title: Evaluation of the operational challenges in implementing reactive screen-and-treat and implications of reactive case detection strategies for malaria elimination in a region of low transmission in southern Zambia.
abstract: As malaria transmission declines in many regions of sub-Saharan Africa, interventions to identify the asymptomatic reservoir are being deployed with the goals of improving surveillance and interrupting transmission. Reactive case detection strategies, in which individuals with clinical malaria are followed up at their home and household residents and neighbours are screened and treated for malaria, are increasingly used as part of malaria elimination programmes.
  
  
  
  A reactive screen-and-treat programme was implemented by the National Malaria Control Centre in Southern Province, Zambia, in which individuals residing within 140 m of an index case were screened with a malaria rapid diagnostic test (RDT) and treated if positive. The operational challenges during the early stages of implementing this reactive screen-and-treat programme in the catchment area of Macha Hospital in Southern Province, Zambia were assessed using rural health centre records, ground truth evaluation of community health worker performance, and data from serial cross-sectional surveys. The proportion of individuals infected with Plasmodium falciparum who were identified and treated was estimated by simulating reactive screen-and-treat and focal drug administration cascades.
  
  
  
  Within the 1st year of implementation, community health workers followed up 32 % of eligible index cases. When index cases were followed up, 66 % of residents were at home in the index households and 58 % in neighbouring households. Forty-one neighbouring households of 26 index households were screened, but only 13 (32 %) were within the 140-m screening radius. The parasite prevalence by RDT was 22 % in index households and 5 % in neighbouring households. In a simulation model with complete follow-up, 22 % of the total infected population would be detected with reactive screen-and-treat but 57 % with reactive focal drug administration.
  
  
  
  With limited resources, coverage and diagnostic tools, reactive screen-and-treat will likely not be sufficient to achieve malaria elimination in this setting. However, high coverage with reactive focal drug administration could be efficient at decreasing the reservoir of infection and should be considered as an alternative strategy.
authors.affiliation: Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA. ksearle1@jhu.edu.|Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA. ksearle1@jhu.edu.
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Searle
authors.affiliation: Macha Research Trust, Choma District, Zambia.
authors.forename: Harry
authors.initials: H
authors.lastname: Hamapumbu
authors.affiliation: Macha Research Trust, Choma District, Zambia.
authors.forename: Jailos
authors.initials: J
authors.lastname: Lubinda
authors.affiliation: Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.|Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Shields
authors.affiliation: Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.|Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Jessie
authors.initials: J
authors.lastname: Pinchoff
authors.affiliation: Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.|Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Tamaki
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.|Macha Research Trust, Choma District, Zambia.
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Stevenson
authors.affiliation: Akros, Cresta Golfview Grounds, Great East Road, Lusaka, Zambia.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Bridges
authors.affiliation: Akros, Cresta Golfview Grounds, Great East Road, Lusaka, Zambia.|Department of Public Health, Food Studies and Nutrition, Syracuse University, Syracuse, NY, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Larsen
authors.affiliation: Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.|Macha Research Trust, Choma District, Zambia.
authors.forename: Philip E
authors.initials: PE
authors.lastname: Thuma
authors.affiliation: Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.|Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: William J
authors.initials: WJ
authors.lastname: Moss
mesh_terms: D000293:Adolescent; D000328:Adult; D000962:Antimalarials / Q000627:therapeutic use*; D002648:Child; D003198:Computer Simulation; D003430:Cross-Sectional Studies; D003955:Diagnostic Tests, Routine / Q000379:methods / Q000706:statistics & numerical data*; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D006302:Health Services Research; D006801:Humans; D016778:Malaria, Falciparum / Q000175:diagnosis* / Q000188:drug therapy* / Q000635:transmission; D008297:Male; D008403:Mass Screening / Q000379:methods / Q000458:organization & administration*; D010963:Plasmodium falciparum / Q000302:isolation & purification*; D055815:Young Adult; D015024:Zambia
chemical_list: D000962:Antimalarials
keywords: Malaria elimination; Reactive case detection; Reactive test-and-treat; Sub-Saharan Africa; Zambia