Detection and characterization of hepatitis A virus and Norovirus in estuarine water samples using ultrafiltration - RT-PCR integrated methods

Waterborne outbreaks of hepatitis A and Norovirus disease have been reported and associated with contaminated water supply in various countries. However, in Mexico, there are no studies that report HAV and NV presence in water. This study reports the application of ultrafiltration and RT-nested PCR methods to concentrate and identify these viruses. Forty estuarine water samples were collected from the Huizache Caimanero Lagunary Complex. Samples were concentrated by ultrafiltration system (UFS) and RT-nested PCR was performed for HAV and NV identification. These viruses were found in 80% and 70% of the samples collected respectively and both were present in 57.5%. The DNA sequences analysis showed that 21 estuarine water samples were associated with HAV and 13 with NV. Faecal coliforms were isolated in 48.57% of the samples, while Escherichia coli were found in 34.28%. DNA sequencing showed that the genotype IB for HAV and GII for NV were predominant in MExico. No significant relationships were detected between indicators and viruses (P < 0.05). This study shows that the UFS is adequate for viral concentration. This is the first study analysing the genetic sequence of HAV and NV isolated from Mexican estuarine water.