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CompletedNCT03526718ComLepUpdated May 11, 2021

Improved Understanding of Ongoing Transmission of Leprosy in the Hyperendemic Comoros (ComLep)

An observational study in Leprosy, sponsored by Institute of Tropical Medicine, Belgium. Completed at 1 site in Comoros. Per ClinicalTrials.gov, last updated 2021-05-11.

Sponsored by Institute of Tropical Medicine, Belgium · Observational

Study type
Observational
Model
Cohort
Time perspective
Cross-sectional
Enrollment
889
Sex
All
01

Study summary

Despite decades of a solid leprosy control program, including active case finding and follow-up on therapeutic outcome, the Comoros islands of Anjouan and Moheli continue to be hyperendemic for leprosy, with leprosy case notifications far exceeding those for tuberculosis, while the third island, Grande Comore, presents few cases. The high proportion (31% in 2015) of disease in children indicates that recent transmission is a major driver of the persistent endemicity, and that present control measures are not sufficient. The low proportion (2.6% average in last 10 years) of grade II disabilities in newly diagnosed cases indicates that case detection is early.

The main objective of the present proposal is to identify which persons would most benefit from prophylactic treatment. The secondary objective is to unravel human, bacterial and environmental risk factors for transmission of and progression to leprosy disease, with the ultimate goal to reduce the leprosy incidence.. The program has remaining expertise to re-establish laboratory confirmation of leprosy patients, allowing to optimize and validate molecular genotyping techniques to complement conventional epidemiological investigations in a 3-year prospective cohort of leprosy patients and their close contacts, aiming to identify transmission links. A third objective is to document diagnostic delays in more detail

As the leprosy control programme has initiated a pilot study on rifampicin prophylaxis in four villages on Anjouan in 2015, a prospective cohort study will permit measuring the leprosy incidence in close contacts as well as those in neighboring houses, who did or did not receive rifampicin prophylaxis.

The expected outcome of this project will be to identify risk factors for leprosy transmission. Specifically, we expect to identify those contacts at highest risk of developing leprosy disease, who would most benefit from rifampicin prophylaxis or other preventive measures.

02

Conditions studied

  • Leprosy

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Keywords

  • Transmission
  • Genotyping
  • Risk factors
03

In context

Leprosy

52 studies on the registry are indexed under Leprosy; 13 are open to participants now.

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Lead sponsor

Institute of Tropical Medicine, Belgium is the lead sponsor of 104 studies on the registry; 21 are open to participants now.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
Child (0–17), Adult (18–64), Older adult (65+)
Sexes eligible
All
Accepts healthy volunteers
No
Sampling method
Probability sample

Study population

The Comoros islands, located between Madagascar and Mozambique, continue to be hyperendemic for leprosy. Periodic active case finding across the entire island of Anjouan is in place, resulting in early case detection, and every patient identified is being treated with highly effective multi drug therapy. Nevertheless, the high proportion of leprosy in children (31% were \<15y old in 2015) in combination with a low relapse rate (\<2%) indicate transmission continues unabated. The majority of the patients in Anjouan are paucibacillary.

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • in the prospective cohort study: All newly diagnosed leprosy patients (any age) on the island of Anjouan who provide written .
  • In the in-depth interviews: Patients who are part of a cluster and provide written informed consent. Additional written informed consent will be asked for questions in which the identity of other member(s) of a cluster needs to be revealed.

Exclusion criteria

Exclusion Criteria:

  • in the prospective cohort study: None.
  • In the in-depth interviews: Patients belonging to clusters not extending beyond the same first or second circle
Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

05

Study design

Observational model
Cohort
Time perspective
Cross-sectional
Enrollment
889 participants (actual)
Target follow-up
3 Years
Patient registry
Yes
Biospecimen retention
Samples with dna
06

What researchers measure

Primary outcomes

  1. Leprosy incidence among contacts of an index patient

    Incidence rate ratios among the contacts by proximity to the index patients will be calculated. Classification of contacts in proximity groups is a dynamic process. Persons belonging to the same household, surrounding households, entire village, or entire island may shift to closer proximity groups when leprosy patients are diagnosed in their environment. Since date of diagnosis, and any recent migration, will be recorded for each patient, we will be able to reallocate contacts to other circles and attribute to each contact a period of exposure within each circle.

    Time frame: The incidence rate ratio will be recorded during the 3-year recruitment period op the study.

Secondary outcomes

  1. Recent transmission cluster

    Transmission links will be defined as identical genotypes based on their "variable number of tandem repeat(VNTR)"- profile. The definition of clustering will be based on comparison of the copy number of the VNTRs using two different stringencies: either considering those that presented identical copy number for all 17 alleles, or considering those that had identical copy number excluding the most variable loci.

    Time frame: All the samples over the three years should be analysed the able to fully explore the transmission links. Therefore, this outcome will be assessed through study completion, which will probably take1 year.

  2. Patient and health system delay.

    Mean patient and health systems delay with 95% confidence interval will be calculated. The questionnaire will comprise questions on the duration of the symptoms and the health seeking behavior of the patient.

    Time frame: This outcome can be calculated at the end of the recruitment phase of the study.Therefore, this outcome will be assessed through study completion, which will probably take1 year.

07

Study locations

1 site
  • Damien Foundation
    Moutsamoudou, Anjouan, Comoros
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References and documents

Individual participant data

Plan to share: Undecided — Data sharing will be considered once the datasets are locked at time of publication.

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Ran from Apr 2017 to primary completion in Dec 2020, 44 months.

How these figures are worked out, and which studies are left out of them.

Registered
Apr 23, 2018
First posted
May 16, 2018
StartActual
Apr 1, 2017
Primary completionActual
Dec 31, 2020
CompletionActual
Dec 31, 2020
Last update
May 11, 2021
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on May 11, 2021, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT03526718
Collaborators
Damien Foundation, Programme National de lutte contre la Lèpre et la Tuberculose, Comores, Instituto Oswaldo Cruz, R2STOP
Responsible party
Sponsor
First posted
May 16, 2018
Start date
Apr 1, 2017
Primary completion
Dec 31, 2020
Completion
Dec 31, 2020
Last update
May 11, 2021

Study contacts

Bouke C de Jong, MD,PhD
principal investigator · Institute of Tropical Medicine

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in May 2021. You cannot join it, but the record below documents what was studied.

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