MalariaPhase 4NCT04094727

Malaria High-Risk Populations in Namibia

A Phase 4 study testing Presumptive treatment with Artemether-lumefantrine (AL) in people with Malaria, run by University of California, San Francisco at 1 site in Namibia.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

Who is it for?: Ages 6 months and olderHealthy volunteers can take part
Conditions the study is for: Malaria
What is being tested?: Presumptive treatment with Artemether-lumefantrine (AL)
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 3,302 participants
Where: 1 siteNamibia
Study dates: 31 Oct 2019to 30 Jun 2020
Phase: Phase 4
Are there results?: None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 6 months and older
All sexes
Healthy volunteers accepted
Child, Adult, Older adult

Who may be able to join

Study participants include those in the 8 selected health facility catchment areas within Zambezi and Ohangwena Regions.
Identify primary occupation as a agricultural worker or cattle herder
Zambezi Region: Have slept or worked outside at a farm or cattle post in the past 7 days or will do over the next 3 weeks (sleeping outside, working outside ploughing or guarding crops/cattle, or sleeping in any type of structure located at a farm or cattle post site)
Ohangwena Region: Report overnight travel to Angola for grazing cattle during the malaria transmission season (November to May) Be willing and able to provide consent (ie mentally fit)
In addition to the above, subjects must report travel outside of Namibia within the past 60 days to be eligible to receive AL.
In addition to the above, participants must not sleep in a structure sprayed with insecticide to be eligible to receive an LLIN or sprayed tent/tarp.

Show all 9Show fewer

Inclusion Criteria: Focus group discussions and key informant interviews
Meet eligibility criteria as a member of an HRP, health facility staff or health extension worker involved in the diagnosis and treatment of HRP populations.
Individuals must be 18 years and older and willing and able to provide consent to be included in the GPS logger, focus group discussions or key informant interviews

Who cannot join

Per national guidelines in Namibia, presumptive treatment with AL will not be given to women who are pregnant in the first trimester, individuals weighing less than 5kg, those with a known AL allergy or suspected severe malaria.
Individuals under the age of 18 will be excluded from the GPS logger study, focus group discussions and key informant interviews.

Trial locations and contacts

1 site in 1 country.

Namibia1 site

University of Namibia, Multidisciplinary Research Centre
Windhoek

About this study

Official title: Targeting Malaria High-risk Populations With Tailored Intervention Packages: A Study to Assess Feasibility and Effectiveness in Northern Namibia

This study aims to determine the effectiveness, cost-effectiveness, acceptability, and feasibility of targeted delivery of a package of malaria interventions for improving effective coverage and reducing Plasmodium falciparum malaria transmission among malaria high-risk populations in Northern Namibia. Previous research identified cattle herders and agricultural workers as populations at higher risk of infection. The investigators hypothesize that targeted delivery of interventions will lead improve coverage in these groups and lead to a reduction in P. falciparum transmission.

Read the detailed description

This study is the second phase of work in Zambezi and Ohangwena Regions, Namibia, building off a formative phase of work that characterized the risk behaviors migratory patterns, health-seeking behaviors, intervention strategies and social networks of agricultural workers and cattle herders, who are previously identified malaria high-risk populations (HRPs). This phase of the study now aims to determine the effectiveness, cost-effectiveness, acceptability, and feasibility of targeted delivery of a package of malaria interventions for improving effective coverage and reducing Plasmodium falciparum malaria transmission in these regions among these populations.

The study will specifically assess the coverage and impact of interventions delivered at worksites to HRPs, including presumptive treatment administered alongside vector control interventions (indoor residual spraying [IRS], long-lasting insecticidal nets [LLINs], and topical repellents). The effectiveness of these interventions will be compared against areas with no study interventions (standard of care) over the course of implementation (November 2019 - May 2020). Primary outcomes will include the coverage of each intervention at worksites over the study period and PCR-based P. falciparum prevalence measured at endline. Following a baseline cross-sectional survey in November/December 2019, the interventions will consist of 2 rounds of presumptive treatment spaced at least one month apart between January and March, and delivery of vector control interventions at worksites and key access points with support from employers, with the primary evaluation to be conducted through an endline cross-sectional survey in April/May 2020. Secondary outcomes around effectiveness will be assessed through incident case data providing measures of incidence in HRP and non-HRP populations, odds of infection associated with each intervention in cases compared to controls and entomological data collection. In addition, operational and feasibility outcomes will be assessed through qualitative data collection, population size estimation of HRP groups and a global positioning system (GPS) logger study.

