Rearing Management and Its Impact on Caseous Lymphadenitis in Sheep.

Two surveys were conducted to assess the prevalence and risk factors of ovine caseous lymphadenitis (CL) and explore the association between its superficial and visceral forms in Sardi sheep in Settat province, Morocco. A total of 1521 sheep, including 318 lambs < 6 months, 572 young sheep aged 6-24 months, and 631 adult sheep > 24 months, were examined from 57 flocks. Superficial CL prevalence levels were as follows: 69/318 in lambs, 292/572 in young sheep, and 114/631 in adult sheep. Additionally, 2124 sheep, including 1813 young and 311 adult sheep, were inspected in slaughterhouses ante- and post-mortem. Among all infected animals, the prevalence of visceral abscesses was notably higher in adult sheep (83%, OR = 9.8, 95% CI = 5.5-17.2) compared to young sheep (35%). Data on flock size, sex, age, body condition score, rearing methods, and hygienic measures were collected. Suspected CL cases were confirmed using quadruplex-PCR. Poor barn ventilation, lack of abscess control, and younger age were identified as key risk factors for CL. Additionally, a high percentage (89%) of animals with thoracic abscesses did not display superficial lesions. While age and abscess control have been reported in previous studies, barn ventilation appears to be a new, but important, risk factor. In conclusion, the identified risk factors in Settat province are linked to breeding management practices. Implementing regular abscess control measures and improving barn ventilation are essential for CL prevention.

Understanding the factors that determine the emergence of anthroponotic cutaneous leishmaniasis due to Leishmania tropica in Morocco: Density and mitochondrial lineage of Phlebotomus sergenti in endemic and free areas of leishmaniasis.

Anthroponotic cutaneous leishmaniasis (ACL) due to Leishmania tropica is spreading to new areas in Morocco. Exposure to the vector, Phlebotomus sergenti, is the only proven risk factor. Our objective was to compare the densities and genetic characteristics of P. sergenti populations in two nearby localities in Morocco, one in an ACL endemic area (El Borouj) and another in a nonendemic area (Sidi Hajjaj). P. sergenti density was significantly higher in the endemic area than in the nonendemic town (p = 0.032). A different predominant P. sergenti mitochondrial lineage was evidenced in each one of the two localities, and for the first time, the P. sergenti lineage acting as a vector of L. tropica has been identified. Bioclimatic differences were detected between both localities. In conclusion we found differences in both the density and the mitochondrial lineage of P. sergenti populations that may explain the different epidemiological situation. Given that the density of P. sergenti in the locality without ACL cases seems sufficient to allow transmission, the main factor that would justify its nonendemic character could be the absence of P. sergenti Lineage IV, which seems to prefer warmer and drier climates.

Accuracy of a Rapid Diagnostic Test Based on Antigen Detection for the Diagnosis of Cutaneous Leishmaniasis in Patients with Suggestive Skin Lesions in Morocco.

In rural areas in Morocco, diagnosing cutaneous leishmaniasis (CL) can be challenging. We evaluated the accuracy of a rapid diagnostic test (RDT) based on antigen detection, CL Detect Rapid Test™ (Inbios International Inc., Seattle, WA), in this setting. We consecutively recruited patients with new skin ulcers in nine primary health centers. We took a dental broach sample for the RDT and two other tissue samples by scraping the border and center of the lesion with a scalpel and smearing it on a slide. We duplicated each smear by pressing a clean slide against it and processed the slides by microscopy, polymerase chain reaction (PCR) internal transcribed spacer 1, and kDNA minicircle PCR. In a subgroup with positive PCR, the Leishmania species was identified using PCR-restriction fragment length polymorphism and PCR-sequencing of hsp70 genes. A participant with positive microscopy and/or PCR was considered a confirmed CL case. We computed sensitivity (Se) and specificity (Sp) of the RDT compared with this reference standard (ClinicalTrials.gov registration: NCT02979002). Between December 2016 and July 2017, we included 219 patients, 50% of them were under 18 years old. Rapid diagnostic test Se was 68% [95% confidence interval (CI): 61-74], Sp 94% [95% CI: 91-97], positive predictive value 95% [95% CI: 92-98], and negative predictive value 64% [95% CI: 58-70]. Despite its low Se, this novel RDT is a useful addition to clinical management of CL in Morocco, especially in isolated localities. Rapid diagnostic test-positive lesions can be treated as CL; but when RDT negative, microscopy should be done in a second step. The Se of the RDT can probably be optimized by improving the sampling procedure.

Risk factors for the expansion of cutaneous leishmaniasis by Leishmania tropica: Possible implications for control programmes.

Cutaneous leishmaniasis (CL) caused by Leishmania tropica is emerging in new areas, initially as outbreaks and then establishing endemic foci. There is little evidence of the risk factors and effectiveness of existing control measures, what limits our ability to generalize in different epidemiological settings. The disease is described as anthroponotic; however, zoonotic outbreaks have been reported in some countries. Our aim was to identify risk factors in a recently reported endemic focus in Morocco in order to design more effective control programmes. A case-control study was conducted from September 2014 to October 2015 for epidemiological data collection from families with and without CL cases. Sandflies were captured and L. tropica infection determined. The presence of potential animal reservoirs was evaluated. 71 CL cases (44 diagnosed between 2013 and 2015) and 137 healthy people were surveyed. The average age of the new cases was 33.1 ± 22.3 years, and 69.0% were women. Phlebotomus sergenti was the most abundant species with a density of 4.27 sandflies/trap/night and differences between houses with and without CL cases were detected (p-value = 0.014). Overall, 2.7% female P. sergenti and 3.0% dogs were positive for L. tropica. Human, cat, rabbit and bird blood was detected in blood-fed P. sergenti females. 45% people used preventive measures that were not translated into a reduction in the individual risk of acquiring CL. Exposure to P. sergenti was the only risk factor found, and the reduction in its density could be achieved through the improvement of water wells management, organic fertilizers' disposal and dogs control. The lack of effectiveness of indoor residual spraying and treated nets are attributable to poor compliance and misuse of them. In addition, result optimization of the awareness campaigns on the public is possible by involving patients with CL to explain their own experience.