The prevalence of dengue in Grenada: a five year retrospective study

ABSTRACT

OBJECTIVE: To determine the prevalence of dengue and its serotypes (DENV 1-4) in symptomatic persons who sought care at the St. George’s University (SGU), University Health Services (UHS) during the five-year period of 2009 – 2013. To compare the dengue serology data with the dengue qRT-PCR data in the target population. DESIGN AND METHODS: The target population consists of 298 samples from dengue suspected patients who sought care at the SGU, UHS between 2009-2013 and completed the Investigation form for Suspected Dengue Infection. Dengue seropositivity of these samples was determined by the Dengue Diagnostic Laboratory with the use of ELISA and/or non-structural protein (NS1) antigen detection. The serology data collected from the Dengue Diagnostic Laboratory was used to create an electronic database. RESULTS: Of the 298 dengue suspected cases over the 5-year period of 2009-2013, 89 were confirmed to be positive for dengue. The annual prevalence of dengue from 2009 to 2013 was found to be; 34.38%, 36.96%, 26.79%, 16.21% and 29.27% respectively. The prevalence of dengue over the 5-year period was found to be 30.2%. CONCLUSIONS: From the data gathered, it appears that dengue cases peak between August to November. This is due to increased levels of rainfall which increases the number of breeding sites for the mosquito vector. The highest prevalence was seen in 2010 and the lowest prevalence was seen in 2012.