Effectiveness of reactive case detection for malaria elimination in three archetypical transmission settings: a modelling study

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.

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Improving the efficiency of reactive case detection for malaria elimination in southern Zambia: a cross-sectional study

Malaria Journal ◽

10.1186/s12936-020-03245-1 ◽

2020 ◽

Vol 19 (1) ◽

Author(s):

Fiona R. P. Bhondoekhan ◽

◽

Kelly M. Searle ◽

Harry Hamapumbu ◽

Mukuma Lubinda ◽

...

Keyword(s):

Malaria Elimination ◽

Cross Sectional Study ◽

Case Detection ◽

Sectional Study ◽

Reactive Case Detection ◽

Cross Sectional

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Reactive Case Detection for Malaria Elimination: Real-Life Experience from an Ongoing Program in Swaziland

PLoS ONE ◽

10.1371/journal.pone.0063830 ◽

2013 ◽

Vol 8 (5) ◽

pp. e63830 ◽

Cited By ~ 76

Author(s):

Hugh J. W. Sturrock ◽

Joe M. Novotny ◽

Simon Kunene ◽

Sabelo Dlamini ◽

Zulisile Zulu ◽

...

Keyword(s):

Malaria Elimination ◽

Life Experience ◽

Real Life ◽

Case Detection ◽

Reactive Case Detection

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Reactive Case Detection (RACD) and foci investigation strategies in malaria control and elimination: a review

Malaria Journal ◽

10.1186/s12936-020-03478-0 ◽

2020 ◽

Vol 19 (1) ◽

Author(s):

Ruwanthi Perera ◽

Amandhi Caldera ◽

A. Rajitha Wickremasinghe

Keyword(s):

Malaria Elimination ◽

World Health ◽

Case Detection ◽

Reactive Case Detection ◽

Target Populations ◽

Online Databases ◽

Health Organization ◽

Criteria For Selection ◽

Selection Of ◽

Country Specific

Abstract Background Reactive case detection (RACD) and foci investigation are key strategies in malaria elimination and prevention of its re-establishment. They are a key part of surveillance that has been recommended by the World Health Organization (WHO) to be considered as a core intervention and as one of the three pillars of the Global Technical Strategy for Malaria 2016–2030. Methods A search using the key words “Reactive Case Detection”, “RACD”, “RCD” and “Malaria” was carried out in PubMed, Scopus, Taylor and Francis online databases for studies published until 31st July 2019. The inclusion criteria for selection of articles for review included (1) how RACD is implemented in each country; (2) challenges faced in RACD implementation; (3) suggestions on how the effectiveness of RACD process can be improved. Results 411 titles were identified, 41 full text articles were screened and 29 were found eligible for inclusion in the review. Published literature on RACD, and case and foci investigations has mostly assessed the process of the activity. Most studies have documented that the yield of positives in RACD has been highest in the index case’s household and the immediate neighbourhood of the index case. Microscopy and RDTs are the common tests used in RACD. The guidelines for case and foci investigation, and RACD and PACD, are not universally adopted and are country-specific. Some of the limitations and challenges identified include lack of proper guidelines, logistic issues and problems with public compliance. Conclusions Although there is no documented evidence that RACD is useful in malaria elimination settings, most authors have opined that RACD is necessary for malaria elimination. Lack of knowledge in the target populations, a target radius and how to carry out the RACD process is a major challenge in the decision-making process.

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Reactive Case Detection for Plasmodium vivax Malaria Elimination in Rural Amazonia

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0005221 ◽

2016 ◽

Vol 10 (12) ◽

pp. e0005221 ◽

Cited By ~ 12

Author(s):

Pablo S. Fontoura ◽

Bruna F. Finco ◽

Nathália F. Lima ◽

Jaques F. de Carvalho ◽

Joseph M. Vinetz ◽

...

