Viral and Bacterial Etiologies of Acute Respiratory Infections Among Children Under 5 Years in Senegal

Assane, Dieng; Makhtar, Camara; Abdoulaye, Diop; Amary, Fall; Djibril, Boiro; Amadou, Diop; Niokhor, Diouf Jean Baptiste; Amadou, Diop; Cheikh, Loucoubar; Ndongo, Dia; Mbayame, Niang; Lamine, Fall; Bouh, Boye Cheikh Saad

In Senegal, adenovirus was the most common pathogen detected from ARIs in children. This study confirms previous results reported between 2013 and 2015 in Senegal by Niang et al. 14 The overall detection rate of adenovirus was 50% among the 162 selected children. This adenovirus infection prevalence seems very high compared with rates documented from other countries, namely, Ghana, 15 Burkina, 10 and Zambia. 9 However, our results are in agreement with data reported in Cameroon. Overall, this confirms the overall high prevalence of adenovirus ARI in Africa. 16 In addition to adenovirus, influenza virus, rhinovirus, and enterovirus are the most common viruses detected, as reported in other studies. 10, 17 Our study revealed viral codetection is frequent in ARIs. Similar results were found in other countries. 9,10,15 Viral codetection in clinical settings is becoming more common since the introduction of molecular-based multiplex tests. Although the clinical significance of these findings remains unclear, this seems to have no impact in disease severity. 18 In this study, we also found that ARIs were associated with bacterial pathogens; among those, S. pneumoniae (17.9%), M. catarrhalis (15.43%), and H. influenzae (8%) were the most common. In contrast with our findings, high rate (56%) of S. pneumoniae detection was observed in Niger among children having ARIs. 13 In our study, prevalence of mono-infections with S. pneumoniae (2%), M. catarrhalis (2%), or H. influenzae (1%) was very low. Thus, this low prevalence of bacterial pathogens in ARIs proves that antibiotics should no longer be systematically used in the treatment of ARIs. However, among low-prevalence bacterial isolates, codetections with viruses were more frequent and S. pneumoniae (16, 6%) coinfection was the most frequent in our findings. Similar results were reported in other studies. 19, 20 There results highlight the pivotal role of viruses in ARIs because primary infection with viral pathogens can predispose children to subsequent bacterial infections. 21 Our study has limitations; among others, the sample size which does not really allow to determine the direct association between viral or bacterial infection and disease severity. Moreover, a case-control study would be more suitable to determine the exact role of viruses in ARIs pathogenesis.