Can insecticide-treated curtains prevent transmission of dengue?

ISRCTN	ISRCTN08474420
DOI	https://doi.org/10.1186/ISRCTN08474420
Protocol serial number	N/A
Sponsor	Liverpool School of Tropical Medicine (UK)
Funder	The Wellcome Trust (UK) (grant ref: 085714)

Submission date: 14/04/2011
Registration date: 18/04/2011
Last edited: 07/03/2022

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Infections and Infestations

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Not provided at time of registration

Contact information

Dr Philip McCall
Scientific

Pembroke Place
Liverpool
L3 5QA
United Kingdom

Phone	+44 (0)151 705 3132
Email	mccall@liv.ac.uk

Study information

Primary study design	Interventional
Study design	Cluster randomised controlled trial
Secondary study design	Randomised controlled trial
Study type	Participant information sheet
Scientific title	A cluster randomised controlled trial of household-based insecticide-treated indoor curtains for control of the dengue vector Aedes aegypti and prevention of transmission of dengue in the community
Study objectives	We investigated whether window curtains made from long-lasting insecticide-treated netting and deployed inside houses, could reduce dengue virus transmission, as measured by seroconversion rates in humans, following reductions in dengue vector populations, as measured by a series of standard indices for Aedes aegypti intra-domiciliary and peri-domestic abundance, in intervention groups compared to control groups.
Ethics approval(s)	1. Research Ethics Committee of the Liverpool School of Tropical Medicine approved on 8th June 2009 (ref: 09/59) 2. Loreto Regional Health (Direccion Regional de Salud de Loreto), Peru approved on 3rd July 2009 (ref 586-2009-GRL-DRS/30.09.01) 3. US Naval Medical Research Center Detachment (NAMRID) Lima approved on 8th September 2009 (project no. 6000 RAD1.S.B0302; Approval ref. NAVMEDRSCHCENDETACHMENTINST 3900.6H)
Health condition(s) or problem(s) studied	Dengue (including Dengue Haemorrhagic Fever [DHF] and Dengue Shock Syndrome [DSS])
Intervention	Insecticide-treated curtains deployed inside human habitations. The curtains are made from PermaNet® deltamethrin-coated polyester netting, a long-lasting impregnated material (Vestergaard-Frandsen, Lausanne, Switzerland), that has been approved for indoor use (World Health Organisation Pesticide Evaluation Scheme [WHOPES]), with proven efficacy against dengue vectors. Householders in treated clusters are permitted to dictate the quantity and location of their insecticide-treated materials (ITMs), with a minimum of one ITM required for the household to be classified as receiving treatment. Control households received no treatment, but will be offered ITMs at the end of the study. Efficacy of the intervention (Insecticide-treated curtains as described in E51) fell to an unacceptably low level (as determined by standard WHO recommended bioassays and other methods), when monitored over a period of months during 2010. Consequently, in October and November 2010, the existing curtains were treated again with a different product ("K-O Tab 1 2 3"; Bayer Environmental Science, Germany) designed to deliver a long-lasting formulation of the same insecticide.
Intervention type	Other
Primary outcome measure(s)	Effect of ITMs on dengue transmission - measured by detection of dengue specific antibodies in human blood, taken from householders within the study area, using the Plaque Reduction Neutralizing Antibody test (PRNT). PRNT is specific to dengue virus serotype, and is the gold standard against which all other dengue virus (DV) serological assays are validated. Blood samples will be collected from the study population at baseline and at three 9-month intervals thereafter (9, 18, 24 months post intervention) in householders that were not positive for all four circulating serotypes during the immediate preceding survey.
Key secondary outcome measure(s)	1. The effect of ITMs on household vector infestation and breeding primarily measured by: 1.1 The adult index (proportion of houses positive for adult Ae. aegypti) 1.2. The Breteau index (number of containers with immature vector stages/100 houses) Secondarily by the other Stegomyia indices: 1.3. Pupae per person index (number of pupae per number of people) 1.4. House index (percentage of houses found with immature stages of Ae. aegypti) 1.5. Container index (percentage of water-holding containers found with immature stages of Ae. aegypti). Six surveys will be conducted: Baseline and 1, 6, 12, 18 and 24 months post intervention. 2. Quantification of spill-over effects from treated clusters on nearby control clusters, a potential confounding effect on analyses as well as an indicator of potential community-level impact 3. Determining factors associated with adoption and continued use of ITMs, including the most effective diffusion mechanism (channel of communication) for ITM promotion, by household questionnaires and focus group discussions. Surveys will coincide with the serological surveys.
Completion date	31/12/2011

Eligibility

Participant type(s)	Patient
Age group	Adult
Sex	All
Target sample size at registration	9200
Key inclusion criteria	1. All occupied households 1.1. Persons aged 3 years or older with parental permission 1.2. Adults consenting to participate in the study living in the study area 1.3. Assent to participation for 8-17 year old persons
Key exclusion criteria	1. Persons younger than 3 years old 2. Temporary visitors to the study areas 3. Adults who do not consent to participate 4. 8-17 year old persons who do not assent or who do not have parental permission to participate in the study
Date of first enrolment	01/11/2009
Date of final enrolment	31/12/2011

Locations

Countries of recruitment

United Kingdom
England
Peru

Study participating centre

Pembroke Place

Liverpool
L3 5QA
United Kingdom

Results and Publications

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
IPD sharing plan	Not provided at time of registration

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article		07/03/2022	07/03/2022	Yes	No
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes

Editorial Notes

07/03/2022: Publication reference added.