First detection of hepatitis E virus in Central Argentina: Environmental and serological survey
Section snippets
Background
The hepatitis E virus (HEV) (Hepevirus, Hepeviridae) is the causative agent of human acute hepatitis E with a worldwide distribution [1], [2], responsible for both sporadic cases and large hepatitis epidemics in developing countries [3], [4]. It is a single strand, positive sense, RNA non-enveloped virus which is classified into 4 genotypes of mammalian HEV [5]. HEV is mostly transmitted by fecal-oral routes following ingestion of contaminated water or consumption of fruits and vegetables that
Objectives
The aim of this study was to provide evidence of HEV circulation in central region of Argentina. For that, molecular detection of HEV was performed on environmental samples, as well as detection of IgG-anti HEV in healthy adult population of Córdoba city.
Environmental samples collection
Wastewater samples (n = 48) were monthly collected in the years 2007, 2009, 2010 and 2011 from the main pipe that enters the treatment plant which receives sewage discharges from about 61% of the population of Córdoba city (1,330,023 inhabitants, census 2010). Samples of the Suquía River (n = 31) were collected seasonally during 2010 in eight sampling points that cover the whole of its course across Córdoba city. During spring, point 7 could not be sampled (Fig. 1).
For each sample, 1500 mL of water
Environmental surveillance
HEV was detected in 6.3% of sewage samples (3/48: April-2007, September-2010 and March-2011) and in 3.2% of river samples (1/31: Spring-2010) by amplification of ORF 2 genomic region. From these, only one sample tested positive to ORF 1 amplification, probably due to a low sensitivity of the technique. The nucleotide sequencing analysis of both regions allowed assigning all HEV strains as Gnt-3. All samples formed distinct sequence clusters with high nucleotide similarity (Fig. 2). No
Discussion
The epidemiology of viral hepatitis has changed in several parts of the world since the introduction of hepatitis A and hepatitis B immunization programs and the incidence of acute infections caused by these viruses has been declining [25]. Hepatitis E virus has been worldwide recognized as an increasingly important cause of acute hepatitis, but testing is not widely available.
This study reports, for the first time in Argentina, the presence of Gnt-3 HEV on environmental samples. Having found
Funding
This study was supported by grants from: Secyt-Universidad Nacional de Córdoba (Secyt UNC-05/H343), Agencia Nacional de Promoción Científica y Tecnológica-Foncyt (PICT 2012-0998), Ministerio de Ciencia y Tecnología, Gobierno de la Provincia de Córdoba (MINCyT-Cba PIO 170/11 and 198/11-CICAL 175/10). SIV-Universidad Católica de Córdoba and Alberto J. Roemmers Fundation. PAB and VER are members of the researcher career from Consejo Nacional de Investigaciones Científicas – CONICET – Argentina.
Competing interests
None declared.
Ethical approval
Ethics committee of the Health Ministry of the Province of Cordoba.
Authors’ contributions
MMW designed the study, collection the data, performed the statistical analysis and drafted the manuscript; MBP, PAB and PDG contributed to the acquisition of samples and data. VER participated in revised the analysis plan, the data analysis and revised critically the manuscript. SVN, OCE, JMO and MAP revised the analysis plan and made an important intellectual contribution in the content. All authors read and approved the final version of this manuscript.
Acknowledgments
We thank Lorena Spinsanti for allowing the use of serum samples and to LACE Laboratories and Vanella Virology Institute for the use of facilities and equipment necessary for the development part of this study.
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