Evaluation of microcapillary culture method for the isolation of Leishmania aethiopica parasites from patients with cutaneous lesions in Ethiopia

Leishmaniasis in deployed military populations: A systematic review and meta-analysis

Leishmaniasis affects military personnel deployed to endemic areas following exposure to sand flies infected with the protozoa Leishmania. This systematic review and meta-analysis of data specific to military populations aims to identify knowledge gaps to mitigate sand fly exposure and Leishmania transmission during deployments. The review was registered on PROSPERO (CRD42023463687). Random-effects meta-analyses and narrative synthesis were performed. Thirty-six studies were included, most of which reported on cutaneous leishmaniasis (CL), showing a mean cumulative incidence of 10% (95% CI: 5-16), suggesting higher rates in the Eastern Mediterranean region (14% [95% CI: 12-16]) compared to the African region (8%) and American region (9%). Asymptomatic Leishmania infection had a cumulative incidence of 11% (95% CI: 6-17), with higher rates in Eastern Mediterranean countries (20% [95% CI: 14-25]). Diagnosis involved parasitological, serological, and molecular methods, with L. (L) mexicana and L. (V.) braziliensis identified as the predominant CL pathogens in deployed troops in the Americas. Visceral leishmaniasis cases were less frequent, all reported from the Eastern Mediterranean and associated with the Leishmania donovani/infantum complex; whereas CL cases in the Old World were due predominantly to L. major and L. tropica. Regular use of long-lasting insecticidal nets to mitigate sand fly exposure demonstrated high potential effectiveness than other reported personal protective measures (PPMs) which yielded mixed or inconclusive results. In summary, the systematic review revealed the substantial variability between study designs and statistical integrity. There is need for more consistent and robustly designed studies including well-define controls and replication. Future studies would be advised to explore the long-term effectiveness and practicality of PPMs, both individually and in combination, across diverse deployment settings.

Epidemiological and clinical profiles of cutaneous leishmaniasis cases in Amhara National Regional State, Northwest Ethiopia: a multicenter retrospective study

Cutaneous leishmaniasis (CL) is caused by Leishmania parasites. Ethiopia is one of the top ten countries with a high CL load, and Amhara National Regional State (ANRS) is one of the CL hotspot areas in the country. This study examined cutaneous leishmaniasis's epidemiology and clinical profiles in the ANRS region. It was conducted from April to October 2023 across eight Leishmaniasis Treatment Centres (LTCs). A data review was done from patients presenting to these centers between June 2018 and July 2023. Chi-square test and logistic regression were performed using SPSS-23. A total of 1729 patients with CL were recorded, resulting in an overall burden of 8.6 cases per 10,000 outpatients. Patients were from 112 districts, and most of them (71.1%) presented with localized cutaneous leishmaniasis (LCL). Approximately 12% of patients lived with the disease for over a year without treatment, while 13.2% of patients were multiple-time comers. Cutaneous leishmaniasis continues to be a significant public health issue in the ANRS region. Approximately onethird of CL patients exhibit the mucocutaneous leishmaniasis (MCL) clinical form. There has been a notable delay among CL patients in seeking diagnosis and treatment. It is essential to conduct large-scale community-based studies and studies focused on both traditional and modern treatment centers to accurately estimate the prevalence of CL in the region. Follow-up and molecular studies are crucial for enhancing our understanding of the clinical features of the disease. Furthermore, raising community awareness about CL prevention and control can help patients obtain early diagnosis and treatment.

Histopathological Patterns of Cutaneous and Mucocutaneous Leishmaniasis Due to L. aethiopica

