Reducing Filth Fly Populations and Transmission of Diarrhoeal Pathogens in Harsh Settings

NCT07272122 | Recruiting Phase 3 DMC

• 2 other identifiers: UNLV-2025-203W911SR2510003
• Study Type: interventional
• Target: 5,556
• Locations: 1 country
• Sites: 1

Brief Summary

Objectives The main trial objective is to evaluate the efficacy of larvicide (LARV) or baited fly traps (TRAP), or both interventions combined, on filth fly density and hence transmission of diarrhoeal diseases. Primary Objective

• To evaluate the efficacy of LARV or TRAP, or both interventions combined, in reducing the number of cases of all-cause diarrhoea (primary epidemiological endpoint). Secondary Objectives
• To evaluate the efficacy of LARV or TRAP, or both interventions combined, in reducing filth fly density and species composition at the latrine level (primary entomological endpoint).
• To evaluate the efficacy of LARV or TRAP, or both interventions combined, in reducing filth fly density and species composition at the shelter level (secondary entomological endpoint). Tertiary Objectives
• To assess the impact of LARV or TRAP, or both interventions combined, on enteric pathogen species composition and density (tertiary entomological endpoint).
• To assess the impact of LARV or TRAP, or both interventions combined, on enteric pathogen antimicrobial resistance (AMR) prevalence (tertiary entomological endpoint). Trial Design The proposed trial will be a 3-period, 3-group, interventional non-randomized cross-over trial with parallel control (Table 1). The unit of intervention will be an individual refugee camp. Each implementation phase will be 6 months, followed by a 1-month wash-out period. The trial arms will be:
• No intervention (control arm)
• Dimilin® larvicide (intervention arm 1)
• iCatchi® ProMax fly traps (intervention arm 2)

Conditions

Diarrheal Diseases

Keywords

Filth flies; Vector control; Conflict displaced people; Temporary shelter; Cross-over trial

Outcome Measures

Primary Outcomes (1)

• Impact of larvicide (LARV) or baited fly traps (TRAP), or both interventions combined, in reducing the number of cases of all-cause diarrhoea (primary epidemiological endpoint).

  The primary outcome will be all-cause diarrhoeal case incidence in children ≤5 and individuals ≥15 years. A diarrhoeal case is defined by WHO as the passage of 3 or more loose or liquid stools per day (or more frequent passage than is normal for the individual). Epidemiological data will be collected from 2 sources during baseline and each of 3 implementation phases. We will collect information on 1) diarrhoea incidence from local health facilities; and 2) shelter level diarrhoea incidence using fortnightly surveys. Passive surveillance data on diarrhoeal cases from camp residents will be obtained from the nearby health facilities. Permission will be sought from these facilities during trial baseline, and fortnightly data will be collected during each 6-month implementation phase.

  At trial baseline and then every fortnight during each of three 6-month intervention phases.

Secondary Outcomes (4)

• Impact of LARV or TRAP, or both interventions combined, on filth fly density - latrine level

  At trial baseline and then every fortnight during each of three 6-month intervention phases.

• Impact of LARV or TRAP, or both interventions combined, on filth fly species composition - latrine level

  At trial baseline and then every fortnight during each of three 6-month intervention phases.

• Impact of LARV or TRAP, or both interventions combined, on filth fly species density - shelter level

  At trial baseline and then every fortnight during each of three 6-month intervention phases.

• Impact of LARV or TRAP, or both interventions combined, on filth fly species composition - shelter level

  At trial baseline and then every fortnight during each of three 6-month intervention phases.

Other Outcomes (3)

• Impact of LARV or TRAP, or both interventions combined, on enteric pathogen density

  At trial baseline and then every fortnight during each of three 6-month intervention phases.

• Impact of LARV or TRAP, or both interventions combined, on enteric pathogen species composition

  At trial baseline and then every fortnight during each of three 6-month intervention phases.

• Impact of LARV or TRAP, or both interventions combined, on enteric pathogen antimicrobial prevalence

  At trial baseline and then every fortnight during each of three 6-month intervention phases.

Study Arms (3)

Control

NO INTERVENTION

Mass deployment of baited fly traps next to pit latrines in refugee camps

EXPERIMENTAL

During each implementation phase, in camps assigned to this intervention arm, one iCatchi® ProMax fly trap will be placed outside (\<5 m) pit latrines at a set trap to pit latrine ratio and will be re-baited every 2 months.

Other: Baited fly traps - iCatchi® ProMax fly traps

Insecticide growth regulator treatment of faeces in pit latrines / open defecation sites

EXPERIMENTAL

All eligible pit latrines (with at least 3 standing walls) assigned to this intervention arm will be treated with Dimilin® GR-2 at 0.5 kg/10m2; granules will be sprinkled onto damp sewage per pit latrine. If waste is desiccated, this intervention will be diluted in water and applied as a spray. This intervention will be re-applied to pit latrines and open defecation sites, every month during each 6-month implementation phase.

