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Completed

NCT Number: NCT01575613

Reducing the Burden of Malaria by Targeting Hotspots of Malaria Transmission

In this study, the investigators propose to determine the value of rolling out four targeted malaria control efforts in reducing overall malaria transmission. These targeted control efforts include local upscaling of IRS and ITNs in hotspots of malaria transmission. In addition, larviciding will be employed to target malaria vectors, also those that are less susceptible to IRS and ITNs as a consequence of outdoor feeding and resting. Lastly, the human infectious reservoir will be reduced in hotspots of malaria transmission by treating parasite carriers and their household members with the current first-line antimalarial drug. The impact of these targeted interventions on overall transmission intensity will be assessed in the context of currently ongoing malaria control activities in a plausibility study. Hotspots of malaria transmission are defined in an area of 100km2 and randomized to receive hotspot targeted interventions and compared with their baseline and with control clusters where the routine (untargeted) malaria control activities continue. The interventions will be evaluated based on changes in parasite prevalence measured in community surveys inside and outside hotspots of malaria transmission. Parasite prevalence will be compared before and after the intervention in intervention clusters and between intervention and control clusters.

In addition to malaria surveys in the human population, an entomological evaluation will take place where the densities of mosquito larvae and adult mosquitoes are monitored longitudinally.

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Key information

Conditions

Malaria Infections Mosquito-Borne Diseases Parasitic Diseases Protozoan Infections Vector Borne Diseases

Age range

6 month and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Rachuonyo District, Kenya

About this study

DEFINITIONS This study uses a plausibility design to determine the plausible impact of hotspot-targeted interventions on overall malaria transmission. Hotspots will be detected in the 100km2 study area. Hotspots are defined as areas with a level of transmission intensity that exceeds that in the surrounding area; indicated by a higher sero-conversion rate and/or age-adjusted density of malaria-specific antibodies.

Clusters for the intervention are defined as a hotspot and the area surrounding this hotspot in each direction up to 500 meters.

INTERVENTION Half of the clusters will be randomized to hotspot-targeted interventions, while the other half will serve as control. The plausible impact of hotspot targeted interventions will be evaluated by comparing malaria indices in intervention clusters with their baseline and with control clusters.

In each phase four hotspot-targeted interventions will be superimposed on ongoing control measures: hotspots will be targeted with a combination IRS, long-lasting insecticide treated nets (LLINs), larviciding and a focal screening and treatment (FSAT).

EVALUATION The primary outcome will be parasite prevalence in evaluation zones (i.e. the area surrounding malaria hotspots) of targeted and untargeted clusters. In addition, parasite prevalence will be determined inside hotspots of malaria transmission and in evaluation zones in relation to distance to the hotspot boundary. For this, community surveys are planned prior to the intervention and at two time-points after the intervention.

An entomological evaluation will take place concurrently in which mosquito breeding sites are monitored for productivity and mosquitoes will be sampled indoors and outdoors.

Malaria morbidity is assessed by passive case detection.

Who can participate

Healthy volunteers accepted: Yes

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

Exclusion criteria

  • For LLINs, IRS and larviciding there are no exclusion criteria
  • Pregnant women and children < 6 months of age are excluded from FSAT

Treatment and study plan

Artemether-lumefantrine combination

Drug

Focal screening and treatment in all households in malaria hotspots prior to the peak transmission season. Screening of a sentinel age group by rapid diagnostic tests; all parasitaemic individuals and household members of parasitaemic individuals will be treated.

Bacillus thuringiensis

Biological

Treatment of all waterbodies within hotspots with Bti or Bs on weekly basis

Long lasting insecticide treated net (LLINs)

Biological

Distribution of LLINs in all households in malaria hotspots; instruction about correct use.

Indoor Residual Spraying (IRS)

Biological

6-monthly IRS with deltamethrin in all households malaria hotspots.

Primary outcomes

  1. Parasite prevalence in the evaluation zone surrounding malaria hotspots

    Time frame: 3 cross-sectional surveys in up to 210 days, the timing being: at enrolment; 45-75 days post enrolment (coinciding with the peak malaria transmission season) and 150-210 days post enrolment (coinciding with the end of the malaria transmission season)

    Parasite prevalence, determined by PCR, in the evaluation zone surrounding hotspots in intervention and control clusters

Secondary outcomes

  1. Parasite prevalence inside malaria hotspots

    Time frame: 3 cross-sectional surveys in up to 210 days, the timing being: at enrolment; 45-75 days post enrolment (coinciding with the peak malaria transmission season) and 150-210 days post enrolment (coinciding with the end of the malaria transmission season)

    Parasite prevalence, determined by PCR, inside hotspot of malaria transmission in intervention and control clusters

  2. Parasite prevalence in the evaluation zone as function of distance to the hotspot boundary

    Time frame: 3 cross-sectional surveys in up to 210 days, the timing being: at enrolment; 45-75 days post enrolment (coinciding with the peak malaria transmission season) and 150-210 days post enrolment (coinciding with the end of the malaria transmission season)

    Parasite prevalence, determined by PCR, in relation to distance to the boundary of malaria hotspots in intervention and control clusters

  3. Anopheles mosquito density

    Time frame: determined during fortnightly trapping, starting at enrolment and continuing until up to 210 days after enrolment

    Indoor and outdoor anopheles mosquito density inside and outside hotspots of malaria transmission in intervention and control clusters

  4. Passive case detection

    Time frame: determined continuously for a period of up to 210 days after enrolment

    Number of malaria cases reporting at health facilities, coming from intervention and control clusters

  5. Safety and acceptability of interventions

    Time frame: at a single cross-sectional survey 15-45 days after enrolment

    Side effects of FSAT, LLINs and IRS in targeted households

  6. Mosquito breeding site productivity

    Time frame: determined on a weekly basis for a period of up to 210 days after enrolment

    The presence and density of anopheles larvae in mosquito breeding sites in malaria hotspots in intervention and control clusters

Sponsors and collaborators

Lead sponsor

Radboud University Medical Center

Other

Collaborators

  • Centers for Disease Control and Prevention
  • Division of Malaria Control, Ministry of Health, Nairobi, Kenya
  • International Centre of Insect Physiology and Ecology (ICIPE)
  • Kenya Medical Research Institute
  • London School of Hygiene and Tropical Medicine

Registry information

Official study title

Reducing the Burden of Malaria by Targeting Hotspots of Transmission and Improving Malaria Control Measures in the Highlands of Western Kenya: Simultaneous Rollout of Four Malaria Control Interventions and Evaluation by Cross-sectional Surveys

Acronym: REDHOT

Important dates

Study start
2012
Primary completion
2012
Study completion
2012
First posted
Apr 11, 2012
Registry last updated
Nov 27, 2012

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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