Title : Viral profile of respiratory infections according to age in hospitals in Brazzaville, Republic of Congo
Abstract:
Context: Respiratory tract infections (RTIs) are one of the most common infectious diseases in children and represent a major cause of morbidity, hospital admission and mortality worldwide, with an estimated 3-5 million deaths per year. Although children are most at risk, adults are also vulnerable to RTIs. There are multiple etiologies of RTIs, with viruses accounting for almost 80%. The most common viruses are HRV, HRSV, HAdV, HCoV, HBoV, HPIV, and FluA/B. In Africa, little is known about respiratory infections in adults and the prevalence of these infections is often underestimated in hospitals due to the small amount of data available. The aim of this study was to determine the viral profile of respiratory infections and its correlations with age in hospitals in Brazzaville, Republic of Congo.
Method: The study was conducted between March 2022 and April 2023 in Brazzaville. Nasopharyngeal samples were collected from patients with respiratory syndrome and enrolled in the study at the Hôpital de Référence de Talangaï and the Hôpital de Référence de Makélékélé. These samples were analyzed for detection of respiratory pathogens using the FTD-21 panel, a commercial multiplex real-time polymerase chain reaction (RT-PCRm) kit targeting 21 pathogens. As the kit does not targets SARS-CoV-2, the TaqPath kit was used specifically for its identification, following the manufacturer's instructions.
Results: A total of 643 patients were enrolled and tested, and 461 of them were found to be infected with at least one respiratory pathogen. Out of these positive patients, 300 (300/461; 65%) were under 5 years old (0-4), 53 (53/461; 11%) were 5-15 years old and 108 (108/461; 23%) were 16-87 years old. Viral diversity was highest in the under 5 years, with the most prevalent and statistically significant pathogens being HRV (120/384; 31.2%), HAdV (83/384; 21.6%), HBoV (57/384; 14.8%) and HRSV (38/384; 9.8%). HPIV-3 (36/384; 9.3%), FluA (34/384; 8.8%) and SARS-CoV-2 (26/384; 6.7%) and many other viruses (with very low proportions) were not significant. For 5-15 years, the most prevalent viruses were FluA (15/70; 21.4%), HRV (12/70; 17.1%), HAdV (10/70; 14.2%), HBoV and SARS-CoV-2 (8/70; 11.4% each). In the oldest age group (16-87 years), the most prevalent viruses were HRV (32/189; 16%), FluA (23/189; 12.1%), HAdV (18/189; 9.5%) and SARS-CoV-2 (11/189; 5.8%). We found 199 cases of co-infection, including 146 (146/199; 73%) in children under 5 years of age (0-4), 20 (20/199; 10%) in those aged 5 to 15, and 33 (33/199; 17%) in older children (16-87).
Conclusion: Respiratory infections were more prevalent in children under 5, with a more varied viral profile. However, adults were found to be as vulnerables as children. The most prevalent viruses in all age groups were HRV, FluA, HAdV and SARS-CoV-2.
