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Causative Agent

Nipah virus, Paramyxoviridae family.

Incubation Period

4-45 days

Infectious Period

Possible human-to-human transmission reported in Bangladesh.


Via direct contact with secretions, tissues or respiratory droplets of sick pigs. Ingestion of raw fruits contaminated with urine or saliva of infected fruit bats reported in India and Bangladesh outbreaks. Contact with secretions and excretions of patients reported as probable mode of transmission in Bangladesh


A newly described human pathogen. The first human cases occurred in a zoonotic encephalitic outbreak between September 1998 and June 1999 in Malaysia and Singapore. Mortality was up to 40%. Bats of the genus Pteropus are reservoirs for Nipah virus in Malaysia. The disease caused a relatively mild disease in pigs. No new cases reported in Singapore or Malaysia since then.

Further outbreaks of Nipah virus infection have occurred elsewhere, mainly in western Bangladesh and also West Bengal, India.

  • Acute encephalitis picture with initial symptoms of fever, headache, myalgia, vomiting and sore throat, followed by dizziness, drowsiness, altered consciousness, seizures and coma..
  • May present as an atypical pneumonia, and acute respiratory distress.
  • Relapse encephalitis and late-onset encephalitis in those with initial non- encephalitic or asymptomatic diseases reported.

  • CSF abnormal in up to 75% of patients with lymphocytic pleocytosis and elevated protein.
  • Magnetic resonance imaging showed distinctive changes of multiple discrete and small high signal lesions, best seen with fluid-attenuated inversion recovery (FLAIR) sequences.
  • Serology is used for diagnosis. Paired samples demonstrating seroconversion confirms the diagnosis. A single sample with a titre of >1:400 is suggestive of acute infection.
  • Reverse-transcriptase PCR in CSF and tissue.

A legally notifiable disease in Singapore. Notify Ministry of Health (Form MD 131 or electronically via CD-LENS) not later than 24 hours from the time of diagnosis. Call MOH Communicable Diseases Surveillance team at: 98171463 as soon as the diagnosis is suspected

  • Supportive
  • Role of ribavirin uncertain.

  • Prevention by avoiding animals that are known to be infected and using appropriate personal protective equipment devices when in contact with potentially infected animals.
  • Early recognition of the disease in the intermediate animal host.
  • Quarantine of affected animal premises.
  • Gloves and protective equipment should be worn when caring for ill patients. Regular hand washing after caring or visiting sick people.


  1. Chua KB, Goh KJ, Wong KT, et al. Fatal encephalitis due to Nipah virus among pig-farmers in Malaysia. Lancet 1999; 354:1257-9
  2. Paton NI, Leo YS, Zaki SR, et al. Outbreak of Nipah-virus infection among abattoir workers in Singapore. Lancet 1999; 354:1253-6
  3. Lee KE, Umapathi T, Tan CB, et al. The neurological manifestations of Nipah virus encephalitis, a novel paramyxovirus. Ann Neurol 1999; 464:28-32
  4. WHO. Nipah virus. July 2009. Available at: Accessed August 2010
  5. Luby SP, Gurley ES, Hossain MJ . Transmission of human infection with Nipah virus. Clin Infect Dis. 2009; 49:1743-8

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