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AzTrials

DengueNCT05505682

Impact of Project Wolbachia - Singapore on Dengue Incidence

A study testing Biological (Male Wolbachia-infected Aedes aegypti) in people with Dengue, run by National Environment Agency, Singapore at 1 site in Singapore.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The study is a cluster-randomised controlled trial set in Singapore, to assess if the deployment of male Wolbachia-infected Aedes aegypti mosquitoes can reduce dengue incidence in intervention clusters. Read more about this study

Who is it for?
Any age
Conditions the study is for
Dengue
What is being tested?
Biological (Male Wolbachia-infected Aedes aegypti)
Could I receive a placebo?
No, everyone receives an active treatment
How many people
724,428 participants
Where
1 siteSingapore
Study dates
28 Jul 2022to 13 Sep 2024
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages Any age
  • All sexes
  • No healthy volunteers
  • Child, Adult, Older adult

Who may be able to join

  • Dengue-suspected patients living in the intervention and non-intervention clusters whose blood samples are collected by a national network of diagnostic laboratories that support private clinics, public polyclinics, or public/private hospitals.
  • Test positive cases: Patients with virologically confirmed DENV infection through RT-qPCR, testing positive for NS1 antigen or IgM. A positive test for any of the three assays would classify the patient as a dengue case.
  • Test negative controls: Patients with negative test results for DENV through RT-qPCR, NS1 antigen ELISA, or DENV IgM.

Who cannot join

None listed.

Trial locations and contacts

1 site in 1 country.

Singapore1 site

  • National Environment Agency

    Singapore

Other trials in Singapore

About this study

Official title: Assessing the Efficacy of Male Wolbachia-infected Mosquito Deployments to Reduce Dengue Incidence in Singapore: a Cluster Randomized Controlled Trial

The study is a cluster-randomised controlled trial set in Singapore, to assess if the deployment of male Wolbachia-infected Aedes aegypti mosquitoes can reduce dengue incidence in intervention clusters.

Read the detailed description

The study is designed as a parallel, two-arm, non-blinded cluster-randomised controlled trial to be conducted in high-rise public housing estates in Singapore. The aim is to determine whether large-scale deployment of male Wolbachia-infected Ae. aegypti mosquitoes can significantly reduce dengue incidence in intervention clusters. The investigators will use the cluster-randomised design, with the study area comprising 15 clusters with a total area of 10.9 km2, covering approximately 722,000 residents in 1,700 apartment blocks. Eight clusters will be randomly selected to receive the intervention, while the other seven will serve as non-intervention clusters. Intervention efficacy will be estimated through two primary endpoints: (1) odds ratio of Wolbachia exposure distribution (i.e. probability of living in an intervention cluster) among laboratory-confirmed reported dengue cases compared to test-negative controls, and (2) laboratory-confirmed reported dengue counts normalized by population size in intervention versus non-intervention clusters.

Conditions
Dengue
Being tested
Biological (Male Wolbachia-infected Aedes aegypti)
Medical subject headings
Dengue

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Biological (Male Wolbachia-infected Aedes aegypti)Biological

    Releases of male Wolbachia-infected Aedes aegypti mosquitoes

Study groups in NCT05505682
Study groupRoleWhat they receive
Intervention clustersExperimentalResidential areas that receive releases of male Wolbachia-infected Aedes aegypti
Receives: Biological: Biological (Male Wolbachia-infected Aedes aegypti)
Non-intervention clustersNo interventionResidential areas that do not receive releases of male Wolbachia-infected Aedes aegypti

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Odds ratio of Wolbachia exposure distribution among laboratory-confirmed reported dengue cases compared to test-negative controls

    Dengue cases and dengue test-negative controls data will be obtained from the national surveillance network of diagnostic laboratories which receive samples for dengue testing.

    Measured: Up to 3 years

  2. Laboratory-confirmed reported dengue case counts normalized by population size in intervention versus non-intervention clusters

    Dengue cases data will be obtained from the national surveillance network of diagnostic laboratories which receive samples for dengue testing.

    Measured: Up to 3 years

Secondary outcomes (2)

  1. Prevalence of Ae. aegypti/Ae. albopictus mosquitoes

    Data will be obtained from the national gravitrap surveillance system

    Measured: Up to 3 years

  2. Public Attitudes, Perceptions & Knowledge (APK) of Wolbachia and other vector control interventions

    Sentiment surveys pre-trial and during the course of the trial, using true/false and Likert-type scales. Higher scores mean better outcomes.

