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TerminatedNCT06595745Updated Mar 19, 2026

Testing Combined IIT-SIT to Control Mosquito-Borne Diseases At Scale

An interventional study of Wolbachia induced incompatible mating and Standard traditional chemical mosquito control in Dengue, Zika and Chikungunya, sponsored by Michigan State University. Terminated at 1 site in Mexico. Per ClinicalTrials.gov, last updated 2026-03-19.

Sponsored by Michigan State University · Not applicable, Interventional, and Prevention

Why this study was terminated
The USAID fund sponsoring this trial was terminated in February 2025.

From the registry’s dates

  • Registered 3 months after the study started (first participant enrolled May 2024, registered Sep 2024).
Phase
Not applicable
Study type
Interventional
Enrollment
15,243
Allocation
Randomized
Sex
All
01

Study summary

Mosquito-borne diseases cause suffering for hundreds of millions of people and claim more than 700,000 lives yearly. Diseases such as dengue, Zika, and chikungunya cause symptoms similar to malaria and are endemic in many parts of the world, yet there are no treatments for them nor vaccines for Zika and chikungunya. Mosquito control, particularly of the Aedes aegypti species, is seen as a potentially effective solution to slow or stop the spread of these diseases but has not yet demonstrated significant, sustainable impacts on disease transmission. The investigators will aim to significantly control or eliminate local foci (hot-spots) of dengue, chikungunya and Zika transmission and significantly reduce disease transmission by implementing a combined incompatible and sterile insect technique (IIT-SIT) program based on the release of male Aedes aegypti carrying Wolbachia (wAlbB strain) that have been previously irradiated with X-rays (to minimize the chance of fertile female releases). The investigators will implement a two-arm cluster randomized controlled trial to evaluate the epidemiological and entomological impact of population suppression via IIT-SIT on Aedes-borne diseases in the city of Merida, Mexico. Primary endpoint of the trial is the incidence of laboratory Aedes-borne viruses detected by the passive surveillance system of Mexico. Secondary endpoints will allow estimating the level of suppression of Ae. aegypti populations. This trial design will allow establishing a link between epidemiologic, entomo-virological and entomological indicators to determine the effectiveness of IIT-SIT in real world conditions. The approach is novel because it effectively eliminate vectors, such as urban, outdoor, daytime biting mosquitoes, which are not susceptible to standard vector control approaches, by targeting cryptic and inaccessible mosquito habitats. In addition, the intervention has the below advantages comparing to existing alternatives: (i) highly competitive males are used for release as Wolbachia-infected males have the mating competitiveness equal to wild-type males; (ii) release can continue until population elimination is reached as a low dose of radiation is used to sterilize females for preventing risk of population replacement; (iii) any residual females contaminated in released male pools is resistant to pathogens; (iv) public acceptance of release of Wolbachia-infected males can be easily achieved, because Wolbachia are bacteria naturally presenting in \~50 percent of insect species, and male mosquitoes neither bite nor transmit diseases and can be self-limiting post release; (v) it will not impact non-target species. Successful findings from this study will pave the way for future expansions of the combined IIT-SIT to the entire city and nationwide using a rolling-carpet strategy, which has been successfully demonstrated for area-wide control of screwworm and medfly in Latin America.

02

Conditions studied

  • Dengue
  • Zika
  • Chikungunya

Keywords

  • Wolbachia
  • IIT
  • SIT
  • Aedes aegypti
  • Dengue
  • Zika
  • Chikungunya
03

In context

Dengue

279 studies on the registry are indexed under Dengue; 45 are open to participants now.

This study's enrollment of 15,243 is above the median of 123 across 195 interventional studies indexed under Dengue.

Browse Dengue studies →

Lead sponsor

Michigan State University is the lead sponsor of 139 studies on the registry; 26 are open to participants now.

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

04

Who can participate

Ages eligible
Child (0–17), Adult (18–64), Older adult (65+)
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • All residents in the release sites will be included in the studies

Exclusion criteria

Exclusion Criteria:

  • No exclusion will be performed.
05

Study design

Phase
Not applicable
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
15,243 participants (actual)

Study arms

  • Experimental
    Release sites

    Traditional mosquito control will be applied, followed by weekly release of Wolbachia wAlbB-infected Aedes aegypti males to induce sterile mating with wild female mosquitoes.

    Genetic: Wolbachia induced incompatible mating · Combination Product: Standard traditional chemical mosquito control

  • Active comparator
    Control sites with traditional mosquito control only

    Traditional mosquito control will be applied but no mosquito release will occur in the control sites

Interventions

  • GeneticWolbachia induced incompatible mating

    The intervention will be performed by weekly release of male Aedes aegypti carrying Wolbachia (wAlbB strain) to mate with wild females, resulting in the death of their eggs for birth control. Before release, these males will be irradiated with X-rays to minimize the chance of any residual fertile female releases. The intervention will lead to Ae. aegypti population suppression or even elimination and preventing dengue transmission in release sites.

