An intestinal parasitological survey among the Jehai Orang Aslis (aborigines) of the Temenggor forest, Perak state, Malaysia

Background: In Malaysia, the most common soiltransmitted helminth infections are A. lumbricoides, T. trichiura and hookworms. However, as there have been no extensive surveys on these infections, it is difficult to estimate with certainty the current overall incidence of infection with soil-transmitted helminths (STHs) among the Malaysian population including the Orang Aslis. Materials and Methods: A study was conducted to determine the infection rate of soil-transmitted helminths and intestinal protozoa among the Jehai Orang Aslis (Aborigines). The study was conducted between December 2005 and August 2006, in four Jehai villages of Perak State, Malaysia. A total of 175 stool samples was collected and personal identification such as name, age, household identification, and date of collection were recorded on the spot during collection. Faecal smears were stained with Trichrome for protozoa cysts and trophozoites and the modified Ziehl-Neelsen acid-fast method for the oocyst of Cryptosporidium and Isospora. Wet mounts with tincture of iodine of both stool samples (10% formalin and PVA) were also examined to detect cysts, ova and larva of intestinal helminths. Results: The prevalence rates of Trichuris trichiura, Ascaris lumbricoides and hookworm among the Jehai were 70.8%, 24.0%, and 10.9% respectively. The prevalence of Entamoeba coli, Entamoeba histolytica, Giardia intestinalis, Blastocystis hominis, and microsporidium was 40.6%, 33.7%, 25.7%, 91.4%, and 27.4% respectively. The difference in prevalence rates among the different age-groups and sex were found not significant. Children aged 0-9 years old had the highest prevalence rate of intestinal parasites and only 2 (1.1%) were free of any intestinal parasites. Conclusion: Intestinal parasitic infections were therefore still common among these people. Children aged 0-9 years old were found to have the highest infection rate of all the intestinal parasites examined. Further investigations are needed to determine more specific transmission of these infections, so that an attempt to control these infections can be made.