Conditions: Malaria
Being tested: Presumptive treatment with Artemether-lumefantrine (AL), Enhanced vector control
Keywords: malaria, Namibia
Medical subject headings: Malaria

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Presumptive treatment with Artemether-lumefantrine (AL)Drug
Also called Coartem
All eligible HRPs will be presumptively treated with artemether-lumefantrine (AL) at two timepoints, separated by at least one month. All individuals who have provided informed consent, meet eligibility criteria, are not pregnant or breastfeeding, and who do not have symptoms associated with severe malaria or another severe illness, will be offered an age-appropriate course of AL (age-specific blister packages). AL is currently the first line drug used for uncomplicated malaria in Namibia, and has been used previously in northern Namibia for focal mass drug administration and has no severe adverse effects and is well-tolerated, with high adherence and acceptability in this context. AL requires two daily doses for three consecutive days, for a total of six doses. The first antimalarial dose will be delivered by directly observed therapy (DOT) and subsequent doses will be left with the subject, with instructions to self-administer them.
Enhanced vector controlOther
Also called Indoor residual spraying (IRS), Long-lasting insecticide treated bed nets, Topical repellents
The mop up indoor residual spraying (IRS) campaign will be targeted to farms and cattle posts/kraals in intervention areas in December 2019 to fill gaps from the routine spray campaign (September to November 2019) and utilize the same insecticides and protocols as the national campaign. The team will spray each unsprayed structure with the recommended solution of dichloro-diphenyl-trichloroethane (DDT) for traditional structures and/or Actellic for modern structures, tarps and tents.
Alternative vector control interventions, including LLINs (long-lasting insecticide treated bed nets), sprayed tents/tarps and topical repellents will be distributed to eligible HRPs between November and January 2020 during one round.

Study groups in NCT04094727
Study group	Role	What they receive
Presumptive treatment and enhanced vector control	Experimental	For all eligible HRPs in intervention areas, after obtaining informed consent, presumptive treatment for malaria will be carried out using artemether-lumefantrine (AL) at two time points. Enhanced vector control activities will include: (1) a mop up indoor residual spraying (IRS) campaign and (2) distribution of long-lasting insecticide-treated nets (LLINs) and/or vector control packs with topical repellent. The intervention arm will also receive the standard of care in Namibia. Receives: Drug: Presumptive treatment with Artemether-lumefantrine (AL); Other: Enhanced vector control
Standard of care	No intervention	The control arm will receive the standard of care in Namibia: passive case detection through health facilities and health extension workers, routine indoor residual spraying (IRS), and reactive case detection (RACD) accompanied by reactive IRS.

What is being measured

The primary outcome is the main question the study is designed to answer.

Effective coverage of AL (presumptive treatment)
This is defined as the proportion of eligible HRPs who report receiving a full course of AL (presumptive treatment) at any time over the study period. The difference in intervention coverage between arms at end-line will be assessed using generalized linear models adjusted for potential confounders and a fixed effect to capture clustering at the health facility level.
Measured: 6 months, measured post-intervention only
Effective coverage of IRS
This is defined as the proportion of eligible HRPs who report sleeping at a worksite in a structure sprayed with insecticide during the past 6 months (IRS), at any time over the study period. The difference in intervention coverage between arms will be assessed using a difference-in-difference approach using generalized linear models adjusted for potential confounders and a fixed effect to capture clustering at the health facility level.
Measured: 6 months, measured pre-and post-intervention
Effective coverage of LLIN
This is defined as the proportion of eligible HRPs who report sleeping under a bednet (LLIN) the last night staying at a worksite, at any time over the study period. The difference in intervention coverage between arms will be assessed using a difference-in-difference approach using generalized linear models adjusted for potential confounders and a fixed effect to capture clustering at the health facility level.
Measured: 6 months, measured pre-and post-intervention
Prevalence of infection measured by polymerase chain reaction (PCR)
Species-specific prevalence of malaria infection will be calculated as the proportion of people testing positive for each species malaria by PCR out of all tested HRPs. The reduction in malaria prevalence will be assessed using a difference-in-difference approach, comparing change (pre- versus post-intervention) in all-species infection between intervention and control groups.
Measured: 6 months

