Morbidity burden, seasonality and factors associated with the human respiratory syncytial virus, human parainfluenza virus, and human adenovirus infections in Kenya

Abstract Background Human respiratory syncytial viruses (HRSV), human parainfluenza viruses (HPIV), and human Adenoviruses (HAdV) cause a substantial morbidity burden globally. Objective The study sought to estimate morbidity burden, assess seasonality, and determine factors associated with these respiratory viruses among the Kenyan population. Methods The data were obtained from Kenyan sites located in the present Koppen-Geiger climate classification system. By descriptive analysis, we defined the proportion of morbidity burden, visualized time-series data from January 2007-December 2013. Logistic regression was used to identify the factors associated with infection outcomes. Results The morbidity burden for HRSV was 3.1%, HPIV 5.3%, and HAdV 3.3%. Infants were more likely to be infected with these viruses compared to other age groups. HRSV exhibited seasonality with high occurrence in January-March (Odds Ratio [OR] =2.73) and April-June (OR=3.01). Hot land surface temperature (≥40°C) was also associated with HRSV infections (OR=2.75), as was warmer air temperature (19-22.9°C) (OR=1.68) compared to cooler air temperature ( Conclusion HRSV, HPIV, and HAdVs contributed to morbidity burden, and infants were significantly affected. HRSV had a clear seasonal pattern and were associated with climate parameters, contrary to HPIV and HAdVs.