Nipah has sparked a health crisis in southern India. Here’s what we know about this deadly virus

The Indian state of Kerala is battling its fourth outbreak of the Nipah virus since 2018. In the state’s Kozhikode district, two people have died and nearly 800 people have been tested in the last 48 hours.

Two adults and one child are in hospital for observation after testing positive.

It is included among them by the World Health Organization (WHO). those considered to be the greatest risk to public health because of their epidemic potential and lack of adequate countermeasures.

Here’s what’s known about the virus and whether people in Canada should be worried.

What is Nipah virus?

Nipah is a zoonotic virus, meaning it can be transmitted between animals and humans, but can also be spread through contaminated food or from person to person.

It kills 40 to 75 percent of people infected, according to the World Health Organization.

Nipah was first identified in 1999 in pig farmers in Malaysia and Singapore. Most of those cases are the result of direct contact by farmers with their sick pigs or contaminated pig tissue. About 300 people were confirmed infected, 100 people died.

There have been no other known outbreaks since then, according to the US Centers for Disease Control (CDC).

In 2001, Nipah was first identified in Bangladesh. Since then, according to the WHO, annual outbreaks have been registered in the country, the cases of which mainly occur in the months of December-May.

Infections in Bangladesh are believed to be caused by people consuming fruit or fruit products, such as raw palm sap or palm sap, that have been contaminated with the urine or saliva of fruit bats that feed on the sap.

According to WHO, the fruit bat is considered the natural host of the virus. Fruit bats in Kerala have tested positive for Nipah virus in the state first outbreak in 2018who died in 21 out of 23 infected.

Subsequent outbreaks in Kerala in 2019 and 2021 claimed two lives.

In the context of the current outbreak in the state, samples of bat urine, animal feces and half-eaten fruit were collected from Marutonkara village, where the first victim of this outbreak lived. The community is located next to 120 hectares of forest, home to several species of bats.

“We are testing people… and at the same time, experts are collecting liquid samples from forest areas that could be hotspots,” Kerala Health Minister Veena George told Reuters.

About 800 people have already been tested in the past week, with at least 77 considered at high risk of infection, according to George.

Government of Canada fact sheet The virus says Nipah has never been found in Canada.

What are the symptoms?

Some people infected with Nipah may be asymptomatic, a complication the WHO says can hinder diagnosis and create “challenges in outbreak detection, effective and timely infection control measures and outbreak response”.

Initial symptoms of Nipah can also be non-specific and the diagnosis is often not immediately suspected at the time of presentation.

Symptoms usually appear four to 14 days after exposure and include fever, headache and respiratory ailments such as sore throat, cough and difficulty breathing, according to the CDC.

In more serious cases, swelling of the brain (encephalitis) occurs, with patients falling into a coma within 48 hours. Although people who develop encephalitis symptoms from Nipah can recover, the CDC says they can experience long-term effects, including seizures and personality changes.

The CDC says there have also been deaths from Nipah months or even years after infection.

How is it treated?

There is no drug treatment or vaccine for Nipah.

“This is what we would call a neglected tropical disease,” said Dr. Isaac Bogoch, an infectious disease specialist at Toronto General Hospital who specializes in tropical diseases and global health. He was speaking to the CBC from Tasmania, where he is presenting at the conference.

“It affects parts of the world that have fewer resources… And when you have limited funding and research dollars that are mostly spent in high-income countries, it’s just not a priority, unfortunately.”

That means current treatment is limited to supportive care: hydration, rest, and treatment of respiratory and neurological symptoms.

According to the CDC, immunotherapeutic treatments (monoclonal antibody therapy) are being developed for Nipah. One has completed its first phase of clinical trials and has been designated on a compassionate use basis.

Where are the currently confirmed cases?

The current outbreak is in the Kozhikode district of the southern Indian state of Kerala.

Public offices, government buildings, schools and religious institutions were closed in nine villages of the district. Public transport was stopped.

Neighboring states Karnataka and Tamil Nadu have ordered tests for visitors from Kerala and plan to isolate anyone showing symptoms that could be linked to the virus.

Is there a concern about wider distribution?

Bogoch said this is not the type of virus that spreads through communities, like COVID-19, because it requires very close contact with an infected individual.

“There have been outbreaks of the virus for decades,” he said. “They are all sad. They are often deadly, but rarely great.”

However, Bogoch calls Nipah a global problem that requires attention because it is carried by an animal that lives in many parts of the world.

“If you look at where the bat house is, it’s huge,” he said. “There are many areas for potential spills and many people live within the bat’s geographic range. And many of these areas are not well equipped to detect and respond to incidents quickly.“

Can further outbreaks be prevented?

Nipah is not a virus that is likely to go away, according to Bogoch, and there will continue to be what are called spillover events, or transmission between species.

He said the keys to reducing Nipah’s deadly impact are reducing the number of cases that spread, early recognition of the virus by health workers, offering good supportive care for patients and working to limit secondary infections.

“Through community education, early detection, use of personal protective equipment and, perhaps in the future, vaccination, all of these goals can be achieved,” Bogoch said.