(Armillifer spp., Porocephalus spp.)
Armillifer spp. are parasitic crustaceans belonging to the group Pentastomida, whose immature forms are incidentally discovered within the abdominal cavity and viscera of dogs and cats. They are mostly non-pathogenic.
|Parasite species: Armillifer armillatus, Armillifer moniliformis, Armillifer grandis, Armillifer agkistrodontis, Porocephalus crotali|
|Common name: Visceral pentastomids|
|Hosts: Snakes and other reptiles are definitive hosts, small mammals (rodents) are intermediate hosts. Dogs, cats and humans are accidental hosts for larval and nymphal stages|
|Pre-patent period: N/A|
|Location in the host: Usually abdominal cavity within viscera|
|Distribution: Tropics and subtropics|
|Transmission route: Ingestion of parasite eggs shed by reptiles, ingestion of undercooked reptile meat/rodents|
|Zoonotic: Yes (snakes are primary reservoirs)|
Visceral pentastomiasis has been reported in humans throughout the tropics and subtropics and is considered an emerging zoonosis in West Africa. Armillifer armillatus is present in West and Central Africa, A. moniliformis in Southeast Asia, A. grandis in Africa, A. agkistrodontis in China, and Porocephalus crotali is worldwide distributed.
Visceral pentastomiasis is usually asymptomatic. Rarely, large parasite loads may result in abdominal or thoracic involvement due to organ dysfunction.
Nymphs may be incidentally discovered within the liver, mesenteries, spleen, and lungs during surgery (Fig. 1) or coiled opacities of calcified dead parasites may be observed on abdominal or chest radiographs.
Visceral pentastomiasis is usually asymptomatic and surgical removal of the nymphs should be considered only for symptomatic animals with high parasite loads.
Owners should be advised to prevent their animals from hunting and roaming freely.
Dog (and cats) do not pose a direct risk to humans