Differentiation between Wild-Type Group A Rotaviruses and Vaccine Strains in Cases of Suspected Horizontal Transmission and Adverse Events Following Vaccination

Abstract

Human group A rotaviruses (RVA) are important enteric pathogens, as they are a leading cause of acute gastroenteritis (AGE) in children worldwide. Since 2013, the German Standing Committee on vaccination recommended the routine rotavirus vaccination for infants in Germany. While vaccination has significantly decreased RVA cases and worldwide mortality, in some cases, infants can develop acute gastroenteritis as an adverse reaction after immunization with an attenuated live vaccine. Pediatricians, as well as clinicians and diagnostic laboratories, contacted the Consultant Laboratory for Rotaviruses and inquired whether cases of RVA-positive AGE after vaccination were associated with vaccine or with wild-type RVA strains. A testing algorithm based on distinguishing PCRs and confirmative sequencing was designed, tested, and applied. Diagnostic samples from 68 vaccinated children and six cases where horizontal transmission was suspected were investigated in this study. Using a combination of real-time PCR, fragment-length analysis of amplicons from multiplex PCRs and confirmative sequencing, vaccine-like virus was detected in 46 samples and wild-type RVA was detected in 6 samples. Three mixed infections of vaccine and wild-type RVA were detectable, no RVA genome was found in 19 samples. High viral loads (>1.0 × 107 copies/g stool) were measured in most RVA-positive samples. Furthermore, information on co-infections with other AGE pathogens in the vaccinated study population was of interest. A commercial multiplex PCR and in-house PCRs revealed three co-infections of vaccinated infants with bacteria (two samples with Clostridioides difficile and one sample with enteropathogenic E. coli) and six co-infections with norovirus in a subset of the samples. Human astrovirus was detected in one sample, with suspected horizontal transmission. The cases of suspected horizontal transmission of vaccine RVA strains could not be confirmed, as they either involved wild-type RVA or were RVA negative. This study shows that RVA-positive AGE after vaccination is not necessarily associated with the vaccine strain and provides a reliable workflow to distinguish RVA vaccine strains from wild-type strains.

Sequencing and phylogenetic analysis of human group A rotavirus genotypes circulating among diarrheic children in Edo State, Nigeria

“…Mixed G2G9[P6] strains responsible for mixed infections were found to circulate among the study participants in the present study. The 0.5% prevalence of G2G9[P6] reported in the present study agreed with previous reports from Pakistan and Nigeria [39][40][41][42][43][44][45][46][47][48][49][50][51]. Unusual G2[P8] strains were also found circulating among the study participants in the present study.…”

“…Based on phylogenetic analysis, the P [8] strains from the present study were found to be closely related to P [8] strains from China. RVA mixed infections have been reported worldwide [49][50]. Mixed G2G9[P6] strains responsible for mixed infections were found to circulate among the study participants in the present study.…”