A 12-year-old boy with fever came to a hospital in Kerala’s Kozhikode on September 1. The boy had already visited two hospitals but treatments were not successful. He was clinically diagnosed with encephalitis, the brain fever. Doctors sent his samples to the National Institute of Virology (NIV) in Pune, Maharashtra. The NIV confirmed it was an infection of NiV, that is, Nipah virus.

The boy died of the Nipah virus infection on September 5 in the Kerala hospital. His death has sent panic among health authorities from Kerala to New Delhi as the governments at both levels have been finding it hard to bring down Covid-19 situation to a comfortable level.

Nipah has put districts of Kozhikode, Malappuram and Kannur on high alert. Neighbouring areas of Tamil Nadu are also on alert with increased vigilance to screen people with Nipah-like symptoms.

WHY IS NIPAH A CONCERN?

The nature of Nipah virus infection is such that if the outbreak spirals out of control, it could pose a bigger threat to public health than the coronavirus pandemic. While Covid-19 has a fatality rate of 1-2 per cent, mortality rate in Nipah virus infections can be up to 75 per cent.

WHERE DID NIPAH COME FROM?

Nipah virus came from fruit bats. A research paper said Nipah virus might have evolved with these bats over millennia. A reverse infection attempt did not make these bats ill.

According to the World Health Organisation (WHO) fact-sheet on Nipah, the virus reached humans through pig. But some research works have also concluded that they can reach humans via a host of other animals including dogs, cats and rats.

HOW DOES NIPAH SPREAD?

Nipah virus has a wider transmission route compared to SARS-CoV-2, the coronavirus that causes Covid-19. It is still not clear whether SARS-CoV-2 is zoonotic or not. But Nipah is a zoonotic virus. This means it can transmit from one species to another — humans to animals, animals to animals, and vice versa.

Host bats contaminate dates and other collected fruit sap through their urine, faeces, or saliva. Humans may get infected with Nipah virus when they eat or drink contaminated food or drink.

According to the US’s Centers for Disease Control and Prevention (CDC), Nipah virus (NiV) can spread to people from:

• Direct contact with infected animals, such as bats or pigs, or their body fluids (such as blood, urine or saliva)
• Consuming food products that have been contaminated by body fluids of infected animals (such as palm sap or fruit contaminated by an infected bat)
• Close contact with a person infected with NiV or their body fluids (including nasal or respiratory droplets, urine, or blood)

Some cases of NiV infection have been reported among people who climb trees where bats often roost, according to the CDC.

NIPAH PATIENT: WHAT IT FEELS LIKE?

Nipah virus infection is troublesome experience in moderate to severe cases. Some patients could also remain asymptomatic, according to the WHO. Infected people initially develop symptoms such as:

• Fever
• Headaches
• Myalgia (pain in muscles)
• Vomiting
• Sore throat.

If the infection aggravates, the initial symptoms could be followed by:

• Dizziness
• Drowsiness
• Altered consciousness
• Neurological signs that indicate acute encephalitis

However, in some cases Nipah virus infection could lead to:

• Acute respiratory infection
• Seizures
• Encephalitis that can turn fatal

Some of the patients of Nipah virus infection could experience:

• Atypical pneumonia
• Severe respiratory problems including acute respiratory distress
• Encephalitis and seizures progressing to coma in 24 to 48 hours

HOW LONG DOES IT TAKE TO GET ILL?

The incubation period in cases of Nipah virus infection ranges from four to 14 days. According to the WHO, an incubation period of 45 days has also been reported.

IS THERE A TREATMENT?

There is no treatment available for Nipah virus infection. The doctors only do symptomatic treatment, much like the cases of Covid-19.

The WHO has identified Nipah as a priority disease for its Research and Development Blueprint. The WHO recommends intensive supportive care for patients infected with Nipah virus for the treatment of severe respiratory and neurologic complications.

HOW FATAL IS NIPAH VIRUS INFECTION?

Nipah has a very high fatality rate, ranging between 40 per cent and 75 per cent, according to the WHO. Fatality rate could be kept on the lower side through efficient epidemiological surveillance and clinical management in affected areas.

WHAT HAPPENS TO THOSE WHO RECOVER?

Most of the Nipah patients who survive make a full recovery. However, in some cases Nipah virus infection leaves the survivor with residual neurological conditions in the aftermath of acute encephalitis. According to the WHO, relapses have been reported after recovery in some cases.

HOW CAN NIPAH BE PREVENTED?

Unlike Covid-19, there is no vaccine against Nipah virus infection. The most effective prevention strategy is to control Nipah virus among intermediary animals such as pigs and adopting Nipah-appropriate eating habits.

Based on the experience gained during the outbreak of Nipah involving pig farms in 1998-99 in Malaysia, routine and thorough cleaning and disinfection of pig farms with appropriate detergents may be effective in preventing infection, the WHO advisory says.

• If an outbreak is suspected, the animal premises should be quarantined immediately.
• Culling of infected animals with close supervision of burial or incineration of carcasses may be necessary to reduce the risk of transmission to people.
• Restricting or banning the movement of animals from infected farms to other areas can reduce the spread of the disease.
• Establishing an animal health or wildlife surveillance system to provide early warning for veterinary and human public health authorities

WHAT YOU CAN DO

The health agencies suggest focusing on reducing the risk of bat-to-human transmission by decreasing bats’ access to date palm sap and other fresh food products.

According to the UN agency Food And Agriculture Organisation (FAO), simple yet effective practices could be adopted as prevention protocol against Nipah.

• Boil freshly collected date palm juice before drinking
• Thoroughly wash and peel fruits before consumption
• Use protective coverings to prevent bat access to date palm sap and other fresh fruit products
• Do not hunt, dress or eat bats
• Avoid consuming organs that the Nipah virus has been found to affect in infected pigs, such as the lungs and respiratory tract, brain, lymph nodes, and kidneys, in affected or at-risk areas
• Do not consume raw or partially cooked meat products
• Wash hands regularly while handling fruit or meat products

PAST EXPERIENCE

In 2018, a Nipah outbreak claimed 17 lives in Kerala. The affected districts were Kozhikode and Malappuram. Another Nipah case was identified in Kochi in 2019.

The first case of Nipah outbreak in India was reported in 2001 in West Bengal’s Siliguri. Drinking of fresh date palm sap led to transmission of Nipah virus to humans. Of 65 persons infected by Nipah virus, 45 had died back then.