Efficacy of Three Novel Bi-treated Long Lasting Insecticidal Nets

Conditions

Anaemia, Malaria

Keywords

Malaria, Vector Control, Long lasting Insecticidal Net

Brief summary

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.

Eliud Lukole, Jackie Cook, Jacklin F Mosha, Nancy S. Matowo, Manisha A. Kulkarni et al. (13 authors)

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Will a lack of fabric durability be their downfall? Impact of textile durability on the efficacy of three types of dual-active-ingredient long-lasting insecticidal nets: a secondary analysis on malaria prevalence and incidence from a cluster-randomized trial in north-west Tanzania

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Mosha JF, Matowo NS, Kulkarni MA, Messenger LA, Lukole E, Mallya E, Aziz T, Kaaya R, Shirima BA, Isaya G, Taljaard M, Hashim R, Martin J, Manjurano A, Kleinschmidt I, Mosha FW, Rowland M, Protopopoff N.

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Messenger LA, Matowo NS, Cross CL, Jumanne M, Portwood NM, Martin J, Lukole E, Mallya E, Mosha JF, Kaaya R, Moshi O, Pelloquin B, Fullerton K, Manjurano A, Mosha FW, Walker T, Rowland M, Kulkarni MA, Protopopoff N.

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Durability of three types of dual active ingredient long-lasting insecticidal net compared to a pyrethroid-only LLIN in Tanzania: methodology for a prospective cohort study nested in a cluster randomized controlled trial.

Martin JL, Messenger LA, Mosha FW, Lukole E, Mosha JF, Kulkarni M, Churcher TS, Sherrard-Smith E, Manjurano A, Protopopoff N, Rowland M.

2022-03-1910 citations

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Effectiveness and cost-effectiveness against malaria of three types of dual-active-ingredient long-lasting insecticidal nets (LLINs) compared with pyrethroid-only LLINs in Tanzania: a four-arm, cluster-randomised trial.

Mosha JF, Kulkarni MA, Lukole E, Matowo NS, Pitt C, Messenger LA, Mallya E, Jumanne M, Aziz T, Kaaya R, Shirima BA, Isaya G, Taljaard M, Martin J, Hashim R, Thickstun C, Manjurano A, Kleinschmidt I, Mosha FW, Rowland M, Protopopoff N.

2022-03-01146 citations

10.1016/s0140-6736(21)02499-5

Protocol for a four parallel-arm, single-blind, cluster-randomised trial to assess the effectiveness of three types of dual active ingredient treated nets compared to pyrethroid-only long-lasting insecticidal nets to prevent malaria transmitted by pyrethroid insecticide-resistant vector mosquitoes in Tanzania

Jacklin F Mosha, Manisha A. Kulkarni, Louisa A. Messenger, Mark Rowland, Nancy S. Matowo et al. (13 authors)

BMJ Open2021-03-0158 citations

10.1136/bmjopen-2020-046664

Assessing the efficacy of two dual-active ingredients long-lasting insecticidal nets for the control of malaria transmitted by pyrethroid-resistant vectors in Benin: study protocol for a three-arm, single-blinded, parallel, cluster-randomized controlled trial

Manfred Accrombessi, Jackie Cook, Corine Ngufor, Arthur Sovi, Edouard Dangbénon et al. (16 authors)

BMC Infectious Diseases2021-02-1951 citations

10.1186/s12879-021-05879-1

Interventions

OTHERChlorfenapyr LLIN

Dual active ingredient Long Lasting Insecticidal Net

OTHERpyriproxyfen LLIN

Dual active ingredient Long Lasting Insecticidal Net

OTHERPiperonyl butoxide LLIN

Combination insecticide and synergist Long Lasting Insecticidal Net

OTHERStandard LLIN

Standard Long Lasting Insecticidal Net with one insecticide

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

PREVENTION

Masking

TRIPLE (Subject, Caregiver, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

6 Months to 14 Years

Healthy volunteers

Yes

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

Design outcomes

Primary

Measure	Time frame	Description
Malaria infection prevalence in children 6 months to 14 years	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

Measure	Time frame	Description
Sporozoite rate	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.
LLIN usage	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.
Malaria infection prevalence in children 6 months to 14 years	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)
Cost & DALYs of each type of bi-treated LLIN	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
Incidence of malaria cases in children 6 months to 10 years	Two years post intervention follow up	Malaria incidence cases will be assessed using Malaria Rapid Diagnostic test (CareStart)
Prevalence of anaemia in children under 5 years old	12, 18, 24, 30, 36 months post intervention	Hemoglobin (Hb) concentration will be tested to assess anaemia (\<8 g/dL) using HemoCue Hb 201+.
Indoor Anopheles density	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)
Insecticide content in Long Lasting Insecticidal Net (LLIN)	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)
Mortality in Anopheles after one hour exposure to every study LLIN	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.

Other

Measure	Time frame	Description
Frequency of Vgsc mutation in wild Anopheles population	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.
P450 over-expression in wild Anopheles population	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)
Insecticide resistance intensity in wild Anopheles population	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

Countries

Tanzania

Outcome results

None listed