Case investigation and reactive case detection for malaria elimination in northern Senegal

Littrell, Megan; Sow, Gnagna Dieng; Ngom, Algaye; Bâ, Mady; Mboup, Balla Mbacké; Dièye, Yakhya; Mutombo, Boniface; Earle, Duncan; Steketee, Richard W.

doi:10.1186/1475-2875-12-331

Cited by 64 publications

(92 citation statements)

References 18 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…26 Studies conducted in Zambia, Senegal, and Swaziland found that the number of tested individuals to identify one infected individual ranged from 37 to 250. 11,12,27 In our study area, a mean of 90 RDTnegative residents were tested for each RDT-positive individual identified and a mean of 66 qPCR-negative residents were tested for each qPCR-positive, RDT-negative individual identified. A mean of 24 qPCR-negative residents of index case households were tested for each qPCR-positive, RDTnegative individual identified within an index case household.…”

Section: Discussionmentioning

confidence: 99%

“…For reactive test-and-treat, residents in the home of a symptomatic index case and those in neighboring households within a defined radius are screened with an RDT and offered treatment if positive. [11][12][13] For reactive focal drug administration, individuals residing within an index case household, and potentially neighboring households, are treated without testing. 14,15 Advantages of focal drug administration are that infected individuals who may otherwise be missed with a low-sensitivity RDT are treated, and the strategy does not increase the demand for RDTs.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Efficiency of a Malaria Reactive Test-and-Treat Program in Southern Zambia: A Prospective, Observational Study

Deutsch-Feldman

Hamapumbu

Lubinda

et al. 2018

The American Journal of Tropical Medicine and Hygiene

View full text Add to dashboard Cite

To improve malaria surveillance and achieve elimination, the Zambian National Malaria Elimination Program implemented a reactive test-and-treat program in Southern Province in 2013 in which individuals with rapid diagnostic test (RDT)-confirmed malaria are followed-up at their home within 1 week of diagnosis. Individuals present at the index case household and those residing within 140 m of the index case are tested with an RDT and treated with artemether-lumefantrine if positive. This study evaluated the efficiency of this reactive test-and-treat strategy by characterizing infected individuals missed by the RDT and the current screening radius. The radius was expanded to 250 m, and a quantitative polymerase chain reaction (qPCR) test was performed on dried blood spot specimens. From January 2015 through March 2016, 145 index cases were identified at health centers and health posts. A total of 3,333 individuals residing in 525 households were screened. Excluding index cases, the parasite prevalence was 1.1% by RDT (33 positives of 3,016 participants) and 2.4% by qPCR (73 positives of 3,016 participants). Of the qPCR-positive cases, 62% of 73 individuals tested negative by RDT. Approximately half of the infected individuals resided within the index case household (58% of RDT-positive individuals and 48% of qPCR-positive individuals). The low sensitivity of the RDT and the high proportion of secondary cases within the index case household decreased the efficiency of this reactive test-and-treat strategy. Reactive focal drug administration in index case households would be a more efficient approach to treating infected individuals associated with a symptomatic case.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Efficiency of a Malaria Reactive Test-and-Treat Program in Southern Zambia: A Prospective, Observational Study

Deutsch-Feldman

Hamapumbu

Lubinda

et al. 2018

The American Journal of Tropical Medicine and Hygiene

View full text Add to dashboard Cite

show abstract

“…Several previous studies which have evaluated the screen-and-treat approach for malaria control and elimination have invariably failed to detect a significant impact [26–31]. While some studies have indicated that the RCD approach can lead to detecting more cases than normal passive case detection [32, 33], it has not yet shown an ability to halt transmission and in some settings appears to be ineffective [34]. This analysis, based on clinical case data and simulated RCD for clinical cases using RDTs, indicates that the RCD approach in this setting is not effective.…”

Section: Discussionmentioning

confidence: 99%

Limitations of malaria reactive case detection in an area of low and unstable transmission on the Myanmar–Thailand border

