RESUMO
Gastroenteritis is one of the most common diseases during childhood, with norovirus (NoV) and sapovirus (SaV) being two of its main causes. This study reports for the first time the incidence of these viruses in hospitalized children with and without gastroenteritis in São Luís, Maranhão. A total of 136 fecal samples were tested by enzyme immunoassays (EIA) for the detection of NoV and by reverse transcription-polymerase chain reaction (RT-PCR) for detection of both NoV and SaV. Positive samples for both agents were subjected to sequencing. The overall frequency of NoV as detected by EIA and RT-PCR was 17.6% (24/136) and 32.6% (15/46), respectively in diarrheic patients and 10.0% (9/90) in non-diarrheic patients (p 0.01). Of the diarrheic patients, 17% had fever, vomiting and anorexia, and 13% developed fever, vomiting and abdominal pain. Of the 24 NoV-positive samples, 50% (12/24) were sequenced and classified as genotypes GII.3 (n = 1), GII.4 (6), GII.5 (1), GII.7 (2), GII.12 (1) and GII.16 (1). SaV frequency was 9.8% (11/112), with 22.6% (7/31) in diarrheic patients and 4.9% (4/81) in nondiarrheic (p = 0.04) ones. In diarrheic cases, 27.3% had fever, vomiting and anorexia, whereas 18.2% had fever, anorexia and abdominal pain. One SaV-positive sample was sequenced and classified as GII.1. These results show a high genetic diversity of NoV and higher prevalence of NoV compared to SaV. Our data highlight the importance of NoV and SaV as enteropathogens in São Luís, Maranhão.(AU)
Assuntos
Animais , Criança , Infecções por Caliciviridae/classificação , Infecções por Caliciviridae/complicações , Infecções por Caliciviridae/diagnóstico , GastroenteriteRESUMO
Mexico virus (MXV) is a genogroup II human calicivirus (HuCV). We conducted an epidemiological study to determine the prevalence of MXV infection in infants and adults in Japan and Southeast Asia by enzyme-linked immunosorbent assays (ELISAs) developed by using baculovirus-expressed recombinant MXV (rMXV) capsids. Of 155 stool specimens obtained from children younger than 10 years old with acute clinical gastroenteritis (diarrhea and vomiting) associated with small, round-structured viruses in Japan from 1987 to 1989, only 2 were positive for MXV antigen. In 42 outbreaks of acute gastroenteritis in Japan from 1986 to 1994, 1 in an infant home and 1 among adults were positive for MXV antigen. The pattern of acquisition of antibody to rMXV was different from that of acquisition of antibody to group A rotavirus, the prototype HuCV Sapporo virus, and Norwalk virus. The prevalence of antibody to rMXV remained low for the first 3 years of life, showed a steep rise during nursery school age, reaching a prevalence of 50%, and another steep rise during adolescence, reaching 80%; and steadily increased thereafter. A high prevalence of antibody (82 to 88%) was observed in adult populations in Japan and Southeast Asia, suggesting that MXV infection is common in these areas. The discrepancy between the high prevalence of antibody to MXV and a low rate of detection of MXV antigen may be explained by a high specificity of the antigen ELISA for the prototype and closely related MXV strains while serological responses can detect responses to a broader group of viruses.