Seroprevalence of Anti-Dengue Virus 2 Serocomplex Antibodies in out-patients with fever visiting selected hospitals in rural parts of Western Kenya in 2010-2011: a cross sectional study

INTRODUCTION: There has been a recent increase in the spread of Dengue to rural areas. Rural parts of western Kenya are naturally prone to mosquito-borne diseases, however, limited research has been documented on infections with Dengue. This study therefore investigated the presence of antibodies against Dengue virus 2 (DENV-2) in a cross-section of febrile adult out-patients visiting three selected hospitals to assess the level of exposure and to possibly identify the epidemiologic and clinical factors of seropositive participants. METHODS: In a cross-sectional study, we administered a questionnaire and used indirect ELISA to test for the presence of DENV-2 antibodies in febrile outpatients (n=422) visiting three selected hospitals in rural western Kenya. All positive and borderline samples were re-evaluated by Plaque Reduction Neutralization Tests.RESULTS: The prevalence of DENV-2 serocomplex antibodies was 8.5% by indirect ELISA and 1.2% by Plaque Reduction Neutralization Test. Using bivariable analysis, age (P=0.0001), headache (OR, 3.4 (1.6-7.4); P=0.002), retro-orbital pain (OR, 3.1 (1.2-7.7); P=0.015), muscle ache (OR, 2.6 (1.3-5.2); P= 0.007), joint pain (OR, 3.5 (1.7-7.3); P=0.001) and abdominal pain (OR, 9.5 (2.44-37.24); P=0.001) were significantly associated with DENV-2 seropositivity. CONCLUSION: This study confirms that there is an existence of Dengue virus 2 circulating in regions of western Kenya. Age, headache, retro-orbital pain, muscle ache, joint pain and abdominal pain were associated with increased DENV-2 seropositivity.