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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
TRIPLE
Enrollment
4,200
Dual active ingredient Long Lasting Insecticidal Net
Dual active ingredient Long Lasting Insecticidal Net
Combination insecticide and synergist Long Lasting Insecticidal Net
Standard Long Lasting Insecticidal Net with one insecticide
District Misungwi
Misungwi, Mwanza Region, Tanzania
Malaria infection prevalence in children 6 months to 14 years
Malaria prevalence will be assessed using Malaria Rapid Diagnostic test (CareStart Malaria histidine-rich protein 2 (HRP2)/plasmodium lactate dehydrogenase (pLDH) Combo, DiaSys, UK)
Time frame: 24 months post intervention
Incidence of malaria cases in children 6 months to 10 years
Malaria incidence cases will be assessed using Malaria Rapid Diagnostic test (CareStart)
Time frame: Two years post intervention follow up
Prevalence of anaemia in children under 5 years old
Hemoglobin (Hb) concentration will be tested to assess anaemia (\<8 g/dL) using HemoCue Hb 201+.
Time frame: 12, 18, 24, 30, 36 months post intervention
Indoor Anopheles density
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)
Time frame: Three years post intervention follow up
Sporozoite rate
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.
Time frame: Three years post intervention follow up
Insecticide content in Long Lasting Insecticidal Net (LLIN)
30 LLINs will be collected at yearly interval and Insecticide content in g/kg assessed with High-performance liquid chromatography (HPLC)
Time frame: at 0, 12, 24, 30, 36 months post intervention
Mortality in Anopheles after one hour exposure to every study LLIN
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.
Time frame: at 0, 6, 12, 18, 24, 30, 36 months post intervention
LLIN usage
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.
Time frame: at 6, 12, 18, 24, 30, 36 months post intervention
Malaria infection prevalence in children 6 months to 14 years
Malaria prevalence will be assessed using Malaria Rapid Diagnostic test (CareStart Malaria histidine-rich protein 2 (HRP2)/plasmodium lactate dehydrogenase (pLDH) Combo, DiaSys, UK)
Time frame: 12 months post intervention
Malaria infection prevalence in children 6 months to 14 years
Malaria prevalence will be assessed using Malaria Rapid Diagnostic test (CareStart Malaria histidine-rich protein 2 (HRP2)/plasmodium lactate dehydrogenase (pLDH) Combo, DiaSys, UK)
Time frame: 18 months post intervention
Malaria infection prevalence in children 6 months to 14 years
Malaria prevalence will be assessed using Malaria Rapid Diagnostic test (CareStart Malaria histidine-rich protein 2 (HRP2)/plasmodium lactate dehydrogenase (pLDH) Combo, DiaSys, UK)
Time frame: 30 months post intervention
Malaria infection prevalence in children 6 months to 14 years
Malaria prevalence will be assessed using Malaria Rapid Diagnostic test (CareStart Malaria histidine-rich protein 2 (HRP2)/plasmodium lactate dehydrogenase (pLDH) Combo, DiaSys, UK)
Time frame: 36 months post intervention
Cost & DALYs of each type of bi-treated LLIN
Cost of each intervention will be gathered and used to calculate cost per malaria case averted and cost per DALY averted
Time frame: Three years post intervention
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.