Surveillance of norovirus infections in the state of Rio De Janeiro, Brazil 2005–2008

Abstract

A 4-year (2005-2008) norovirus (NoV) surveillance study was conducted in the state of Rio Janeiro, Brazil, to demonstrate the role of these viruses in outbreaks and sporadic cases of acute gastroenteritis. A cohort of 1,687 fecal samples was obtained from patients with gastroenteritis; 324 were rotavirus-positive. Of the remainder 1,363 rotavirus-negative samples, 1,087 samples were tested for NoV RNA in this study. The study enrolled 267 outpatients from Municipal Public Health Centers and 820 inpatients, whose samples were obtained by active surveillance in Public Hospitals. Fecal samples were tested by reverse transcription (RT) followed by polymerase chain reaction (PCR) using the MON 431-434 set of degenerate primers for NoV GI and GII detection, and there were 35.1% (381/1,087) positive samples for NoV, consisting of 30.2% (248/820) and 49.8% (133/267) from inpatient and outpatient, respectively. Children infected by NoV had significantly more frequent mucus in feces, vomiting and fever. No seasonal pattern in NoV infections was observed in patients admitted to hospital; however, two peaks of NoV infections were observed from ambulatory cases, suggesting that there was an occurrence of outbreaks in those time periods. Molecular characterization revealed GII to be the most prevalent genogroup, totaling 96.3% (104/108) of all sequences analyzed, and GII.4 was the genotype detected most frequently (80.7%), followed by GII.6, 3, 14, 7, and 8. Two GI strains, GI.2 and GI.3, were also observed. The number of outbreaks and sporadic cases described in this study highlights the need to implement diagnosis of NoV in surveillance laboratories.

Acute norovirus gastroenteritis in children in a highly rotavirus-vaccinated population in Northeast Brazil

“…In temperate regions NoV has a higher frequency during the winter and spring [22,23], but seasonal patterns become less well established in tropical areas [24]. This blurred pattern was also present in this study, as infections were detected all year round.…”

Burden of Norovirus and Rotavirus in Children After Rotavirus Vaccine Introduction, Cochabamba, Bolivia

“…8 Few studies have described norovirus prevalence relative to rotavirus after vaccine introduction. 4,7,30,31 To our knowledge, we are the first to describe norovirus infections in Bolivia. The effectiveness of available rotavirus vaccines in reducing hospital admissions because of AGE suggests that non-rotavirus pathogens will represent a greater proportion of enteropathogens detected in hospitalized children.…”

“…2 Norovirus and rotavirus are the major causes of diarrheal illness in South American children. [3][4][5][6][7][8][9] Recent data suggest that the relative burden of norovirus versus rotavirus in children with AGE may be changing after widespread adoption of rotavirus vaccine. Relatively little is known of viral etiology of pediatric AGE in low income, high mortality settings after vaccine introduction.…”

Norovirus GII.17 Predominates in Selected Surface Water Sources in Kenya

“…The GII.6 strains were the second most predominant strains identified and clustered together with strains from Sweden (JN183165) and Japan (AB818398). After NoV GII.4, NoV GII.6 has been shown to be the second most dominant strain in clinical studies in a number of countries namely, SA, Brazil, Japan, and Finland (Phan et al 2005;Mans et al, 2010;Ferreira et al 2010;Puustinen et al 2011;Chan-it et al 2012). Norovirus GII.6 strains were previously identified in clinical specimens from Kenya (Mans et al 2014), indicating the presence of clinically relevant strains in the water sources.…”