Nipah and Ebola Viruses
On this page
Direct answer
Nipah virus is a bat-borne henipavirus that causes encephalitis and respiratory illness with high case fatality, while Ebola virus is a filovirus that causes severe haemorrhagic fever. Both are zoonotic viruses with negative-sense single-stranded RNA genomes, and fruit bats are the natural or suspected reservoirs. Both viruses require biosafety level 4 containment in the laboratory, and early RT-PCR confirmation drives outbreak control.
What you must remember
- Nipah family: A henipavirus in the family Paramyxoviridae, with a negative-sense single-stranded RNA genome.
- Nipah reservoir: Pteropus fruit bats, commonly called flying foxes, are the natural reservoir.
- Nipah transmission: Contaminated date palm sap in Bangladesh, intermediate pig hosts in the Malaysian outbreak, and person-to-person spread in households and hospitals.
- Nipah in India: Recurrent outbreaks in Kerala are confirmed by RT-PCR on throat swabs, urine or cerebrospinal fluid.
- Ebola family: A filovirus with a negative-sense single-stranded RNA genome, and Zaire ebolavirus is most often linked with large outbreaks.
- Ebola transmission: Direct contact with blood, body fluids and contaminated objects, including during traditional burial practices.
- Ebola vaccine: The rVSV-ZEBOV vaccine protects against Zaire ebolavirus and is used in ring vaccination.
- Containment: Both viruses are handled at biosafety level 4 facilities, and suspected samples go to designated reference laboratories.
Responding to a suspected case
A suspected case of either virus triggers a standard sequence of isolation, testing and contact tracing. The steps below reflect the principles followed in national surveillance frameworks such as the Integrated Disease Surveillance Programme.
- Isolate early: Patients are isolated with strict barrier nursing, since both viruses spread through contact with body fluids and Nipah can also spread through respiratory droplets between people.
- Collect the right samples: For Nipah, throat swabs, urine and cerebrospinal fluid are tested by RT-PCR, while for Ebola, blood is tested by RT-PCR and antigen detection.
- Route samples to reference laboratories: Suspected samples go to designated reference laboratories with containment facilities, and in India the National Institute of Virology in Pune handles Nipah confirmation.
- Trace contacts: Every contact is listed and monitored through the incubation period, which is commonly about 4 to 14 days for Nipah and up to 21 days for Ebola.
- Report and close the outbreak: Cases are notified through surveillance, and an outbreak is declared over only after a full incubation period has passed without new cases.
Where the exam tries to catch you
Questions on these viruses test the reservoir, the transmission route and the correct laboratory test.
- Trap: Assuming Nipah spreads only from bats to humans. Correct: Pig amplification and person-to-person spread in hospitals show that Nipah can move onward through several routes.
- Trap: Calling Ebola an airborne infection. Correct: Ebola spreads through direct contact with body fluids, so it is not transmitted by air in standard circumstances.
- Trap: Relying on IgM serology for an acute Nipah diagnosis. Correct: RT-PCR on throat swab, urine or cerebrospinal fluid is the preferred acute test.
Frequently asked questions
Which bat is the natural reservoir of Nipah virus?
Pteropus fruit bats, commonly called flying foxes, are the natural reservoir of Nipah virus. Infection reaches people through contaminated date palm sap, through intermediate animals such as pigs, or directly through close contact with infected people.
Why is Nipah virus a concern in India?
Nipah virus causes recurrent outbreaks in Kerala, with encephalitis and respiratory illness and high case fatality. Early RT-PCR testing and rapid contact tracing are central to controlling each outbreak.
Which Ebola species is most often linked with large outbreaks?
Zaire ebolavirus is the species most often associated with large outbreaks, including the West Africa epidemic of 2014 to 2016. Its person-to-person transmission and high case fatality make it the most important species for surveillance.
Which vaccine protects against Zaire ebolavirus?
The rVSV-ZEBOV vaccine protects against Zaire ebolavirus and was used in ring vaccination during recent outbreaks. Ring vaccination involves vaccinating contacts and contacts of contacts to contain spread.
What biosafety level is required for Nipah and Ebola viruses?
Both viruses are handled at biosafety level 4 containment in the laboratory, because they cause severe disease and handling them carries a risk of laboratory-acquired infection. Clinical samples are therefore routed to designated reference laboratories.