title: Solar water disinfection (SODIS): Impact on hepatitis A virus and on a human Norovirus surrogate under natural solar conditions.
abstract: This study evaluates the effectiveness of solar water disinfection (SODIS) in the reduction and inactivation of hepatitis A virus (HAV) and of the human Norovirus surrogate, murine Norovirus (MNV-1), under natural solar conditions. Experiments were performed in 330 ml polyethylene terephthalate (PET) bottles containing HAV or MNV-1 contaminated waters (10(3) PFU/ml) that were exposed to natural sunlight for 2 to 8 h. Parallel experiments under controlled temperature and/or in darkness conditions were also included. Samples were concentrated by electropositive charged filters and analysed by RT-real time PCR (RT-qPCR) and infectivity assays. Temperature reached in bottles throughout the exposure period ranged from 22 to 40ºC. After 8 h of solar exposure (cumulative UV dose of ~828 kJ/m2 and UV irradiance of ~20 kJ/l), the results showed significant (P<0.05) reductions from 4.0 (+/-0.56)x10(4) to 3.15 (+/-0.69)x10(3) RNA copies/100ml (92.1%, 1.1 log) for HAV and from 5.91 (+/-0.59)x10(4) to 9.24 (+/-3.91)x10(3) RNA copies/100 ml (84.4%, 0.81 log) for MNV-1. SODIS conditions induced a loss of infectivity between 33.4% and 83.4% after 4 to 8 h in HAV trials, and between 33.4% and 66.7% after 6 h to 8 h in MNV-1 trials. The results obtained indicated a greater importance of sunlight radiation over the temperature as the main factor for viral reduction.
authors.affiliation: Department of Microbiology and Parasitology, CIBUS-School of Biology, University of Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Polo
authors.affiliation: Solar Platform of Almería, CIEMAT, Tabernas, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: García-Fernández
authors.affiliation: Solar Platform of Almería, CIEMAT, Tabernas, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Fernández-Ibáñez
authors.affiliation: Department of Microbiology and Parasitology, CIBUS-School of Biology, University of Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: Jesús L
authors.initials: JL
authors.lastname: Romalde
mesh_terms: D000818:Animals; D004203:Disinfection / Q000379:methods*; D030041:Hepatitis A virus / Q000528:radiation effects*; D006801:Humans; D051379:Mice; D029322:Norovirus / Q000528:radiation effects*; D011093:Polyethylene Terephthalates; D013472:Sunlight; D013696:Temperature; D014466:Ultraviolet Rays; D014871:Water Microbiology / Q000592:standards; D018508:Water Purification / Q000379:methods
chemical_list: D011093:Polyethylene Terephthalates
keywords: Solar water disinfection (SODIS); hepatitis A virus (HAV); murine Norovirus (MNV-1); water disinfection