Secondary outcomes (12)

Odds of symptomatic malaria associated with receiving each intervention
The odds of clinical malaria associated with receiving each intervention will be measured by comparing the risk of exposure in cases (RDT-positive) to the risk in controls (RDT-negative) in HRPs within study areas.
Measured: 6 months
Total confirmed outpatient (OPD) malaria case incidence by health facility, stratified by HRP status
The total confirmed outpatient malaria case incidence will be estimated for each of the study health catchment areas and stratified by HRP status. RDTs used for routine malaria diagnosis will be collected and a short questionnaire affixed to the back to allow collection of key indicators to stratify incidence estimates. Denominators will be based on health catchment populations and population size estimates obtained through this study. A reduction in malaria incidence in HRPs and the overall catchment population will be evaluated using a difference-in-difference approach, comparing change (pre- versus post-intervention) between intervention and control groups.
Measured: 6 months
Malaria seroprevalence in HRPs
Malaria exposure in HRPs will be measured as the proportion of people with antimalarial antibodies present in their blood serum. ELISA assays will be used to detect biomarkers of Pf exposure, using collected dried blood spots during baseline and endline cross-sectional surveys. The reduction in malaria exposure will be assessed using a difference-in-difference approach, comparing change (pre- versus post-intervention) between intervention and control groups.
Measured: 6 months
Test positivity rates from RACD
Test positivity rates will be calculated as the proportion of individuals screened during routine RACD who test positive for malaria by RDT and PCR. Rates will be stratified by HRP status and location of event (either within villages or at an HRP worksite).Differences in prevalence measures between HRP and non-HRP populations will be assessed using a χ2 test, as well as logistic regression models to account for potential confounding factors.
Measured: 6 months
Entomological Indicators
Entomological measurements including descriptions of vector occurrence, estimates of human biting rates, measures of indoor and outdoor densities, and insecticide susceptibility status and frequency. Measures will be compared between intervention and control study areas, for each type of intervention.
Measured: 6 months
Intervention acceptability as evaluated by participation rate
The acceptability of a targeted delivery of presumptive treatment and vector control interventions to HRPs will be assessed as the proportion of targeted individuals refusing each intervention, among those eligible for inclusion. Acceptability of IRS will be assessed as the proportion of targeted farms refusing LLIN, among those with at least one sprayable structure missed during the spray campaign.
Measured: 6 months
Intervention acceptability as evaluated by qualitative assessment
Qualitative data collection methods such as focus groups and key informant interviews with HRPs, health extension workers, employers and other health sector staff will be implemented to assess intervention acceptability.
Measured: 6 months
Cost effectiveness
The costs and cost-effectiveness of the intervention package will be assessed as an incremental cost effectiveness ratio (ICER), as well as cost per population and case averted as measured through the difference in infections identified subsequent to the intervention. Program data on costs/expenditure for each intervention will be collected and combined with estimates of program effectiveness to estimate these measures.
Measured: 6 months
Adherence to presumptive treatment intervention as evaluated by pill count
Participant adherence to presumptive treatment will be assessed within a sub-sample of people distributed the drug and measured as the proportion of people who complete all pills in the pill pack after receiving the first dose of AL by DOT. Changes in proportions over time will be quantified between the two distribution rounds.
Measured: 6 months
Self-reported compliance to LLIN and topical repellents.
Self-reported user compliance to LLINs and topical repellents will be assessed through the quantitative baseline and endline cross-sectional surveys, as well as through a use tracking log tracking compliance over a 30-day period (Appendix 16 and 17) in the cohort included in the pill count. LLIN use and condition will be empirically assessed during the endline cross-sectional survey and at 30 days, as well as repellent containers weighed after 30 in the cohort. Qualitative information on use of these interventions will be collected during key informant interviews and focus group discussions.
Measured: 6 months
HRP population size
The population size of target HRPs will be estimated in intervention areas using a combination of multiplier and multiple capture-recapture (CR) methods. In Ohangwena Region, the population is assumed fixed, although accessibility of cattle herders in Namibia may vary throughout the year. In Zambezi Region, the population is estimated at two distinct time periods in order to capture turnover between agricultural seasons.
Measured: 6 months
HRP movement patterns
The proportion of individual's time spent in different locations will be measured from aggregating GPS readings (located within pre-defined space-time windows) which are spatially located within a given type of area (farm, cattle post, grazing location, village etc). Where possible, common locations will be tagged and classified by field workers to distinguish individual farms, fields and other points of interests (such as bars, homes, etc). Aggregated GPS readings (located within pre-defined space-time windows) will be plotted to distinguish individual trips and measure specific characteristics of each trip, including distance of travel and frequency of trips.
Measured: 6 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

