Biology - Angiostrongyliasis, Abdominal
The nematode (roundworm) Angiostrongylus (=Parastrongylus) costaricensis is the causal agent of abdominal angiostrongyliasis (intestinal angiostrongyliasis). The related species A. cantonensis (rat lungworm), which causes neural angiostrongyliasis, is discussed here.
The main definitive host for A. costaricensis is the hispid cotton rat (Sigmodon hispidus); but adult worms have been found in other rodent species, such as black rats (Rattus rattus), short-tailed zygodonts (Zygodontomys brevicauda), spiny pocket mice (Heteromys adspersus), and pygmy rice rats (Oligoryzomys fulvescens). Slugs in the families Veronicellidae and Limacidae are the typical intermediate hosts.
Aberrant abdominal infections have been documented in humans, non-human primates, and other mammals, including raccoons and one opossum.
Abdominal angiostrongyliasis has mainly been reported from parts of Latin America and the Caribbean. Although A. costaricensis has been found in various animals in the southern United States, the sporadic human cases identified in the United States are thought to have been travel associated.
The clinical manifestations of abdominal angiostrongyliasis (A. costaricensis infection) arise from the parasite’s invasion of the gastrointestinal wall, and may mimic those of other conditions, such as appendicitis, Crohn’s disease, or Meckel’s diverticulum. Eosinophilia is commonly noted. Intestinal obstruction, perforation, and other complications may occur, as may ectopic infection (e.g., in the liver).