Major human Hepatitis A virus genotype in Hong Kong marine waters and detection by real-time PCR
MARINE POLLUTION BULLETIN
Authors: Yang, Ning; Chu, Daniel Ling Ho; Wong, Minnie Man Lai; Qi, Huizhou; Wu, Rudolf Shiu Sun; Kong, Richard Yuen Chong
Abstract
Marine waters from seven sites around Hong Kong with varying levels of sewage pollution were analyzed for Hepatitis A virus (HAV) by PCR cloning and DNA sequencing of the highly variable VP1/2A junction of the HAV genome. Phylogenetic analysis of 10 PCR clones from each of the HAV-positive marine sites indicated that human HAV genotype IB is the most widely distributed type in Hong Kong waters. A sensitive and quantitative TaqMan-based PCR method targeting the 5'-noncoding region (5'-NCR) of HAV was used to quantify HAV particles in marine water samples along with the total Escherichia coli counts being enumerated on TBX medium for comparison. Our results showed that no correlation of any significance between HAV and E. coli counts was observed which underscores the inadequacy in using E. coli as a sanitary standard to predict the levels of HAV in marine waters. (C) 2011 Elsevier Ltd. All rights reserved.
Molecular characterization of hepatitis-A-virus infections, in the context of two outbreaks in southern Thailand
ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY
Authors: Theamboonlers, A; Jantaradsamee, P; Chatchatee, P; Chongsrisawat, V; Mokmula, M; Poovorawan, Y
Abstract
As hepatitis A virus (HAV) is usually transmitted through the faecal-oral route, hepatitis A is a communicable disease. In countries of intermediate to low endemicity, sudden outbreaks of human infection with the virus may occur. Between September 2001 and April 2002, there were two outbreaks of HAV infection in the Ruso and Yeengor districts of Narathiwas province, in southern Thailand. Isolates of HAV were recovered during these outbreaks, from 14 in-patients with acute hepatitis in Ruso (12 positive for anti-HAV IgM and all positive for HAV RNA), 16 children with asymptomatic infection in Yeengor (14 positive for anti-HAV IgM and nine for HAV RNA), and four isolated cases in Bangkok (all positive for anti-HAV IgM). Molecular characterization of the VP1-P2A region of each isolate was followed by phylogenetic analysis. All of the isolates from Narathiwas province were found to be of genotype 1a, to have the same VP1 nucleotide sequence, and to show a high level of sequence homology (greater than or equal to99.5%) with the isolates from Bangkok and with previous Thai isolates. These results should facilitate further research into HAV transmission and genotype identification in community outbreaks.