Plasmodium Falciparum MalariaCOMBATNCT04416945
Targeting High Risk Populations With Enhanced Reactive Case Detection in Southern Lao Peoples Democratic Republic
A study testing Household Reactive Case Detection, RACD of cases' co-workers/co-travelers and Case Management and Follow-up in people with Plasmodium Falciparum Malaria and Plasmodium Vivax Malaria, run by University of California, San Francisco at 1 site in Laos.
Trial summary
This study assesses the effectiveness and feasibility of enhanced reactive case detection (RACD) targeting high-risk villages and forest workers for reducing Plasmodium falciparum and Plasmodium vivax transmission in southern Lao Peoples Democratic Republic. Read more about this study
- Who is it for?
- Ages 18 months and olderHealthy volunteers can take part
- Conditions the study is for
- Plasmodium Falciparum Malaria, Plasmodium Vivax Malaria
- What is being tested?
- Household Reactive Case Detection, RACD of cases' co-workers/co-travelers and Case Management and Follow-up
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 0 participants
- Where
- 1 siteLaos
- Study dates
- 20 Sep 2020to 1 Nov 2021
- Phase
- Interventional
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 18 months and older
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
RACD:
- Inclusion Criteria
- Inclusion Criteria for index cases: Presented as a confirmed malaria case to an intervention health facility or village malaria worker, and lives in a village within a selected intervention health facility catchment area, or worked or spent at least one night at a forest or forest-fringe site in the past 30 days located within an intervention health facility catchment area
- Inclusion criteria for village residents: Lives in a village within a selected intervention health facility catchment area and in one of the five households closest to the residence of an index case of malaria
- Inclusion criteria for co-worker/traveler referral: Worked or traveled and spent at least one night in forest in past 30 days in same location within an intervention health facility catchment area as an index case of malaria
- Inclusion criteria for all participants: Willing and available to participate in the study
Informed consent for participant under the age of 18 will be provided by the parent or guardian.
- Exclusion Criteria:
- Previous participation in the study as a result of any RACD event in the past 30 days.
- Individuals with suspected severe malaria or other severe illness (including those with symptoms of severe anemia, prostration, impaired consciousness, respiratory distress, convulsions, circulatory collapse, abnormal bleeding, jaundice or passing dark urine) will be excluded from the treatment component and referred to the nearest health facility for clinical assessment and treatment
Trial locations and contacts
1 site in 1 country.
Laos1 site
Center for Malariology, Parasitology, Entomology, Laos Ministry of Health
Vientiane
About this study
Official title: Targeting High-risk Populations With Enhanced Reactive Case Detection: a Study to Assess the Effectiveness and Feasibility for Reducing Plasmodium Falciparum and P. Vivax Malaria in Southern Lao Peoples Democratic Republic
This study assesses the effectiveness and feasibility of enhanced reactive case detection (RACD) targeting high-risk villages and forest workers for reducing Plasmodium falciparum and Plasmodium vivax transmission in southern Lao Peoples Democratic Republic. The authors hypothesize that enhanced community-based RACD will be more effective than standard of care case management and RACD at reducing P. falciparum and P. vivax confirmed case incidence and parasite prevalence over an 18-month period in Lao Peoples Democratic Republic.
Read the detailed description
In the Greater Mekong Subregion (GMS), the risk of malaria infection is often due not to village-based transmission but rather to occupational and behavioral risk factors leading to exposure in forest settings. Additionally, a substantial portion of infections are asymptomatic and/or submicroscopic, limiting the scope of current diagnostics and surveillance approaches. The proposed research will evaluate the effectiveness of reactive case detection (RACD) using highly-sensitive rapid diagnostic tests (HS-RDTs), targeting both village and forest working populations, compared to control for reducing the health center catchment-level incidence and prevalence of P. falciparum and P. vivax within two provinces in Lao People's Democratic Republic.
To test this hypothesis, this study will employ a cluster randomized controlled trial design with two comparison arms: (1) Control: standard of care - passive case management provided through community-based Village Malaria Workers (VMWs) and existing health facilities; includes village-based RACD with conventional rapid diagnostic tests (RDTs) conducted by district surveillance teams and (2) enhanced community-based RACD: RACD conducted by community-based VMWs using both HS-RDTs and conventional RDTs within villages and among forest workers.
The primary outcome measures to assess effectiveness include P. falciparum and P. vivax confirmed case incidence over the study period; PCR-based P. falciparum and P. vivax prevalence at end line; and HS-RDT test positivity rate in village and forest worker RACD. Secondary outcomes measures will examine the operational feasibility, safety, and acceptability of VMW-led reactive approaches and glucose-6-phosphate dehydrogenase (G6PD) testing, referral to district or provincial-level facilities, safety and treatment adherence for P. vivax cases.
