Clinical trial NCT03526718: Improved Understanding of Ongoing Transmission of Leprosy in the Hyperendemic Comoros (ComLep)
Official title: Improved Understanding of Ongoing Transmission of Leprosy in the Comoros, a Region Hyperendemic for the Disease.
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Leprosy
Keywords: Transmission
Genotyping
Risk factors
Lead sponsor: Institute of Tropical Medicine, Belgium
Sponsor class: OTHER
Collaborators: name: Damien Foundation
name: Programme National de lutte contre la Lèpre et la Tuberculose, Comores
name: Instituto Oswaldo Cruz
name: R2STOP
First posted: 2018-05-16
Enrollment: 889
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: CROSS_SECTIONAL
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.

Brief 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.


Eligibility criteria: Inclusion Criteria:

* in the prospective cohort study: All newly diagnosed leprosy patients (any age) on the island of Anjouan who provide written informed consent.
* 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:

* in the prospective cohort study: None.
* In the in-depth interviews: Patients belonging to clusters not extending beyond the same first or second circle

Primary outcomes:
measure: Leprosy incidence among contacts of an index patient
timeFrame: The incidence rate ratio will be recorded during the 3-year recruitment period op the study.
Secondary outcomes:
measure: Recent transmission cluster
timeFrame: 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.
measure: Patient and health system delay.
timeFrame: 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.
Other outcomes:
Locations:
city: Moutsamoudou
country: Comoros
facility: Damien Foundation
state: Anjouan
Study officials:
affiliation: Institute of Tropical Medicine
name: Bouke C de Jong, MD,PhD
role: PRINCIPAL_INVESTIGATOR
References: