Nipah Virus Infection (NiV) : Causative Agent, History, Epidemiology, Outbreaks, Mode of Infection, Spread, Host, Clinical Signs & Symptoms, Diagnosis, Treatment, Cure, Prevention, Vaccine, & Risk of Exposure
Introduction
- Nipah virus infection ((NiV) is a newly emerging zoonotic disease that causes severe disease in both animals and humans.
- Incubation period: 3-14 days
Causative Virus
- Causing agent : Nipah virus (NiV)
Nipah virus (NiV)
- Nipah virus is a zoonotic paramyxovirus that is able to infect and cause disease in humans.
- It lacks neuraminidase activity.
- Family: Paramyxoviridae
- Genus: Henipavirus
- Biosafety Level 4 pathogen
History
- Nipah & Hendra virus from genus Henipavirus were recognized in the late 1990s in disease outbreaks in Australasia.
Epidemiology
In 1998-99, the Nipah virus, caused an epidemic of severe encephalitis amongst Malaysian pig farmers.
- Mode of Infection: Direct contact with pig secretions.
- Intermediate hosts: Pigs
- Mortality rate> 30%
- Antibodies to the Hendra virus are present in 76% of cases.
In Bangladesh in 2004, humans became infected with NiV as a result of consuming date palm sap that had been contaminated by infected fruit bats.
- No intermediate hosts.
Outbreaks in INDIA
- Siliguri, West Bengal (2001)- 45 deaths
- Nadia, West Bengal (2001)- 05 deaths
- Kerala (2018)
Host
- Natural host for both Nipah and Hendra viruses: Fruit bats (flying foxes) of the Pteropodidae Family, Pteropus genus.
Mode of Transmission
- Direct contact with pigs (secretions).
- Fruits contaminated by infected fruit bats.
- Human-to-human transmission (Documented in a hospital setting in India)
Symptoms
NiV infection in humans has a range of clinical presentations, from asymptomatic infection to acute respiratory syndrome and fatal encephalitis. Some patients (<10%) may develop late onset encephalitis months to several years after the initial Nipah virus infection. Some may develop persistent neurologic deficits.
Following symptoms are observed in patients:
- Headache
- Fever
- Drowsiness
- Confusion
- Disorientation
- Coma
Diagnosis
- Real time polymerase chain reaction (RT-PCR): Detection during acute and convalescent stage.
- Viral RNA Isolation: Isolated from saliva.
- IgG and IgM antibody detection: Only after recovery to confirm NiV infection.
- Immunohistochemistry on tissues collected during autopsy: To confirm the NiV infection.
Treatment
No effective treatment is available.
- No effective antiviral drugs are available.
Primary treatment : Intensive Supportive Care
Treatment approach in trial
- Ribavirin.
- Passive immunization using a human monoclonal antibody that targets the Nipah G glycoprotein.
- Chloroquine (Block the critical functions needed for maturation of Nipah virus).
- m102.4 (human monoclonal antibody).
Prevention
There is no vaccine for either humans or animals.
Prevention of NiV infection is critical because there is no proven treatment for the disease. Consider the following the measures to prevent infection:
- Avoiding direct contact with infected pigs, bats and humans in endemic regions.
- Avoid drinking of palm toddy (contaminated by bat excrete), eating of partially consumed fruits and using water from wells infested by bats.
- Health professionals & caretakers of such patients should take precautionary measures, such as wearing masks and gloves.
- Implementing the strict control practices prevent nosocomial infections.
- Awareness.
- Surveillance.
Risk of exposure
- High in hospital workers and caretakers of infected patients.
If you feel uneasiness or any other matching symptom, when in and around an infected region, get yourself checked immediately!
