Prevalência mundial de Norovírus em crianças com gastroenterite aguda entre 2006 e 2015: Revisão Sistemática e Meta-Análise

Abstract

Acute gastroenteritis is a leading cause of morbimortality in children under 5 years of age and mainly caused by Rotavirus. Rotavirus vaccines (Rotarix and Rotateq) licensed in 2006 decreased the cases of diarrhea as well as hospitalizations and death. However, after vaccine introduction in national immunization programs, studies showed an epidemiological change in diarrhea, being reported less cases of gastroenteritis due to Rotavirus and more cases of new pathogens, such as Norovirus. Norovirus is typically described as cause of outbreaks in small community settings like military camps and cruise ships but it has been playing an important role in sporadic diarrhea cases in the last years, resulting in direct public health costs and work absence. Once Norovirus can cause disease in all age groups, many studies have results of prevalence and morbimortality among general populations, so it is difficult to assess their findings in specific populations, such as the pediatrics. Therefore, in order to understand Norovirus trends in children, this study aims to evaluate the global Norovirus prevalence among infants under 5 years during a 10-year period after Rotavirus vaccine introduction. We searched for studies of AGE cases due to Norovirus among children younger than 5 years of age on MEDLINE, SCOPUS and LILACS databases from January 1st, 2006, to December 31st, 2016. We included studies that: (1) were conducted between 2006 and 2015; (2) were published in English, Portuguese or Spanish; (3) were conducted continuously for at least 1 year; (4) specified the location; (5) included children under 5 years with signs or symptoms of AGE; (6) used PCR as Norovirus detection method. Data on Norovirus prevalence were extracted and divided into three periods: 2006-2008, 2009-2011 and 2012-2015. Estimates of Norovirus prevalence were calculated using logit transformation. A total of 64 articles were included in the meta-analysis. Out of 41 671 children presenting with AGE symptoms, 18.3% were due to Norovirus through 2006-2015. From 2006 to 2008, the overall prevalence was 18.4% (95% CI, 15.2– 22.1; I2 = 95.1%) and the highest was observed in Europe (34.5%; 95% CI, 20.8 – 51.5); from 2009 to 2011, overall prevalence was 19.2% (95% CI, 16.4 – 22.5; I2 = 96.2%) and most cases were found in America (22.2%; 95% CI, 17.0 – 28.4); from 2012 to 2015, overall Norovirus prevalence was 18.9% (95% CI, 13.1 – 26.5; I2 = 97.7%) and the highest prevalence was observed in Asia (19.6%; 95% CI, 11.6 – 31.1). Although it was observed an increasing and decreasing trends of Norovirus prevalence in different regions, the overall prevalence remained stable through the years. Our results show the global Norovirus prevalence in pediatric in populations. They represent the impact of this burden disease which highlights the need of new preventive strategies.