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

Summary

Objectives The main trial objective is to evaluate the efficacy of insecticidal paint (PAINT) or larvicide (LARV), or both interventions combined, on filth fly density and hence transmission of diarrhoeal diseases.

Primary Objective

• To evaluate the efficacy of PAINT or LARV, or both interventions combined, in reducing the number of cases of all-cause diarrhoea (primary epidemiological endpoint).

Secondary Objectives

* To evaluate the efficacy of PAINT or LARV, or both interventions combined, in reducing filth fly density and species composition at the latrine level (primary entomological endpoint).
* To evaluate the efficacy of PAINT or LARV, 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 PAINT or LARV, or both interventions combined, on enteric pathogen species composition and density (tertiary entomological endpoint).
* To assess the impact of PAINT or LARV, 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 2-month wash-out period.

The trial arms will be:

1. No intervention (control arm)
2. Inesfly® Carbapaint 10 insecticidal paint (intervention arm 1)
3. Dimilin® larvicide (intervention arm 2)

Conditions

• Diarrheal Diseases

Interventions

OTHER

Long-lasting insecticidal paint - 1.0% (w/w) propoxur

Inesfly® Carbapaint 10 (Inesfly Corporation, Valencia, Spain) is a water-based polymer coating containing a microencapsulated suspension of 1.0% (w/w) propoxur (carbamate), for slow release to prolong efficacy. Propoxur is a non-repellent active ingredient (AI) and when used on pit latrine walls, flies will land on the surface and receive a lethal insecticidal dose. All eligible pit latrines assigned to this intervention arm will be treated with Inesfly® Carbapaint 10 at the beginning of each 6-month implementation phase; pit latrines with at least 3 standing walls, will be eligible.

OTHER

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

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.

Sponsors & Collaborators

• University of Nevada, Las Vegas

  collaborator OTHER

• The Mentor Initiative

  lead OTHER

Principal Investigators

• Richard J Allan, PhD · The Mentor Initiative

Study Design

Allocation

NON_RANDOMIZED

Purpose

PREVENTION

Masking

SINGLE

Model

CROSSOVER

Eligibility

Min Age

1 Year

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2025-12-10

Primary Completion

2027-10-31

Completion

2027-12-19

Countries

• South Sudan

Study Locations