Clinical severity and molecular characteristics of circulating and emerging rotaviruses in young children attending hospital emergency departments in France

Group A rotavirus (RVA) is the leading cause of acute gastroenteritis in young children worldwide. A prospective surveillance network has been set up to investigate the virological and clinical features of RVA infections and to detect the emergence of potentially epidemic strains in France. From 2009 to 2014, RVA-positive stool samples were collected from 4800 children <5 years old attending the paediatric emergency units of 16 large hospitals. Rotaviruses were then genotyped by RT-PCR with regard to their outer capsid proteins VP4 and VP7. Genotyping of 4708 RVA showed that G1P[8] strains (62.2%) were predominant. The incidence of G9P[8] (11.5%), G3P[8] (10.4%) and G2P[4] (6.6%) strains varied considerably, whereas G4P[8] (2.7%) strains were circulating mostly locally. Of note, G12P[8] (1.6%) strains emerged during the seasons 2011-12 and 2012-13 with 4.1% and 3.0% prevalence, respectively. Overall, 40 possible zoonotic reassortants, such as G6 (33.3%) and G8 (15.4%) strains, were detected, and were mostly associated with P[6] (67.5%). Analysis of clinical records of 624 hospitalized children and severity scores from 282 of them showed no difference in clinical manifestations or severity in relation to the genotype. The relative stability of RVA genotypes currently co-circulating and the large predominance of P[8] type strains may ensure vaccine effectiveness in France. The surveillance will continue to monitor the emergence of new reassortants that might not respond to current vaccines, all the more so as all genotypes can cause severe infections in infants.

Relationship between GII.3 norovirus infections and blood group antigens in young children in Tunisia

Noroviruses (NoVs) constitute a major cause of gastroenteritis in Tunisia. One hundred and fourteen matched saliva and stool samples were collected from children (n = 114) suffering from acute gastroenteritis at the hospital of Monastir during the winter season 2011-2012. For 98 of 114 children, blood samples were collected for secretor genotyping. NoVs were associated with 36.8% (n = 42/114) of the gastroenteritis cases. The GII.3 genotype was the most common (69% of all NoVs). For patients who were phenotyped (n = 114) for human blood group antigens (HBGAs), the secretor and non-secretor phenotypes represented 79% and 21%, respectively. Of the NoV infections, 83% were detected in all ABO groups. Five GII.3 isolates, one GII.1 isolate and one GII.7 isolate were detected in Lewis-positive non-secretors, confirmed by genotyping of the FUT2 gene. Even though our data showed that GII.3 NoVs could infect non-secretors, no binding was observed with saliva and GII.3 baculovirus-expressed virus-like particles from the same symptomatic non-secretor individual. This suggests that other factors might also participate in NoV attachment in children and newborns.

Unexpected substitution of dominant rotavirus G genotypes in French hospitalized children over five consecutive seasons

The study was designed to evaluate the circulation of group A rotaviruses in French hospitalized children, and to detect unusual strains. This prospective study was conducted from 2001 to 2006 in children consulting for acute diarrhea at the pediatric emergency department in three French University Hospitals. The rotaviruses were detected by rapid test and genotyped by RT-PCR on the basis of their outer capsid proteins VP4 (P-type) and VP7 (G-type). The stools from 757 children were analyzed. G1P[8] strains were predominant (44.0%), followed by G9P[8] (17.7%), G3P[8] 13.1%, G4P[8] (9.5%), and G2P[4] (1.8%); mixed rotavirus infections occurred in 2.3%. G9 rotaviruses emerged during the 2004-2005 season (73.4%) and remained the second most prevalent strains. Few unusual strains, G6, G8, G12 and P[6]-types, were detected. The monitoring of rotavirus infections should be maintained to document strain distribution and to assess the emergence of new reassortants that may not respond to current rotavirus vaccines.

[Sensitivity and specificity of the VIKIA Rota-Adeno immuno-chromatographic test (bioMérieux) and the ELISA IDEIA Rotavirus kit (Dako) compared to genotyping]

The performances of two diagnostic tests for rotavirus infection in stool samples were evaluated during a prospective study in children of less than 36 months in child-care centers of Lyon from November 2004 to May 2005. The VIKIA Rota-Adeno immuno-chromatographic test (bioMérieux) and the ELISA IDEIA Rotavirus kit (Dako) were compared with a referral method, the genotyping. Fifty-seven stool samples were collected and analyzed by RT-PCR. The virus genome was detected in 29 samples. The most frequent genotypic combinations were G9P[8] with a prevalence of 75.9%. Sensitivity and specificity of the VIKIA Rota-Adeno test and the ELISA IDEIA Rotavirus kit were strictly comparable and very good: 96.6% (83.0; 99.9) and 96.4% (81.6; 99.9), respectively. The immuno-chromatographic technique were in concordance with the ELISA tests in 93.6% of cases. Thus, the VIKIA Rota-Adeno test is a good alternative for the occasional analysis of stool samples in ambulatory practice.