Diarrhoea in patients infected with Blastocystis hominis

Abstract

Stool specimens received in the last two years at the Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur were screened for faecal pathogens (parasites, bacteria and viruses). Blastocystis hominis was the commonest parasitic infection, occurring in 59 of the 1041 stool specimens examined. Giardia was present in 6 patients and Trichuris in 6 others. B. hominis was present as the only pathogen in 24 stool samples. Diarrhoea was the leading symptom and was present in 20 of 24 Blastocystis-infected patients. The next common symptom was abdominal pain occurring in 12 patients, followed by bloated sensation in the abdomen in 6 cases, fever in 5, vomiting and nausea in 4, and heartburn in 3 others. A few non-specific symptoms like anorexia, headache, fatigue, backache, myalgia and arthralgia were present in a small number of patients. The parasite race was highest in the age group 20-40 years. This study provides evidence to incriminate Blastocystis as a diarrhoea causing pathogen, as we could detect no other pathogen in these 20 Blastocystis-infected patients. As more report around the world implicate the pathogenic potential of the parasite, clinicians should consider Blastocystis hominis as a possible cause of diarrhoea.