To assess whether a combination of two insecticides on mosquito nets provides better protection against clinical malaria than pyrethroid-treated nets

ISRCTN ISRCTN21853394
DOI https://doi.org/10.1186/ISRCTN21853394
Secondary identifying numbers 2013-02-011
Submission date
13/03/2013
Registration date
03/04/2013
Last edited
21/01/2019
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

Background and study aims
Malaria is a serious tropical disease spread by mosquitoes. Recent reductions in malaria in sub-Saharan Africa have been associated with the increased use of pyrethroid-treated long-lasting insecticidal nets (LLINs). Pyrethroids are currently the only class of insecticide used for treating nets, and the rapid increase in resistance to pyrethroids in mosquitoes may jeopardise future mosquito control. Nets containing a new combination of permethrin and pyriproxyfen (PPF-LLIN) may enhance malaria control and reduce the spread of pyrethroid-resistant mosquitoes. This study will determine whether PPF-LLINs provide better protection against malaria than LLINs in an area with pyrethroid-resistant mosquitoes.

Who can participate?
Children resident in Burkina Faso, aged 6 months to 5 years old.

What does the study involve?
Participants will be provided with LLINs at the start of the study, and their previous nets will be removed. The LLINs will be gradually exchanged for PPF-LLINs so that at three months before the end of the two-year study all participants will have a PPF-LLIN.

What are the possible benefits and risks of participating?
Study children will benefit from a health check at the surveys and all participants will benefit from the health facility clinical services which will be supported by training and the presence of study nurses in addition to government staff. There are no apparent risks to the safety of individuals or communities in the use of the conventional nets. Permethrin-treated long-lasting nets have been fully evaluated by the WHO Pesticide Evaluation Scheme (WHOPES) and approved for mosquito control. However, PPF-LLINs have not previously been evaluated in the field before, apart from small-scale studies. Whilst we do not anticipate any serious impacts of the combination of permethrin and PPF, since the safety profile of both these active compounds is deemed acceptable by WHOPES, we cannot exclude the possibility that there might be side effects when using the combination. For this reason it is important to assess adverse events and especially any serious adverse events in study subjects during the course of the study to determine whether there is an excess of side effects associated with the PPF-LLINs.

Where is the study run from?
Durham University (UK)

When is the study starting and how long is it expected to run for?
May 2014 to May 2015

Who is funding the study?
EC Seventh Framework Programme

Who is the main contact?
Prof Steve Lindsay
S.W.Lindsay@durham.ac.uk

Contact information

Prof Steve Lindsay
Scientific

School of Biological and Biomedical Sciences
Science Laboratories
South Road
Durham
DH13LE
United Kingdom

Phone +44 (0)191 334 1291
Email S.W.Lindsay@durham.ac.uk

Study information

Study designTwo-armed cluster randomized wedge-shaped trial
Primary study designInterventional
Secondary study designCluster randomised trial
Study setting(s)Home
Study typePrevention
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific titleTo assess whether addition of a second insecticide to long-lasting insecticidal mosquito nets provides additional protection against clinical malaria over current best practice. Protocol for a two-armed cluster randomized wedge-shaped trial in Burkina Faso
Study objectivesOur hypothesis is that mosquito nets treated with two insecticides will provide significant incremental protection against malaria than pyrethroid-treated nets in an area with moderate levels of pyrethroid resistance.
Ethics approval(s)1. Comite d’ethique pour la recherché en sante, Ministere de la recherché scientifique et de l’innovation, Burkina Faso, 13/05/2014, ref: 2014-3-24
2. School of Biological and Biomedical Ethics Committee, Durham University, UK, 17/01/2014
Health condition(s) or problem(s) studiedMalaria
InterventionLong-lasting insecticidal mosquito nets (LLINs) and new net.

Long-lasting insecticidal mosquito nets (LLINs)
The LLINs distributed will be manufactured by Sumitomo Chemical Company. These LLINs are WHO recommended and meets WHO specifications (http://www.who.int/whopes/Long_lasting_insecticidal_nets_Aug09.pdf) with 2% w/w permethrin incorporated into polyethylene fibres giving adequate release of permethrin for about five years. These nets will be distributed in May 2013, at the beginning of the main transmission season, at no cost to the recipients. We will use white 'extra family' size rectangular nets (180cm wide x 190cm l x 150 cm h) throughout. Government Roll Back Malaria information, education and communication procedures will be followed to encourage correct net use and maintenance. This will include supplying the nets in individual pre-opened bags labelled by the manufacturers.

