Risk Factors of Visceral Leishmaniasis among Residents of Chemolingot, Baringo Kenya

• Visceral Leishmaniasis (VL): This is a disease caused by a protozoan, Leishmania, and is transmitted to humans and other mammals by the bite of a female phlebotomite sandfly.
• Low socio-economic status, socio-cultural factors, and pastoralism practices have been identified to increase exposure to visceral leishmaniasis.
• Baringo County is an endemic focus of VL, However, its associated risk factors are not well documented.

Analysis established some statistical associations between the various categories. The age group below  20 years reported the highest positivity rate of VL 90 (42.1%). The lowest positivity rate of 5 (27.8%) was observed in the age groups 41-60. The difference in positivity by age group was not statistically significant (χ2 2.184 df3 p = 0.535). The prevalence rates significantly varied between males 88 (44.2%) and females 43 (32.6%) (χ24.500 df1 P = 0.034). There is a statistical difference between those who were employed 4 (7.3%) and the unemployed 127(46.0%), where employed respondents had fewer positive cases than unemployed with a significant difference (χ2 28.784 df1 P=0.001). Education-wise, respondents with at least secondary level were least affected 13 (9.93%) compared to those with lower than secondary education 118(90.07%) with a significant difference ( χ2= 22.039 df 6 p=0.001), Occupation-wise, pastoralists 62 (45.6 %) and casual laborers 7(100%) were affected more than those with employment 8(14.5%) (χ2= 46.501 df 7 p = 0.001).

The current study reported a high positivity rate of 90 (42.6%) among respondents below age 20, the findings are similar to that of a study by Argaw et al (2013) and Priyamvada et al (2021) that reported age as a risk factor for 59% of those below 20 years [17,18].  Justification for this age group being more infected may be due to the active nature of these groups of people and therefore they are involved in many outdoor activities like herding of cattle, charcoal burning, and beekeeping that are likely to increase exposure to the sand-fly bites.

It is noted from this study that more males 88 (67.17%) were affected by visceral leishmaniasis than females 43(32.83%) (OR 0.649; 95% CI 0.385-0.964, p= 0.034) these findings are in concordance with those of a study done in Humera, Western Tigray, where univariate analysis of infection of VL based on potential risk factors found a high male infection rate 132 (87%) than female counterparts [19]. This may be explained by the fact that culturally, in the Pokot community males usually take part in outdoor activities like pastoralism and at times are faced with the fact that they have to sleep outside at night to protect their families and their livestock.

Education level was also significantly associated with VL with those who were more educated, secondary certificate, diploma degree, and postgraduate combined n=75 (22.65%) were less affected with the disease as compared to those with no education combined 257(77.3) with 118 (54.0%) being VL positive and 1.6 times likely to suffer than those who are literate. The findings are comparable to those of a study by Kiptui et al (2021)that reported a risk factor of 60% for the uneducated [20]. The findings are also similar to those of another study in India and Nepal where a prospective study showed seroconversion and risk of VL were strongly associated with illiteracy levels OR=0.63 [21].  The high-risk factor for the uneducated may be explained that they may not be aware of leishmaniasis and how it is transmitted and therefore they don't take any precautions to protect themselves from it.

On occupational activities, participants who engaged in herding were majority 136 (41.1%), with 62(45.6) being positive for VL  and 2.0 times more likely to suffer VL than those who engaged in other forms of occupation thus independently associated with risk for visceral leishmaniasis. The findings are in agreement with those of Wijerathna et al (2020) on the assessment of risk factors for visceral leishmaniasis among residents of Baringo [22]. This may be attributed to the harsh scorching effects of the sun at the lowlands of Chemolingot therefore they prefer grazing their animals at night when the temperatures are low coinciding with the feeding time of the sandflies thus get more exposed.

Temporary houses played a key role as regards exposure to VL. The study recorded a threefold likelihood of exposure in temporary houses as compared to living in permanent houses.  The findings are comparable to those of a study by Mandal et al (2019) and Kiptui et al (2021) that demonstrated the high-risk factors for visceral leishmaniasis in selected high endemic areas are attributed to poor housing structures and conditions [20,23]. The poor housing structures in this context are mud walls, stick walls, and grass-thatched houses. The mud walls and grass thatched roofs will act as the hideouts and breeding sites for the sandflies and the stick walls allow the sandflies to move into the houses.

It is also worth noting that; Homes with ant hills around the compound (radius 50 meters) were majority 277(83.7%) and significantly influenced the number of cases with 117(42.3%) positive reports and participants were 1.6 times likely to suffer VL than those with anthills far away. These results are consistent with those of a study conducted in eastern Ethiopia which demonstrated that termite mounds near the compound were strongly associated with increased VL risk. Justification for this increased risk to VL among participants with anthills near homesteads is that eroded anthills could provide better habitat for sandfly vectors as such kinds of mounds provide small vertical and horizontal channels which are related to termite hill ventilations which provide conducive shelter to sandflies [15].

CONCLUSION

The following risk factors independently associated with VL were male gender, herding, having no education, temporary houses, having 1-2 rooms, grass thatched roof and stick/mud wall, and presence of anthills near the compound.

Recommendation

This study recommends Ministry of Health and the Department of Health Baringo County in conjunction with other partners come up with effective measures in disseminating information on integrated control and prevention with the objective of lowering morbidity and mortality.

Ethical approval:

Ethical approval to conduct the study was granted by Maseno University Scientific Research and Ethics Committee (MUSREC), Nacosti, and the County government of Baringo. Consent was sought from the patients before administering the questionnaire, and anonymity and confidentiality were maintained throughout the study period.

Acknowledgment

We would like to thank the residents of Chemolingot, Baringo County for consenting to participate in this study and the county government of Baringo for permitting us to undertake the study.

Author contribution: We declare that all listed authors have made substantial contributions to all of the following three parts of the manuscript:

- Research design, or acquisition, analysis, or interpretation of data;

- drafting the paper or revising it critically;

- approving the submitted version.

We also declare that no one who qualifies for authorship has been excluded from the list of authors.

 Funding

None.

Conflict of interest

None.