Epidemiology of Cutaneous Leishmaniasis in Niger, Mali, Togo : Mapping of Clinical Cases, Species, Reservoirs and Vectors of the Disease (LEISHAFRICA)

November 18, 2024 updated by: Centre Hospitalier de Cayenne

Sentinel Surveillance of Cutaneous Leishmaniasis in Sub-Saharan Africa Based on Non-invasive Molecular Diagnostics: Mapping of Human Cases, Description of Leishamania Species Involved

Cutaneous leishmaniasis is a neglected tropical disease caused by parasites belonging to the genus Leishmania. This infection can cause skin and sometimes mucous membrane lesions with significant damage. LC has been little studied in sub-Saharan Africa where its incidence is probably underestimated, especially in West Africa. Leishmania major is almost the only isolated species in this region, although recent data suggest the existence of other species, such as L. enrietti. It is said that CL is only present in the arid areas of Africa, but recent outbreaks in wetlands and forests tend to contradict this theory. Due to the lack of availability of the PCR method, the diagnosis of LC in West Africa, especially in Mali, is rarely confirmed. Treatment options are also scarce and their effectiveness is poorly documented. The objectives of this study are to map the occurrence of LC cases with molecular biology confirmation in Niger, Mali and Togo; to determine the different species involved in human cases; evaluate the different treatment options available.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Leishmaniasis is a parasitosis common to humans and animals (anthropozoonosis), caused by flagellated protozoa called Leishmanias, transmitted by the infective bite of the blood-sucking female of a dipteran insect called sandfly. The parasite reservoirs are wild rodents, humans, dogs. Many species of leishmania can infect humans with a multiplicity of clinical pictures that include visceral, localized, diffuse cutaneous forms and mucocutaneous forms.

Cutaneous leishmaniasis (CL) is a neglected tropical disease whose transmission to humans is based on the bite of sandflies previously contaminated on mammalian reservoirs. Worldwide, more than 200,000 new cases are reported annually. While the Americas and the Near or Middle East are the most important areas, sub-Saharan Africa is also concerned. In a systematic review of the literature published in 2018, Sunyoto et al. identified 54 clinical and epidemiological studies on LC in sub-Saharan Africa. Publications were found in 13 of the 48 countries in sub-Saharan Africa. This review highlighted inconsistent case reporting, clear under-publication and data gaps regarding the exact incidence of CL and its transmission factors, particularly in West Africa.

Indeed, cutaneous leishmaniasis is widely described in East Africa, where many studies have been carried out in Ethiopia, Kenya and Sudan. The presence of Leishmania major and Leishmania aethiopica is well documented, and the dynamics of the infection and its risk factors are studied. In West Africa, on the other hand, the data are more fragmented. The disease is historically reported in the "Cutaneous Leishmaniasis Belt", a Sahelian strip of semi-arid zones extending from Senegal to Sudan. WHO nevertheless estimates that the real number of LC contaminations in the sub-region is 5 to 10 times higher than reported.

Thus, no cases were reported between 2015 and 2017 in the sub-region, which is not very credible in view of the dynamics of declarations during the previous or following years. Over the period 2004-2008, only 155 cases per year were reported, across the following countries: Ghana, Mali, Cameroon, Nigeria, Senegal, DRC and Ivory Coast. No data were available for neighbouring countries with similar ecological contexts, such as Niger, Benin, Guinea or Burkina Faso. The latter is probably the country reporting cases on the most regular basis, with between 500 and 1500 cases/year between 1995 and 2015. Nevertheless, no case was reported between 2007 and 2010, which seems difficult to explain scientifically and again testifies to a lack of diagnosis or reporting.

WHO establishes " country profiles " on the epidemiology of LC for each endemic country and designs regional programmes to control the disease. It should be noted that while East African countries such as Kenya or Ethiopia have a well-documented profile, no profile is available for West African countries. In addition, no regional programme has been set up for sub-Saharan Africa, unlike the Americas, South-East Asia, the Eastern Mediterranean or Europe regions. These absences show how neglected this public health problem is in the African region.

Ghana was considered non-endemic to CL until a major outbreak in 2002-2003. More than 2000 cases were then diagnosed, and this after an active screening, following an initial epidemic signal of only about fifteen cases. It is therefore possible that other epidemics, or even a sporadic presence, have remained undetected in some areas of the country. It should be noted that the region of the epidemic (Ho district, Volta region) was bordered by neighbouring Togo, and the testimonies collected in the affected communities suggested an imported pathology. Moreover, it should be noted that this epidemic area in Ghana was located in a forest region, therefore ou tside the LC Belt classically described and the semi-arid areas generally incriminated. This example illustrates the need to explore the epidemiology of LC in areas that are considered non-endemic by their climate.

In a later study carried out in 2015 in 15 villages affected by this epidemic, samples were taken to isolate strains belonging to the Leishmania enriettii complex from three crops. This rarely described species was not generally considered pathogenic to humans. This example illustrates the need for better species diagnosis in some areas where Leishmania major is considered to be the only species involved, although recent data do not support this statement with certainty. The diagnosis of cutaneous leishmaniasis in West Africa is too often based on a simple clinical diagnosis, sometimes supported by a parasitological smear. However, this does not allow the diagnosis of the offending Leishmania species. The lack of molecular biology in isolated areas or populations with limited resources prevents precise knowledge of the species involved.

