PUBLIC HEALTH PROBLEM OF INTESTINAL PARASITES IN NEPAL

Research Completed entitled "Public Health Problem of Intestinal Parasites in Nepal" 

funded by 

Ministry of Education, Science and Technology, Singhadurbar, Kathmandu

SUMMARY

BACKGROUND:

Consumption of raw vegetables is a common practice in Nepal. However, the contamination of such raw vegetables with intestinal parasites possess potential threat to the health of the population especially to immunocompromised groups such as children. Hence the study was conducted with objectives to determine the contamination rate of intestinal parasites on raw vegetables sold in Kathmandu valley and to know the level of contamination of farming sites and water sources used for irrigation. The study also aimed to determine the parasitic infections among the school children.

METHODS:

The study was conducted from January to May 2018 at Central Department of Microbiology, Tribhuvan University. A total of 212 stool samples were collected from different public and private schools at Kathmandu valley. Similarly, 190 vegetable samples (90 from field and 100 from markets), 100 water samples from irrigation sites and 100 soil samples from farming site were collected and processed following standard protocol. Each sample was processed for concentration of parasites by sedimentation and floatation techniques. Each the concentrated samples were observed under microscope by wet mount and iodine preparation.  Additionally, modified acid-fast staining technique was done for the detection of coccidian oocysts. 

RESULTS:

The overall intestinal parasitosis among school children was found to be 16.0% with significantly higher among the those using untreated water for drinking. The infection rate was slightly higher in male children and comparatively higher in the age group of 9-12 years however the results were not statistically significant. Altogether 8 different parasites were reported among which the protozoa Entamoeba histolyticatop the list followed by Giardia lamblia, Trichuria trichiura, Taenia spp. Ascaris lumbriciodes, Cyclospora cayetanensis, Hookworm and Blastocystis hominis.

The intestinal parasitic contamination was found in 44.2% of the vegetable samples. The maximum contamination was found in coriander followed by leafy vegetables such as mustard leaves, onion leaves etc. The lowest contamination rate was observed in cucumber. Since cucumber was not found in field, the contamination in that vegetable might be during transportation. The contamination rate was found higher in the vegetable samples collected from field than that of collected from markets. E. histolytica was the most common protozoa and A. lumbricoides was the most predominant helminths isolated from raw vegetables. Likewise, 43% of the soil samples and 61% of water samples were found to be contaminated with different intestinal parasites. The predominant parasites in soil and water samples were A. lumbricoides and G. lamblia respectively.

CONCLUSION:

Although parasitic infection among the human population was found to be in decreasing trend, the contamination rate of vegetable samples was found to be still high. These raw vegetables could be the sources of parasitic outbreaks in the community. The use of untreated sewage water for the irrigation and washings, use of night soils as fertilizers and unproperly transportation and storage were observed during the study which might be the main factors for the contamination of vegetables by intestinal parasites.

RECOMMENDATION:

1.  Similar parasites were identified in both from human and environmental samples which clearly showed the possibility of parasitic infection to human from the environment via different routes, hence we should identify those routes, sanitize our surrounding and manage good hygiene practice (handwashing, safe drinking water, good food hygiene) to control all possible parasitic infections.