Background: Cutaneous leishmaniasis (CL) is an endemic disease in Ethiopia, mainly caused by L. aethiopica. Limited reports are available related to histopathological features of the skin lesion caused by L. aethiopica. This study aimed to analyze the histopathological features of CL due to L. aethiopica. Materials and Methods: A similar cohort polymerase chain reaction (PCR) confirmed CL patients from a previous own study, who were prospectively enrolled from All Africa Leprosy, Tuberculosis and Rehabilitation Training (ALERT) Hospital Addis Ababa, Kela Health Center in Gurage Zone, Siliti Health Center in Silit zone of southern nations and nationalities, as well as Ankober Health Center in Amhara region was used for data analysis. The histopathology was analyzed by performing hematoxylin and eosin (H&E) staining to look for the presence of general and specific histopathology patterns of the disease. Descriptive statistics was utilized using SPSS version 26.0 (SPSS, Inc., Chicago, United States of America). Results: Amastigotes were observed in skin biopsies of 29% (n = 2) mucocutaneous leishmaniasis (MCL) and 58% (n = 6) localized cutaneous leishmaniasis (LCL) patients. Diffused inflammatory cell infiltrate was observed in the dermal compartment of 77% (n = 20) samples while the remaining 23% (n = 6) had patchy or nodular inflammatory cell infiltrate. The dominant type of inflammatory cell infiltrate in the dermal compartments is macrophages and lymphocytes with a similar proportion, 23/26 (88.5%), followed by plasma cells, 21/26 (80.8%). Among all cases, 38.5% (n = 10) of them were categorized under the Type I pattern while Types IV and V patterns were reported in 26.9% (n = 7) and 34.6% (n = 9) of the remaining samples, respectively. The study found statistically significant correlations between necrosis and MCL (p=0.01), unorganized granulomas and LCL (p=0.04), and the presence of eosinophils and giant cell Langerhans with MCL (p=0.002 and p < 0.001, respectively). Conclusion: In our study, the histopathological patterns of the CL caused by L. aethiopica were shown to have a dermal change that was characterized by a domination of diffused inflammatory cell infiltrate. Most of the cell types in the infiltrate were macrophages and lymphocytes. In addition, amastigote resided in the histiocyte with a varying degree of intensity, and both the organized and unorganized granulomas were shown with a considerable proportion.

The need for culture in tegumentary leishmaniasis diagnosis in Bolivia: A comparative evaluation of four parasitological techniques using two sampling methods

Leishmaniases are zoonotic diseases caused by protozoa of the genus Leishmania. In Bolivia, leishmaniasis occurs mainly in the cutaneous form (CL) followed by the mucosal or mucocutaneous form (ML or MCL), grouped as tegumentary leishmaniosis (TL), while cases of visceral leishmaniasis (VL) are rare. The cases of TL are routinely diagnosed by parasitological methods: Direct Parasitological Exam (DPE) and axenic culture, the latter being performed only by specialized laboratories. The aim of the present study was to optimize the parasitological diagnosis of TL in Bolivia, using two sampling methods. Samples from 117 patients with suspected TL, obtained by aspiration (n = 121) and scraping (n = 121) of the edge of the lesion were tested by: direct parasitological exam, culture in TSTB medium, and miniculture and microculture in Schneider's medium. A positive laboratory result by any of the four techniques evaluated using either of the two sampling methods was considered the gold standard. Of the 117 suspected patients included, TL was confirmed in 96 (82 %), corresponding 79 of the confirmed cases (82.3 %) to CL and 16 (16.7 %) to ML. Parasitological techniques specificity was 100 % and their analytical sensitivity was greater with scraping samples in TSTB culture (98 %). Scraping samples in TSTB and miniculture correlated well with the reference (Cohen's kappa coefficient=0.88) and showed good reliability (Cronbach's alpha coefficient ≥0.91). Microculture provided positive results earlier than the other culture methods (mean day 4.5). By day 14, 98 % of positive cultures had been detected. Scraping sampling and miniculture were associated with higher culture contamination (6 % and 17 %, respectively). Bacterial contamination predominated, regardless of the sampling and culture method, while filamentous fungi and mixed contamination were more frequently observed in cultures from scraping samples. In conclusion: (i) scraping samples proved more suitable for the diagnosis of TL as they increased analytical sensitivity, are less traumatic for the patient and are safer for laboratory personnel than aspirates; (ii) culture, mainly in TSBT medium, should be used for the diagnosis of TL due to its high sensitivity (doubling the number of cases diagnosed by DPE) and its low cost compared to other culture media.