As for the treatment, it is often inaccessible due to its price or the logistical constraints related to transport. Meglumine antimoniate is the first-line treatment in Senegal but rarely available, while metronidazole is used in Niger. However, its effectiveness has not been strongly demonstrated. In Mali, dermatologists use cryotherapy and thermotherapy, and more rarely meglumine antimoniate. Cyclin-based ointments are also used to treat bacterial superinfection.

Across the subregion, patients are frequently lost to follow-up, due to the high cost of transport for populations in rural areas, which are mainly at risk. The lack of follow-up consultations does not make it possible to reliably assess the proportion of patients who recover spontaneously, those requiring active treatment, the effectiveness of the various treatments offered as well as the possible sequelae (disfiguring scars, etc.) in the absence of active treatment. A prospective cohort with active patient follow-up would provide valuable data to assess whether or not new treatment options are needed.

Overall, it therefore seems relevant to map more precisely the incidence of LC in West Africa, to identify in molecular biology the Leishmania species responsible, to deepen knowledge on the vectors and reservoirs involved and to evaluate the effectiveness and usefulness of current therapeutic options.

Study Type

Observational

Enrollment (Actual)

270

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Mali
      • Bamako, Mali, BP 1805
        • Faculté de Médecine et d'Odonto-Stomatologie / Université des Sciences, des Techniques et des Technologies de Bamako, Mali
  • Niger
      • Zinder, Niger
        • Faculté de médecine/Université André Salifou BP806 Zinder NIGER
  • Togo
      • Lomé, Togo
        • Service de Dermatologie, CHR TSEVIE, Faculté des Sciences de la Santé, Université de Lomé

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The human study population will consist of all subjects of all ages with suspicious skin lesions.

Description

Inclusion Criteria:

  • Clinical suspicion of cutaneous leishmaniasis during a consultation in one of the partner centres (or by the country physicians) = presence of an ulcerative lesion, papules or nodules
  • Obtaining informed and voluntary consent

Non inclusion / Exclusion Criteria:

  • Objection to the use of their data and/or the taking of the questionnaire
  • Refusal to participate
  • Withdrawal of participation

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Single group
Patient of any age with suspicious skin lesions
Other: Clinical and epidemiological data
Collection of clinical and epidemiological data on day 0
Other: Parasitological samples
Parasitological samples : smear for on-site analysis and swabs to be sent to the Cayenne Hospital for PCR at day 0
Other: Assessment of clinical course and response to treatment
Follow-up visit with assessment of clinical course and response to treatment at M6
Other: DLQI questionnaire
DLQI questionnaire at M6

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Presence of a positive test (smear or PCR) for Leishmaniasis Cutaneous (LC)
Time Frame: Day 0
Presence of a positive test (smear or PCR) for Leishmaniasis Cutaneous (LC) at Day 0
Day 0

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Leishmania species
Time Frame: Day 0
DNA (DesoxyriboNucleic Acid) sequences of Leishmania species identified in PCR at Day 0
Day 0
Number of participants with therapeutic failure or success
Time Frame: Month 6

Number of participants with therapeutic failure or success defined as follows:

  • Therapeutic success: re-epithelialization/collapse of all lesions
  • Therapeutic failure: re-epithelialization/collapse of less than 100% or less than 50% of lesions (criteria recommended in international studies according to Olliaro et al. (Plos Negl Trop Dis 2017) Therapeutic failure or success should be assessed at least six weeks according to international recommendations. The follow-up visit may take place between 3 and 6 months after the initial visit.
Month 6
Presence of scars with impact on quality of life
Time Frame: Month 6

Presence of scars with impact on quality of life measured by the DLQI (Dermatology Life Quality Index) Dermatology Life Quality Index (DLQI) scores assess quality of life in a wide range of dermatological conditions (non-specific to dermatological conditions).

It is easy to implement and assesses the impact of the disease on daily activities, including work, social activities and intimate relationships. The scores ranges from 0 to 30 (most impaired quality of life) and correlates well with disease severity :

No effect: 0 - 1 Low effect: 2 - 5 Moderate effect: 6 - 10 Important effect: 11 - 20 Extremely important effect: 21 - 30
Month 6

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Centre Hospitalier de Cayenne

Investigators

  • Principal Investigator: Romain BLAIZOT, MCU-PH, Centre Hospitalier de Cayenne (CHC)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 1, 2023

Primary Completion (Actual)

March 1, 2024

Study Completion (Actual)

March 1, 2024

Study Registration Dates

First Submitted

November 6, 2024

First Submitted That Met QC Criteria

November 14, 2024

First Posted (Actual)

November 18, 2024

Study Record Updates

Last Update Posted (Estimated)

November 20, 2024

Last Update Submitted That Met QC Criteria

November 18, 2024

Last Verified

November 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • LEISHAFRICA

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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