title: Mass screening and treatment on the basis of results of a Plasmodium falciparum-specific rapid diagnostic test did not reduce malaria incidence in Zanzibar.
abstract: BACKGROUND
  Seasonal increases in malaria continue in hot spots in Zanzibar. Mass screening and treatment (MSAT) may help reduce the reservoir of infection; however, it is unclear whether rapid diagnostic tests (RDTs) detect a sufficient proportion of low-density infections to influence subsequent transmission.
  
  
  METHODS
  Two rounds of MSAT using Plasmodium falciparum-specific RDT were conducted in 5 hot spots (population, 12 000) in Zanzibar in 2012. In parallel, blood samples were collected on filter paper for polymerase chain reaction (PCR) analyses. Data on confirmed malarial parasite infections from health facilities in intervention and hot spot control areas were monitored as proxy for malaria transmission.
  
  
  RESULTS
  Approximately 64% of the population (7859) were screened at least once. P. falciparum prevalence, as measured by RDT, was 0.2% (95% confidence interval [CI], .1%-.3%) in both rounds, compared with PCR measured prevalences (for all species) of 2.5% (95% CI, 2.1%-2.9%) and 3.8% (95% CI, 3.2%-4.4%) in rounds 1 and 2, respectively. Two fifths (40%) of infections detected by PCR included non-falciparum species. Treatment of RDT-positive individuals (4% of the PCR-detected parasite carriers) did not reduce subsequent malaria incidence, compared with control areas.
  
  
  CONCLUSIONS
  Highly sensitive point-of-care diagnostic tools for detection of all human malaria species are needed to make MSAT an effective strategy in settings where malaria elimination programs are in the pre-elimination phase.
authors.affiliation: Department of Microbiology and Tumor and Cell Biology.
authors.forename: Jackie
authors.initials: J
authors.lastname: Cook
authors.affiliation: Department of Microbiology and Tumor and Cell Biology.
authors.forename: Weiping
authors.initials: W
authors.lastname: Xu
authors.affiliation: Zanzibar Malaria Elimination Programme, Ministry of Health.
authors.forename: Mwinyi
authors.initials: M
authors.lastname: Msellem
authors.affiliation: Department of Microbiology and Tumor and Cell Biology.
authors.forename: Marlotte
authors.initials: M
authors.lastname: Vonk
authors.affiliation: Department of Microbiology and Tumor and Cell Biology.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Bergström
authors.affiliation: Global Health Group, University of California-San Francisco.
authors.forename: Roly
authors.initials: R
authors.lastname: Gosling
authors.affiliation: Zanzibar Malaria Elimination Programme, Ministry of Health.
authors.forename: Abdul-Wahid
authors.initials: AW
authors.lastname: Al-Mafazy
authors.affiliation: US President's Malaria Initiative and Centers for Disease Control and Prevention Tanzania Malaria Branch, Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Peter
authors.initials: P
authors.lastname: McElroy
authors.affiliation: Swiss Tropical and Public Health Institute University of Basel, Switzerland.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Molteni
authors.affiliation: Zanzibar Malaria Elimination Programme, Ministry of Health.
authors.forename: Ali K
authors.initials: AK
authors.lastname: Abass
authors.affiliation: RTI International, Dar es Salaam, Tanzania.
authors.forename: Issa
authors.initials: I
authors.lastname: Garimo
authors.affiliation: RTI International, Dar es Salaam, Tanzania.
authors.forename: Mahdi
authors.initials: M
authors.lastname: Ramsan
authors.affiliation: Zanzibar Malaria Elimination Programme, Ministry of Health.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Ali
authors.affiliation: Department of Microbiology and Tumor and Cell Biology Global Health, Department of Public Health Sciences, Karolinska Institutet, Stockholm Centre for Clinical Research Sörmland, Uppsala University, Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Mårtensson
authors.affiliation: Department of Microbiology and Tumor and Cell Biology.
authors.forename: Anders
authors.initials: A
authors.lastname: Björkman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000962:Antimalarials / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D016778:Malaria, Falciparum / Q000175:diagnosis* / Q000188:drug therapy*; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D010963:Plasmodium falciparum; D016133:Polymerase Chain Reaction / Q000379:methods; D012621:Seasons; D012680:Sensitivity and Specificity; D013636:Tanzania / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000962:Antimalarials
keywords: Plasmodium falciparum; Plasmodium malariae; Plasmodium ovale; Plasmodium vivax; Zanzibar; diagnostic tests; malaria elimination; mass screening and treatment; molecular methods; subpatent