- Being tested
- Household Reactive Case Detection, RACD of cases' co-workers/co-travelers, Case Management and Follow-up
- Medical subject headings
- Malaria, Falciparum, Malaria, Vivax
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Household Reactive Case DetectionOther
Within 7 days of the index case notification, all members of the index case's household and everyone in the neighboring five households will then be invited to participate in the study. After consenting, a finger stick blood sample will be collected for each consenting individual for testing with the HS-RDT for P. falciparum, a standard combination RDT, and four blood spots on filter paper.
RACD of cases' co-workers/co-travelersOther
Index cases will be screened by the VMW at their households at the time of case investigation to determine if they have traveled or worked in a forest or forest-fringe area within the past 30 days. If eligible, the case will trigger two reactive recruitment strategies to screen and treat others who recently traveled or worked with the case in a forest or forest-fringe location:
- Peer-referral RACD (PR-RACD): In this strategy, the case will identify specific co-travelers or co-workers resident in their village who had spent the night with the case at a forest or forest-fringe area and spent the night there in the past 30 days.
- Venue-based RACD (VB-RACD): In this strategy, co-workers will be recruited directly from (accessible) forest or forest-fringe work sites where the index case worked and spent at least one night in the past 30 days.
Case Management and Follow-upOther
All individuals who test positive by either HS-RDT or Standard RDT will be told of their results and treated on site per national guidelines:
- Individuals with P. falciparum infection will be treated with an age-appropriate course of artemether-lumefantrine (AL) and a single low dose of primaquine (SLD-PQ). Weight-based dosing is described in Tables 2 and 3 below.
- At all study sites in Lao Peoples Democratic Republic, patients with a P. vivax infection identified by RDT (both febrile and asymptomatic) will be given a unique coded and signed informational letter directing them to the nearest district hospital (or other testing facility) for G6PD deficiency testing and possible radical cure administration depending on results. At the health facility, G6PD normal individuals will be treated with AL and a 14-day course of PQ, whereas G6PD deficient individuals will receive AL alone as per the national guidelines and referred to a hospital for further primaquine management decisions.
| Study group | Role | What they receive |
|---|---|---|
| RACD | Experimental | Reactive case detection led by VMWs in response to cases in study area HCCA, with follow up testing with HS-RDTs/RDTs in both villages and forest workers; referrals for qualitative G6PD testing for P. vivax cases and 14-day PQ for G6PD non-deficient Receives: Other: Household Reactive Case Detection; Other: RACD of cases' co-workers/co-travelers; Other: Case Management and Follow-up |
| Control | Active comparator | Standard of care including case management through health facilities and malaria posts/VMWs; village-based RACD conducted by district staff in some areas Receives: Other: Case Management and Follow-up |
What is being measured
The primary outcome is the main question the study is designed to answer.
Confirmed P. falciparum and P. vivax malaria parasite incidence
This is defined as the number of outpatient (OPD) malaria confirmed and suspected cases per person per year for each Health Center Catchment Area (HCCA), as ascertained from the health facility registers, utilizing administrative catchment population size estimates for the exposure denominator.
Measured: 4 months
PCR-based P. falciparum and P. vivax parasite prevalence in sampled HCCAs
This is defined as the proportion of individuals ≥18 months old with P. falciparum or P. vivax infection (detected by PCR) out of all individuals ≥18 months tested within the end line survey (2020).
Measured: 4 months
HS-RDT/RDT-based test positivity rate in village and forest-based reactive case detection
This is defined as the proportion of all individuals tested by HS-RDT/RDT in response to an index cases, with a positive HS-RDT/RDT, among the population older than 18 months.
Measured: 4 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jun 2020
- Study start20 Sep 2020 (estimated)
- Primary completion30 Sep 2021 (estimated)
- Study completion1 Nov 2021 (estimated)
Why it stopped: Did not reach enrollment requirements of clinical trial due to Covid-19 pandemic restrictions
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (18)Papers the sponsor has linked to this study.
- Other trials for Plasmodium Falciparum 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 N/A
- Primary purpose
- Screening
- Allocation
- Randomised
- Intervention model
- Factorial
- Masking
- None (open label)
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of California, San Francisco
- Sponsor type
- University, hospital or other
- Collaborators
- Center for Malariology, Parasitology, and Entomology, Tulane University School of Public Health and Tropical Medicine, Centers for Disease Control and Prevention, University of Massachusetts, Amherst
- Responsible party
- Sponsor
- Investigators
- Adam Bennett, MA, PhD, Principal investigator, University of California, San FranciscoViengxay Vanisaveth, MD, Principal investigator, Center of Malariology, Parasitology, Entomology in Laos
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04416945
- Sponsor's protocol ID
- 19-27966
- Acronym
- COMBAT
- Status last verified
- Apr 2026
- First submitted
- 1 Jun 2020
- Last updated
- 29 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- 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
Bousema T, Griffin JT, Sauerwein RW, Smith DL, Churcher TS, Takken W, Ghani A, Drakeley C, Gosling R. Hitting hotspots: spatial targeting of malaria for control and elimination. PLoS Med. 2012 Jan;9(1):e1001165. doi: 10.1371/journal.pmed.1001165. Epub 2012 Jan 31.
