[Intestinal myiasis in Macao]

Six cases of intestinal myiasis were diagnosed in Macao from January 1987 to August 1989, during a survey of intestinal parasites in inhabitants and on stool routine examination in hospitalized patients. The species of flies identified were Stomoxys calcitrans in 4 cases and Megalesia (Megalesia) insulana in 2 cases, M. insulana being a new record in mainland of China. During the survey of intestinal parasites 1889 human fecal samples were collected from Chinese inhabitants. 45 samples were collected on September 2 and 15 samples on September 11, 1987 in an aged home. Among them 4 samples were found to have some moving larvae, which were later identified morphologically as S. calcitrans. All these four cases were old ladies living in the aged home and they complained of mild diarrhea and abdominal pain. The fifth case was a patient with dermatosis, who had an eosinophil count of 18%. On stool examination, eggs of Clonorchis sinensis and larvae of flies were found. These larvae were cultured in food stuff containing wheat bran (100g), milk powder (18g) and water (200ml) at 30 degrees C. Within a week these larvae became pupa from which hatched adult flies identified as M. insulana which were known to be distributed in the Philippines and Hawaii but not found in the mainland of China before. 3 months later the stool from the patient was re-examined, about 200 larvae were counted in 5 ml of feces, the fly species being the same. The sixth patient was a pediatric case, again in his stool sample larvae of flies were found which were identified as M. insulana after culture. M. insulana is distributed in the Philippines, Hawaii, etc. Since a great amount of fruits was constantly imported from the Philippines and Hawaii, it remains to be confirmed whether M. insulana is imported into Macao through fruits.