Nipah Virus: What you need to know !!

The Nipah virus is a relatively new virus that affects the brains of humans and certain animals like bats, pigs, and horses, causing neurological symptoms and death. This was first reported in 1998 when it caused encephalitis (brain fever) in pigs and pig farmers in Malaysia. Since then, there have been multiple outbreaks in Bangladesh, India, and the Philippines. The most recent outbreak has been reported in the south Indian state of Kerala where the disease is thought to have been acquired from bats.

Being fairly new, limited research has been done to study the virus.

Transmission of Nipah Virus

The virus is thought to be found present predominantly in Asia and a few parts of West Africa, carried in bats of the genus Pteropus (flying foxes). The virus is transmitted directly to humans or through another animal via contact with infected secretions. This includes blood, saliva, urine, and respiratory secretions. Fruits bitten by an infected bat can also be a source of infection. Humans can acquire if from close contact with infected humans.

Symptoms begin about 7 to 40 days after contact with an infective source.

Symptoms of Nipah Virus Infection

The initial symptoms are similar to the flu with fever, headache, nausea, vomiting, and body aches. This is followed by neurological symptoms such as

• Drowsiness
• Reduced consciousness or comatose state
• Seizures or fits
• Weakness in muscle
• Respiratory failure from loss of neural respiratory drive

The disease is associated with high rates of death, ranging from 30% to 70%, as seen in the different outbreaks.

Some of the survivors were noted to have long term fatigue and weakness, a few months following their illness.

Diagnosis of Nipah Virus Infection

During an outbreak, all patients showing symptoms of Nipah virus infection who have a history of contact with an infective source are isolated and tested for the infection.

• Blood tests look for antibodies to the virus which is diagnostic of infection.
• Imaging: MRI scans show distinct features in the brains of affected patients
• EEG (electroencephalogram): this is used to see the electrical activity in the brain, which may assist in making the diagnosis, but is not specific to Nipah.

Treatment of Nipah Virus infection

There is currently no effective treatment for the disease. Some antivirals have been tried for treatment with no success. Supportive care is the only measure available.

In general, patients suffering from Nipah virus infection require isolation and care in an intensive care unit. They may require mechanical ventilation (breathing through a tube inserted into the trachea) in case of respiratory failure.

Prognosis of Nipah Virus Infection

This is a deadly disease is associated with high rates of mortality, ranging from 30% to 70%, as seen in the different outbreaks.

Some of the survivors were noted to have long term fatigue and weakness when studied a few months following their illness.

Prevention of Nipah Virus Infection

It is important to remain alert and vigilant to outbreaks and effectively prevent the transmission of the virus.

• Stay away from bats and pigs in case of an outbreak
• Do not eat fruits or vegetables which appear to have been bitten into by bats
• Avoid travel to an area which is reporting an outbreak
• Avoid contact with sick individuals during an outbreak
• Use gowns, gloves, and masks in case of necessary contact with suspected infective material

Scientists are working hard to create a safe and effective vaccine to prevent this fatal infection.

References:

• Goh KJ, Tan CT, Chew NK, Tan PS, Kamarulzaman A, Sarji SA, et al. Clinical features of Nipah virus encephalitis among pig farmers in Malaysia. N Engl J Med. 2000 Apr 27;342(17):1229–35.
• Luby SP, Gurley ES. Epidemiology of henipavirus disease in humans. Curr Top Microbiol Immunol. 2012;359:25–40.
• Daniels P, Ksiazek T, Eaton BT. Laboratory diagnosis of Nipah and Hendra virus infections. Microbes Infect. 2001 Apr;3(4):289–95.
• Satterfield BA, Dawes BE, Milligan GN. Status of vaccine research and development of vaccines for the Nipah virus. Vaccine. 2016 03;34(26):2971–5.