Water is a vital resource to every living thing on the earth. Once the water is contaminated (physically, chemically, biologically, or radiologically), it brought negative impacts to the living thing. This paper provides a brief review of the characterization of biological pollutants in drinking water and their effects on human health. Some biological contamination was detected in water resources such as pathogenic bacteria (Escherichia coli, Vibrio cholerae, Salmonella, etc.), viruses (hepatitis A virus, hepatitis E virus, rotavirus, etc.), parasites (Giardia, Entamoeba, Cyclospora, etc.), and parasitic worm (Ascaris lumbricoides, Ancylostoma duodenale, Strongyloides stercoralis, etc.). The diseases were significantly prevalent in developing countries due to limited access to clean water and poor sanitation. Most of the diseases had common symptoms such as diarrhea, fever, and body and muscle aches that were transmitted to humans through the fecal–oral route. About 1.7 billion children were affected by diarrhea each year and about 525,000 of the children died each year. Besides, nearly 1 million adults were killed by diarrhea every year. Some treatment was implemented to remove the biological contamination in drinking water, such as oxidation treatment, ultraviolet radiation, distillation, biologically active carbon filtration, electrochemical, and nanotechnology.

In this study, we have evaluated the efficacy of propidium monoazide quantitative polymerase chain reaction (PMA-qPCR) to differentiate between viable and non-viable Ancylostoma caninum ova. The newly developed method was validated using raw wastewater seeded with known numbers of A. caninum ova. Results of this study confirmed that PMA-qPCR has resulted in average of 88 % reduction (P < 0.05) in gene copy numbers for 50 % viable +50 % non-viable when compared with 100 % viable ova. A reduction of 100 % in gene copies was observed for 100 % non-viable ova when compared with 100 % viable ova. Similar reductions (79–80 %) in gene copies were observed for A. caninum ova-seeded raw wastewater samples (n = 18) collected from wastewater treatment plants (WWTPs) A and B. The newly developed PMA-qPCR method was applied to determine the viable ova of different helminths (A. caninum, A. duodenale, Necator americanus and Ascaris lumbricoides) in raw wastewater, human fecal and soil samples. None of the unseeded wastewater samples were positive for the above-mentioned helminths. N. americanus and A. lumbricoides ova were found in unseeded human fecal and soil samples. For the unseeded human fecal samples (1 g), an average gene copy concentration obtained from qPCR and PMA-qPCR was found to be similar (6.8 × 10⁵ ± 6.4 × 10⁵ and 6.3 × 10⁵ ± 4.7 × 10⁵) indicating the presence of viable N. americanus ova. Among the 24 unseeded soil samples tested, only one was positive for A. lumbricoides. The mean gene copy concentration in the positively identified soil sample was 1.0 × 10⁵ ± 1.5 × 10⁴ (determined by qPCR) compared to 4.9 × 10⁴ ± 3.7 × 10³ (determined by PMA-qPCR). The newly developed PMA-qPCR methods were able to detect viable helminth ova from wastewater and soil samples and could be adapted for health risk assessment.