Hendra and Nipah viruses

At a glance

Shape

Pleomorphic, with a helical nucleocapsid

Genome

Single-stranded, negative-sense RNA, non-segmented

Envelope

Enveloped

Family

Paramyxoviridae, genus Henipavirus

Size

About 40 to 600 nm (pleomorphic)

Morphology

• Envelope with an attachment glycoprotein (G) that binds ephrin-B2 and B3 and a fusion protein (F)
• Ephrin-B2 is present on endothelium and neurons, which explains vasculitis and brain involvement
• Related to measles and mumps viruses (same family)

Transmission

• Fruit bats (Pteropus, flying foxes) shed virus in urine, saliva and droppings
• Nipah, Malaysia 1998 to 1999: from pigs to pig farmers
• Nipah, Bangladesh and India: raw date palm sap contaminated by bats, then person to person among family members and in hospitals
• Hendra, Australia: bats to horses, then horses to people through blood, secretions or birthing material; no person-to-person spread documented
• Nursing care for Nipah: standard, contact and droplet precautions

Reservoir: Pteropus fruit bats (flying foxes)

Vector: No vector; spread by direct contact with bats, amplifying animals (pigs, horses), contaminated food or patients

Isolation precautions

What the care team adds to standard precautions.

Contact

Gown and gloves; dedicated equipment. For C. difficile, soap-and-water hand washing.

Droplet

Surgical mask within about a metre; single room.

Virulence factors

• Systemic vasculitis of small vessels with thrombosis and micro-infarcts, especially in the brain
• Direct infection of neurons causes encephalitis
• Nipah can stay latent and cause relapsing or late-onset encephalitis months to years later
• Infection of respiratory epithelium explains cough, pneumonia and person-to-person spread of Nipah

Diseases it causes

• Acute encephalitis from Nipah or Hendra virus Viral encephalitis (herpes simplex encephalitis) →
• Severe respiratory illness and pneumonia (Nipah, Hendra)
• Relapsing or late-onset Nipah encephalitis

Clinical picture

• Nipah incubation 3 to 14 days (rarely up to 45): fever, headache, myalgia, vomiting, then drowsiness, confusion, seizures and coma
• Cough and breathing difficulty, often prominent in Bangladesh and India outbreaks
• Case fatality 40 to 75% for Nipah; about 57% of the few Hendra cases died
• About 1 in 5 survivors keep long-term neurological problems

Diagnosis

• RT-PCR on throat or nasal swabs, CSF, blood or urine early in illness
• IgM and IgG ELISA later in illness
• Samples are handled in maximum-containment laboratories
• Brain MRI may show multiple small lesions in white matter

Treatment

There is no proven specific treatment; early intensive supportive care (airway, ventilation, seizure control, fluids) improves survival. Monoclonal antibodies and antivirals are under study in trials.

Drug class only; doses and regimens are set by the clinician from the current guideline.

Prevention

• Do not drink raw date palm sap; cover sap collection pots and boil fresh juice
• Wash and peel fruit; discard fruit with bite marks
• Gloves and protective clothing when handling sick pigs or horses, at slaughter and in culls
• Infection control in hospitals; a vaccine for horses (Hendra) exists in Australia; no human vaccine yet

Test yourself

Think of the answer, then tap the question to see it.

Add to my cards (3)

Connections

← Back to the group: Other viruses and prions

Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: Nipah virus (World Health Organization (WHO), 2026); About Hendra Disease (CDC, 2024).

Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake

Send

Representative model, for educational purposes only.