    Measured: Up to 3 years

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted18 Aug 2022
  2. Study start28 Jul 2022
  3. Primary completion13 Sep 2024
  4. Study completion13 Sep 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Model description
Parallel, two-arm, non-blinded cluster-randomised controlled trial
Masking
None (open label)
Enrolment
724,428 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05505682
Sponsor's protocol ID
IRB024
Status last verified
May 2025
First submitted
19 Jul 2022
Last updated
22 May 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Anders KL, Indriani C, Ahmad RA, Tantowijoyo W, Arguni E, Andari B, Jewell NP, Rances E, O'Neill SL, Simmons CP, Utarini A. The AWED trial (Applying Wolbachia to Eliminate Dengue) to assess the efficacy of Wolbachia-infected mosquito deployments to reduce dengue incidence in Yogyakarta, Indonesia: study protocol for a cluster randomised controlled trial. Trials. 2018 May 31;19(1):302. doi: 10.1186/s13063-018-2670-z.

    PubMed 29855331

  • Utarini A, Indriani C, Ahmad RA, Tantowijoyo W, Arguni E, Ansari MR, Supriyati E, Wardana DS, Meitika Y, Ernesia I, Nurhayati I, Prabowo E, Andari B, Green BR, Hodgson L, Cutcher Z, Rances E, Ryan PA, O'Neill SL, Dufault SM, Tanamas SK, Jewell NP, Anders KL, Simmons CP; AWED Study Group. Efficacy of Wolbachia-Infected Mosquito Deployments for the Control of Dengue. N Engl J Med. 2021 Jun 10;384(23):2177-2186. doi: 10.1056/NEJMoa2030243.

    PubMed 34107180

  • Chang CC, Lim JT, Chong CS, Mailepessov D, Dickens B, Zhai Y, Deng L, Lee C, Tan LY, Chain G, Zulkifli MF, Liew JWK, Vasquez K, Chau ML, Ng Y, Lee V, Sim S, Tan CH, Ng LC. Impact of Wolbachia-mediated incompatible and sterile insect techniques on dengue incidence: a large-scale cluster randomised controlled trial. EBioMedicine. 2026 Sep 10;132:106476. doi: 10.1016/j.ebiom.2026.106476. Online ahead of print.

    PubMed 42721898

  • Lim JT, Chong CS, Chang CC, Mailepessov D, Dickens B, Lai YL, Deng L, Lee C, Tan LY, Chain G, Zulkifli MF, Liew JWK, Vasquez K, Chau ML, Ng Y, Lee V, Wong JCC, Sim S, Tan CH, Ng LC; Project Wolbachia-Singapore Consortium. Dengue Suppression by Male Wolbachia-Infected Mosquitoes. N Engl J Med. 2026 Mar 26;394(12):1175-1183. doi: 10.1056/NEJMoa2503304. Epub 2026 Feb 11.

    PubMed 41671481

  • Lim JT, Mailepessov D, Chong CS, Chang CC, Dickens B, Lai YL, Deng L, Lee C, Tan LY, Chain G, Ho SH, Zulkifli MF, Liew J, Vasquez K, Lee V, Wong JCC, Sim S, Tan CH, Ng LC. Update to: Assessing the efficacy of male Wolbachia-infected mosquito deployments to reduce dengue incidence in Singapore. Trials. 2024 Jun 20;25(1):400. doi: 10.1186/s13063-024-08148-z.

    PubMed 38902790

  • Ong J, Ho SH, Soh SXH, Wong Y, Ng Y, Vasquez K, Lai YL, Setoh YX, Chong CS, Lee V, Wong JCC, Tan CH, Sim S, Ng LC, Lim JT. Assessing the efficacy of male Wolbachia-infected mosquito deployments to reduce dengue incidence in Singapore: study protocol for a cluster-randomized controlled trial. Trials. 2022 Dec 17;23(1):1023. doi: 10.1186/s13063-022-06976-5.

    PubMed 36528590

Questions about this trial

What is this clinical trial studying?

A study testing Biological (Male Wolbachia-infected Aedes aegypti) in people with Dengue, run by National Environment Agency, Singapore at 1 site in Singapore.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 0 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 22 May 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Odds ratio of Wolbachia exposure distribution among laboratory-confirmed reported dengue cases compared to test-negative controls (time frame: Up to 3 years). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05505682, which also lists 6 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 May 2025.

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