Nipah Virus Outbreak
After over a decade, the rare Nipah virus has struck India, and this time in Kerala's Kozhikode district, by claiming ten lives within 48 hours.
What is Nipah virus (NiV)?
According to World Health Organisation, Nipah virus (NiV) infection is a newly emerging zoonosis (a disease which can be transmitted to humans from animals) that causes severe disease in both animals and humans. The natural host of the virus is fruit bats of the Pteropodidae Family, Pteropus genus (fruit-eating species, popularly known as flying foxes).
Who are in danger?
NiV affects humans as well as pigs and other domestic animals.
What are the symptoms of NiV infection?
According to the WHO, the symptoms of NiV infection in humans has a range of clinical presentations, from asymptomatic infection to the acute respiratory syndrome and fatal encephalitis
When was Nipah virus first identified?
NiV was first identified during an outbreak of disease that took place in Kampung Sungai Nipah, Malaysia in 1998. According to WHO, pigs were intermediate hosts, however, no intermediate hosts were found in subsequent NiV outbreaks.
According to a 2013 ICMR-sponsored research paper, "the outbreak started in the pig farmers near Ipoh in the Kinta District of Perak, some 200 kilometres north of Kuala Lumpur and spread to three other major pig-rearing areas (the largest in Southeast Asia) in Negeri Sembilan and Sungei Buloh in Selangor. The disease was named after Kampung Sungai Nipah (Nipah River Village), where the first viral isolate was obtained and therefore named as NiV".Total 265 cases were reported of which 105 died. Around 1.1 million pigs had to be destroyed to control the outbreak, the report adds.
How does NiV transmit?
According to the report, in Malaysia and Singapore, NiV transmitted to humans through infected pigs. However, during the NIV outbreaks in India and Bangladesh, the disease transmitted "directly from bats to human followed by a human to human" and "the drinking of raw date palm sap contaminated with fruit bat urine or saliva containing NiV is the only known cause of outbreak" of the disease in Bangladesh outbreaks."
When was the first NiV outbreak observed in India?
The first NiV outbreak in India was observed in 2001 in Siliguri, West Bengal. Though the agent for the outbreak was not known, analysis of the limited sequence data suggested that the NiV strains associated with the outbreak were more closely related to NiV isolated in Bangladesh than to NiV isolated in Malaysia. According to some, Siliguri's proximity to Bangladesh, which had been seeing recurrent cases of NiV infection from 2001 through 2013 could have been behind it. A second infection had reportedly emerged in Nadia district, again close to the border with Bangladesh in 2007. The outbreak of NiV in Kerala is the latest and third such incident, according to reports.
Is there a vaccine for NiV infection?
No. According to WHO, there is no vaccine for either humans or animals. The only treatment available for NiV infection is intensive supportive care.
What precautions to take?
Contact with bats saliva or urine either via a contaminated item (like palm sap or fruit dropped from a tree) or via animals contaminated by the virus (such as pigs or other livestock animals) or humans already infected with NiV are considered to be the prime reason for NiV infection. If NiV is endemic to your area, it's best to avoid areas that bats inhabitate.
What is Nipah?
According to the World Health Organisation, Nipah Virus (NiV) Infection is “a newly emerging zoonosis that causes severe disease in both animals and humans.” In other words, it is a virus that spreads from animals to humans and then spreads among humans.
It normally affects human beings initially in the form of encephalitis. It is accompanied by fever, headache, cough, drowsiness and finally coma.
With no specific drugs to treat the disease apart from life-supporting medical care, many patients die within a few days. Alarmingly, Nipah has a mortality rate of close to 75 percent, making it one of the most dreaded diseases after Ebola.
The virus is found to be present in the urine, faeces and saliva of the fruit bats. It is believed that half-eaten fruits or faecal droppings of bats could be potential carries of the virus when they come in contact with human beings.
In the case of the family in Perambra, it is believed that one of the members of the family might have come in contact with a half-eaten fruit dropped by a bat in the courtyard of their house or consumed water from the well adjoining their house in which dead bats were found.
The disease could have then spread from one person to another in the household, leading to the death of three.
The virus was first found among pigs in Malaysia in 1998. At that time, about a million pigs had to be culled across farms after more than 100 people came in contact with the virus. Here also, fruit bats were believed to have spread the virus to the pigs.
Fear of spread of virus
Although the state claims that the outbreak is limited to a small area in Kozhikode, developments in the adjoining district of Malappuram are not encouraging. Four deaths of people who showed similar symptoms have already been reported from Malappuram. Health workers suspect that the cause may be Nipah.
“The symptoms in Malappuram suggest that the cases were of encephalitis. However, whether the disease is actually Nipah can only be confirmed after we get the samples tested in Pune. At the moment, that is what we are doing. We are not taking any chances. All measures to contain the virus have been put in place here too,’’ said Dr Sakhina, District Medical Officer, Malappuram.
As ‘fruit bats’ found in large numbers all over rural Kerala are the natural hosts of this deadly virus, it becomes doubly challenging for health officials to contain it. These bats fly for at least 200 kilometres in search of food at night. This means that containing the virus in a densely populated state like Kerala becomes an even tougher task.
What makes the situation worse is that Nipah has an incubation period of four to 15 days which means that unless effective quarantine measures are put in place to ensure that people do not travel to affected areas, the number of cases could rise the coming days.
“Anyone can travel to Kozhikode and also travel from the town elsewhere at the moment. We will have to tackle the issue of quarantining, failing which this virus can spread in any direction in the state. It will then become absolutely impossible to contain it. The measures being taken at the moment are inadequate to contain the virus,’’ a senior doctor from Malappuram
Health officials clueless about Nipah's arrival in Kerala
What troubles health experts in Kerala is the lack of clarity on the manner in which the virus came to the state.
The only other reported case of Nipah in India was from Siliguri in West Bengal way back in January 2001. But Nipah has been common in many parts of Bangladesh where, from 2001 to 2011, the disease had been reported every year without fail.
Health officials in Kerala are clueless on how the virus could have travelled from Bangladesh or West Bengal to northern Kerala.
“At the moment, we are absolutely clueless about how the virus reached Kerala. Fruit bats are not migratory. The maximum they will fly is 300 miles. How did a virus earlier reported thousands of miles away come to northern Kerala? This can only be revealed through a minute study of all the circumstances,’’ Dr PS Jinesh
Comments
Post a Comment