Nipah Virus : A Review

 

Vigy Elizebth Cherian

Assistant Professor, Sharda University, Greater Noida, NCR, Delhi

 

ABSTRACT:

Nipah virus (NiV) infection is a newly emerging zoonosis that causes severe disease in both animals and humans. The natural host of the virus are fruit bats of the Pteropodidae Family, Pteropus genus. The Nipah virus is a type of RNA virus in the genus Henipavirus.  It can both spread between people and from other animals to people.  Spread typically requires direct contact with an infected source. The virus normally circulates among specific types of fruit bats.  Diagnosis is based on symptoms and confirmed by laboratory testing. NiV infection in humans has a range of clinical presentations, from asymptomatic infection to acute respiratory syndrome and fatal encephalitis. NiV is also capable of causing disease in pigs and other domestic animals. There is no vaccine for either humans or animals. The primary treatment for human cases is intensive supportive care. There is no approved specific therapy for this infection.

 

 

 

INTRODUCTION:

NiV was first identified during an outbreak of disease that took place in Kampung Sungai Nipah, Malaysia in 1998; the virus was named after the village. On this occasion, pigs were the intermediate hosts. This first recorded outbreak began in 1998-1999 and reached Singapore. A new strain occurred in 2001 in Bangladesh and India. Small outbreaks of NiV have happened in these countries since 2001.  An outbreak in India (state of Kerala) occurred in May 2018. Fruit bats and rabbits are the likely sources of NiV that infected people. The Indian government sources say that the situation is currently under control. During this outbreak, at least 11 people have died and another 14 people contracted the virus, while another 22 are awaiting test results. Human-to-human transmission has also been documented, including in a hospital setting in India¹.

 

 

 

WHAT IS NIPAH VIRUS INFECTION (NIV)?

Nipah virus infection is a zoonosis transferred by contact with an NiV-infected animal or person or their secretions that has a high fatality rate in infected humans¹.

 

WHAT CAUSES A NIPAH VIRUS INFECTION?

Nipah virus causes NiV².

 

IS A NIPAH VIRUS INFECTION CONTAGIOUS?

Yes, the virus is moderately contagious as it needs close contact and usually infects the family members and/or medical caregivers of NiV-infected individuals².

 

WHAT IS THE INCUBATION PERIOD FOR A NIPAH VIRUS INFECTION?

The incubation period (time from initial exposure to virus to when symptoms begin) for NiV usually varies from about five to 14 days. There have been a few cases with much longer incubation periods, as long as 45 days².

 

WHAT IS THE CONTAGIOUS PERIOD FOR A NIPAH VIRUS INFECTION?

There is not a complete understanding the contagious period for infection, but it likely begins during the incubation period (proven in pigs) and continues until the patient stops shedding virus. In most patients, this occurs when the symptoms and signs of the infection are diminished or gone³.

 

WHAT ARE RISK FACTORS FOR A NIPAH VIRUS INFECTION?

The risk factors for this infection include having close contact with infected animals such as pigs, bats, and/or humans infected with the virus. In addition, consumption of raw date palm sap is a significant risk factor since bat excrement often contaminates this substance³.

 

WHAT ARE SIGNS AND SYMPTOMS OF A NIPAH VIRUS INFECTION?

The signs and symptoms of NiV infection begin with

·      Fever and headache,

·      Myalgia (muscle aches),

·      Sore throat,

·      Vomiting,

·      Dizziness and/or

·      Acute respiratory syndrome or atypical pneumonia.

 

Encephalitis follows and those infected may exhibit drowsiness, disorientation, mentaln confusion, altered consciousness, and seizures that can progress, within 24-48 hours, to coma and eventually death⁴.

 

WHAT TESTS DIAGNOSE A NIPAH VIRUS INFECTION?

A combination of tests diagnose NiV. Viral isolation, RT-PCR, and antibody detection by the ELISA tests are the tests that health care professionals use most often to diagnose Nipah virus infection⁴.

WHAT ARE TREATMENTS FOR A NIPAH VIRUS INFECTION?

According to the U.S. Centers for Disease Control and Prevention (CDC), supportive care is the only current treatment for this viral infection. There is no vaccine specifically available to protect humans. In some researchers suggest that the antiviral drug ribavirin may be useful, but there is little or no data to support this. A human monoclonal antibody that targets the G glycoprotein of NiV has shown benefit in a ferret animal model of this disease, but researchers have not studied the effects of the antibody in humans⁴.

 

WHAT IS THE PROGNOSIS OF A NIPAH VIRUS INFECTION?

The prognosis of NiV infections is fair to poor. The fatality rate is estimated by the World Health Organization (WHO) to range from 40%-75%, depending upon the local capabilities for surveillance and clinical management (supportive care). Survivors may have residual neurological problems such as seizures and/or personality changes. A few survivors who recover may subsequently relapse or develop delayed onset encephalitis⁵.

 

IS THERE A WAY TO PREVENT NIPAH VIRUS INFECTIONS?

There are ways to reduce the risk of developing NiV infections. For example, individuals should avoid date palm sap and any bats or potentially infected domestic animals such as infected pigs. The WHO suggests that health care professionals wear gloves and other protective clothing during any pig slaughtering and culling procedures. Avoid contagion, the communication of disease from one person to another by close contact. Medical caregivers should employ quarantine methods and use barrier methods such as gloves, masks, and disposable gowns, as they are at high risk of person-to-person transmission of NiV⁵.

 

REFERENCE:

1.     Signs and Symptoms Nipah Virus (NiV)". CDC. Retrieved 24 May 2018.

2.     WHO Nipah Virus (NiV) Infection". www.who.int. Archived from the original on 18 April 2018. Retrieved 21 May 2018.

3.     Transmission Nipah Virus (NiV)". CDC. 20 March 2014. Retrieved 24 May 2018.

4.     Diagnosis Nipah Virus (NiV)". CDC. 20 March 2014. Retrieved 24 May 2018.

5.     Prevention Nipah Virus (NiV)". CDC. 20 March 2014. Retrieved 24 May 2018.

 

 

 

Received on 03.08.2018       Modified on 16.08.2018

Accepted on 09.09.2018       ©A&V Publications All right reserved