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NCT Number: NCT03554616

Efficacy of Three Novel Bi-treated Long Lasting Insecticidal Nets

The massive scale-up of Long Lasting Insecticidal Nets (LLIN) has led to a major reduction in malaria burden (up to 50%) in many sub-Saharan African countries. This progress is threatened by the wide scale selection of insecticide resistant malaria vectors. New types of LLIN combining a mixture of two insecticides or an insecticide and a synergist have been developed to control resistant mosquitoes.

The efficacy of three bi-treated LLIN are compared to a standard LLIN in a four-arm, single blinded, cluster-randomized trial in Misungwi district, Tanzania. The arms are; 1/ Royal Guard, a net combining pyriproxyfen (PPF), which is known to disrupt female reproduction and fertility of eggs, and the pyrethroid alpha-cypermethrin, 2/Interceptor G2, LLIN incorporating a mixture of two adulticides with different modes of action; chlorfenapyr and a pyrethroid (alpha-cypermethrin), and 3/ Olyset Plus an LLIN which incorporates a synergist, piperonyl butoxide (PBO), to enhance the potency of pyrethroid insecticides, and 4/ The control arm: Interceptor treated a standard LLIN treated with alpha-cypermethrin.

The primary outcome of the trial will be cross-sectional community prevalence of malaria infection (by RDT) in children aged 6 months to 14 years at 12 and 24 months post-intervention.

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Key information

Conditions

Malaria Anaemia Anemia Hematologic Diseases Hemic and Lymphatic Diseases Infections Mosquito-Borne Diseases Parasitic Diseases Protozoan Infections Vector Borne Diseases

Age range

6 month–14 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

District Misungwi

Misungwi, Mwanza Region, Tanzania

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • At least one child between 6 months to 14 years old having permanent residence in selected household
  • Having an adult caregiver willing to provide written consent for the household and clinical survey

Exclusion criteria

  • Dwelling not found or vacant during the survey
  • No adult caregiver capable to give informed consent
  • Children severely ill

Treatment and study plan

Chlorfenapyr LLIN

Other

Dual active ingredient Long Lasting Insecticidal Net

pyriproxyfen LLIN

Other

Dual active ingredient Long Lasting Insecticidal Net

Piperonyl butoxide LLIN

Other

Combination insecticide and synergist Long Lasting Insecticidal Net

Standard LLIN

Other

Standard Long Lasting Insecticidal Net with one insecticide

Primary outcomes

  1. Malaria infection prevalence in children 6 months to 14 years

    Time frame: 24 months post intervention

    Malaria prevalence will be assessed using Malaria Rapid Diagnostic test (CareStart Malaria histidine-rich protein 2 (HRP2)/plasmodium lactate dehydrogenase (pLDH) Combo, DiaSys, UK)

Secondary outcomes

  1. Incidence of malaria cases in children 6 months to 10 years

    Time frame: Two years post intervention follow up

    Malaria incidence cases will be assessed using Malaria Rapid Diagnostic test (CareStart)

  2. Prevalence of anaemia in children under 5 years old

    Time frame: 12, 18, 24, 30, 36 months post intervention

    Hemoglobin (Hb) concentration will be tested to assess anaemia (<8 g/dL) using HemoCue Hb 201+.

  3. Indoor Anopheles density

    Time frame: Three years post intervention follow up

    Anopheles density per house per night will be assess every quarter in 8 houses per cluster using light trap. Anopheles density and sporozoite rate will be used to estimate the entomological inoculation rate (EIR)

  4. Sporozoite rate

    Time frame: Three years post intervention follow up

    A sub-samples of Anopheles collected indoor will be tested for Plasmodium falciparum circumsporozoite protein using an ELISA test. Sporozoite rate will be used to estimate the EIR with Anopheles density.

  5. Insecticide content in Long Lasting Insecticidal Net (LLIN)

    Time frame: at 0, 12, 24, 30, 36 months post intervention

    30 LLINs will be collected at yearly interval and Insecticide content in g/kg assessed with High-performance liquid chromatography (HPLC)

  6. Mortality in Anopheles after one hour exposure to every study LLIN

    Time frame: at 0, 6, 12, 18, 24, 30, 36 months post intervention

    30 LLINs will be sampled every 6 months and tested in cone bio assay or tunnel test using resistant Anopheles and susceptible Kisumu Anopheles to assess for bio efficacy. 24, 48 and 72 hours mortality post exposure will be recorded.

  7. LLIN usage

    Time frame: at 6, 12, 18, 24, 30, 36 months post intervention

    The proportion of study participant declaring sleeping under a LLIN the previous night will be assessed during household survey every 6 months using a questionnaire.

  8. Malaria infection prevalence in children 6 months to 14 years

    Time frame: 12 months post intervention

    Malaria prevalence will be assessed using Malaria Rapid Diagnostic test (CareStart Malaria histidine-rich protein 2 (HRP2)/plasmodium lactate dehydrogenase (pLDH) Combo, DiaSys, UK)

  9. Malaria infection prevalence in children 6 months to 14 years

    Time frame: 18 months post intervention

    Malaria prevalence will be assessed using Malaria Rapid Diagnostic test (CareStart Malaria histidine-rich protein 2 (HRP2)/plasmodium lactate dehydrogenase (pLDH) Combo, DiaSys, UK)

  10. Malaria infection prevalence in children 6 months to 14 years

    Time frame: 30 months post intervention

    Malaria prevalence will be assessed using Malaria Rapid Diagnostic test (CareStart Malaria histidine-rich protein 2 (HRP2)/plasmodium lactate dehydrogenase (pLDH) Combo, DiaSys, UK)

  11. Malaria infection prevalence in children 6 months to 14 years

    Time frame: 36 months post intervention

    Malaria prevalence will be assessed using Malaria Rapid Diagnostic test (CareStart Malaria histidine-rich protein 2 (HRP2)/plasmodium lactate dehydrogenase (pLDH) Combo, DiaSys, UK)

  12. Cost & DALYs of each type of bi-treated LLIN

    Time frame: Three years post intervention

    Cost of each intervention will be gathered and used to calculate cost per malaria case averted and cost per DALY averted

Other outcomes

  1. Insecticide resistance intensity in wild Anopheles population

    Time frame: Three years post intervention follow up

    Twice a year insecticide resistance will be assessed in wild Anopheles. 24 hours mortality will be recorded in Anopheles exposed to different concentrations of insecticides in CDC bottle assay or WHO test

  2. P450 over-expression in wild Anopheles population

    Time frame: Three years post intervention follow up

    P450 genes involved in pyrethroid insecticide resistance will be monitored in the 4 arms once a year using reverse-transcription quantitative polymerase chain reaction (PCR)

  3. Frequency of Vgsc mutation in wild Anopheles population

    Time frame: Three years post intervention follow up

    A sub sample of mosquitoes collected in the 4 arms will be tested for the Vgsc mutation involved in pyrethroid resistance using Taq Man PCR.

Sponsors and collaborators

Lead sponsor

London School of Hygiene and Tropical Medicine

Other

Collaborators

  • Kilimanjaro Christian Medical Centre, Tanzania
  • National Institute for Medical Research, Tanzania
  • University of Ottawa

Registry information

Official study title

Efficacy of Three Different Bi-treated Long Lasting Insecticidal Nets and Deployment Strategy for Control of Malaria Transmitted by Pyrethroid Resistant Vectors: A Randomised Controlled Trial

Important dates

Study start
2019
Primary completion
2022
Study completion
2023
First posted
Jun 13, 2018
Registry last updated
Nov 26, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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