<![CDATA[According to World Health Organisation (WHO) estimates, at least 1,8 billion people consume contaminated water worldwide, hence most of the diarrheal disease in the world is attributable to unsafe water, and the lack of sanitation and hygiene. Water utilization by humans and animals can generate biological pollutants which may contaminate the water. These contaminants come from waste products that may contain bacteria, protozoa, and other parasites. This was a descriptive study with cross sectional design and simple random sampling to determine the contamination of water source by pathogens, particularly parasites at Region V Pangkalan Masyhur sub-district, Medan Johor district, Medan, North Sumatera in 2012. Samples were obtained from each house, depending on the main water source used, either from tap water, open wells, or the nearby river streams. Modified Caldwell’s sedimentation technique was applied to examine the samples under light microscope. Out of the 103 water samples collected, most were from tap water (78 samples), followed by open wells (19 samples), and only six were from the nearby river streams. We found Paramecium caudatum from nine samples (8,7%) collected from the open wells and the nearby river streams, followed by hookworm larva in one tap water sample (1%). No protozoa such as Entamoeba spp., Cryptosporidium spp., and Giardia spp. found in any of the samples. Based on this data, the abundant presence of P.caudatum represented the condition of high organic debris in the open wells and the nearby river streams. Additionally, the presence of hookworm larva in the tap water indicated the distribution system was contaminated with the surrounding soil. Hence it is imperative to provide counseling about optimal environmental sanitation and clean water management, including proper maintenance for water source and its distribution system. Tap water distribution, including its network of pipe deliverance system, must be checked and maintained regularly.]]>
