Nipah Virus: A Dissection
Recently, Nipah virus has struck the Indian state of Kerala, killing at least 18 people till now. One of the fatalities was a nurse treating the patients. This shows the hazards of the disease, and attending doctors and nurses need to take precaution while treating the patients. Nipah virus is a disease that affects the brain and respiratory system. It is transmitted by fruit bats, also called flying foxes, of the family Pteropodidae, especially the genus Pteropus. The bats do not get infected by the virus but can transmit it to people or animals like pigs.
The disease can develop into encephalitis and respiratory complications. The disease rarely infects people but when it does the infection could be fatal. The symptoms of the disease include fevers, a headache, myalgia, emesis, a sore throat, a cough, shortness of breath, drowsiness, disorientation, mental confusion, etc. It can cause long-term disabilities in survivors. Further, it can infect people without giving rise to any symptoms. Its incubation period ranges from five to 14 days. The patient develops pneumonia, acute respiratory distress, seizures or a coma within 24 to 48 hours. The virus can remain in the human body for months, even years.
Nipah virus first emerged in Malaysia way back in 1998 and the virus was first isolated and identified in 1999 when an outbreak of encephalitis and respiratory ailments attacked pig farmers and those in contact with pigs in Malaysia. Around the same time, the disease also struck Singapore. The disease did not affect the pigs to a great extent but over 300 people were affected by the disease. Out of them, over 100 people succumbed to the disease. And over a million infected pigs were culled. Till now, over 700 people have been infected by the disease.
The disease saw its outbreak again in Bangladesh and India in 2001. Outbreaks of the disease occur almost annually in Bangladesh. This is the third time India has been struck by the disease. Malaysia and Singapore have, however, not witnessed a repeat of the disease. Nipah virus is a fatal disease with a mortality of 70 per cent. No vaccine or drug has been developed yet to combat the disease. The mode of treatment is supportive care.
The incidence of Nipah virus in India is a matter of concern for Nepal, too. Nepal and India have open borders. Thousands of people cross the borders every day. As human-to-human transmission of the disease has been confirmed, fears loom large over the import of the disease to Nepal. However, it seems the government has not taken any precautionary measures to prevent the outbreak of the disease.
Nipah virus is a highly infectious disease. It is not only a zoonosis but also a human-to-human infection. The transmission of the disease is attributed to an infected source such as fruit bats and infected pigs. Fruit bats do not bite people or come into contact with people but carry the virus. It is found that fruit bats carry a variety of such viruses. And every outbreak of the disease could help the emergence of a new strain of virus. Fruit bats are found in the tropical and subtropical regions of Asia, Australia, East Africa and numerous islands in the Indian and Pacific Oceans.
As there is no treatment for the disease, it is essential to take precautionary measures to prevent the disease. Avoiding fruit bats and sick pigs is the best caution to prevent the disease. It is necessary to avoid fruits or fruit juices contaminated by fruit bats and water from wells contaminated by such bats. In India and Bangladesh, people catch the disease due to consumption of raw date-palm sap (toddy) contaminated by fruit bats and contact with the bats. In contrast, the disease occurred in Malaysia and Singapore due to contact with sick pigs.
Due to high risks of Nipah virus, healthcare workers are always exposed to the disease. The death of a nurse in India while treating the patients has also confirmed this. So while treating the patients, they should be isolated from other patients to prevent the nosocomial transmission of the disease. At the same time, the healthcare workers should also take precautionary measures to avoid the infection. An awareness campaign needs to be initiated right now. As the areas inhabited by fruit bats or where pig farms are operated are exposed to Nipah virus, such a campaign needs to be concentrated in those areas.
The chance of Nipah virus striking countries other than Malaysia, Singapore, Bangladesh and India is there. The virus has been found in fruit bats of the genus Pteropus and other species in such countries as Cambodia, Thailand, Indonesia, the Philippines, Ghana and Madagascar. Although the disease has not taken epidemic proportions, the possibility of it turning into an epidemic like Ebola virus cannot be ruled out. As such, the World Health Organisation has taken the disease seriously, counting the Nipah virus among the top ten pathogens of concern. The WHO is supporting at-risk countries by providing them with guidance on how to prevent and manage the disease. The WHO has also instructed researchers to work on developing a Nipah virus vaccine and exploring treatment methods. The project is expected to take at least five years.