Deadly Kala-Azar Disease Spreads to Four New Kenyan Counties Despite Being Preventable
Nairobi, 14 February 2026
Kenya faces a alarming expansion of kala-azar, a fatal parasitic disease that has spread from eight to twelve counties by February 2026. Despite being both preventable and treatable, the disease maintains a mortality rate approaching 100% when untreated, with children under 15 accounting for over 67% of cases. Climate change is driving sandflies into new territories, whilst surveillance gaps allow the disease to advance unchecked across Kenya’s arid regions.
Current Outbreak Reaches Critical Threshold
The disease outbreak has reached unprecedented levels in 2025, with Kenya recording over 3,000 cases—representing a 100 per cent increase from the six-year average of 1,500 cases [1]. This surge culminated in a significant outbreak in Wajir County during 2025, underlining the deteriorating situation [1]. By January 2026, Kajiado West Sub-County alone reported 12 new cases, contributing to over 214 diagnosed cases in the past year within that single sub-county [5]. The disease has particularly affected Osonorua and Oltepesi areas, which have emerged as major hotspots in the region [5].
Vulnerable Demographics Bear Greatest Burden
Children and young people continue to bear the heaviest toll from this preventable disease. Nationally, children under 15 account for over 67% of reported kala-azar cases, whilst males represent about 66% of infections [1]. The demographic impact becomes even more stark when examining specific regions—most cases occur in individuals under 19 years old, with some areas including Wajir and Kajiado counties detecting infections in children younger than four [3]. Dr Daniel Masiga of the International Centre of Insect Physiology and Ecology noted that finding cases in very young children indicates ‘transmission is happening close to homesteads,’ rather than being limited to traditional pastoral grazing areas [3]. The tragedy of this demographic distribution is exemplified by the February 2022 incident at Mwingi level IV hospital, where four children died after being admitted with kala-azar [5].
Climate Change Drives Geographic Expansion
Climate variability and ecological shifts are fundamentally altering the disease’s geographic footprint across East Africa [1][3]. According to Dr Masiga, rising temperatures and changing rainfall patterns are expanding suitable habitats for sandflies, increasing transmission risk in areas that were previously too cool or dry to sustain large vector populations [3]. East Africa has now become the global epicentre of kala-azar, with transmission patterns that are shifting due to ecological changes including land use, settlement expansion and environmental degradation [3]. The dominant sandfly species, Phlebotomus orientalis, has become more abundant in Kenya since around 2015, with research in Marsabit County showing increased female sandfly populations during July and infection rates among sampled sandflies reaching approximately 9.6 per cent [1].
Treatment Challenges and Elimination Goals
Despite being both preventable and treatable, critical gaps in Kenya’s health system continue to hamper disease control efforts. Dr Wycliffe Omondi, head of Vector-Borne and Neglected Tropical Diseases Research at KEMRI, emphasised during the KASH scientific conference on 13 February 2026 that ‘leishmaniasis is preventable and treatable, yet despite these critical components, we still see high morbidity and mortality’ [1]. The healthcare infrastructure remains inadequate, with only three health facilities in the Kajiado West region equipped to test for kala-azar, forcing patients to be referred to Kajiado County Referral Hospital [5]. Kenya has set ambitious targets to eliminate visceral leishmaniasis as a public health problem by 2030, including a 60% case reduction by 2027 and a 90% reduction in new cases, alongside achieving 90% of cases detected and treated within 30 days of symptom onset [1]. However, experts warn that current approaches remain largely reactive, responding only when cases are already high instead of preventing outbreaks before they occur [1].