Burden of neglected tropical diseases and access to medicine and diagnostics in Ethiopia: a scoping review

BACKGROUND

More than 1.7 billion people are affected by neglected tropical diseases (NTDs) worldwide. Forty percent of the NTD-affected people live in Africa with the poorest, most vulnerable, and hard to reach geographical areas. The NTDs cause significant social and economic burden and deepen marginalization and stigmatization. The World Health Organization's current roadmap for NTD aims to prevent, control, eliminate, or eradicate 20 tropical diseases. Ethiopia experiences a high burden of these diseases, but current access to diagnostics, medicine, and/or care has been little explored to inform the country's NTD strategic plan. The overall purpose of the scoping review was to map and characterize the burden of NTDs and challenges in access to diagnostics, medicine, and/or care in Ethiopia.

METHODS

A systematic search of evidence was conducted in PubMed, Cochrane Library, and Google Scholar from January 2000 until May 2022, without restrictions of language or study design. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Review was followed for screening of studies. Key findings were extracted and narrated qualitatively.

RESULTS

The search resulted in 4532 articles, of which 105 met the inclusion criteria and were included in the scoping review under three themes: burden of NTDs, access to diagnostics, medicine and/or care, and key barriers. Although gains have been made in the prevention and control of NTDs in Ethiopia, the burden remains high, and progress in access to diagnostics, medicine/drugs, and/or care is very slow. Poverty, poor quality of life, and underfunding of NTD programs decelerate the process of NTD elimination program in the country.

CONCLUSIONS

The scoping review identified a considerable number of studies on the burden of NTDs in Ethiopia and strategies for diagnosis, treatment, and/or care; however, there is a paucity of evidence on the suitability and potential benefits of novel diagnostic technologies and medicines in the country. A regular review and analysis of such country-level evidence is important to inform the country NTDs roadmap and local implementation strategies.

Laboratory diagnostics for human Leishmania infections: a polymerase chain reaction-focussed review of detection and identification methods

Leishmania infections span a range of clinical syndromes and impact humans from many geographic foci, but primarily the world's poorest regions. Transmitted by the bite of a female sand fly, Leishmania infections are increasing with human movement (due to international travel and war) as well as with shifts in vector habitat (due to climate change). Accurate diagnosis of the 20 or so species of Leishmania that infect humans can lead to the successful treatment of infections and, importantly, their prevention through modelling and intervention programs. A multitude of laboratory techniques for the detection of Leishmania have been developed over the past few decades, and although many have drawbacks, several of them show promise, particularly molecular methods like polymerase chain reaction. This review provides an overview of the methods available to diagnostic laboratories, from traditional techniques to the now-preferred molecular techniques, with an emphasis on polymerase chain reaction-based detection and typing methods.

A Convenient and Sensitive kDNA-PCR for Screening of Leishmania infantum Latent Infection Among Blood Donors in a Highly Endemic Focus, Northwestern Iran

BACKGROUND

Recent global evidences showed that asymptomatic blood donor carriers of Leishmania infection will appear as a threat for blood transfusions recipients in endemic areas. As yet, there is no appropriate diagnostic procedure for detecting infection of blood donors in blood banks.

SUBJECTS AND METHODS

The present study was aimed to apply various current diagnostic tests among blood donors in an endemic area of visceral leishmaniasis (VL), Ardabil Province, northwestern Iran. Blood samples were gathered from 860 blood donors in endemic areas of the province between 2017 and 2018, at eight blood donation centers. These samples was assessed using microculture, serological (DAT and rK39-ICT) and molecular based (conventional kDNA-PCR and HRM-PCR) tests.

RESULTS

Of 860 eligible donors, 24 (2.8%) were seropositive for VL by DAT, and 388 (45%) were positive by kDNA-PCR. Moreover, 19 (19/860) were positive for both of them. Out of 19 subjects, 5.3% (1/19) was positive by rK39-ICT, 10.5% (2/19), and 79% (15/19) were detected positive in microculture and HRM-PCR methods, respectively. Nineteen donors were followed up for 2 years, of which 16 (84.2%) had a serological conversion, and 4 (21%) were positive by kDNA-PCR. The sensitivity of kDNA-PCR, and HRM-PCR procedures in detecting Leishmania parasite was found to be 98.7%, and 79%, respectively.

CONCLUSIONS

Our findings justify the use of kDNA-PCR as a convenient and sensitive tool for screening subjects with leishmanial latent infection in blood banks at least in endemic regions. In these areas, however, a PCR-based test should be used to validate Leishmania infection among seropositive donors.