Sunday, September 26, 2021

Nipah virus

The central government and its agencies do not appear to have learnt any lessons from the past experiences when virus outbreak in an epidemic forms was detected in different parts of the country. This is the main reason why different virus have been detected in various states from time to time despite the consolation that they have been brought under control by the state governments well in time. In the recent weeks, after a gap more than a year, Kerala health authorities acted promptly and brought the deadly Nipah virus infection outbreak under check in its two districts of Kizhikode and Malappuram. It has also shown its alacrity in dealing with a reported case in past weeks. A 23-year old student brought to the private hospital in Ernakulam on May 30 tested positive for the virus on June 4 and the number of cases detected till June 6 rose to three. While the government was awaiting confirmation from the National Institute of Virology, Pune, steps were initiated to prevent spread of the disease by tracing the contacts, setting up isolation wards and public engagement. The two healthcare workers, who came in contact with the patient also showed some symptoms and were treated for the virus infection. Till date, at least 311 persons, who had come in close contact with the student are being kept in isolation wards to check spread of the disease, the numbers could be more as the patient has travelled to four districts of Ernakulam, Thrissur, Kollam and Idukki in the recent past. His travel to these districts could also have spread the infection to other people and they are being scanned and likely to be kept in isolation for the necessary tests to check their status. Containing the spread of the Nipah virus is important as the mortality rate was 89 percent last year, according to a paper in the journal “Emerging Infectious Diseases”. The source of infection in the index case i.e. the student continues remains unknown. However, transmission to 18 contacts last year and the two health-care workers this year has been only through the human-to-human route. This has been established through the diagnostics carried out on the patient and two healthcare workers. The recent recurrence strongly suggested that the Nipah virus is in circulation in fruit bats, as is suspected by medical practitioners. It is not surprising that Kerala was taken by surprise by the first outbreak in an epidemic form last year. After all, the virus isolated from four people and three fruit bats last year from Kerala clearly indicated that the carrier of the Nipah virus which caused the outbreak was the fruit bat, according to the paper in “Emerging Infectious Diseases”. Analysing the evolutionary relationships, the study found 99.7-100 percent similarity between the virus in humans and bats. The confirmation of the source and the recurrence mean that Kerala must be alert to the possibility of frequent outbreaks in future also. Even in the absence of hard evidence of the source of the virus till a few days ago, fruit bats were widely believed to be the likely candidates. If that is the case and considering the very high mortality rate when infected with the virus, it is shocking that Kerala had not undertaken continuous monitoring and surveillance for the virus in fruit bats. One reason for the failure could be the absence of a public health protection agency, which the state government has been in the process of formulating for over five years, to track such infective agents before they strike. Not only should Kerala get this agency up and functional soon, it should also equip the Institute of Advanced Virology in Thiruvananthapuram to undertake testing of dangerous pathogens. Known for high health indicators, Kerala cannot lag behind on the infectious diseases front if it wants to protect its people from falling prey to such infections in future. The centre should also join efforts in detecting the source besides help contain the virus which has the potential of spreading to neighbouring states.