- Infections with Capillaria philippinensis are rare, but potentially fatal
- Transmission by eating infected fish
- Endogenous multiplication resulting in chronic malabsorption and diarrhoea
Capillaria philippinensis is a nematode which causes severe infections. The parasite was discovered in 1960 in Luzon, an island in the Philippines. Subsequently it was also found in Thailand, Indonesia, Egypt, Japan, Taiwan, Korea and Iran. It is a parasite of fish-eating waterbirds. The infection occurs due to eating infected fish which live in fresh or brackish water. The larvae are found in the muscles of the fish. It is an intestinal nematode which has an intermediate host (most nematodes don’t). After developing to adult forms the parasites, which are 2 to 4 mm long, live in the mucosa of the small intestine. The worm is capable of multiplication in the human intestine (cf. Strongyloides). This phenomenon may lead to severe infection (high worm load). The incubation period can be very long (many months). Chronic watery diarrhoea, malabsorption and cachexia follow. The diarrhoea can be high volume (several litres per day). Ascites, pleural fluid and severe electrolyte imbalance including hypokalaemia may occur. The infection is sometimes fatal if not treated in time.
Diagnosis and treatment
Diagnosis is made by means of faecal examination. Often it is necessary to analyse multiple stool samples before eggs are found. Intestinal biopsy can show worm fragments. Every infection must be treated promptly with mebendazole, 200 mg x 2 per day for 20 days or albendazole x 10 days. Cooking fish prevents the infection. Eating raw fish is a culinary habit in many Asiatic countries and this is difficult to change.