Modelling risk factors, transmission and mortality rate of Visceral Leishmaniasis at Marsabit County Referral Hospital

Abstract

Visceral leishmaniasis (V.L.), also known as visceral leishmaniasis, is a tropical infectious disease caused by female sand flies. This type of Leishmaniasis affects the internal organs, usually the spleen, liver, and bone marrow. Globally, an estimated 700 000 to 1 million new cases of V.L. occur annually. In Kenya, 4000 cases arise, while 5 million people are at risk of infection annually. The purpose of the study was to evaluate the risk factors; estimate the transmission and mortality rate of visceral leishmaniasis at Marsabit County referral hospital and give an insight understanding of V.L. dynamics to create awareness. The study's specific objectives were to: Evaluate the risk factors associated with mortality among V.L. patients, estimate the mortality and transmission rate of V.L. and establish the level of endemicity of V.L. The study adopted a retrospective cohort design. The study used secondary data from 2890 visceral leishmaniasis patients enrolled at Marsabit County referral hospital from September 2015 to September 2019. Cox proportional hazard model was used to establish the relationship between the survival time of V.L. patients and predictor variables. The Susceptible, Infected, and Recovered (S.I.R.) model was fitted to estimate the transmission and mortality rates and establish the disease's endemic nature. Data analysis was carried out using R statistical software. The risk factors that were found to be significant predictors for survival time of Visceral leishmaniasis patients included; household design (cracked walls and thatched roof) [β =.435, p=.0001], living near anthills [β =.320, p=.0012], using bed nets [β= -.151, p=.0080], contact with infected dogs [β =.200, p=.0006], forest surroundings [β=.151, p=.0340] and sleeping outside at night [β =.169, p=.0260]. The mortality and transmission rates were estimated at 13.19% and 13.63%, respectively. The control reproductive number (level of endemicity) was 0.0141, implying that the disease was not endemic. In conclusion, there was significantly higher mortality among patients who are not using bed nets, those living in cracked mud walls, those living near the forests, residing near ant hills, sleeping outside, and those in contact with infected dogs. The study recommends the adoption of appropriate practices such as avoiding contact with infected dogs, use of bed nets at night, clearing forests surrounding homesteads, avoiding sleeping in the open at night, repair wall cracks,reduce house proximity to ant hills and termite mounds to reduce the transmission and subsequent mortality from Visceral leishmaniasis.