Other: Insect growth regulator (IGR) - effervescent granule containing 2% diflubenzuron (20g/kg)

Interventions

Insect growth regulator (IGR) - effervescent granule containing 2% diflubenzuron (20g/kg) OTHER

This intervention will interrupt filth fly development at the larval / pupal stage, to reduce overall population density. All eligible pit latrines (with at least 3 standing walls) assigned to this intervention arm will be treated with Dimilin® GR-2 at 0.5 kg/10m2; granules will be sprinkled onto damp sewage per pit latrine. If waste is desiccated, this intervention will be diluted in water and applied as a spray. This intervention will be re-applied to pit latrines and open defecation sites, every month during each 6-month implementation phase.

Also known as: Dimilin® GR-2

Insecticide growth regulator treatment of faeces in pit latrines / open defecation sites

Baited fly traps - iCatchi® ProMax fly traps OTHER

iCatchi® ProMax fly traps are 10 L containers which hold 3 L of proprietary fly bait, formulated to maximize fly attractiveness to ensure high capture rates. The container design minimizes spillage and allows for easy set up and maintenance in different environments, including agricultural settings, waste management sites and urban areas. Each TRAP requires re-baiting every 8 weeks. TRAP will be placed on the ground outdoors and flies enter the large black container through rectangular holes between the bait bowl and larger trap chamber and are unable to exit; they will eventually die from starvation / dehydration.

Also known as: iCatchi® ProMax

Mass deployment of baited fly traps next to pit latrines in refugee camps

Eligibility Criteria

• Age: 1 Year+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Individuals of either ≤5 years old or ≥15 years old all ages
• Slept in camp ≥27 nights during any given month
• Individual is not severely malnourished, sick, anemic (self-reported), has signs of clinical decompensation, and/or has any other chronic co-morbidities (e.g. HIV or cancer)
• No plans for extended travel (\>1 month) outside of camp during study
• Resides in an easily accessible dwelling and is present at time of enrolment
• Not participating in another clinical trial investigating a vaccine, drug, medical device, or a medical procedure during the trial
• Provision of informed consent form signed by the parent(s) or guardian (≤5s), able to give informed consent as an adult or able to give informed assent for children ≥15 years

You may not qualify if:

• Child \< 1 years old (due to breastfeeding) or aged \>5 and \<15 years old
• Slept in camp \<27 nights during any given month
• Individual is severely malnourished, sick, anemic, has signs of clinical decompensation, and/or has any other chronic co-morbidities (e.g. HIV or cancer)
• Plans for extended travel (\>1 month) outside of camp during study
• Not present at time of enrollment
• Participating or planning to participate in another clinical trial investigating a vaccine, drug, medical device, or a medical procedure during the trial
• No provision of informed consent form signed by the parent(s) or guardian (≤5s), unable to give informed consent as an adult or unable to give informed assent for children ≥15 years

Sponsors & Collaborators

• The Mentor Initiative: lead
• University of Nevada, Las Vegas: collaborator

Study Sites (1)

The MENTOR Initiative, Bunj Town, Maban

Bunj, Maban County, South Sudan

RECRUITING

Related Publications (26)

• Cohen D, Green M, Block C, Slepon R, Ambar R, Wasserman SS, Levine MM. Reduction of transmission of shigellosis by control of houseflies (Musca domestica). Lancet. 1991 Apr 27;337(8748):993-7. doi: 10.1016/0140-6736(91)92657-n.

  PMID: 1673210 BACKGROUND

• Chavasse DC, Shier RP, Murphy OA, Huttly SR, Cousens SN, Akhtar T. Impact of fly control on childhood diarrhoea in Pakistan: community-randomised trial. Lancet. 1999 Jan 2;353(9146):22-5. doi: 10.1016/s0140-6736(98)03366-2.

  PMID: 10023946 BACKGROUND

• Das JK, Hadi YB, Salam RA, Hoda M, Lassi ZS, Bhutta ZA. Fly control to prevent diarrhoea in children. Cochrane Database Syst Rev. 2018 Dec 17;12(12):CD011654. doi: 10.1002/14651858.CD011654.pub2.

