Nipah Virus Infection

Nipah virus (NiV) is an important emerging infectious pathogen between humans and animals. It can infect a variety of animals, including humans, and cause Nipah virus disease (NVD). NVD first broke out in Malaysia in 1998 and then became popular in Singapore and Bangladesh. The NVD epidemic broke out in India in 2019, and NVD once again attracted worldwide attention. NVD has a high fatality rate for humans and animals, and there is a phenomenon of cross-species transmission. BioVenic has long been concerned with the etiology, epidemiology, and pathogenic mechanism of NiV, and has developed innovative diagnostics and customized vaccines for customers.

Etiology and Epidemiology

NiV is a pleomorphic RNA virus in the Paramyxoviridae family, Henipavirus genus, with a size ranging from 40 to 600 nm and an enveloped structure. The NiV genome is a single-stranded, non-fragmented, negative-sense RNA, 18,2 KB long, containing six genes corresponding to structural proteins.

In 1998, Malaysia experienced an outbreak of NiV. The virus then spread to other countries such as Singapore, India, Bangladesh, and the Philippines, causing several subsequent outbreaks. As of May 2018, there have been around 20 NiV outbreaks in varying sizes, with a case fatality rate ranging from 50% to 75%.

Fig. 1 Structure diagram of the Nipah virus.¹

Epidemiological Characteristics

• Source of Infection and Natural Host
  NiV is primarily hosted by fruit bats and is highly contagious and has a broad host range, infecting humans, pigs, dogs, cats, horses, and goats. Pigs are the main source of human infection with NiV.
• Transmission Modes
  NiV transmission occurs through the consumption of food containing the virus and contact with infected animals or human body fluids. Risk factors include proximity, contact, feeding, virus carriers, or aerosols.

Fig. 2 The host and transmission cycle of the Nipah virus.²

• Crowd Susceptibility
  The crowd is generally susceptible, especially the staff who are in direct contact with NiV-infected pigs are the most susceptible, such as veterinarians, breeders, sewage workers, and slaughterhouse workers in pig farms.
• Disease Distribution Characteristics
  Although the NiV epidemic is mainly limited to 5 countries and regions in Southeast Asia and South Asia. NiV has obvious seasonal distribution characteristics. For example, NiV outbreaks in Bangladesh mostly occur from January to May each year, which may be related to bat breeding, human activities, and date palm fruit ripening season.
• Epidemic Risk Factors
  The main risk factors for NiV infection and prevalence are related to the host, exposure method, and exposure time, whether the case, symptoms, virus replication, and strain variation.

Signs and Symptoms

It is classified as a biosafety level 4 pathogen by the World Organization for Animal Health (OIE) due to the high mortality rate it causes after human infection. People infected with the virus may develop the following symptoms.

• The symptoms of NiV infection in humans
  
  • Fever
  • Headache
  • Myalgia
  • Sore Throat

  • Vomiting
  • Dizziness
  • Lethargy
  • Confusion

  • Acute encephalitis
  • Atypical pneumonia

The morbidity and mortality caused by NiV infection in pigs are not significant. It is difficult to identify the virus after it infects pigs, because symptoms may not appear after infection, and it may also cause a series of related symptoms such as respiratory tract and encephalitis symptoms in pigs.

• The symptoms of NiV infection in animals
  
  • Pigs infected with the virus will develop symptoms such as fever, difficulty breathing, and cerebral palsy.
  • Sows exhibit neurological symptoms such as ataxia and may miscarry or die suddenly.
  • Nursery pigs have symptoms such as difficulty breathing, loud screaming, coughing, uncoordinated gait, trembling, and hind leg paralysis.

Diagnosis of NiV

Different detection methods can be used to diagnose the acute attack and recovery stages of NiV infection. Currently, BioVenic mainly helps customers develop immunodiagnostic and molecular diagnostics solutions in the table.

Treatment

There are currently no specific drugs for NiV infection. Clinical management of NiV-infected patients primarily involves life support and symptomatic treatment. Severe respiratory and nervous system complications are addressed through intensive supportive care.

Several experimental treatments, such as monoclonal antibodies and antiviral drugs, are being investigated for their potential use in treating NiV infection. However, their effectiveness has not been proven.

Prevention and Control

BioVenic recommends the following measures to stop the spread of NiV, including:

• Limit Exposure
  Limit contact of sensitive species with infected animals and contaminated products.
• Personal Protective Measures
  People who are in close contact with NiV-infected people/animals should wear personal protective equipment to prevent NiV.
• Isolation Measure
  Isolation of infected animals/individuals and proper disposal of contaminated materials, such as syringes or needles, are essential to prevent further spread of the virus.
• Public Awareness
  Help the public gain a deeper understanding of NiV transmission routes and infection risks to improve early detection and control.
• Vaccination
  There is no approved vaccine for NiV, however, our researchers help customers develop reliable vaccines for vulnerable populations.

BioVenic works with researchers around the world to identify the reason for NiV cross-species transmission to develop effective vaccines and drugs. In addition, we will make sufficient technical and material preparations in the development of NiV diagnostic reagents. If you want to reach a cooperation with us, please feel free to contact us.

References

1. Singh, Raj Kumar, et al. "Nipah virus: epidemiology, pathology, immunobiology and advances in diagnosis, vaccine designing and control strategies–a comprehensive review." Veterinary Quarterly 39.1 (2019): 26-55.
2. Alam, Ali M. "Nipah virus, an emerging zoonotic disease causing fatal encephalitis." Clinical Medicine 22.4 (2022): 348.