31 Oct 201930 Jun 2020

First posted19 Sep 2019
Study start31 Oct 2019
Primary completion30 Jun 2020
Study completion30 Jun 2020

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Publications (12)Papers the sponsor has linked to this study.
Other trials for MalariaStudies of the same condition, open and under way.
More trials run by University of California, San FranciscoThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 4
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: None (open label)
Enrolment: 3,302 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT04094727
Sponsor's protocol ID: Malaria HRP in Namibia
Status last verified: Nov 2020
First submitted: 16 Sep 2019
Last updated: 3 Nov 2020
Results posted: No
Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No
Individual data sharing: No: Individual participant data will not be shared with any parties outside of the study team.

Publications

Jacobson JO, Cueto C, Smith JL, Hwang J, Gosling R, Bennett A. Surveillance and response for high-risk populations: what can malaria elimination programmes learn from the experience of HIV? Malar J. 2017 Jan 18;16(1):33. doi: 10.1186/s12936-017-1679-1.
PubMed 28100237
Smith JL, Ghimire P, Rijal KR, Maglior A, Hollis S, Andrade-Pacheco R, Das Thakur G, Adhikari N, Thapa Shrestha U, Banjara MR, Lal BK, Jacobson JO, Bennett A. Designing malaria surveillance strategies for mobile and migrant populations in Nepal: a mixed-methods study. Malar J. 2019 May 3;18(1):158. doi: 10.1186/s12936-019-2791-1.
PubMed 31053075
Smith JL, Auala J, Haindongo E, Uusiku P, Gosling R, Kleinschmidt I, Mumbengegwi D, Sturrock HJ. Malaria risk in young male travellers but local transmission persists: a case-control study in low transmission Namibia. Malar J. 2017 Feb 10;16(1):70. doi: 10.1186/s12936-017-1719-x.
PubMed 28187770
Wu L, van den Hoogen LL, Slater H, Walker PG, Ghani AC, Drakeley CJ, Okell LC. Comparison of diagnostics for the detection of asymptomatic Plasmodium falciparum infections to inform control and elimination strategies. Nature. 2015 Dec 3;528(7580):S86-93. doi: 10.1038/nature16039.
PubMed 26633770
Kern SE, Tiono AB, Makanga M, Gbadoe AD, Premji Z, Gaye O, Sagara I, Ubben D, Cousin M, Oladiran F, Sander O, Ogutu B. Community screening and treatment of asymptomatic carriers of Plasmodium falciparum with artemether-lumefantrine to reduce malaria disease burden: a modelling and simulation analysis. Malar J. 2011 Jul 29;10:210. doi: 10.1186/1475-2875-10-210.
PubMed 21801345
Hsiang M, Ntuku H, Roberts K, Dufour M-s, Whittemore B, Tambo M, et al. The effectiveness of malaria reactive focal mass drug administration (rfMDA) and reactive vector control (RAVC), a cluster-randomised controlled two-by-two factorial design trial from the low-endemic setting of Namibi. 2019. Unpublished.
Initiative ME. Planning for targeted malaria interventions in high-risk populations (HRPs) in Northern Namibia: Findings from a rapid formative assessment in Zambezi Region. University of California, San Francisco, 2019.
The Global Health Group. Screen and treat strategies for malaria elimination: a review of evidence. 2018.
Malaria Elimination Initiative. Planning for targeted malaria interventions in high-risk populations (HRPs) in Northern Namibia: Findings from a rapid formative assessment in Ohangwena Region. University of California, San Francisco, 2019.
Naing C, Whittaker MA, Tanner M. Inter-sectoral approaches for the prevention and control of malaria among the mobile and migrant populations: a scoping review. Malar J. 2018 Nov 16;17(1):430. doi: 10.1186/s12936-018-2562-4.
PubMed 30445959
IOM (International Organization for Migration). A global report on population mobility and malaria: moving towards elimination with migration in mind. 2013.
Smith JL, Ntuku H, Rerolle F, Burke AM, Mwema T, Turcios K, Uusiku P, Haikali JK, Lifasi M, Smith-Gueye C, Vajda E, Jacobson JO, Greenhouse B, Gosling R, Bennett A, Mumbengegwi DR. Targeting malaria in high-risk populations in low endemic regions in northern Namibia: a quasi-experimental controlled trial to reduce malaria in seasonal agricultural workers and cattle herders. BMJ Glob Health. 2025 Feb 17;10(2):e015565. doi: 10.1136/bmjgh-2024-015565.
PubMed 39961693