  PMID: 30556598 BACKGROUND

• Chan AW, Boutron I, Hopewell S, Moher D, Schulz KF, Collins GS, Tunn R, Aggarwal R, Berkwits M, Berlin JA, Bhandari N, Butcher NJ, Campbell MK, Chidebe RCW, Elbourne DR, Farmer AJ, Fergusson DA, Golub RM, Goodman SN, Hoffmann TC, Ioannidis JPA, Kahan BC, Knowles RL, Lamb SE, Lewis S, Loder E, Offringa M, Ravaud P, Richards DP, Rockhold FW, Schriger DL, Siegfried NL, Staniszewska S, Taylor RS, Thabane L, Torgerson DJ, Vohra S, White IR, Hrobjartsson A. SPIRIT 2025 statement: Updated guideline for protocols of randomised trials. PLoS Med. 2025 Apr 28;22(4):e1004589. doi: 10.1371/journal.pmed.1004589. eCollection 2025 Apr.

  PMID: 40294521 BACKGROUND

• Council for International Organizations of Medical Sciences. International ethical guidelines for biomedical research involving human subjects. Bull Med Ethics. 2002 Oct;(182):17-23.

  PMID: 14983848 BACKGROUND

• Capone D, Cumming O, Flemister A, Ilevbare V, Irish SR, Keenum I, Knee J, Nala R, Brown J. Sanitation in urban areas may limit the spread of antimicrobial resistance via flies. PLoS One. 2024 Mar 20;19(3):e0298578. doi: 10.1371/journal.pone.0298578. eCollection 2024.

  PMID: 38507457 BACKGROUND

• Capone D, Adriano Z, Cumming O, Irish SR, Knee J, Nala R, Brown J. Urban Onsite Sanitation Upgrades and Synanthropic Flies in Maputo, Mozambique: Effects on Enteric Pathogen Infection Risks. Environ Sci Technol. 2023 Jan 10;57(1):549-560. doi: 10.1021/acs.est.2c06864. Epub 2022 Dec 14.

  PMID: 36516327 BACKGROUND

• Hamer GL, Kelly PH, Focks DA, Goldberg TL, Walkers ED. Evaluation of a novel emergence trap to study Culex mosquitoes in urban catch basins. J Am Mosq Control Assoc. 2011 Jun;27(2):142-7. doi: 10.2987/10-6090.1.

  PMID: 21805846 BACKGROUND

• Amsterdam, U. o. Constipation in infancy and childhood: New insights into pathophysiological aspects and treatment. https://pure.uva.nl/ws/files/1294622/73258_07.pdf (2010).

  BACKGROUND

• Australia, C. F. o. Faecal Bristol Stool Chart, 2024).

  BACKGROUND

• Rego R, Watson S, Alam MAU, Abdullah SA, Yunus M, Alam IT, Chowdhury ASMHK, Haider SMA, Faruque A, Khan AI, Hofer T, Gill P, Islam MS, Lilford R. A comparison of traditional diarrhoea measurement methods with microbiological and biochemical indicators: A cross-sectional observational study in the Cox's Bazar displaced persons camp. EClinicalMedicine. 2021 Nov 20;42:101205. doi: 10.1016/j.eclinm.2021.101205. eCollection 2021 Dec.

  PMID: 34849477 BACKGROUND

• Organization, W. H. How to design vector control efficacy trials: guidance on phase III vector control field trial design provided by the Vector Control Advisory Group. ttps://iris.who.int/bitstream/handle/10665/259688/WHO-HTM-NTD-VEM-2017.03-eng.pdf (2017).

  BACKGROUND

• Nazni WA, Luke H, Wan Rozita WM, Abdullah AG, Sa'diyah I, Azahari AH, Zamree I, Tan SB, Lee HL, Sofian MA. Determination of the flight range and dispersal of the house fly, Musca domestica (L.) using mark release recapture technique. Trop Biomed. 2005 Jun;22(1):53-61.

  PMID: 16880754 BACKGROUND

• Zaki, A. M., Darwish, E. T. E. & Abdella, M. M. H. Bio-efficacy of certain chitin synthesis inhibitors on dipterous flies and mites inhabiting dung of farm animals. Journal of Pest Science 63, 69-73 (1990).

  BACKGROUND

• Albayyar, E. A. & Qader, R. A. A. A. Effect of Insect Growth Regulators "Dimilin25% wp and Match 50 EC" Against House Fly (Musca domestica) Life Stages (Diptera: Muscidae). Indian Journal of Forensic Medicine & Toxicology 15, 2867-2870 (2021).

  BACKGROUND

• Mahase E. Measles: South Sudan reports 12 000 cases in three months. BMJ. 2024 Mar 28;384:q777. doi: 10.1136/bmj.q777. No abstract available.

  PMID: 38548295 BACKGROUND

• Public Health Weekly Reports for MAY 9, P. H. R. W. & 669-96., D. C. 17 Classification, I. F. S. P. South Sudan: acute malnutrition situation for July - September 2023 and projections for October 2023 - March 2024 and April - June 2024, 2024).

