Return of the Nipah virus: 2 deaths in India, symptoms, in France?

In India, the state of Kerala has had to close its schoolsrestrict collective gatherings and test hundreds of people after the death of 2 people with Nipah virus in Kozhikod district, announced Pinarayi Vijayan, chief minister in a statement relayed on Instagram on September 14 2023. To date, 4 other people tested positive and more than 700 people, including 153 medical sector employees, are under observation after having been in contact with infected people, according to health authorities. “You should not be afraid, but face this situation with caution. Everyone must be ready to follow the instructions of the Ministry of Health and the police and to cooperate fully with the restrictions”, he says. With a mortality rate between 40 and 75%the WHO has classified the Nipah virus among the diseases that present “the greatest risk to public health because of their epidemic potential”, like Covid-19 or Ebola. Currently, there is no treatment or vaccine to stop it.

What is the Nipah virus?

Appeared in 1998 among pig breeders in the village of Nipah in Malaysia, the Nipah virus (NiV) is a so-called virus “zoonotic”in other words, who is transmitted from animals to humans and vice versa. In an infected person, it causes illness that can range froman asymptomatic infection has an acute respiratory infection (mild or severe) which can progress into fatal encephalitis (inflammation of the brain). Symptoms usually appear in 4 to 14 days which follow exposure to the virus, but according to the World Health Organization (WHO)“longer incubation periods, up to 45 dayswere also observed“.

In which countries does the Nipah virus circulate?

No Nipah virus infections have been detected in Europe.

Nipah virus is present throughout South and Southeast Asia. Signs of infection have been highlighted:

• In Malaysia: country in which the first outbreak of Nipah was detected in 1998. It cost the lives of more than a hundred people, as well as the slaughter of a million pigs to contain the advance of the virus.
• In Singapore: the Nipah virus then emerged via slaughterhouse workers who came into contact with infected pigs in Malaysia. It affected 11 people and caused one death.
• In India: in 2001, the virus affected India where it caused hundreds of cases and around fifty deaths. A 12-year-old child died on September 5, 2021. Since then, the state of Kerala has been “on alert,” the news agency said. Associated Press. As of September 2023, the state of Kerala recorded four cases and two deaths linked to the Nipah virus.
• In Bangladesh, since 2001.
• In Cambodia
• In Ghana
• In Indonesia
• In Madagascar
• In the Phillippines
• In Thailand

For the moment, no Nipah virus infection has been detected in Europe and therefore in France.

“The risk of Nipah virus transmission depends on the characteristics of the patient, such as age and the presence of respiratory symptoms.“, indicates thePastor Institute. The Nipah virus can be transmitted in several ways:

► from an animal to Man (and vice versa), particularly pork (Nipah virus is very contagious in pigs) or the infected batmore rarely domestic animals such as horses, goats, sheep, dogs and cats,

► directly between two humans, through close contact with the secretions or excretions of infected people,

► by contaminated food.

During the first epidemic outbreaks (Malaysia, Singapore), infections resulted from direct contact with sick pigs or with their contaminated tissues. “Transmission is believed to have occurred through contact with pig secretions or with tissues from a diseased animal“, reports theWHO. In subsequent outbreaks (Bangladesh, India), the most likely source of transmission was the consumption of fruits or derived products (date or palm juice) contaminated with urine or saliva from infected bats. It’s about bats frugivores of the species Pteropusthat is to say, they feed on fruit. A case of human-to-human transmission has also been reported among families and caregivers of infected patients.

What symptoms does the Nipah virus cause?

Nipah virus can cause asymptomatic illness or acute respiratory infection up to fatal encephalitis.

>> Firstly:

• Fever
• Headaches (headaches)
• Muscle pain (myalgia)
• Vomiting
• Sore throat

>> Secondly:

• Dizziness
• Drowsiness
• Altered state of consciousness (disorientation, mental confusion, etc.)

>> In serious cases:

• Atypical pneumonia
• Severe respiratory problems including acute respiratory failure
• Typical neurological signs of acute encephalitis (brain swelling)
• Convulsions which may progress to coma within 24 to 48 hours.

Is he mortal?

Around 20% of cured patients have neurological after-effects

Researchers know how dangerous and contagious the Nipah virus is. It is capable of infecting a large number of animal species, including pigs, and causing serious illness and death in humans, says the World Health Organization. The fatality rate (proportion of deaths in relation to the total number of cases affected by the disease) is between 40 and 75%. “Most patients who survive acute encephalitis recover completely, but long-term neurological conditions have been reported among survivors. Around 20% of cured patients have neurological sequelae, such as seizure disorders and personality changes. In a small number of cases, cured subjects subsequently suffer a relapse orlate-onset encephalitis“, indicates the WHO. In September 2023, the WHO classified the Nipah virus among the diseases that present “the greatest risk to public health because of their epidemic potential.

What is the incubation period?

The WHO estimates that the incubation period (time from infection to the appearance of symptoms) varies from 4 to 14 days. However, longer incubation periods, up to 45 dayshave already been observed.

As the symptoms are not specific to the disease, it is difficult to diagnose Nipah virus infection during a consultation. Infection can be diagnosed at the same time as examining the clinical history during the acute phase and the convalescent phase of the disease. The main tests that are used include the test of RT-PCR (real-time polymerase chain reaction) from biological fluids, as well as the detection of antibodies throughan ELISA test. This method is mainly used to detect the presence of an antibody or antigen in a blood sample.

What treatment?

To date, there is no medication to treat Nipah virus infection. Alone intensive supportive care can treat severe respiratory and neurological complications.

Is there a vaccine for Nipah virus?

There is no vaccine capable of treating or preventing Nipah virus infection, whether in humans or animals.

In the absence of a vaccine, the only way to reduce the number of human infections is to educate people about the risk factors and what steps they can take to reduce their exposure to Nipah virus:

• Boil, wash and peel fruits harvested from risk areas (listed above) before consumption.
• Discard fruit partially eaten by bats.
• Wear gloves and other protective clothing when handling sick animals or their tissues, as well as during slaughter.
• Take into account the presence of fruit bats and protect pigsties and animal food from bats.
• Avoid close unprotected physical contact with people infected with Nipah virus and wash your hands regularly after providing care or visiting sick people.