Impact of Wolbachia Deployment on Arboviral Disease Incidence in Medellin and Bello, Colombia (WMP-COL)

March 31, 2022 updated by: Universidad de Antioquia

World Mosquito Program - Colombia (WMP-COLOMBIA): The Impact of City-wide Deployment of Wolbachia-infected Mosquitoes on Arboviral Disease Incidence in Medellin and Bello, Colombia

Study setting: Medellin and Bello municipalities, Colombia Health condition(s) studied: Dengue, Zika and chikungunya virus infection Intervention: Deployment of Wolbachia-infected Aedes aegypti mosquitoes in Medellin and Bello.

Study design:

  1. An interrupted time-series analysis utilising routine disease surveillance data collected by the Medellín and Bello Health Secretariats, which aims to compare incidence of dengue, chikungunya and Zika pre- and post-Wolbachia release.
  2. A test-negative study using an incident case-control design, which aims to quantify the reduction in disease incidence among people living within a Wolbachia-treated zone compared with an untreated zone that has a similar dengue risk profile at baseline.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

  • Selection and enrolment of participants: Enrolment of patients will commence after completion of Wolbachia releases in the early zones. Study processes for enrolling patients presenting with febrile illness will be established at a network of primary health care facilities that serve the population who reside in the study area. Trained research staff will be employed to assist with study processes in each site. Participants will be enrolled from within the population of patients (aged ≥3 years old) presenting with undifferentiated fever of 1-4 days' duration. All patients meeting the inclusion criteria will be eligible for enrolment and will be asked to provide written informed consent before participating in the study.
  • Recruitment procedures: All eligible participants meeting study inclusion criteria will be invited to enroll continuously throughout the study period. Recruitment will occur during normal clinic hours. Participants will be managed according to standard clinical practice by the attending physicians. Recruitment rates in each clinic and across the study site as a whole will be monitored weekly, including a review of the screening logs to identify the proportion of eligible participants who did not consent to participate. The field coordinator will make regular visits to low-enrolling clinics to identify clinic-based, patient-based or other causes for low recruitment, and put measures in place to address these.
  • Screening: All patients presenting with febrile illness will be screened against the study inclusion criteria by trained staff. All eligible febrile individuals will be recorded in a screening log and invited to participate. Participation status (consent/decline) will be recorded against each participant in the log.
  • Informed consent: Written informed consent will be sought from participants (or their guardian where the participant is a minor) by trained local staff, after explaining the study objectives, processes, data, and sample collection, and the participant has had an opportunity to ask questions. A verbal explanation of the written Explanatory Statement will be provided to all participants in the local language. In addition, participants aged between 7 and 17 years will be invited to sign an assent form indicating they understand the research and agree to participate. Data and sample collection procedures
  • Data collection: A unique identifier will be assigned to each participant at enrollment. Basic demographic details, eligibility against the inclusion criteria and illness onset date will be recorded in a standardized case report form.

Study Type

Observational

Enrollment (Actual)

834

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

  • Colombia
    • Antioquia
      • Medellín, Antioquia, Colombia
        • Universidad de Antioquia

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

3 years and older (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

The case-control study area as a whole has a population of approximately 564,000, of which approximately half will be resident in areas that receive early Wolbachia deployments ('early-release') and half in areas that will receive late Wolbachia deployments ('late-release').

The study population for measurement of the efficacy endpoint is the population of patients who reside in the study area, presenting to the network of participating primary health care facility with febrile illness, and meeting the eligibility criteria.

Description

Inclusion Criteria:

  • Fever (either self-reported or objectively measured, e.g. axillary temperature ≥38oC, with a date of onset between 1-4 days prior to the day of presentation.
  • Aged ≥3 years old.
  • Lived (i.e. slept) in the study area every night (or day) for the 10 days preceding illness onset.

Exclusion Criteria:

  • Localising features suggestive of a specific diagnosis e.g. severe diarrhea, otitis, pneumonia
  • Prior enrollment in the study within the previous 4 weeks.

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
Early-release
Resident in areas that receive early Wolbachia deployments.
Biological: Wolbachia-carrying Ae.aegypti mosquitoes
Wolbachia-infected Ae. aegypti mosquito eggs and adults sequentially deployed into Medellin and Bello, Colombia. Deployments cease once Wolbachia prevalence has reached a predetermined frequency (usually ≥60%).
Late-release
Resident in areas that receive late Wolbachia deployments.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Dengue cases notified to surveillance system
Time Frame: 5 years
Incidence of dengue cases (suspected, epidemiological link, and IgM positive for dengue) notified to the disease surveillance system
5 years
Virologically-confirmed dengue
Time Frame: 2 years
Virologically-confirmed dengue virus infection in patients reporting febrile illness recruited from health clinics. Participants are classified as dengue cases if plasma samples collected 1-4 days after onset of fever test positive for dengue virus NS1 antigen or dengue virus nucleic acid by RT-qPCR.
2 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
IgM test positive for dengue
Time Frame: 5 years
Number of cases who were IgM test positive for dengue
5 years
Severe dengue cases
Time Frame: 5 years
Incidence of severe dengue cases reported to the surveillance system, by release zone and overall.
5 years
Zika cases notified to surveillance system
Time Frame: 5 years
Incidence of Zika cases reported to the surveillance system.
5 years
Chikungunya cases notified to surveillance system
Time Frame: 5 years
Incidence of chikungunya cases reported to the surveillance system.
5 years
Spatial analysis
Time Frame: 5 years
The spatial distribution of notified dengue cases with geolocated primary address available, before and after Wolbachia deployment
5 years
Virologically-confirmed chikungunya infection
Time Frame: 2 years
Virologically-confirmed chikungunya virus infection in patients reporting febrile illness recruited from health clinics. Participants are classified as chikungunya cases if plasma samples collected 1-4 days after onset of fever test positive for chikungunya virus NS1 antigen or chikungunya virus nucleic acid by RT-qPCR.
2 years
Virologically-confirmed Zika infection
Time Frame: 2 years
Virologically-confirmed Zika virus infection in patients reporting febrile illness recruited from health clinics. Participants are classified as Zika cases if plasma samples collected 1-4 days after onset of fever test positive for Zika virus NS1 antigen or Zika virus nucleic acid by RT-qPCR.
2 years

Collaborators and Investigators

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

Sponsor

Universidad de Antioquia

Collaborators

United States Agency for International Development (USAID)
Bill and Melinda Gates Foundation
Monash University
Wellcome Trust

Investigators

  • Study Director: Cameron Simmons, Prof., Monash University

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)

October 25, 2017

Primary Completion (Actual)

December 31, 2021

Study Completion (Actual)

December 31, 2021

Study Registration Dates

First Submitted

July 13, 2018

First Submitted That Met QC Criteria

August 14, 2018

First Posted (Actual)

August 15, 2018

Study Record Updates

Last Update Posted (Actual)

April 8, 2022

Last Update Submitted That Met QC Criteria

March 31, 2022

Last Verified

March 1, 2022

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • PEC004_18
  • PECET-002 (Registry Identifier: Impact Assessment of Wolbachia deployment)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

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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