India restricts public life: How dangerous is the Nipah virus?

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Medical professionals collect samples of fruit in the village of Maruthonkara to test for the virus

Photo: REUTERS

It starts with fever and other flu-like symptoms, in the worst case the brain becomes inflamed: In India, two people have died who had been infected with the life-threatening Nipah virus.

Since then, public life has been restricted in the affected areas in the southern Indian state of Kerala: authorities and schools have been closed, and public gatherings have been banned.

The restrictions are a reminder of the precautions taken during the corona pandemic. Is there even a threat of the next global epidemic?

In fact, the World Health Organization (WHO) lists the Nipah virus as a "pathogen with pandemic potential." That's why outbreaks like the one in India are being closely monitored," the Friedrich Loeffler Institute, which researches pathogens, told SPIEGEL. However, so far there have only been local outbreaks.

How do people get infected?

Like many other pathogens, the Nipah virus first circulated in animals and eventually made the leap to humans. Pigs, for example, are known as so-called animal intermediate hosts, from which humans become infected.

In addition, fruit bats carry the virus without getting sick themselves. Experts speak of a virus reservoir. The fruit bats excrete the virus through their urine and saliva.

Is there a cure?

Some people do not notice the Nipah infection, but many sufferers get a fever, they vomit, their muscles ache. In severe cases, the brain becomes inflamed, the sufferers have severe headaches, are drowsy, can only speak indistinctly or fall into a coma. So far, there is no vaccine or special drugs against the Nipah virus.

In initial experiments, specially obtained antibodies were able to eliminate the virus in the laboratory, and these were also successfully tested in infected primates. However, the therapy has not yet been approved for humans. The most effective protection is therefore to contain the spread.

The first known outbreak dates back more than twenty years and affected about 200 people. Back then, in 1998 and 1999, the virus spread to Malaysia and Singapore. In about 40 percent of cases, the infection was fatal.

It is likely that those affected had been infected by infected pigs – through contact with their tissue, saliva or blood. This is supported, for example, by the fact that many workers in slaughterhouses fell ill during the first outbreak in Malaysia. At that time, there was no evidence that people could infect each other. However, this changed in the following years.

Since 2001, there have been smaller outbreaks in India and Bangladesh practically every year. However, pigs probably do not play a role in the current outbreak in India. Probably, people became infected because they drank fresh juice from date palms contaminated with urine or saliva from fruit bats. This transmission route is considered the main source of infections, but some patients apparently also became infected with other infected people.

How high is the danger for Germany?

"Human-to-human transmission is also known from Bangladesh and the Philippines," says the Friedrich Loeffler Institute. For example, the virus spread within families and in health care facilities, through close contact with infected people or their urine, blood or droplets released when sneezing and coughing.

It is precisely this human-to-human transmission that worries experts. Because then pathogens can spread quickly and, in the worst case, trigger a pandemic. This was the case with the coronavirus, for example. However, the Nipah virus has so far only spread among humans when there is close contact.

In India, more than 700 people are under observation because they may have been infected. More than 150 of them work in the healthcare sector.

Humans make it easier for the virus to spread. New plantations and fattening facilities are reducing the natural habitat of fruit bats, which means that there is more frequent contact between wild animals and humans.

The danger to Europe from the Nipah virus is considered low as long as it does not spread from person to person on a large scale. Fruit bats, which are the only known reservoir for the viruses so far, do not occur in Europe. So far, not a single case is known in Germany.