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

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Study at a glance

From the registry record, last updated by the sponsor on 3 Nov 2020. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Targeting Malaria High-risk Populations With Tailored Intervention Packages: A Study to Assess Feasibility and Effectiveness in Northern Namibia
ClinicalTrials.gov ID: NCT04094727
Acronym / sponsor ID: Malaria HRP in Namibia
Conditions: Malaria
Keywords: malaria, Namibia
Phase: Phase 4
Study type: Interventional
Recruitment status: Completed
Enrolment: 3,302 participants (actual)
Lead sponsor: University of California, San FranciscoUniversity, hospital or other
Collaborators: University of Namibia, Ministry of Health and Social Services, Namibia, University of Texas Southwestern Medical Center, University of Notre Dame, London School of Hygiene and Tropical Medicine
Study start: 31 Oct 2019 (actual)
Primary completion: 30 Jun 2020 (actual)
Study completion: 30 Jun 2020 (actual)
First posted: 19 Sep 2019 (actual)
Results: Not posted in the source record

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: None (open label)
Number of arms: 2

Arm	Type	Receives
Presumptive treatment and enhanced vector control	Experimental	Drug: Presumptive treatment with Artemether-lumefantrine (AL), Other: Enhanced vector controlFor all eligible HRPs in intervention areas, after obtaining informed consent, presumptive treatment for malaria will be carried out using artemether-lumefantrine (AL) at two time points. Enhanced vector control activities will include: (1) a mop up indoor residual spraying (IRS) campaign and (2) distribution of long-lasting insecticide-treated nets (LLINs) and/or vector control packs with topical repellent. The intervention arm will also receive the standard of care in Namibia.
Standard of care	No intervention	–The control arm will receive the standard of care in Namibia: passive case detection through health facilities and health extension workers, routine indoor residual spraying (IRS), and reactive case detection (RACD) accompanied by reactive IRS.

Who may qualify

Ages: 6 months and older
Sex: All
Healthy volunteers: Accepted
Age groups: Child, Adult, Older adult

Key inclusion criteria (9 listed)

Study participants include those in the 8 selected health facility catchment areas within Zambezi and Ohangwena Regions.
Identify primary occupation as a agricultural worker or cattle herder
Zambezi Region: Have slept or worked outside at a farm or cattle post in the past 7 days or will do over the next 3 weeks (sleeping outside, working outside ploughing or guarding crops/cattle, or sleeping in any type of structure located at a farm or cattle post site)
Ohangwena Region: Report overnight travel to Angola for grazing cattle during the malaria transmission season (November to May) Be willing and able to provide consent (ie mentally fit)
In addition to the above, subjects must report travel outside of Namibia within the past 60 days to be eligible to receive AL.

