Nipah Virus: What you should know

Nipah virus (NiV) is a zoonotic virus (spreads from animals to humans) that can cause severe respiratory and neurological disease in humans. It is classified as a member of the Henipavirus genus within the Paramyxoviridae family, same as that of mumps and measels. Nipah virus was first identified during an outbreak in Malaysia in 1998 and has since been responsible for sporadic outbreaks in South and Southeast Asia. In India there have been four outbreaks including the ongoing one where we have seen four deaths, the virus has also been seen in neighbouring Bangladesh The virus can infect a wide range of animals and can spread from animals to humans and humans to humans too .At present there is no specific treatment or vaccine available.

History:

Nipah virus was first recognized in September 1998 during an outbreak of encephalitis in Malaysia, primarily affecting pig farmers and individuals in close contact with pigs. The virus was named after the village of Sungai Nipah, where the initial outbreak occurred. Over 100 cases of severe respiratory illness and encephalitis were reported, with a high mortality rate. Subsequent investigations identified fruit bats of the Pteropodidae family as the natural reservoir of Nipah virus, with pigs serving as intermediate hosts. The fox bats as they are called are reservoirs for the virus , the pigs acquired the disease by consuming dates and fruits half eaten by bats infected with the virus .The virus found in the saliva of the bats was this ingested and caused disease. Humans are infected by close contact with the infected animals or consumption of contaminated foods too.

Transmission:

Nipah virus is primarily transmitted to humans from infected animals, particularly through close contact with infected pigs or consumption of contaminated pork products. Additionally, transmission can occur through direct contact with body fluids or secretions of infected individuals. Human-to-human transmission has been reported, especially in healthcare settings and close household contacts, where there is close contact with patients’ respiratory secretions and sometimes urine and blood too.

Symptoms

Nipah virus infection can present with a range of symptoms, including fever, headache, dizziness, nausea, muscle pain and vomiting. In severe cases, it progresses to acute respiratory distress syndrome (ARDS) similar to COVID 19 and encephalitis (swelling of brain), leading to altered consciousness, seizures, and coma. The mortality rate of Nipah virus infection can be as high as 75%, making it a significant public health concern. In a recent outbreak in Malaysia out of 265 infected 105 died taking the mortality to 40%.

Diagnosis:

The diagnosis of Nipah virus infection can be challenging due to its similarity to other viral illnesses like influenza and other forms of encephalitis. Laboratory tests, including reverse transcription-polymerase chain reaction (RT-PCR), serological assays, and viral culture, are used to confirm Nipah virus infection. Samples for testing should be collected from respiratory secretions, cerebrospinal fluid, blood, and urine. Nipah virus is rapidly inactivated by heat, but can be recovered after a 60-min incubation in solutions ranging from pH 3 to 11, it can survive for days in bat urine, in fruit juice, or on the surface of a cut mango. Which means consumption of contaminated fruits and juices can cause disease even after days of contact with infected animal. Nipah virus can infect a wide range of mammals including pigs, dogs, cats, ferrets, hamsters, African green monkeys, and horses too making domestic animals likely source for infection.

Treatment:

There is no specific antiviral treatment for Nipah virus infection. Therefore, the management of Nipah virus infection primarily focuses on supportive care and infection control measures. Here are key aspects of Nipah virus treatment:

• Isolation and Infection Control: Infected individuals should be isolated to prevent further transmission of the virus. Healthcare workers should use appropriate personal protective equipment (PPE) to avoid direct contact with infected patients’ body fluids.
• Supportive Care: Supportive care is crucial in managing Nipah virus infection. This includes maintaining hydration, providing respiratory support if necessary, and addressing specific symptoms like fever and pain. Patients may require intensive care in severe cases like ARDS and Encephalitis.
• Experimental Treatments: Some experimental treatments, such as antiviral drugs like Ribavarin and monoclonal antibodies, have been explored in the context of Nipah virus infection. These treatments are still in the early stages of development and may not be widely available.
• Symptom Management: Medications like pain relievers and fever reducers can help alleviate symptoms. However, it’s essential to consult healthcare professionals for guidance on medication use.
• Prevention of Complications: Vigilant monitoring of patients is necessary to identify and manage complications promptly. Nipah virus infection can lead to severe respiratory and neurological symptoms, which may require specialized care.

It’s important to seek medical attention promptly if you suspect you or someone you know has been exposed to Nipah virus. Early diagnosis and supportive care can improve the chances of recovery.

Prevention:

Preventing Nipah virus infection involves several measures to reduce the risk of exposure and transmission. Here are some key prevention strategies:

• Avoid Contact with Infected Animals – Nipah virus can be transmitted from animals to humans. Avoid close contact with bats, pigs, and other animals that may carry the virus, especially in endemic areas.
• Practice Good Hygiene, Frequent handwashing with soap and water is essential, especially after handling animals or being in close contact with sick individuals.
• Use Personal Protective Equipment (PPE), Healthcare workers and caregivers should use appropriate PPE, such as gloves and masks, when caring for infected individuals to prevent direct contact with body fluids.
• Avoid Consuming Raw Date Palm Sap, in endemic regions, avoid drinking raw date palm sap, as it can be contaminated with the virus through bat droppings. Don’t eat fruits left over after consumption from animals or bats. Cutting the form part does not help, the virus is already inside.
• Quarantine and Isolation, Isolate infected individuals and practice strict infection control measures in healthcare settings to prevent nosocomial (hospital-acquired) transmission.
• Public Health Measures, Health authorities may implement measures such as contact tracing, quarantine, and isolation to contain outbreaks.
• Vaccine Development, Keep up to date with developments in Nipah virus vaccine research, as vaccination may become an important preventive measure in the future. A vaccine for Hendra virus, a close relative of Nipah, available for horses in Australia appears to offer a degree of protection against Nipah infection.But right now prevention of contact is best.

Preventing Nipah virus infection primarily involves reducing exposure to the virus and practicing good hygiene and infection control measures. If you suspect someone has been exposed to Nipah virus or is showing symptoms, seek medical attention immediately, and follow the guidance of healthcare professionals and public health authorities.

Conclusion:

Nipah virus remains a significant global health concern due to its high mortality rate, potential for human-to-human transmission, and lack of specific antiviral treatments. Public health efforts continue to focus on surveillance, early detection, and preventative measures to reduce the risk of Nipah virus outbreaks. Understanding the virus’s biology, transmission, and clinical manifestations is essential in mitigating its impact on both human and animal populations. Most of these viruses are emerging due to increase contact between animals and humans as we tend to intrude into their space and deplete first covers. A good long term planning strategy should include steps to reduce this conflict too.

Dr. Madhav Prabhu
MD Medicine Professor and Consultant Physician