration of Kozhikode district and the Government Medical College there. The incidents also called for prompt state-centre coordination spearheaded by Kerala Health Minster K K Shailaja to contain this highly dangerous and rapidly contagious virus in 40 days. The minister, in an exclusive interview with Editor, said that it was a great lesson as the epidemic could have otherwise caused a much bigger rate of mortality, even as many scientific aspects of the outbreaks and possible methods of prevention are yet to be established. Edited excerpts:
Nipah is a comparatively new zoonosis with a varied nature of viral transmission — perhaps due to changes in the strain — going by the analysis of Malaysia and Bangladesh outbreaks. Do we have any finding in this regard to ascertain the specific nature of the virus strain in the Kerala outbreak?
Those aspects are still being studied and what was observed by the technical team, including scientists from ICMR (Indian Council of Medical Research), is that the virus found in the patients who tested positive, as well as in the samples from fruit bats, was similar to the type that was found in Bangladesh as far as the Kozhikode (Calicut) outbreak is concerned. But, the nature of the 2019 infection in Ernakulam district is yet to be ascertained.
The operation led by you to contain the infection deserves real honour and it has set a new standard for the country, perhaps even for the world. How did you prepare for it? Perhaps, it can help the doctors, hospitals and the social and healthcare groups to handle such epidemics effectively in future?
The quick reference about the virus, which came from a team of alert doctors at a private hospital where the index case patient was admitted, was the turning point. The samples were immediately sent to virology labs for confirmation, following which we contacted concerned experts and agencies worldwide. A very quick and proper coordination between all the concerned groups, including the hospital, local administration, state and central health departments ensured the availability of all possible information about the virus, potential medicines and other technical factors. Tracing the direct, indirect and even distant contacts of the diseased and putting them under quarantine was the next big task towards arresting the spread. We could also manage the isolation and critical care of patients immediately. Chances of infection within the hospital was also brought under control. We could quickly trace all the probable cases — mainly the people who were in contact with the index patient as well as the people who probably died of the infection earlier. Still, most frightening were facts about the nature of the epidemic caused by this most dangerous and rapidly infectious virus. The mortality rate of Nipah typically ranges from 75 to 100 percent. The experts feared that the death toll could go up to at least 200. The other big scare was the fact that there is no treatment. Since there was no specific protocol for the hospitals and health volunteers for handling Nipah, we had to make one mostly in line with Ebola and H1N1. We didn’t waste any time in collecting protection accessories and training volunteers, hospital staff and isolation ward attendants. In brief, our preparation was in anticipation of a much larger outbreak.
How did you choose the medicine that was used finally?
There were many pharma companies that came forward claiming potential treatment. We also searched all other options available across the world. As we left it to the discretion of the experts, Ribavirin was chosen as the closest one that is sensitive to the virus. Since it wasn’t actually indicated for Nipah as such, it was started as a symptomatic treatment in the three who survived. But it hasn’t been confirmed yet that it was the medication that worked in them. We had also airlifted some doses of the human monoclonal antibody (mAb 102.4), which was found effective as a post-exposure prophylaxis for both humans as well as horses exposed to Hendra virus in Australia. This mAb, which is still under trial, was used under a compassionate use protocol in some 13 patients infected in the 1994 henipavirus outbreak. But we didn’t use it here because the patients who were given ribavirin were already showing improvements by that time. Secondly, we didn’t want to take the risk of experimenting with it. Therefore, the stock was kept safely at the National Virology Institute, Pune.
What is the message that the Kerala experience can provide to doctors and hospitals across the country as outbreaks of new diseases are expected anytime?
Create awareness in the community about the probability of such new diseases. The health authorities should also be made vigilant. Doctors and hospitals should investigate and raise an alert immediately when they see intense symptoms of diseases such as encephalitis. Keep the healthcare setup equipped to handle emergencies, including investigation and isolation of patients, and follow proper hygiene standards and health protocol such as those of H1N1 or Ebola immediately when a case is reported when tracing and quarantining suspected cases. This preparation, which we formulated at the time of the Kozhikode case, actually helped us to achieve zero mortality and a complete elimination of virus spread in the second outbreak that took place in Ernakulam district.