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.

BACKGROUND On 23 July 2018, Hajjah governorate surveillance officer notified Ministry of Health about increased number of cutaneous leishmaniasis (CL) cases in Bani-Oshb, Kuhlan district, Hajjah governorate. On 24 July 2018, Yemen Field Epidemiology Training Program sent a team to perform investigation. OBJECTIVE To describe a CL outbreak in Hajjah governorate and determine its risk factors. METHODS A descriptive study followed by a case-control study were conducted. Cases were defined as any person who met the suspected or confirmed case definition of WHO and live in Bani-Oshb sub-district during the period August 2017 - July 2018. Controls were defined as any person living for at least one year in Bani-Oshb without new or old skin lesions. Crude or adjusted Odd Ratios (cOR or aOR) with 95% Confidence Interval (CI) was used to test the significance of the association. RESULTS Thirty cases with leishmaniasis were found in Bani-Oshb sub-district during the period August 2017 - July 2018. Twenty-three percent of patients were younger than 5 years, 57% aged 5-14 year, 57% were females and 77% of cases had one lesion. The attack rate was 7 per 1000 population in the age group < 15 year and 1 per 1000 population in the age group ≥15 year. On bi-variate 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 bed net (cOR 14.5, 95% CI 1.7–122.4), poor house lightening (cOR 6.4, 95% CI 2.1–19.7), poor house hygiene (cOR 11.2, 95% CI 3.1–40.7), and poor sanitation (cOR 14.5, 95% CI 1.7–122.4), living in houses without windows net (OR 5.2, 95% CI 1.3–21.2), plantation around the house (cOR 6.5, 95% CI 2.1–20.5), animals 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’s dung in or near the house (cOR 6.8, 95% CI 1.7–27.7). The following risk factors remained significant after application of 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 in Hajjah governorate was endemic and a wave of increase in cases was confirmed. Many individual, housing, and animal related factors had been shown to contribute to CL endemicity. Implementation of control measures directed towards altering the factors favoring contact between vectors, reservoirs, and susceptible humans are strongly recommended to control future outbreaks. Further studies focusing on species of parasite, vectors and reservoir are also recommended.