Keyword(s):

Plasmodium Vivax ◽

Malaria Elimination ◽

Vivax Malaria ◽

Case Detection ◽

Reactive Case Detection ◽

Plasmodium Vivax Malaria

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Using Mobile Technology to Facilitate Reactive Case Detection of Malaria

Online Journal of Public Health Informatics ◽

10.5210/ojphi.v9i1.7647 ◽

2017 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Gordon Cressman ◽

Michael McKay ◽

Abdul-wahid Al-Mafazy ◽

Madhi M. Ramsan ◽

Abdullah S. Ali ◽

...

Keyword(s):

Mobile Technology ◽

Malaria Elimination ◽

Indoor Residual Spraying ◽

Geographic Area ◽

Geographical Information ◽

Bed Nets ◽

Case Detection ◽

Malaria Surveillance ◽

Reactive Case Detection ◽

Notification System

ObjectiveThis presentation will share findings from more than three years ofusing mobile technology for reactive case detection (RACD) to helpeliminate malaria in a well-defined geographic area. It will reviewthe concepts of RACD, the application of mobile technology, lessonslearned from more than three years of application, and considerationsin applying this technology in other malaria elimination contexts.IntroductionZanzibar is comprised primarily of two large islands with apopulation of 1.3 million. Indoor Residual Spraying (IRS) campaigns,distribution of long-lasting insecticide treated bed nets (LLINs),and use of Rapid Diagnostic Tests (RDTs) have reduced Malariaprevalence from 39% in 2005 to less than 1% in 2011-2012. Asmalaria burden decreases, there is an increasing need to track andfollow up individual cases to contain transmission that could lead toresurgence. One method being used to achieve these aims is reactivecase detection (RACD).RACD is generally understood to be triggered whenever a case isidentified by passive case detection. The response involves visiting thehousehold of the newly reported case and screening family members.Depending on program protocol, it may also involve screeningneighbors within a defined radius. RACD has been used or testedin Cambodia, China, India, Peru, Senegal, Swaziland, Tanzania,and Zambia. RACD can be resource intensive. Several studies raisequestions concerning whether and how RACD can be prioritized andtargeted effectively as case numbers continue to decline.MethodsSince September 2012 Zanzibar Malaria Elimination Programme(ZAMEP) has used RACD to limit onward transmission, reduce thelocal parasite reservoir, and gather data needed improve programeffectiveness. Zanzibar is one of very few malaria eliminationcontexts using a mobile technology system to support RACD.1Thissystem, called the Malaria Case Notification system (MCN) usesmobile software called Coconut Surveillance.Coconut Surveillance is free and open source software designed formalaria elimination. It includes an interactive SMS system for casenotification, a mobile software application designed to guide mobilecase workers through RACD, and an analytics software applicationdesigned for surveillance and response program managers.Data were collected in the Coconut Surveillance database formore than three years, beginning in September 2012. Reports weremonitored in real time and periodically to assess RACD responsetimes against protocol targets, case trends, case locations, and otherdata. Geographical Information System (GIS) software was usedto produce detailed maps of case households. Three independentassessments were conducted of various aspects of the malariasurveillance system.ResultsFrom September 2012 to December 2015, Coconut Surveillancehas helped malaria surveillance officers in Zanzibar respond tomore than 8,617 (84%) reported cases of malaria, complete nearly10,245 household visits, test more than 36,185 household members,and identify and treat 2,032 previously unknown cases. The averagenumber of RACD activities occurring within 48 hours increased from72% in 2013 to 89% in 2015. The number of household membersscreened during RACD also increased from 7,589 in 2013 to 14,987in 2015. Challenges included incomplete registers at health carefacilities, lack of transport, inadequate training for clinicians andsurveillance officers, and insufficient communication to the affectedcommunities.ConclusionsIn Zanzibar twenty malaria surveillance officers equipped withinexpensive Android tablets and motorbikes are keeping malariaprevalence at less than 1%. The effectiveness of the system mightbe enhanced by improving training for clinicians and surveillanceofficers, ensuring the availability of transportation for surveillanceofficers, and improving communications to the affected communities.These results suggest key considerations for applying this and similarsystems in other malaria elimination contexts.

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