Incidence of Rotavirus and Circulating Genotypes in Northeast Brazil during 7 Years of National Rotavirus Vaccination

Abstract

Background and AimsRotavirus causes severe diarrhoea and Brazil introduced the Rotarix G1P[8] vaccine in 2006. We aimed to describe changes in rotavirus incidence and diarrhoea epidemiology before and after vaccine introduction.MethodsDesign: (i) hospital-based survey of children with diarrhoea (2006–2012); (ii) diarrhea-mortality and hospitalization surveillance (1999–2012).Setting(i) Aracaju and (ii) state and national level.Results1841 children were enrolled and 231 (12.5%) had rotavirus. Rotavirus was less frequent from January-June than from July-December (9.4% versus 20.9%, p<0.01), but the seasonal variation was less defined after 2009. Very few rotavirus cases (8–3.9%) were detected in 2011, with an increase in 2012 (13–18.5%). In 2006, unvaccinated children were more likely to have rotavirus, but thereafter unvaccinated and vaccinated children had equally low incidence. Older children and those with rotavirus were more likely to have severe diarrhea episodes. The most frequent genotype from 2006 to 2010 was G2P[4]; except in 2009, when most cases were G1P[8]. Very few G2P[4] were detected from 2011 and 50% cases in 2012 were G8P[4]. Diarrhoea-hospitalizations decreased nationally from 89,934 (2003) to 53,705 (2012; 40.3% reduction) and in the state from 1729 to 748 (56.7% reduction). Diarrhoea-deaths decreased nationally from 4368 in 1999 to 697 in 2012 (84% reduction, p<0.001) and in the state from 132 to 18 (86% reduction). These changes were much larger after vaccine introduction.ConclusionsThe vaccine was associated with substantial reductions in rotavirus incidence and diarrhoea-hospitalizations and deaths. The G2P[4] genotype predominance disappeared over time and may be replaced by other heterotypic genotypes.

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

“…Although our data suggests an annual increase in the proportion of cases, similar detection rates had been reported from Chile, India and Nicaragua prior to rotavirus vaccine introduction [18][19][20]. This relative increase may also be due to the decrease of number of rotavirus-related hospitalizations [10,11] and all-cause diarrhoea cases due to the effectiveness of the rotavirus vaccine [21] and the herd effect of the vaccine that has resulted in an overall and not a real increase in the overall number of NoV cases. The increasing trend reported here however is rare and could be an early indication of changes in the epidemiology of the pathogen in a population with a high rotavirus vaccination coverage.…”

“…The increasing trend detected therefore might be an artefact of aggregation of small outbreaks over time. The apparent increase in norovirus infection can also be an artefactual consequence of the reduction in in the burden of rotavirus and all-cause diarrhoea brought about by the rotavirus vaccination program [10,11]. Furthermore, only participants who provide a stool specimen were included in the analysis, which is likely to select children who stayed longer in the rehydration units and to introduce a bias towards higher disease severity.…”

“…This was a cross sectional survey conducted from October 2006 to January 2013 aiming to establish the proportion and severity of acute diarrhoea episodes due to rotavirus [11] and NoV. Children <12 years old presenting with acute diarrhoea attending the paediatric emergency service of Sergipe Emergency Hospital (Hospital de Urgência de Sergipe -HUSE) were enrolled consecutively at the time of presentation. HUSE provides 24-hour free medical services and is a reference hospital for Sergipe State (~2 million population).…”

“…Brazil was one of the first countries to introduce a monovalent rotavirus vaccine (Rotarix) on a large scale in March 2006 [9], reaching high vaccine coverage levels (>80%) within a year of vaccine introduction and rapidly reducing the incidence of rotavirus-related hospitalizations [10,11].…”

Human rotavirus vaccine (Rotarix): focus on effectiveness and impact 6 years after first introduction in Africa

“…In terms of vaccine impact, there have been over 80% reductions, after introduction of RV vaccine into NIPs, in RVGE hospitalizations in children aged <12 months reported from both high-and middle-income countries [18][19][20][21][22][23]. In addition, a noted reduction in RV cases among nonvaccinated older children, suggestive of herd protection with HRV, has been demonstrated in culturally and economically diverse countries, including Austria [24], Belgium [19], Brazil [23,25] and El Salvador [18]. At the most severe end of the disease spectrum, robust evidence suggests that RV vaccination can save lives.…”