Visceral leishmaniasis follow-up and treatment outcomes in Tiaty East and West sub-counties, Kenya: Cure, relapse, and Post Kala-azar Dermal Leishmaniasis.

BACKGROUND: Visceral Leishmaniasis (VL) is a neglected tropical disease (NTD) with the highest regional burden in East Africa. Relapse and Post Kala-azar Dermal Leishmaniasis (PKDL) contribute to the spread of VL in endemic areas, making their surveillance imperative for control and elimination. Little is known about long-term patient outcomes in Kenya through follow-up after VL treatment, despite its requirement for control and elimination by the World Health Organization (WHO) and the Kenya Ministry of Health (KMOH). METHODOLOGY/PRINCIPAL FINDINGS: 36 follow-up patients in Tiaty East and West, sub-counties, Kenya, and records from 248 patients at the regional Chemolingot Sub-county Hospital (CSCH) were analyzed separately using Fisher's Exact Tests, two-sample t-tests, and Welch's t-tests in R (Version 4.3.0). The study found a prevalence rate of 88.89% (n = 32) final cure, 5.56% (n = 2) relapse, and 5.56% (n = 2) PKDL in follow-up patients and 92.74% (n = 230) initial cure, 6.86% (n = 17) relapse, and 0.80% (n = 2) PKDL in overall CSCH patients. The mean lengths of time at which follow-up patients relapsed and developed PKDL were 4.5 and 17 months, respectively. Young age (p = 0.04, 95% CI 0.63-24.31), shorter length of time from initial treatment to follow-up (p = 0.002, 95% CI 1.03-∞), lower Hb level at primary treatment (p = 0.0002, 95% CI 1.23-3.24), and living in Tiaty East sub-county (p = 0.04, 95% CI 0.00-1.43) were significantly associated (p<0.05) with VL relapse in follow-up study patients. Female sex (p = 0.04, 95% CI 0.84-∞) and living in Tiaty East sub-county (p = 0.03, 95% CI 0.00-1.43) were significantly associated with PKDL in follow-up study patients. CONCLUSIONS/SIGNIFICANCE: More research should be done on PKDL in Kenya with active follow-up to understand its true burden. These results on prevalence and risk factors for PKDL and relapse in Kenya should inform knowledge of patient outcomes and interventions in the region.

Environmental Risk Factors for Visceral Leishmaniasis: An Analysis of Housing Types and Behavioral Factors in Baringo County, Kenya.

Visceral leishmaniasis (VL) is endemic in Baringo County, Kenya, and contributes significantly to the burden of disease in the region. Housing structures and other environmental risk factors contribute to transmission dynamics, but these have not been specifically studied in Baringo. The aim of this study was to increase understanding of VL transmission in the region through determining relationships between VL infection, housing, and other environmental factors. Data collection occurred from February 1 to May 31, 2023 at Chemolingot Sub-County Hospital and patients' homesteads via questionnaires of primary VL patients being treated and VL follow-up patients who were still residing in the same house as when the infection occurred. Factors assessed were housing structures, proximity to vector breeding and resting sites, and prevention and control measure practices. A baseline assessment of housing types was conducted through direct ethnographic observation and used in the analysis. Forty-one patients were included in the study. A χ2 analysis and Fisher's test were used to determine association between VL infection and housing materials, where VL patient housing data were compared with the regional baseline assessment. Significant associations with VL infection were found between mud and stick walls (P <0.001); mud walls (P <0.001); mud, stick, and grass combination walls (P = 0.02); and stick and grass walls (P <0.001). Behavior comparison showed that most VL-protective behaviors were practiced by follow-up patients after infection. Results showed an increased need for VL prevention focusing on environmental factors.