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Accurate detection of viable Leishmania parasites is critical for evaluating visceral leishmaniasis (VL) treatment response at an early timepoint. We compared the decay of kinetoplast DNA (kDNA) and spliced-leader RNA (SL-RNA) in vitro, in vivo, and in a VL patient cohort. An optimized combination of blood preservation and nucleic acid extraction improved efficiency for both targets. SL-RNA degraded more rapidly during treatment than kDNA, and correlated better with microscopic examination. SL-RNA quantitative polymerase chain reaction emerges as a superior method for dynamic monitoring of viable Leishmania parasites. It enables individualized treatment monitoring for improved prognoses and has potential as an early surrogate endpoint in clinical trials., Competing Interests: Potential conflicts of interest. All authors: No reported conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Leishmaniasis is a common neglected tropical disease in Ethiopia. Visceral leishmaniasis (VL) caused by Leishmania donovani presents in the lowlands, while cutaneous leishmaniasis (CL) affects people living in the highlands. Although CL is described as being caused by Leishmania aethiopica, there is also evidence of L. tropica and L. major isolated from a patient, sand flies and potential reservoirs. Information on species causing CL in Ethiopia is patchy, and no nation-wide study has ever been done. Understanding which species are causing CL in Ethiopia can have important implications for patient management and disease prevention., Methods: We analyzed stored routine samples and biobanked DNA isolates from previously conducted studies of CL patients from different centers in the north, center and south of Ethiopia. Species typing was performed using ITS-1 PCR with high-resolution melt (HRM) analysis, followed by HSP70 amplicon sequencing on a selection of the samples. Additionally, sociodemographic, clinical and laboratory data of patients were analyzed., Results: Of the 226 CL samples collected, the Leishmania species could be determined for 105 (45.5%). Leishmania aethiopica was identified in 101 (96.2%) samples from across the country. In four samples originating from Amhara region, northwestern Ethiopia, L. donovani was identified by ITS-1 HRM PCR, of which two were confirmed with HSP70 sequences. While none of these four patients had symptoms of VL, two originated from known VL endemic areas., Conclusions: The majority of CL was caused by L. aethiopica, but CL due to L. tropica and L. major cannot be ruled out. Our study is the first to our knowledge to demonstrate CL patients caused by L. donovani in Ethiopia. This should spark future research to investigate where, how and to which extent such transmission takes place, how it differs genetically from L. donovani causing VL and whether such patients can be diagnosed and treated successfully with the currently available tools and drugs., (© 2023. The Author(s).)

Background: Visceral leishmaniasis is a disease caused by disseminated Leishmania donovani infection which affects almost half a million people annually. Most of the patients are reported from the Indian sub-continent, Eastern Africa and Brazil. In this study, we aimed to determine the levels of antibodies and cytokines in visceral leishmaniasis patients and to examine associations of parasitemia with the clinical states of patients. A prospective study was carried out, enrolling a total of 48 active VL patients who were evaluated before, during different time points and, three months after treatment. Serum cytokine concentrations, antibody levels, parasitemia, laboratory (hematologic and biochemical) measurements, and clinical parameters were assessed., Results: Counts of WBC and platelets, and measurements of hemoglobin (Hb) increased during treatment (P ≤ 0.05). Elevated levels of circulating IL-10, IFN-γ, and TGF-β1 were measured before treatment. The observed increase in serum IL-10 remarkably declined within 7 days after the start of treatment. Anti-leishmanial antibody index (AI) was high in all VL patients irrespective of spleen aspirate parasite grade before treatment and at different times during treatment. However, a significant (P ≤ 0.05) decrease of AI was observed 120 days post-treatment. IL-2 serum levels were below the detection limit at all sampling points., Conclusions: The present results suggest that IL-10, IFN-γ, and TGF-β1 can be used as markers of active visceral leishmaniasis. In addition, measuring circulating cytokines concentrations, particularly IL-10, in combination with other clinical evaluations, could be used as criteria for the cure. The observation that a high serum concentration of IFN-gamma at baseline was associated with low parasitemia deserves further investigations., Competing Interests: The authors have declared that no competing interests exist.

Background: Visceral leishmaniasis (VL), a vector-borne disease caused by species of the L.donovani complex, has (re)-emerged in Ethiopia during the last two decades and is currently of increasing public health concern. However, very little is known about VL epidemiology in the Somali Region of Ethiopia. The aim of this study was to provide detailed epidemiological information on seroprevalence, associated factors and incriminated vectors of VL in Shebelle Zone and Ethiopian Somali Region in general., Methods: A cross-sectional epidemiological study was conducted between March and May 2016 in Gode and Adadle districts of Shebelle Zone, Ethiopian Somali Region. Two-stage semi-random sampling was applied for selecting study participants for the field survey. The study included structured questionnaire interviews, serological assays (rK39-immunochromatographic test), ELISA and entomological surveys., Results: From a total of 361 participants, 57 (15.8%) were seropositive for VL including 46 (12.7%) rK39 positive and 11 (3.0%) positive by both rK39 and ELISA. VL seroprevalence was higher (P < 0.001) in Adadle (31.1%) compared to Gode (12.7%) district. The VL seroprevalence rate was higher in females than in males [rK39 (17.2 vs 14.0%) and ELISA (3.4 vs 2.5%)]. Children under the 15 years of age were the most highly affected group [rK39 (20.4%) and ELISA (4.4%)]. Increased VL risk was associated with presence of termite hills, study district, outdoor sleeping, Acacia trees and domestic animals [odds ratio (95% confidence interval): 12.58 (5.911-26.763), 5.40 (2.90-10.07), 5.31 (2.283-12.364), 2.37 (1.1190-4.728) and 0.199 (0.097-0.410), respectively]. The entomological survey identified 74 Phlebotomus [P. (Larroussius) orientalis (52/74), P. (Anaphlebotomus) rodhaini (14/74), P. (Paraphlebotomus) sergenti (8/74)] and 11 Sergentomyia sand flies. The average frequency of P. orientalis (3.06 ± 0.66) collected by all traps per night was higher than that of other species. The average frequency of total and specific (P. orientalis) female sand flies was higher in Adadle (1.89 ± 0.423 vs 1.11 ± 0.309) than in Gode (0.62 ± 0.324 vs 0.38 ± 0.183) district. The highest mean numbers of total (8 ± 1.5) and P. orientalis (6 ± 0.913) sand flies were collected in termite hills., Conclusions: The present findings revealed potential new VL-transmission foci in the study districts. Therefore, the need for parasitological and molecular characterization of the parasite in humans and vector sand flies is of paramount importance to confirm transmission.