Nematode larvae (Spirurida: Physalopteridae) causing an acute abdominal syndrome, requiring surgical intervention, in an infant

Abstract

Laparotomy performed on an 11-mth-old baby with an acute abdominal syndrome revealed a gangrenous loop of distal small bowel. Following resection of the affected bowel, the child progressed satisfactorily for 5 days. His condition then deteriorated and operation revealed a further segment of necrotic small bowel which was resected; after this the child gradually recovered. The resected specimens consisted of infarcted bowel and small segments of mesentery. Histopathological examination of the necrotic portions showed ischaemic necrosis. Inflammatory cells, including polymorphs, eosinophils, histiocytes and plasma cells extended through the more viable portions of the submucosa, muscularis and serosa. The inflammatory process extended into the mesentery where vessels showing focal necrosis, thrombosis and endarteritis were found. Sections of larval nematode worms were present in the lumen, walls and in the adventitial coats of some of the vessels. The worms were identified as belonging to the order Spirurida, family Physalopteridae and probably to the genus Physaloptera, which are intestinal parasites of many vertebrate animals. In Australia a number of species have either been described, or are known from bandicoots, rats and other mammals. These worms use a variety of terrestrial arthropods as intermediate hosts and infection results from ingestion of the arthropod. When some larval Physalopteridae are ingested by an unusual vertebrate host they are unable to develop to maturity and burrow through the intestinal wall and encyst in the tissues. This particular variety of Physaloptera would appear to have had an affinity for utilizing blood vessels in its migratory pathway. This baby must have become infected by eating insects when placed out on grass to play during the day. Bandicoots which are surprisingly common around houses in Queensland are a likely source of the infection, but definitive identification must await studies on the life-histories of this family. Laparotomy performed on an 11-mth-old baby with an acute abdominal syndrome revealed a gangrenous loop of distal small bowel. Following resection of the affected bowel, the child progressed satisfactorily for 5 days. His condition then deteriorated and operation revealed a further segment of necrotic small bowel which was resected; after this the child gradually recovered. The resected specimens consisted of infarcted bowel and small segments of mesentery. Histopathological examination of the necrotic portions showed ischaemic necrosis. Inflammatory cells, including polymorphs, eosinophils, histiocytes and plasma cells extended through the more viable portions of the submucosa, muscularis and serosa. The inflammatory process extended into the mesentery where vessels showing focal necrosis, thrombosis and endarteritis were found. Sections of larval nematode worms were present in the lumen, walls and in the adventitial coats of some of the vessels. The worms were identified as belonging to the order Spirurida, family Physalopteridae and probably to the genus Physaloptera, which are intestinal parasites of many vertebrate animals. In Australia a number of species have either been described, or are known from bandicoots, rats and other mammals. These worms use a variety of terrestrial arthropods as intermediate hosts and infection results from ingestion of the arthropod. When some larval Physalopteridae are ingested by an unusual vertebrate host they are unable to develop to maturity and burrow through the intestinal wall and encyst in the tissues. This particular variety of Physaloptera would appear to have had an affinity for utilizing blood vessels in its migratory pathway. This baby must have become infected by eating insects when placed out on grass to play during the day. Bandicoots which are surprisingly common around houses in Queensland are a likely source of the infection, but definitive identification must await studies on the life-histories of this family.