SEASONALITY OF RESPIRATORY SYNCYTIAL VIRUS (RSV) INFECTION IN INFANTS AND YOUNG CHILDREN IN LUSAKA, ZAMBIA Ruth Nakazwe1, William MacLeod2, Leah S. Forman2, Lawrence Mwananyanda3, Magdalena Mwale3, Benard Ngoma3, Charles Chimoga3, Gertrude Munanjala3 , Zacharia Mupila3, Geoffrey Kwenda4, Caitriona Murphy3, Rachel C. Pieciak2, Donald M. Thea2, Christopher J. Gill2 1University Teaching Hospital, Lusaka, Zambia; 2Department of Global Health, Boston University School of Public Health, Boston, MA, USA; 3Right to Care Zambia, Lusaka, Zambia; 4Department of Biomedical Sciences, University of Zambia, Lusaka, Zambia Results Conclusions Introduction Research Question • Does RSV infection in infants in Lusaka, Zambia have a predictable seasonality? Rationale • By understanding the seasonality of RSV outbreaks we can create and implement targeted intervention strategies and improve the outcomes of Respiratory Syncytial Virus (RSV) infections among infants in Lusaka, Zambia. Longitudinal RSV Surveillance in Zambia • We have observed and tested infants for RSV across three cohort studies: the Pneumonia Etiology Research for Child Health study (PERCH); the Southern African Mothers Infants Pertussis study (SAMIPS) and the Zambia Pertussis/RSV Infant Mortality Estimation study (ZPRIME). Together these studies give us a clue into the patterns of RSV infection over several years. • PCR-confirmed RSV infection in infants is cyclical across PERCH, SAMIPS and ZPRIME (Fig 1). • Counts of PCR-confirmed RSV in the ZPRIME cohort peaked from February-April (Fig 2). • RSV is a significant cause of seasonal deaths among Zambian infants. • The number of PCR confirmed RSV infections is highest from January-April. • More data collection is needed to understand the drivers behind RSV seasonality in this location. Methods SAMIPS Figure 1. Longitudinal Surveillance of RSV Positivity in Infants across 3 cohort studies in Lusaka, Zambia Enrollment • Infants were enrolled at the University Teaching (PERCH, SAMIPS, ZPRIME) and Level 1 hospitals in Lusaka Zambia (ZPRIME) Sampling and Testing • Trained hospital staff collected Copan nasopharyngeal (NP) swab samples, and RSV (RSV-A, RSV-B) was identified using real-time PCR. • All samples were run with positive and negative controls and RNase P as a housekeeping enzyme control Study Duration Study Populations Infant Age Range PERCH Oct 2011 – Oct 2013 1,154 children hospitalized with severe pneumonia, sampled once 1-59 months SAMIPS Mar 2015 – Jan 2016 939 healthy infants sampled fortnightly 1-13 weeks old ZPRIME Sep 2017 – June 2019 (ongoing) 1,306 deceased infants sampled within 48 hours of death 4 days to <6 months Table 1. Summary table of cohort studies conducted in Lusaka, Zambia. We would like to recognize the families in Zambia who have suffered great loss and were willing to participate in these cohort studies. We hope that this research will help to prevent future deaths. The authors declare no financial conflicts of interest. Funding for the ZPRIME research is provided by the Bill and Melinda Gates Foundation, grant number OPP1163027. Figure 2. Percent PCR-confirmed RSV-positive NP swabs of total NP swabs tested by month in ZPRIME cohort. 2017 2018 2019 Gap between studies Gap between studies PERCH ZPRIME