A new net with two insecticides will be provided by Sumitomo Chemicals and are currently undergoing evaluation by the WHO Pesticide Evaluation Scheme (WHOPES). The nets contain 2% w/w permethrin and another insecticide incorporated into polyethylene fibres giving adequate release of both insecticides for an estimated three years. We will provide white 'extra family' size rectangular nets (180cm wide x 190cm l x 150 cm h) throughout. The new nets will be supplied in individual bags labelled by the manufacturers and they will be distributed to recipients in pre-opened individual sachets in August 2013 in five village clusters and rolled out in a wedge-shaped design at monthly intervals thereafter during the main transmission seasons in 2013 and 2014.

New net distribution will be carried out by the study team in a similar manner to the LLINs.
Intervention typeDevice
Pharmaceutical study type(s)
Phase
Drug / device / biological / vaccine name(s)
Primary outcome measureTo assess whether a pyrethroid insecticide combined with another class of insecticide incorporated into a LLIN provides added protection against clinical malaria in children compared with pyrethroid-only LLINs (LLIN) over two malaria transmission seasons of follow up.
Secondary outcome measuresEfficacy
1. To assess whether two insecticides on LLINs provide added protection compared to LLINs against anaemia and/or parasite prevalence in children.
2. To assess and compare the prevalence of microscopy confirmed gametocyte carriers (GC) in LLINs group versus doublke insecticide-LLIN group.

Safety
To assess whether the double-insecticide LLINs have a safety profile comparable with LLINs in the trial population
Overall study start date01/05/2013
Completion date31/12/2014

Eligibility

Participant type(s)Patient
Age groupChild
Lower age limit6 Months
Upper age limit5 Years
SexBoth
Target number of participants2000
Key inclusion criteriaResident children, aged 6 months to 5 years old will be enumerated and an average of 50 per cluster (range 30-100, depending on village size) will be selected randomly, stratified by age and invited to participate in the clinical surveys and passive case detection (PCD). No distinctions will be made regarding gender, ethnic group, medical condition or physical health.

As is customary in Burkina Faso, sensitisation will start by discussions with community elders and then representatives of the whole study community in order to explain the nature of the study and what will be required during the interventions and investigations. Informed consent will be sought at the village level after sensitization meetings attended by village community leaders and health staff. The key attendees names and roles will be documented for each village. Witnessed written consent will be sought from each net recipient, before net donation and exchange. We will seek written consent from room owners before positioning of mosquito traps, and written informed consent from the parents or caregivers of all enrolled study children. During these procedures it will be made clear that people will be able to leave the study at any time but their original net will not be returned.
Key exclusion criteriaThose who have not provided their consent for inclusion in the study
Date of first enrolment01/05/2014
Date of final enrolment01/05/2015

Locations

Countries of recruitment

  • Burkina Faso
  • England
  • United Kingdom

Study participating centre

Durham University
School of Biological and Biomedical Sciences
Science Laboratories
South Road
Durham
DH13LE
United Kingdom

Sponsor information

Durham University (UK)
University/education

c/o Professor Andrew Deeks
Pro-Vice Chancellor of Science
School of Engineering and Computing Sciences
South Road
Durham
DH13LE
England
United Kingdom

Phone +44 (0)191 334 1017
Email pvc.science@durham.ac.uk
ROR logo "ROR" https://ror.org/01v29qb04

Funders

Funder type

Government

Seventh Framework Programme
Government organisation / National government
Alternative name(s)
EC Seventh Framework Programme, European Commission Seventh Framework Programme, EU Seventh Framework Programme, European Union Seventh Framework Programme, FP7

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryAvailable on request
Publication and dissemination planTo be confirmed at a later date
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Protocol article protocol 25/03/2015 Yes No
Results article results 18/08/2018 21/01/2019 Yes No

Editorial Notes

21/01/2019: Publication reference added
28/01/2016: Publication reference added.