The Impact of the Extreme Amazonian Flood Season on the Incidence of Viral Gastroenteritis Cases.
During the Amazonian flood season in 2012, the Negro River reached its highest level in 110 years, submerging residential and commercial areas which appeared associated with an elevation in the observed gastroenteritis cases in the city of Manaus. The aim of this study was to evaluate the microbiological water quality of the Negro River basin during this extreme flood to investigate this apparent association between the illness cases and the population exposed to the contaminated waters. Forty water samples were collected and analysed for classic and emerging enteric viruses. Human adenoviruses, group A rotaviruses and genogroup II noroviruses were detected in 100, 77.5 and 27.5% of the samples, respectively, in concentrations of 103-106GC/L. All samples were compliant with local bacteriological standards. HAdV2 and 41 and RVA G2, P[6], and P[8] were characterised. Astroviruses, sapoviruses, genogroup IV noroviruses, klasseviruses, bocaviruses and aichiviruses were not detected. Statistical analyses showed correlations between river stage level and reported gastroenteritis cases and, also, significant differences between virus concentrations during this extreme event when compared with normal dry seasons and previous flood seasons of the Negro River. These findings suggest an association between the extreme flood experienced and gastrointestinal cases in the affected areas providing circumstantial evidence of causality between the elevations in enteric viruses in surface waters and reported illness.
Laboratory of Comparative and Environmental Virology, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (FIOCRUZ), Pavilhão Helio e Peggy Pereira, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, 21040-360, Brazil. c.baur@ioc.fiocruz.br.
Carmen Baur
CB
Vieira
Virological Diagnosis Laboratory, Department of Microbiology and Parasitology (MIP), Biomedical Institute, Federal Fluminense University (UFF), Rua Professor Hernani Melo, 101, São Domingos, Niterói, RJ, 24210-130, Brazil.
Adriana
A
de Abreu Corrêa
Laboratory of Infectious Disease Ecology in the Amazon, Leônidas & Maria Deane Institute (ILMD), Oswaldo Cruz Foundation (FIOCRUZ), Rua Terezina, 476, Adrianópolis, Manaus, AM, 69057-070, Brazil.
Michele Silva
MS
de Jesus
Laboratory of Infectious Disease Ecology in the Amazon, Leônidas & Maria Deane Institute (ILMD), Oswaldo Cruz Foundation (FIOCRUZ), Rua Terezina, 476, Adrianópolis, Manaus, AM, 69057-070, Brazil.
Sérgio Luiz Bessa
SLB
Luz
Department of Geography and Earth Sciences (DGES), Aberystwyth University, Penglais Campus, Aberystwyth, Ceredigion, SY23 3DB, UK.
Peter
P
Wyn-Jones
Department of Geography and Earth Sciences (DGES), Aberystwyth University, Penglais Campus, Aberystwyth, Ceredigion, SY23 3DB, UK.
David
D
Kay
Laboratory of Comparative and Environmental Virology, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (FIOCRUZ), Pavilhão Helio e Peggy Pereira, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, 21040-360, Brazil.
Mônica Simões
MS
Rocha
Laboratory of Comparative and Environmental Virology, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (FIOCRUZ), Pavilhão Helio e Peggy Pereira, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, 21040-360, Brazil.
Marize Pereira
MP
Miagostovich
D001938:Brazil / Q000453:epidemiology; D055868:Floods; D005759:Gastroenteritis / Q000453:epidemiology / Q000821:virology*; D006801:Humans; D015994:Incidence; D045483:Rivers / Q000737:chemistry / Q000821:virology; D012621:Seasons; D014777:Virus Diseases / Q000453:epidemiology / Q000821:virology*; D014780:Viruses / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D014876:Water Pollution; D060753:Water Quality
Amazon; Enteric viruses; Flood; Negro River; qPCR