PubMed 22303287Cotter C, Sturrock HJ, Hsiang MS, Liu J, Phillips AA, Hwang J, Gueye CS, Fullman N, Gosling RD, Feachem RG. The changing epidemiology of malaria elimination: new strategies for new challenges. Lancet. 2013 Sep 7;382(9895):900-11. doi: 10.1016/S0140-6736(13)60310-4. Epub 2013 Apr 15.
PubMed 23594387Moonen B, Cohen JM, Snow RW, Slutsker L, Drakeley C, Smith DL, Abeyasinghe RR, Rodriguez MH, Maharaj R, Tanner M, Targett G. Operational strategies to achieve and maintain malaria elimination. Lancet. 2010 Nov 6;376(9752):1592-603. doi: 10.1016/S0140-6736(10)61269-X. Epub 2010 Oct 28.
PubMed 21035841Hustedt J, Canavati SE, Rang C, Ashton RA, Khim N, Berne L, Kim S, Sovannaroth S, Ly P, Menard D, Cox J, Meek S, Roca-Feltrer A. Reactive case-detection of malaria in Pailin Province, Western Cambodia: lessons from a year-long evaluation in a pre-elimination setting. Malar J. 2016 Mar 1;15:132. doi: 10.1186/s12936-016-1191-z.
PubMed 26931488Rossi G, Van den Bergh R, Nguon C, Debackere M, Vernaeve L, Khim N, Kim S, Menard D, De Smet M, Kindermans JM. Adapting Reactive Case Detection Strategies for falciparum Malaria in a Low-Transmission Area in Cambodia. Clin Infect Dis. 2018 Jan 6;66(2):296-298. doi: 10.1093/cid/cix781.
PubMed 29020325Das S, Peck RB, Barney R, Jang IK, Kahn M, Zhu M, Domingo GJ. Correction to: Performance of an ultra-sensitive Plasmodium falciparum HRP2-based rapid diagnostic test with recombinant HRP2, culture parasites, and archived whole blood samples. Malar J. 2019 Feb 4;18(1):33. doi: 10.1186/s12936-019-2669-2.
PubMed 30717748Landier J, Parker DM, Thu AM, Lwin KM, Delmas G, Nosten FH; Malaria Elimination Task Force Group. Effect of generalised access to early diagnosis and treatment and targeted mass drug administration on Plasmodium falciparum malaria in Eastern Myanmar: an observational study of a regional elimination programme. Lancet. 2018 May 12;391(10133):1916-1926. doi: 10.1016/S0140-6736(18)30792-X. Epub 2018 Apr 24.
PubMed 29703425Howes RE, Dewi M, Piel FB, Monteiro WM, Battle KE, Messina JP, Sakuntabhai A, Satyagraha AW, Williams TN, Baird JK, Hay SI. Spatial distribution of G6PD deficiency variants across malaria-endemic regions. Malar J. 2013 Nov 15;12:418. doi: 10.1186/1475-2875-12-418.
PubMed 24228846White MT, Karl S, Battle KE, Hay SI, Mueller I, Ghani AC. Modelling the contribution of the hypnozoite reservoir to Plasmodium vivax transmission. Elife. 2014 Nov 18;3:e04692. doi: 10.7554/eLife.04692.
PubMed 25406065Douglas NM, Poespoprodjo JR, Patriani D, Malloy MJ, Kenangalem E, Sugiarto P, Simpson JA, Soenarto Y, Anstey NM, Price RN. Unsupervised primaquine for the treatment of Plasmodium vivax malaria relapses in southern Papua: A hospital-based cohort study. PLoS Med. 2017 Aug 29;14(8):e1002379. doi: 10.1371/journal.pmed.1002379. eCollection 2017 Aug.
PubMed 28850568Ministry of Health Lao PDR. The Evaluation of G6PD Rapid Tests and the Use of Primaquine for the Treatment of Plasmodium Vivax Infections in Luangprabang, Savannakhet and Champasak Provinces (Apr-Nov 2015). (2015).
Center for Malariology Parasitology and Entomology Lao PDR. Lao PDR Malaria National Strategic Plan 2016-2020. (2015).
WHO. Updated WHO policy recommendation: Single dose primaquine as a gametocytocide in Plasmodium falciparum malaria. World Health Organisation (2012).
Baum E, Sattabongkot J, Sirichaisinthop J, Kiattibutr K, Davies DH, Jain A, Lo E, Lee MC, Randall AZ, Molina DM, Liang X, Cui L, Felgner PL, Yan G. Submicroscopic and asymptomatic Plasmodium falciparum and Plasmodium vivax infections are common in western Thailand - molecular and serological evidence. Malar J. 2015 Feb 25;14:95. doi: 10.1186/s12936-015-0611-9.
PubMed 25849211Corran P, Coleman P, Riley E, Drakeley C. Serology: a robust indicator of malaria transmission intensity? Trends Parasitol. 2007 Dec;23(12):575-82. doi: 10.1016/j.pt.2007.08.023. Epub 2007 Nov 7.
PubMed 17988945