  BACKGROUND

• (UNHCR), U. N. H. C. F. R. Vector and pest control in refugee situations. (1997). 15 Board, A. F. P. M. Filth Flies: Significance and Control in Contingency Operations Technical Guide No. 30 (2011).

  BACKGROUND

• Onwugamba FC, Mellmann A, Nwaugo VO, Suselbeck B, Schaumburg F. Antimicrobial resistant and enteropathogenic bacteria in 'filth flies': a cross-sectional study from Nigeria. Sci Rep. 2020 Oct 12;10(1):16990. doi: 10.1038/s41598-020-74112-x.

  PMID: 33046808 BACKGROUND

• Graczyk TK, Knight R, Gilman RH, Cranfield MR. The role of non-biting flies in the epidemiology of human infectious diseases. Microbes Infect. 2001 Mar;3(3):231-5. doi: 10.1016/s1286-4579(01)01371-5.

  PMID: 11358717 BACKGROUND

• Agency, T. U. R. Refugee population in Maban, South Sudan, 31 October 2023, 2023). 11 Hewitt, C. G. Houseflies and how they spread disease. (1912).

  BACKGROUND

• Riddle MS, Martin GJ, Murray CK, Burgess TH, Connor P, Mancuso JD, Schnaubelt ER, Ballard TP, Fraser J, Tribble DR. Management of Acute Diarrheal Illness During Deployment: A Deployment Health Guideline and Expert Panel Report. Mil Med. 2017 Sep;182(S2):34-52. doi: 10.7205/MILMED-D-17-00077.

  PMID: 28885922 BACKGROUND

• Organization, W. H. Diarrhoeal disease (2024).

  BACKGROUND

• GBD 2021 Diarrhoeal Diseases Collaborators. Global, regional, and national age-sex-specific burden of diarrhoeal diseases, their risk factors, and aetiologies, 1990-2021, for 204 countries and territories: a systematic analysis for the Global Burden of Disease Study 2021. Lancet Infect Dis. 2025 May;25(5):519-536. doi: 10.1016/S1473-3099(24)00691-1. Epub 2024 Dec 18.

  PMID: 39708822 BACKGROUND

• GBD 2019 Under-5 Mortality Collaborators. Global, regional, and national progress towards Sustainable Development Goal 3.2 for neonatal and child health: all-cause and cause-specific mortality findings from the Global Burden of Disease Study 2019. Lancet. 2021 Sep 4;398(10303):870-905. doi: 10.1016/S0140-6736(21)01207-1. Epub 2021 Aug 17.

  PMID: 34416195 BACKGROUND

• Allan RJ, Kamal M, Ahmad S, Badia-Ruis X, Ali MS, Attawei A, Lopes S, Pasquale HA, Oxborough RM, Chilito KLF, Wickramasinghe T, Cross CL, Messenger LA. Reducing filth fly populations and transmission of diarrhoeal pathogens in harsh settings: study protocol for a cross-over trial in South Sudan. BMC Infect Dis. 2026 Apr 21. doi: 10.1186/s12879-026-13296-5. Online ahead of print.

  PMID: 42015057 DERIVED

MeSH Terms

Interventions

Juvenile Hormones; Diflubenzuron

Intervention Hierarchy (Ancestors)

Insect Hormones; Invertebrate Hormones; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Phenylurea Compounds; Urea; Amides; Organic Chemicals; Benzene Derivatives; Hydrocarbons, Aromatic; Hydrocarbons, Cyclic; Hydrocarbons

Study Officials

• Richard James Allan, PhD

  The Mentor Initiative

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Richard James Allan, PhD

CONTACT

+44 796193670; richard.allan@mentor-initiative.org

Louisa Alexandra Messenger, PhD

CONTACT

+1 702-449-3295; louisa.messenger@unlv.edu

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NON RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: DSMB committee Trial Steering Committee NB: these committees can request unblinding of data if they have serious concerns regarding adverse event monitoring.
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: 3-period, 3-group, interventional non-randomised cross-over trial with parallel control

Study Record Dates

• First Submitted: September 24, 2025
• First Posted: December 9, 2025
• Study Start (Estimated): August 17, 2026
• Primary Completion (Estimated): October 31, 2027
• Study Completion (Estimated): December 19, 2027
• Last Updated: July 29, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: IPD will be available upon publication of the main trial manuscript, following trial completion and will be available indefinitely.
• Access Criteria: Summary findings from trial IPD will be published in open-access, peer reviewed papers and their supporting information. Following trial completion, IPD will be available indefinitely, upon publication of the main trial manuscript. All other relevant de-identified IPD are available from the trial Principal Investigators upon reasonable request.

Locations

SO (1)