Key exclusion criteria (2 listed)

Per national guidelines in Namibia, presumptive treatment with AL will not be given to women who are pregnant in the first trimester, individuals weighing less than 5kg, those with a known AL allergy or suspected severe malaria.
Individuals under the age of 18 will be excluded from the GPS logger study, focus group discussions and key informant interviews.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
Presumptive treatment with Artemether-lumefantrine (AL)Also: CoartemAll eligible HRPs will be presumptively treated with artemether-lumefantrine (AL) at two timepoints, separated by at least one month. All individuals who have provided informed consent, meet eligibility criteria, are not pregnant or breastfeeding, and who do not have symptoms associated with severe malaria or another severe illness, will be offered an age-appropriate course of AL (age-specific blister packages). AL is currently the first line drug used for uncomplicated malaria in Namibia, and has been used previously in northern Namibia for focal mass drug administration and has no severe adverse effects and is well-tolerated, with high adherence and acceptability in this context. AL requires two daily doses for three consecutive days, for a total of six doses. The first antimalarial dose will be delivered by directly observed therapy (DOT) and subsequent doses will be left with the subject, with instructions to self-administer them.	Drug	Presumptive treatment and enhanced vector control
Enhanced vector controlAlso: Indoor residual spraying (IRS), Long-lasting insecticide treated bed nets, Topical repellentsThe mop up indoor residual spraying (IRS) campaign will be targeted to farms and cattle posts/kraals in intervention areas in December 2019 to fill gaps from the routine spray campaign (September to November 2019) and utilize the same insecticides and protocols as the national campaign. The team will spray each unsprayed structure with the recommended solution of dichloro-diphenyl-trichloroethane (DDT) for traditional structures and/or Actellic for modern structures, tarps and tents. Alternative vector control interventions, including LLINs (long-lasting insecticide treated bed nets), sprayed tents/tarps and topical repellents will be distributed to eligible HRPs between November and January 2020 during one round.	Other	Presumptive treatment and enhanced vector control

Primary outcome

Effective coverage of AL (presumptive treatment)
Time frame: 6 months, measured post-intervention only
This is defined as the proportion of eligible HRPs who report receiving a full course of AL (presumptive treatment) at any time over the study period. The difference in intervention coverage between arms at end-line will be assessed using generalized linear models adjusted for potential confounders and a fixed effect to capture clustering at the health facility level.
Effective coverage of IRS
Time frame: 6 months, measured pre-and post-intervention
This is defined as the proportion of eligible HRPs who report sleeping at a worksite in a structure sprayed with insecticide during the past 6 months (IRS), at any time over the study period. The difference in intervention coverage between arms will be assessed using a difference-in-difference approach using generalized linear models adjusted for potential confounders and a fixed effect to capture clustering at the health facility level.
Effective coverage of LLIN
Time frame: 6 months, measured pre-and post-intervention
This is defined as the proportion of eligible HRPs who report sleeping under a bednet (LLIN) the last night staying at a worksite, at any time over the study period. The difference in intervention coverage between arms will be assessed using a difference-in-difference approach using generalized linear models adjusted for potential confounders and a fixed effect to capture clustering at the health facility level.
Prevalence of infection measured by polymerase chain reaction (PCR)
Time frame: 6 months
Species-specific prevalence of malaria infection will be calculated as the proportion of people testing positive for each species malaria by PCR out of all tested HRPs. The reduction in malaria prevalence will be assessed using a difference-in-difference approach, comparing change (pre- versus post-intervention) in all-species infection between intervention and control groups.

12 secondary outcomes

Odds of symptomatic malaria associated with receiving each intervention
Time frame: 6 months
Total confirmed outpatient (OPD) malaria case incidence by health facility, stratified by HRP status
Time frame: 6 months
Malaria seroprevalence in HRPs
Time frame: 6 months
Test positivity rates from RACD
Time frame: 6 months
Entomological Indicators
Time frame: 6 months
Intervention acceptability as evaluated by participation rate
Time frame: 6 months
Intervention acceptability as evaluated by qualitative assessment
Time frame: 6 months
Cost effectiveness
Time frame: 6 months
Adherence to presumptive treatment intervention as evaluated by pill count
Time frame: 6 months
Self-reported compliance to LLIN and topical repellents.
Time frame: 6 months
HRP population size
Time frame: 6 months
HRP movement patterns
Time frame: 6 months

