Dengue in Western Uganda: a prospective cohort of children presenting with undifferentiated febrile illness

Ross M Boyce,Jonathan J Juliano,Regina Nakakande,Yerun Zhu,Moses Ntaro,Michael Matte,Daniel Espinoza,Emily J Ciccone,Samantha Grounds,Dan Nyehangane,Matthew Collins,Rabbison Muhindo,Edgar M Mulogo

doi:10.1186/s12879-020-05568-5

Abstract

BackgroundThe spatial distribution and burden of dengue in sub-Saharan Africa remains highly uncertain, despite high levels of ecological suitability. The goal of this study was to describe the epidemiology of dengue among a cohort of febrile children presenting to outpatient facilities located in areas of western Uganda with differing levels of urbanicity and malaria transmission intensity.MethodsEligible children were first screened for malaria using rapid diagnostic tests. Children with a negative malaria result were tested for dengue using a combination NS1/IgM/IgG rapid test (SD Bioline Dengue Duo). Confirmatory testing by RT-PCR was performed in a subset of participants. Antigen-capture ELISA was performed to estimate seroprevalence.ResultsOnly 6 of 1416 (0.42%) children had a positive dengue rapid test, while none of the RT-PCR results were positive. ELISA testing demonstrated reactive IgG antibodies in 28 (2.2%) participants with the highest prevalence seen at the urban site in Mbarara (19 of 392, 4.9%, p < 0.001).ConclusionsOverall, these findings suggest that dengue, while present, is an uncommon cause of non-malarial, pediatric febrile illness in western Uganda. Further investigation into the eocological factors that sustain low-level transmission in urban settings are urgently needed to reduce the risk of epidemics.

Highlights

The spatial distribution and burden of dengue in sub-Saharan Africa remains highly uncertain, despite high levels of ecological suitability
There are favorable precipitation and temperature conditions, the Aedes aegypti mosquito the primary vector of dengue, along with yellow fever and Rift Valley fever - is ubiquitous in Uganda
While little is known about the seasonality of dengue transmission in Uganda, malaria transmission is characterized by semi-annual transmission peaks typically following the end of the rainy seasons [13]

Summary

Introduction

The spatial distribution and burden of dengue in sub-Saharan Africa remains highly uncertain, despite high levels of ecological suitability. While more than half of the world’s population is thought to be at risk, the global burden of dengue remains highly uncertain [3]. Nowhere is this epidemiological uncertainty more pronounced than in Africa, The East African highlands, including areas of Uganda, Rwanda, and Burundi, represent a region of especially high uncertainly [3]. Other factors favoring the likelihood of dengue transmission in Uganda include an increasingly globalized economy and rapid urbanization [8, 9]

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