Effectiveness of rotavirus vaccination in prevention of hospital admissions for rotavirus gastroenteritis among young children in Belgium : case-control study

Objective : To evaluate the effectiveness of rotavirus vaccination among young children in Belgium. Design : Prospective case-control study. Setting : Random sample of 39 Belgian hospitals, February 2008 to June 2010. Participants : 215 children admitted to hospital with rotavirus gastroenteritis confirmed by polymerase chain reaction and 276 age and hospital matched controls. All children were of an eligible age to have received rotavirus vaccination (that is, born after 1 October 2006 and aged >= 14 weeks). Main outcome measure : Vaccination status of children admitted to hospital with rotavirus gastroenteritis and matched controls. Results : 99 children (48%) admitted with rotavirus gastroenteritis and 244 (91%) controls had received at least one dose of any rotavirus vaccine (P= 12 months. The G2P[4] genotype accounted for 52% of cases confirmed by polymerase chain reaction with eligible matched controls. Vaccine effectiveness was 85% (64% to 94%) against G2P[4] and 95% (78% to 99%) against G1P[8]. In 25% of cases confirmed by polymerase chain reaction with eligible matched controls, there was reported co-infection with adenovirus, astrovirus and/or norovirus. Vaccine effectiveness against co-infected cases was 86% (52% to 96%). Effectiveness of at least one dose of any rotavirus vaccine (intention to vaccinate analysis) was 91% (82% to 95%). Conclusions : Rotavirus vaccination is effective for the prevention of admission to hospital for rotavirus gastroenteritis among young children in Belgium, despite the high prevalence of G2P[4] and viral co-infection

Transformation de cellules de drosophile en culture

CNRS AR 13133 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Higher proportion of G2P[4] rotaviruses in vaccinated hospitalized cases compared with unvaccinated hospitalized cases, despite high vaccine effectiveness against heterotypic G2P[4] rotaviruses

AbstractThe overall vaccine effectiveness of the monovalent rotavirus vaccine in an observational, prospective, multicentre, hospital-based case-control study in Belgium (RotaBel) was 90%. However, rotavirus genotype and co-infecting pathogens are important parameters to take into account when assessing vaccine effectiveness. In this study we specifically investigated the effect of rotavirus genotypes and co-infecting pathogens on vaccine effectiveness of the monovalent vaccine. In addition, we also investigated the effect of co-infecting pathogens on disease severity. From February 2008 to June 2010 stool samples of rotavirus gastroenteritis cases of a random sample of 39 Belgian hospitals were collected and subsequently genotyped. Fisher’s exact tests were performed to investigate the relationships between rotavirus genotype, co-infecting pathogens and disease severity. The vaccine effectiveness of a full series of the monovalent rotavirus vaccine against hospitalized rotavirus gastroenteritis caused by GIP[8] rotavirus strains was 95% (95% CI 77.5-98.7). Against G2P[4], the vaccine effectiveness was 85% (95% CI: 63.7-93.8). G4P[8]- and G3P[8]-specific vaccine effectiveness was 90% (95% CI 19.2-98.7) and 87% (95% CI -5.2 to 98.4), respectively. A post-hoc analysis showed that the genotype distribution was significantly related to the vaccination status (p <0.001), whereby G2P[4] strains were proportionally more prevalent in vaccinated cases than in unvaccinated cases. No statistical associations were found between co-infection status and vaccination status, Vesikari severity score or rotavirus genotype. The high vaccine effectiveness against the individual genotypes implies robust protection of the monovalent rotavirus vaccine against hospitalized rotavirus gastroenteritis caused by the major human rotavirus genotypes. The prevalence of G2P[4] requires continued monitoring

Coevolution of Drosophila melanogaster mtDNA and Wolbachia Genotypes

Maternally inherited microorganisms can influence the mtDNA pattern of variation in hosts. This influence is driven by selection among symbionts and can cause the frequency of mitochondrial variants in the population to eventually increase or decrease. Wolbachia infection is common and widespread in Drosophila melanogaster populations. We compared genetic variability of D. melanogaster mitotypes with Wolbachia genotypes among isofemale lines associated with different geographic locations and time intervals to study coevolution of the mtDNA and Wolbachia. Phylogenetic analysis of D. melanogaster mtDNA revealed two clades diverged in Africa, each associated with one of the two Wolbachia genotype groups. No evidence of horizontal transmission of Wolbachia between maternal lineages has been found. All the mtDNA variants that occur in infected isofemale lines are found in uninfected isofemale lines and vice versa, which is indicative of a recent loss of infection from some maternal fly lineages and confirms a significant role of Wolbachia in the D. melanogaster mtDNA pattern of variation. Finally, we present a comparative analysis of biogeographic distribution of D. melanogaster mitotypes all over the world