Hepatitis department, National Institute of Virology, 130/1, Sus Road, Pashan, Pune-411021, India.
Abstracts of the papers presented at the International Conference of Indian Virological Society on “Emerging and Re-emerging viral Diseases of the Tropics and Subtropics” at Indian Agricultural Research Institute, New Delhi, India, December 11–14, 2007.
Unsafe drinking water is a leading cause of preventable disease in developing countries. Low-income populations are particularly at risk of such diseases because of the unavailability of safe water and sanitation. Interventions to treat and maintain the microbial quality of water at the household level are a promising alternative for households without access to a reliable supply of safe drinking water. This study describes the development of a sensitive methodology for Virological evaluation of domestic water purifiers using Hepatitis E Virus (HEV) as a model virus. Various commercially available domestic water purification systems widely used through out the country were evaluated for their efficacy to effectively remove/destroy the seeded HEV particles. Seven water purification units used for household water treatment were procured. These units were using technologies such as Activated carbon filtration, Sediment filter, Resin filter, Polyester filter, UV radiation treatment, Hollow fiber poly-acrylo nitrile(PAN) membrane. Five liter of distilled water was spiked with virus stock containing ∼106 viral particles and passed through the purification unit according to the manufacturer's instructions. The purified water was concentrated to a volume 0f ∼3ml by two-step membrane filtration based concentration protocol which uses combination of tangential flow filtration technology and ultra filtration. Each concentrated sample was subjected to quantitative real time PCR. Copy number of viral particles recovered from the purified water was determined. Real time PCR results showed that 6/7 concentrated samples were positive for HEV Type I RNA. Geometric mean viral log reductions for the units varied between 0 (no reduction) to 6 log (complete removal). Membrane filtration was found to be the only efficient method for the removal of viruses.
