Cutaneous Leishmaniasis Outbreak Investigation in Hajjah Governorate, Yemen, in 2018: Case-Control Study

Abstract

Background Cutaneous leishmaniasis (CL) is endemic in Yemen. About 4440 cases were reported in 2019. On July 23, 2018, a Hajjah governorate surveillance officer notified the Ministry of Public Health and Population about an increase in the number of CL cases in Bani-Oshb, Kuhlan district, Hajjah governorate. On July 24, 2018, Yemen Field Epidemiology Training Program sent a team to perform an investigation. Objective We aimed to describe a CL outbreak in Hajjah governorate and determine its risk factors. Methods A descriptive study and case-control study (1:1 ratio) were conducted. Cases included people who met the suspected or confirmed case definition of the World Health Organization and lived in Bani-Oshb subdistrict during the period from August 2017 to July 2018. Controls included people living for at least 1 year in Bani-Oshb without new or old skin lesions. Crude odds ratios (cORs) and adjusted odds ratios (aORs) with 95% CI were used to test the significance of associations. Results We identified 30 CL cases. Among the 30 patients, 7 (23%) were younger than 5 years, 17 (57%) were 5 to 14 years, 17 (57%) were females, and 23 (77%) had one lesion. The attack rate was 7 per 1000 population in the age group <15 years and 1 per 1000 population in the age group ≥15 years. On bivariate analysis, the following factors were significantly associated with CL: female gender (cOR 5.2, 95% CI 1.7-16.5), malnutrition (cOR 5.2, 95% CI 1.7-16.5), not using a bed net (cOR 14.5, 95% CI 1.7-122.4), poor house lighting (cOR 6.4, 95% CI 2.1-19.7), poor house hygiene (cOR 11.2, 95% CI 3.1-40.7), poor sanitation (cOR 14.5, 95% CI 1.7-122.4), living in houses without window nets (cOR 5.2, 95% CI 1.3-21.2), plantation around the house (cOR 6.5, 95% CI 2.1-20.5), animal barn inside or close to the house (cOR 9.3, 95% CI 1.9-46.7), raising animals (cOR 8.1, 95% CI 1.6-40.7), and having animal dung in or near the house (cOR 6.8, 95% CI 1.7-27.7). The following risk factors remained significant on multivariate stepwise analysis: female gender (aOR 22.7, 95% CI 1.6-320.5), malnutrition (aOR 17.2, 95% CI 1.3-225.8), poor house hygiene (aOR 45.6, 95% CI 2.5-846.4), plantation around the house (aOR 43.8, 95% CI 1.9-1009.9), and raising animals (aOR 287.1, 95% CI 5.4-15205.6). Conclusions CL was endemic in Hajjah governorate, and an increase in cases was confirmed. Many individual, housing, and animal related factors were shown to contribute to CL endemicity. Implementation of control measures directed toward altering the factors favoring contact among vectors, reservoirs, and susceptible humans is strongly recommended to control future outbreaks.

Determinants of cutaneous leishmaniasis among students in Delanta district, Northeast Ethiopia: A case–control study

“…This finding was similar to studies conducted in Kenya 27 and Colombia 43 . The same association between CL and plantation around houses was observed in Yemen 33 and with the presence of a gardening area in Sri Lanka 35 . In addition, studies conducted in Ethiopia showed that plants, dry river banks, farm fields, and dry irrigation tanks are the preferred breeding sites of sand flies 44 …”

“…Another study in highland areas of Ethiopia also showed that involvement in outdoor activity was the main risk factor for the acquisition of CL 18 . However, this finding was contradicted by studies conducted in Yemen, 33 Morocco, 34 and Sri Lanka 35 that CL was observed more likely in females than in males. This discrepancy might be due to the difference in the sociodemographic characteristics of study participants and the study designs employed.…”

Outbreak of Cutaneous Leishmaniasis among military personnel in French Guiana, 2020: Clinical, phylogenetic, individual and environmental aspects

“…Military outbreaks of CL are associated with very different risk factors than civilian ones. For example in an 2018 study in Yemen, risk factors of infection (agricultural activities of women, malnutrition, proximity of plantations and animals) were mostly linked to the poor living conditions and rural habits of the studied community [56]. A civilian outbreak in the Communidad Valenciana (Spain) led to the implementation of several vector control measures and personal protection against sandfly bites.…”

Leishmaniasis: Recent epidemiological studies in the Middle East

“…In Yemen, (CL) was reported in the northwestern, southwestern, and central highlands ( Mahdy et al, 2016 , 2010 ; Alkulaibi et al, 2019 ) and appears to be endemic in the northwestern highlands, Hajjah governorate region. In a previous study, L. tropica was reported as the main cause in about 95% of cases, while L. donovani and L. infantum were identified in 4.1% of cases ( Alvar et al, 2012 ; Nassar et al, 2021 ).…”