High genotypic diversity of Rhinoviruses obtained from Tunisian children with severe acute respiratory infection

Introduction: Rhinoviruses (HRV) are among the leading causes of Severe Acute Respiratory Infection (SARI). Their burden and genetic diversity vary from one region to another and little is known in Northern African regions. This study describes epidemiological patterns and genotypic diversity of HRV in SARI cases during a two and half year's study, in Northern Tunisia. Methodology: A total of 271 SARI cases, admitted into the Pediatric Intensive Care Unit of Bechir Hamza Children's Hospital in Tunis, were collected between September 2015 and December 2017. The investigation concerned 104 samples positive for HRV and/or HEV (Human Enterovirus) obtained among these cases. Specific HRV and HEV detections were assessed by real-time PCRs. The HRV molecular typing was based on the VP4-VP2 genomic region analyses. Results: Among the viral SARI cases, 33.5% and 12.3% were positive for HRV and HEV respectively. Molecular investigations showed high prevalence of HRV-A (63.3%) followed by HRV-C (30.6%) and HRV-B (6.1%) and high genotypic diversity with 27 types. HRV cases were mostly detected in toddlers younger than 6 months. A total of 16 cases (28%) were found with bacterial and/or viral co-infection. HRV-C infection and HRV-A with bacterial co-infection were associated with complicated infection. Some of the detected types showed a continuous circulation or turnover during an extended period. HRV-A101 and HRV-C45 were the most frequently detected types. Conclusions: This study revealed, for the first time, the high HRV diversity in Tunisia, a North-African region. Specific phylogenetic investigations may help to evaluate their diversity and to trace their spread and epidemiological origin.