Active case finding for malaria: A 3-year national evaluation of optimal approaches to detect infections and hotspots through reactive case detection in the low-transmission setting of eswatini

Michelle S. Hsiang, Nyasatu Ntshalintshali, Mi Suk Kang Dufour, Nomcebo Dlamini, Nomcebo Nhlabathi, Sibonakaliso Vilakati, Calsile Malambe, Zulisile Zulu, Gugu Maphalala, Joseph Novotny, Maxwell Murphy, Alanna Schwartz, Hugh Sturrock, Roly Gosling, Grant Dorsey, Simon Kunene, Bryan Greenhouse

Research output: Contribution to journalArticle

2 Scopus citations

Abstract

Background: Reactive case detection (RACD) is a widely practiced malaria elimination intervention whereby close contacts of index cases receive malaria testing to inform treatment and other interventions. However, the optimal diagnostic and operational approaches for this resource-intensive strategy are not clear. Methods: We conducted a 3-year prospective national evaluation of RACD in Eswatini, a malaria elimination setting. Loop-mediated isothermal amplification (LAMP) was compared to traditional rapid diagnostic testing (RDT) for the improved detection of infections and for hotspots (RACD events yielding ≥1 additional infection). The potential for index case-, RACD-, and individual-level factors to improve efficiencies was also evaluated. Results: Among 377 RACD events, 10 890 participants residing within 500 m of index cases were tested. Compared to RDT, LAMP provided a 3-fold and 2.3-fold higher yield to detect infections (1.7% vs 0.6%) and hotspots (29.7% vs 12.7%), respectively. Hotspot detection improved with ≥80% target population coverage and response times within 7 days. Proximity to the index case was associated with a dose-dependent increased infection risk (up to 4-fold). Individual-, index case-, and other RACD-level factors were considered but the simple approach of restricting RACD to a 200-m radius maximized yield and efficiency. Conclusions: We present the first large-scale national evaluation of optimal RACD approaches from a malaria elimination setting. To inform delivery of antimalarial drugs or other interventions, RACD, when conducted, should utilize more sensitive diagnostics and clear context-specific operational parameters. Future studies of RACD's impact on transmission may still be needed.

Original languageEnglish (US)
Pages (from-to)1316-1325
Number of pages10
JournalClinical Infectious Diseases
Volume70
Issue number7
DOIs
StatePublished - Mar 17 2020

Keywords

  • Eswatini
  • efficiency
  • loop-mediated isothermal amplification
  • malaria elimination
  • reactive case detection

ASJC Scopus subject areas

  • Microbiology (medical)
  • Infectious Diseases

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    Hsiang, M. S., Ntshalintshali, N., Kang Dufour, M. S., Dlamini, N., Nhlabathi, N., Vilakati, S., Malambe, C., Zulu, Z., Maphalala, G., Novotny, J., Murphy, M., Schwartz, A., Sturrock, H., Gosling, R., Dorsey, G., Kunene, S., & Greenhouse, B. (2020). Active case finding for malaria: A 3-year national evaluation of optimal approaches to detect infections and hotspots through reactive case detection in the low-transmission setting of eswatini. Clinical Infectious Diseases, 70(7), 1316-1325. https://doi.org/10.1093/cid/ciz403