Parker

Landier

Seidlein

et al. 2016

Malar J

View full text Add to dashboard Cite

BackgroundReactive case detection is an approach that has been proposed as a tool for malaria elimination in low-transmission settings. It is an intuitively justified approach based on the concept of space–time clustering of malaria cases. When an index malaria clinical case is detected, it triggers reactive screening and treatment in the index house and neighbouring houses. However, the efficacy of this approach at varying screening radii and malaria prevalence remains ill defined.MethodsData were obtained from a detailed demographic and geographic surveillance study in four villages on the Myanmar–Thailand border. Clinical cases were recorded at village malaria clinics and were linked back to patients’ residencies. These data were used to simulate the efficacy of reactive case detection for clinical cases using rapid diagnostic tests (RDT). Simulations took clinical cases in a given month and tabulated the number of cases that would have been detected in the following month at varying screening radii around the index houses. Simulations were run independently for both falciparum and vivax malaria. Each simulation of a reactive case detection effort was run in comparison with a strategy using random selection of houses for screening.ResultsIn approximately half of the screenings for falciparum and 10% for vivax it would have been impossible to detect any malaria cases regardless of the screening strategy because the screening would have occurred during times when there were no cases. When geographically linked cases were present in the simulation, reactive case detection would have only been successful at detecting most malaria cases using larger screening radii (150-m radius and above). At this screening radius and above, reactive case detection does not perform better than random screening of an equal number of houses in the village. Screening within very small radii detects only a very small proportion of cases, but despite this low performance is better than random screening with the same sample size.ConclusionsThe results of these simulations indicate that reactive case detection for clinical cases using RDTs has limited ability in halting transmission in regions of low and unstable transmission. This is linked to high spatial heterogeneity of cases, acquisition of malaria infections outside the village, as well missing asymptomatic infections. When cases are few and sporadic, reactive case detection would result in major time and budgetary losses.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-016-1631-9) contains supplementary material, which is available to authorized users.

show abstract

“…Reactive case detection, whereby households within an established radius surrounding a symptomatic positive index case are screened, is also increasingly being used as a strategy that bridges passive and active surveillance [59,60,61]. Many of these efforts are applying molecular methods to find and treat asymptomatic infections [23,62,63,64].…”

Section: Sparse Data Exist From Elimination Efforts Using Active Survmentioning

confidence: 99%

The role of submicroscopic parasitemia in malaria transmission: what is the evidence?

Lin¹,

Saunders²,

Meshnick³

2014

Trends in Parasitology

215

230

View full text Add to dashboard Cite

Achieving malaria elimination requires targeting the human reservoir of infection, including those with asymptomatic infection. Smear-positive asymptomatic infections detectable by microscopy are an important reservoir because they often persist for months and harbor gametocytes, the parasite stage infectious to mosquitoes. However, many asymptomatic infections are submicroscopic and can only be detected by molecular methods. While there is some evidence that persons with submicroscopic malaria can infect mosquitoes, transmission is much less likely to occur at submicroscopic gametocyte levels. As malaria elimination programs pursue mass screening and treatment of asymptomatic individuals, further research should strive to define the degree to which submicroscopic malaria contributes to the infectious reservoir, and in turn, what diagnostic detection threshold is needed to effectively interrupt transmission.

show abstract

Case investigation and reactive case detection for malaria elimination in northern Senegal

Cited by 64 publications

References 18 publications

Efficiency of a Malaria Reactive Test-and-Treat Program in Southern Zambia: A Prospective, Observational Study

Efficiency of a Malaria Reactive Test-and-Treat Program in Southern Zambia: A Prospective, Observational Study

Limitations of malaria reactive case detection in an area of low and unstable transmission on the Myanmar–Thailand border

The role of submicroscopic parasitemia in malaria transmission: what is the evidence?

Contact Info

Product

Resources

About