VOLUME 14 (Supplement)

Detection of enteric viruses in five important tributaries of Laguna Lake, Philippines by PCR assays

Fecal contamination of water sources caused by humans and animals presents public health risks due to the presence of pathogens. Enteric viruses are important waterborne pathogens since their occurrence in contaminated water is subsequently linked to outbreaks. However, detection of these viruses is not routinely done in water quality analyses, and there is a paucity of reports on the surveillance of these pathogens. Hence establishing a baseline data for these viruses is of utmost importance. Water samples from five important tributaries of Laguna Lake in the Philippines were collected to detect the presence of human adenoviruses, noroviruses, hepatitis E and A, and rotaviruses. Samples were processed via double filtration method using 0.45 µm and 0.2 µm nitrocellulose membrane filters. Viral DNA were extracted from the 0.22 µm membranes using commercially available DNA extraction kit before doing polymerase chain reaction (PCR) assays. Real-time PCR assays showed that human adenoviruses, noroviruses, Hepatitis E, rotaviruses, astroviruses, and enteroviruses were found in the tributaries. Phylogenetic analyses of the identified adenoviruses and astroviruses revealed that they were of human origin indicating human sources of contamination in the lake. A simple filtration method coupled with a real-time PCR assay can be used to detect common enteric viruses in water samples. Identifying the sources of fecal contamination in bodies of water will contribute to an efficient risk assessment of environmental systems.