Evaluation of Long-Lasting Microbial Larvicides in Reducing Malaria Transmission and Clinical Malaria Incidence (LLML)

University of California Irvine (UCI)

Status: Completed

Conditions: Malaria

Treatments: Biological: Fourstar® granule, 90 day and 180 day briquettes Bti/Bs

Study type: Interventional

Funder types: Other

Identifiers

NCT02392832

R01A1050243 [HS# 2008-6148]

Details and patient eligibility

About

In the past decade, massive scale-up of insecticide-treated nets (ITN) and indoor residual spraying (IRS), together with the introduction of artemisinin-combination treatments, have led to substantial reductions in malaria prevalence and incidence in African highlands. However, rising insecticide resistance and increased outdoor transmission have greatly hampered the effectiveness of ITN and IRS because the current indoor-based interventions do not target the outdoor-biting mosquitoes. Therefore, new supplemental interventions that can tackle outdoor transmission and pyrethroid insecticide resistance are urgently needed. The central objective of this study is to determine the efficacy and cost-effectiveness of EPA-approved long-lasting microbial larvicides in reducing malaria transmission and clinical malaria incidence in western Kenya highlands.

Full description

In the past decade, massive scale-up of insecticide-treated nets (ITNs) and indoor residual spraying (IRS), together with the use of artemisinin combination treatments, have led to major changes in malaria epidemiology and vector biology. Along with the significant reduction in overall malaria prevalence and incidence, extensive use of insecticides has created large selection pressures for resistance in the malaria vector populations and for potential outdoor transmission, which appears to be limiting the success of ITNs and IRS. Because IRS and ITN have little impact on outdoor resting and early biting vectors, outdoor transmission represents one of the most important challenges in malaria control. Therefore, new interventions that can augment the current public health measures to reduce outdoor transmission are urgently needed. Larval control has historically been very successful and is widely used for mosquito control in many parts of the world, except in Africa. Factors limiting the use of larvicides include high costs associated with frequent habitat re-treatment. Now a new US EPA-approved long-lasting formulation, potentially effective for 6 months is available. The central objective of this study is to determine the effect of long-lasting microbial larviciding on the incidence of clinical malaria and reduction of transmission intensity. Our hypothesis is that addition of long-lasting microbial larviciding to ongoing ITN and IRS programs will lead to significant reductions in both indoor and outdoor malaria transmission and malaria incidence.

Enrollment: 240,000 patients

Sex: All

Ages: 7+ months old

Volunteers: No Healthy Volunteers

Inclusion criteria

• All clinical malaria cases from participated local hospitals and clinics.

Exclusion criteria

• Infants younger than 6 months.

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

---

240,000 participants in 2 patient groups

Intervention arm

Experimental group

Description:

Fourstar® granule formulation, 90day and 180 day briquettes Bti/Bs in larval habitats of malaria vectors.

Treatment:

Biological: Fourstar® granule, 90 day and 180 day briquettes Bti/Bs

Control arm

No Intervention group

Description:

No larvicide application.