Epidemiological characteristics and factors associated with Visceral Leishmaniasis in Marsabit County, Northern Kenya

Abstract

Introduction: Visceral Leishmaniasis (VL) is endemic in 14 of the 47 counties in Kenya. An upsurge of VL cases started in March 2017, the number of cases continued rising and by June 2017, 104 cases and 3 deaths had been reported. We conducted an investigation to describe the magnitude and pattern of the outbreak and to assess factors associated with VL infection among the cases. Methods: We conducted a secondary data analysis of VL data from 1st January 2014 to 11th July 2017 obtained from Marsabit county referral hospital and Laisamis Mission Hospitals, with a VL case being defined as any entry with a clinical or laboratory diagnosis of VL. We also conducted a frequency matched case-control study among 76 case-patients and 152 controls. A confirmed case was a person with positive rK39 serology for VL from 1st April 2017 through 11th July 2017; whereas a control was a person within a defined age-category as a case, without signs/symptoms of VL since 1st January 2017, and negative on serology. We calculated attack rates (AR) and case fatality rates (CFR) over the study period. In the case control study, we conducted unconditional logistic regression with adjusted odds ratio (AOR) and 95% confidence interval (CI). Results: A total of 383 records were reviewed, out of which 308(80%) were rK39 positive. Of the 308 confirmed cases. 256 (83%) were males. The overall AR was 169/1000 while AR among children <5 was 149 cases/100000. Overall CFR was 4.2% (13/308). History of travel to VL endemic areas (AOR =3.23, 95% CI 1.63-6.40), being a male (AOR=2.49, 95% CI 1.29-4.81), presence of termites mounds around homesteads (AOR=2.29, 95% CI 1.17-4.47), and residing in rural sub-counties (AOR=2.99, 95% CI 1.26-7.13) were factors independently associated with the VL infection. Conclusion: The burden of Visceral Leishmaniasis is high affecting males and children < 5 years of age. We recommended health education, increase community awareness on Leishmaniasis, indoor residual spraying and intensifying the use of insecticide impregnated bed nets targeting children < 5 years.