Results and safety

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 3 Nov 2020.
Background: PubMed 28100237Jacobson JO, Cueto C, Smith JL, Hwang J, Gosling R, Bennett A. Surveillance and response for high-risk populations: what can malaria elimination programmes learn from the experience of HIV? Malar J. 2017 Jan 18;16(1):33. doi: 10.1186/s12936-017-1679-1.
Background: PubMed 31053075Smith JL, Ghimire P, Rijal KR, Maglior A, Hollis S, Andrade-Pacheco R, Das Thakur G, Adhikari N, Thapa Shrestha U, Banjara MR, Lal BK, Jacobson JO, Bennett A. Designing malaria surveillance strategies for mobile and migrant populations in Nepal: a mixed-methods study. Malar J. 2019 May 3;18(1):158. doi: 10.1186/s12936-019-2791-1.
Background: PubMed 28187770Smith JL, Auala J, Haindongo E, Uusiku P, Gosling R, Kleinschmidt I, Mumbengegwi D, Sturrock HJ. Malaria risk in young male travellers but local transmission persists: a case-control study in low transmission Namibia. Malar J. 2017 Feb 10;16(1):70. doi: 10.1186/s12936-017-1719-x.
Background: PubMed 26633770Wu L, van den Hoogen LL, Slater H, Walker PG, Ghani AC, Drakeley CJ, Okell LC. Comparison of diagnostics for the detection of asymptomatic Plasmodium falciparum infections to inform control and elimination strategies. Nature. 2015 Dec 3;528(7580):S86-93. doi: 10.1038/nature16039.
Background: PubMed 21801345Kern SE, Tiono AB, Makanga M, Gbadoe AD, Premji Z, Gaye O, Sagara I, Ubben D, Cousin M, Oladiran F, Sander O, Ogutu B. Community screening and treatment of asymptomatic carriers of Plasmodium falciparum with artemether-lumefantrine to reduce malaria disease burden: a modelling and simulation analysis. Malar J. 2011 Jul 29;10:210. doi: 10.1186/1475-2875-10-210.
BackgroundHsiang M, Ntuku H, Roberts K, Dufour M-s, Whittemore B, Tambo M, et al. The effectiveness of malaria reactive focal mass drug administration (rfMDA) and reactive vector control (RAVC), a cluster-randomised controlled two-by-two factorial design trial from the low-endemic setting of Namibi. 2019. Unpublished.
BackgroundInitiative ME. Planning for targeted malaria interventions in high-risk populations (HRPs) in Northern Namibia: Findings from a rapid formative assessment in Zambezi Region. University of California, San Francisco, 2019.
BackgroundThe Global Health Group. Screen and treat strategies for malaria elimination: a review of evidence. 2018.
BackgroundMalaria Elimination Initiative. Planning for targeted malaria interventions in high-risk populations (HRPs) in Northern Namibia: Findings from a rapid formative assessment in Ohangwena Region. University of California, San Francisco, 2019.
Background: PubMed 30445959Naing C, Whittaker MA, Tanner M. Inter-sectoral approaches for the prevention and control of malaria among the mobile and migrant populations: a scoping review. Malar J. 2018 Nov 16;17(1):430. doi: 10.1186/s12936-018-2562-4.
BackgroundIOM (International Organization for Migration). A global report on population mobility and malaria: moving towards elimination with migration in mind. 2013.
Derived from this study: PubMed 39961693Smith JL, Ntuku H, Rerolle F, Burke AM, Mwema T, Turcios K, Uusiku P, Haikali JK, Lifasi M, Smith-Gueye C, Vajda E, Jacobson JO, Greenhouse B, Gosling R, Bennett A, Mumbengegwi DR. Targeting malaria in high-risk populations in low endemic regions in northern Namibia: a quasi-experimental controlled trial to reduce malaria in seasonal agricultural workers and cattle herders. BMJ Glob Health. 2025 Feb 17;10(2):e015565. doi: 10.1136/bmjgh-2024-015565.
Individual participant dataSharing planned: No. Individual participant data will not be shared with any parties outside of the study team.

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Jennifer Smith, PhD principal investigator

University of California, San Francisco

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Presumptive treatment with Artemether-lumefantrine (AL) in people with Malaria, run by University of California, San Francisco at 1 site in Namibia.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 9 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 3 Nov 2020. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Namibia. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Effective coverage of AL (presumptive treatment) (time frame: 6 months, measured post-intervention only). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04094727, which also lists 12 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Nov 2020; AzTrials last refreshed its copy on 2 Nov 2026.