Targeted Indoor Residual Spraying Against Malaria

NCT ID: NCT02556242

Last Updated: 2020-07-23

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE4
• Total Enrollment: 393387 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2015-10-31
• Study Completion Date: 2017-07-31

Brief Summary

Since 2000, annual numbers of malaria cases in South Africa have sharply declined to about 5,000, with case numbers fairly stable since 2007. The principal malaria prevention strategy has consisted of generalised Indoor Residual Spraying (IRS) of all houses in malaria endemic districts. As recent case data indicate that the levels of transmission in many districts have been reduced to very low levels, the continuation of untargeted IRS in areas where there is little or no evidence of recent transmission may be unwarranted. Efforts to eliminate malaria will only be sustainable if mass prevention efforts can be scaled down in an evidence-based manner, whilst maintaining or enhancing high sensitivity of the surveillance system of the disease. This trial will provide scientific evidence for targeted malaria prevention responding to localised transmission in pre-elimination settings, compared to continuation of generalised IRS of all houses.

Two methods of IRS delivery for community malaria prevention will be compared through an open-label cluster-randomised trial consisting of two study arms with 30 clusters per arm of approximately 8,000 inhabitants per cluster.

Comparison is on the basis of non-inferiority by showing that malaria incidence in the targeted IRS arm is no higher than malaria incidence in the generalised IRS arm within a specified margin of difference, and on the basis of superiority showing that the proportion of houses targeted for spraying is higher in the intervention than the reference arm. Neighbourhood investigation in response to each locally acquired case in the intervention arm, and comparison neighbourhoods in the reference arm, will include testing for antibody sero-conversion to malarial antigens to assess whether cases arise in communities with long term exposure to malaria parasites.

The trial will be carried out in the South African provinces of Limpopo and Mpumalanga, in localities which have average reported incidence of malaria of <5 cases per 1000 per annum over the past five years.

Detailed Description

Two methods of IRS delivery for malaria prevention, targeted spraying versus annual generalised spraying, will be compared through an open-label cluster randomised trial consisting of two trial arms with 30 clusters per arm. Clusters will be artificial constructs made up of groups of spray localities or complete wards to comprise populations of about 5,000 to 10,000 persons. The unit of randomisation will be the cluster.

The intervention arm of the trial will receive IRS delivery through targeted reactive spraying in the neighbourhood of recent local cases only; the reference (control) arm of the trial will receive IRS through generalised annual spraying of all structures as per standard current practice.

Comparison will be on the basis of non-inferiority by showing that malaria incidence in the targeted IRS arm is no higher than malaria incidence in the generalised IRS arm within a specified margin of difference, and on the basis of superiority showing that the proportion of houses sprayed, of those targeted for spraying, is higher in the intervention than the reference arm. Neighbourhood investigation in response to each locally acquired case in the intervention arm, and comparison neighbourhoods in the reference arm will include testing for antibody sero-conversion to malarial antigens to assess whether cases arise in communities with long term exposure to malarial parasites.

Conditions

Malaria

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: NONE

Study Groups

Targeted indoor residual spraying

The intervention arm of the trial will receive Indoor Residual Spraying delivery through targeted spraying in the neighbourhood of recent local cases only.

Group Type: EXPERIMENTAL

Targeted indoor residual spraying

Intervention Type: OTHER

IRS is carried out in neighbourhoods of cases

Generalised Indoor residual spraying

The reference (control) arm of the trial will receive Indoor Residual Spraying through generalised annual spraying of all structures, as is the current standard practice.

Group Type: ACTIVE_COMPARATOR

Generalised Indoor residual spraying

Intervention Type: OTHER

IRS is carried out as normally practiced

Interventions

Targeted indoor residual spraying

IRS is carried out in neighbourhoods of cases

Intervention Type: OTHER

Generalised Indoor residual spraying

IRS is carried out as normally practiced

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

1. Entire communities of approximately 8000 persons

2. Residents in malaria endemic districts of Limpopo and Mpumalanga Province

3. Areas with local malaria incidence <5 cases per 1000 per year on average over 5 years

• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Witwatersrand, South Africa

OTHER

Sponsor Role: collaborator

National Department of Health, South Africa

UNKNOWN

Sponsor Role: collaborator

Medical Research Council

OTHER_GOV

Sponsor Role: collaborator

National Institute for Communicable Diseases, South Africa

OTHER

Sponsor Role: collaborator

London School of Hygiene and Tropical Medicine

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Maureen Coetzee, Phd

Role: PRINCIPAL_INVESTIGATOR

University of Witwatersrand, South Africa

Immo Kleinschmidt, Phd

Role: PRINCIPAL_INVESTIGATOR

London School of Hygiene and Tropical Medicine

Locations

Provincial Malaria Control Programme

Tzaneen, Limpopo, South Africa

Provincial Malaria Control Programme

Mbombela, Mpumalnga, South Africa

Countries

South Africa

References

Bath D, Cook J, Govere J, Mathebula P, Morris N, Hlongwana K, Raman J, Seocharan I, Zitha A, Zitha M, Mabuza A, Mbokazi F, Machaba E, Mabunda E, Jamesboy E, Biggs J, Drakeley C, Moonasar D, Maharaj R, Coetzee M, Pitt C, Kleinschmidt I. Effectiveness and cost-effectiveness of reactive, targeted indoor residual spraying for malaria control in low-transmission settings: a cluster-randomised, non-inferiority trial in South Africa. Lancet. 2021 Feb 27;397(10276):816-827. doi: 10.1016/S0140-6736(21)00251-8.

Reference Type: DERIVED

PMID: 33640068 (View on PubMed)

Other Identifiers

EPIDZC8610

Identifier Type: -

Identifier Source: org_study_id