Infectious Disease Compendium

Pentastomiasis

Microbiology

Snake Parasite:  

"The Pentastomida are a peculiar group of gonochoric, vermiform endoparasites, currently classified as a unique phylum, related to branchiuran crustaceans. The main characteristics of this group of ancient parasitic arthropods are an often annulated elongate body and a mouth typically flanked by 2 pairs of hooks.

Human visceral pentastomiasis can be caused by several species of pentastomes: Linguatula serrata (worldwide, predominantly the Middle East), A. armillatus (West and Central Africa), A. moniliformis (Southeast Asia), A. grandis (Africa), A. agkistrodontis (China), Porocephalus crotali (worldwide, predominantly the Americas), and P. taiwana (China).

Reported cases of human visceral pentastomiasis were caused mainly by A. armillatus pentastomes from infected snakes, which shed ova in excretions and respiratory secretions, thereby contaminating vegetation and water. Intermediate hosts are mainly rodents and small mammals. After oral uptake by the intermediate host, the ova hatch and free 4-legged primary larvae that migrate to the viscera, become encapsulated, and after several molts transform into legless nymphs. The cycle is complete when the intermediate host is in turn consumed by a snake of an appropriate species." (PubMed for icky pictures).

Epidemiologic Risks

Humans can become intermediate hosts eating environmental ova (mmmmmmm), by eating undercooked infected snake meat (my snake is always well done), or by sucking in ova when in close contact with snakes. Like I am going to be in close contact with snakes.

Syndromes

Usually asymptomatic and found incidentally in the abdomen during surgery for other reasons.

Treatment

None except take them out.

Notes

Ocular involvement has been reported in the southern United States.

Last Update: 12/18/18.