Geographic distribution. Japan, Korea, China, Taiwan, Armenia, etc.
Life cycle. The adult worms develop in man without lung migration. The third larval stages, which are capable of invasion when ingested orally, establish themselves directly in the small intestinal wall (duodenum and jejunum) and grow to sexually mature worms.
Morphology. Adult worms are very slender, measuring 3.8-4.8 mm (male) and 4.9-6.7 mm (female) in length. The eggs differ from hookworm in their size (75-91 x 47 ㎛), having more pointed ends with advanced morula stages.
Pathology and clinical symptoms. The worms ingest blood and produce toxin in the mucosa of small intestine. Symptoms are usually mild, but in heavy infection; abdominal pain, malaise and other symptoms can be seen.
Diagnosis. Detection of eggs in fresh stool samples. Fecal culture methods can also be used.
Prevention. Avoiding consumption of raw vegetables in affected countries with poor living conditions..
An egg of Trichostrongylus orientalis at morular stage. x400.
Male reproductive organ of Trichostrongylus orientalis. Brown colored paired spicules are characteristic features.
Tai Soon Yong