FieldDxMenangle virus infectionClinical signs, differential diagnosis, treatment and prevention in pigs.
Overview
A rare zoonotic viral disease first identified in an Australian pig herd, causing severe reproductive losses. Menangle virus, a paramyxovirus carried by fruit bats (Pteropus spp.).
Clinical signs
- Pigs (Reproductive form): Characterized by a sudden outbreak of reproductive disease with fetal death and severe fetal abnormalities (congenital skeletal and neurologic defects, osteomyelitis).
- Sows exhibit mummified and stillborn fetuses, smaller litters with fewer live-born piglets, and a reduced farrowing rate (farrowing rate fell from 80%+ to a low of ~38%, averaging 60%).
- Sows return to estrus 28 days post-mating (indicating early embryonic/fetal death) or remain in pseudopregnancy for more than 60 days.
- The virus readily crosses the placenta and spreads from fetus to fetus.
- Once the infection becomes endemic in a farrow-to-finish herd, reproductive failures cease.
- No clinical signs are reported in growing/finishing pigs, but young pigs are infected around 14 to 16 weeks of age as maternal antibody declines.
- Humans: Causes a nonfatal, influenza-like febrile illness or febrile encephalitis in pig farmers and abattoir workers who have close contact with infected pigs or pig tissues.
- Lesions: Congenital skeletal and neurologic defects, osteomyelitis in fetuses; caseous necrosis.
Predisposing factors
- Presence of fruit bats/flying foxes (such as grey-headed flying-fox, black fruit bat, spectacled fruit bat) nesting in trees near the farm.
- Fruit bats are the asymptomatic natural reservoir, and bat feces/urine are the source of infection.
- The disease spreads between farms via the introduction of infected pigs.
Look-alikes to rule out
Porcine reproductive and respiratory syndrome (PRRS) Porcine Reproductive and Respiratory Syndrome (PRRS) Classical Swine Fever
Treatment
- No treatment is available.
- Young pigs are infected naturally when maternal antibodies decline at 14 to 16 weeks of age; by the time they enter the breeding herd, their active immunity is quite strong and protective.
Prevention
1. Avoid contact with all fruit bats (e.g., do not plant bat food trees in horse/pig paddocks). 2. Keep pigs on farms where there are no fruit bats nesting in surrounding trees. 3. Isolation and quarantine are the best control methods; rapid slaughter of infected animals is necessary. 4.
Source
A Textbook of the Diseases of Cattle, Horses, Sheep, Pigs and Goat by ELSEVIER (Pages 2135–2136); A Textbook of the Diseases of Cattle, Horses, Sheep, Pigs and Goat by ELSEVIER (Pages 2135–2136).
MSD Veterinary Manual — Menangle Virus Infection (accessed 2026-08-11)
Condensed and attributed, never reproduced whole. Open the full entry in the app.