Authors: Prof Lawrence Mwananyanda, R Nakazwe2, W MacLeod1, G Kwenda3,Z Mupila3, C Murphy6, DM Thea1, CJ Gill1 ,L Mwananyanda1,3 1. Boston University School of Public Health, Department of global health 2. University Teaching Hospital, Zambia 3. Right to Care, Zambia
Citation Style For This Article: Mwananyanda L, Nakazwe R, MacLeod W, et al. Respiratory Syncytial Virus seasonality across three cohorts in Zambia The Health Press Zambia Bull. 2020; 4(4); pp 30
Respiratory Syncytial Virus (RSV) is among the significant causes of lower respiratory tract infections with high morbidity, hospitalization, and mortality in infants and young children. Globally, it affects 60 – 70% of children before the age of 1 year. With regard to the prevention, diagnosis, and treatment of RSV, it is important to understand the timings of the RSV outbreaks in local settings. Especially now that all efforts are focusing on having an approved maternal vaccine for RSV to passively immunize the newborns. We looked at the trends in the seasonality of RSV in infants and/or children from three studies that measured RSV via nasopharyngeal swabs over a period of 8 years in Lusaka, Zambia.
We present data from three respiratory disease studies conducted in Lusaka from October 2011 to December 2018. These studies took nasopharyngeal swab samples (NPS) from a combination of sick and healthy infants and/or young children. The NPS were tested for the presence of RSV using PCR. We recorded counts of samples positive for by the calendar month that the sample was taken.
The positivity of RSV was high in the rainy season from December to April averaging 26 cases/ month with high peaks being in February and April at 35 and 34 cases respectively. The cool-dry season in the months of May to August recorded a lower average of 19 cases/ month. The hot-dry season months of September to November had the lowest RSV positivity with1.3 cases/month.
These findings demonstrate that there are indeed seasons of RSV activity in Zambia. The rainy and the cool-dry seasons. This knowledge is important for informing public health initiatives to effectively manage RSV. Targeted passive immunization of RSV can be planned immediately before the RSV seasons for third-trimester pregnant women when the vaccine is available in Zambia.