    Also known as: Incompatible insect technique, Sterile insect technique

  • Combination productStandard traditional chemical mosquito control

    Traditional and commonly used chemical insecticide will be applied to reduce the mosquito population

06

What researchers measure

Primary outcomes

  1. Epidemiological impact of combined IIT-SIT

    Incidence of symptomatic Aedes-borne virus (dengue, chikungunya, Zika) confirmed by laboratory testing by the Yucatan Ministry of Health.

    Time frame: Up to 19 months

Secondary outcomes

  1. Entomological impact of combined IIT-SIT

    Number of Aedes aegypti females infected with dengue, chikungunya or Zika virus (quantified as minimum infection rate, MIR); Number of Aedes aegypti females collected indoors (during 10-minute collections) using Prokopack aspirators; Number of Aedes aegypti females collected in the peridomicile with BG-sentinel traps.

    Time frame: Up to 19 months

07

Study locations

1 site
  • Laboratorio para el Control Biolo´gico de Aedes aegypti (LCB-UADY), Universidad Autónoma de Yucatán
    Mérida, Yucatán 97160, Mexico
08

References and documents

Publications

  • Liang X, Tan CH, Sun Q, Zhang M, Wong PSJ, Li MI, Mak KW, Martin-Park A, Contreras-Perera Y, Puerta-Guardo H, Manrique-Saide P, Ng LC, Xi Z. Wolbachia wAlbB remains stable in Aedes aegypti over 15 years but exhibits genetic background-dependent variation in virus blocking. PNAS Nexus. 2022 Sep 22;1(4):pgac203. doi: 10.1093/pnasnexus/pgac203. eCollection 2022 Sep. PubMed 36714832 ↗
  • Lim JT, Bansal S, Chong CS, Dickens B, Ng Y, Deng L, Lee C, Tan LY, Chain G, Ma P, Sim S, Tan CH, Cook AR, Ng LC. Efficacy of Wolbachia-mediated sterility to reduce the incidence of dengue: a synthetic control study in Singapore. Lancet Microbe. 2024 May;5(5):e422-e432. doi: 10.1016/S2666-5247(23)00397-X. Epub 2024 Feb 8. PubMed 38342109 ↗
  • Martin-Park A, Che-Mendoza A, Contreras-Perera Y, Perez-Carrillo S, Puerta-Guardo H, Villegas-Chim J, Guillermo-May G, Medina-Barreiro A, Delfin-Gonzalez H, Mendez-Vales R, Vazquez-Narvaez S, Palacio-Vargas J, Correa-Morales F, Ayora-Talavera G, Pavia-Ruz N, Liang X, Fu P, Zhang D, Wang X, Toledo-Romani ME, Xi Z, Vazquez-Prokopec G, Manrique-Saide P. Pilot trial using mass field-releases of sterile males produced with the incompatible and sterile insect techniques as part of integrated Aedes aegypti control in Mexico. PLoS Negl Trop Dis. 2022 Apr 26;16(4):e0010324. doi: 10.1371/journal.pntd.0010324. eCollection 2022 Apr. PubMed 35471983 ↗
  • Zheng X, Zhang D, Li Y, Yang C, Wu Y, Liang X, Liang Y, Pan X, Hu L, Sun Q, Wang X, Wei Y, Zhu J, Qian W, Yan Z, Parker AG, Gilles JRL, Bourtzis K, Bouyer J, Tang M, Zheng B, Yu J, Liu J, Zhuang J, Hu Z, Zhang M, Gong JT, Hong XY, Zhang Z, Lin L, Liu Q, Hu Z, Wu Z, Baton LA, Hoffmann AA, Xi Z. Incompatible and sterile insect techniques combined eliminate mosquitoes. Nature. 2019 Aug;572(7767):56-61. doi: 10.1038/s41586-019-1407-9. Epub 2019 Jul 17. PubMed 31316207 ↗

Individual participant data

Plan to share: No

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Mar 19, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT06595745
Lead sponsor
Michigan State University
Collaborators
Universidad Autónoma de Yucatán, Emory University
Responsible party
Zhiyong Xi (Professor, Michigan State University) — Principal investigator
First posted
Sep 19, 2024
Start date
May 28, 2024
Primary completion
Jan 31, 2025
Completion
Jan 31, 2025
Last update
Mar 19, 2026

Study contacts

Gonzalo Vazquez Professor Prokopec, PhD
study chair · Emory University

Oversight

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

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This study is terminated, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.

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