Nipah Virus: Transmission, Symptoms & Prevntion

What is Nipah Virus?

• Nipah virus is a zoonotic virus i.e. it spreads from animals to humans.
• Nipah virus is a highly pathogenic and deadly virus which has high fatality rate
• In ill people, it causes a range of ailments from asymptomatic (subclinical) infection to acute respiratory illness and lethal encephalitis.
• The virus can cause severe disease in animals for instance pigs, resulting in substantial economic losses for agriculturalists.
• Though the Nipah virus has caused simply a few identified outbreaks in Asia, it affects wide range of animals and causes life-threatening disease and death in people, making it a public health concern.

Global Facts About Nipah Virus

• Nipah Virus was first identified in Malaysia in 1998.
• Fruit bats of the genus (Pteropus), also known as flying fox, are the natural reservoir/host of the Nipah Virus.
• Nipah virus has the capacity to transmit from animals to humans and also possesses transmission potential from human-to-human transmission.
• Nipah virus infection in humans causes a range of medical expositions, from asymptomatic infection (subclinical) to acute respiratory infection and serious encephalitis.
• The case fatality rate is expected at 40% to 75%. This rate can differ by outbreak reliant on local competencies for epidemiological surveillance and clinical management.
• Nipah virus can be transmitted to humans from animals (such as bats or pigs), or contaminated foods and can be transferred directly from human-to-human.
• There is no treatment or vaccine accessible for either one i.e. people or animals. The crucial treatment for humans is supportive care.

Transmission of Nipah Virus

1. Animal to human transmission

– Direct contact with infected animals

– Contaminated foods: consumption of raw date palm sap contaminated by bat secretions.

2. Human-to-human transmission

– Close contact with infected persons through respiratory droplets or body fluids

• Human-to-human transmission of Nipah virus has also been described among family and care supporters of infected patients.

3. Environmental contamination

– Contamination of the objects/subjects where bats feed or excrete.

Incubation Period

• The incubation period (interval from infection to the onset of symptoms) of Nipah virus is supposed to range from 4 to 14 days. Yet, an incubation period as long as 45 days has been stated.

Symptoms of Nipah virus

• Human infections range from asymptomatic infection to acute respiratory infection (mild, severe), and fatal encephalitis.
• Initial symptoms (3-14 days of exposure)
  • Fever
  • Sore throat
  • Vomiting
  • Muscle pain
  • Headache
• Advanced symptoms
• Seizures
• Dizziness
• Altered mental status
• Encephalitis
• Coma (in severe cases)
• Unusual pneumonia and severe respiratory problems (in some cases)
• Most people who persist acute encephalitis make a complete recovery, but long-term neurologic conditions have been reported in survivors.  Roughly, 20% of patients are left with remaining neurological consequences such as seizure disorder and personality changes

Fatality Rate

• The case fatality rate is projected at 40% to 75%.
• This rate can differ by outbreak dependent on local competencies for epidemiological surveillance and clinical management.

Diagnosis of Nipah Virus

Nipah Virus can be diagnosed through laboratory tests. It includes:

Laboratory tests

RT-PCR: Gold standard

ELISA (Enzyme-Linked Immunosorbent Assay)

Virus isolation

Immunohistochemistry

Prevention and control measures

• Repetitive and comprehensive cleaning and decontamination of pig farms with suitable detergents may be effective in inhibiting infection.
• If an outbreak is doubted, the animal locations should be detained instantly.
• Removing of infected animals with close management of burial or ignition of carcasses might be essential to lessen the risk of spread to people.
• Controlling or prohibition the movement of animals from plague-ridden farms to other areas can lessen the extent of the disease.
• As Nipah virus outbreaks have tangled pigs and/or fruit bats, forming an animal health/wildlife surveillance system, by a One Health approach, to identify Nipah cases is crucial in providing early warning for veterinary and human public health specialists.

Treatment

• There are presently no drugs or vaccines particular for Nipah virus infection though WHO has recognized Nipah as a priority disease for the WHO Research and Development Blueprint. Intensive supportive care is suggested to treat severe respiratory and neurologic problems.