title: Adherence to chemoprophylaxis and Plasmodium falciparum anti-circumsporozoite seroconversion in a prospective cohort study of Dutch short-term travelers.
abstract: BACKGROUND
  We conducted a prospective study in a cohort of short-term travelers assessing the incidence rate of anti-circumsporozoite seroconversion, adherence to chemoprophylaxis, symptoms of malaria during travel, and malaria treatment abroad.
  
  
  METHODS
  Adults were recruited from the travel clinic of the Public Health Service Amsterdam. They kept a structured daily travel diary and donated blood samples before and after travel. Blood samples were serologically tested for the presence of Plasmodium falciparum anti-circumsporozoite antibodies.
  
  
  RESULTS
  Overall, the incidence rate (IR) of anti-circumsporozoite seroconversion was 0.8 per 100 person-months. Of 945 travelers, 620 (66%) visited high-endemic areas and were advised about both chemoprophylaxis and preventive measures against mosquito bites. Most subjects (520/620 = 84%) took at least 75% of recommended prophylaxis during travel. Travel to Africa, use of mefloquine, travel duration of 14-29 days in endemic areas, and concurrent use of DEET (N,N-diethyl-meta-toluamide) were associated with good adherence practices. Four travelers without fever seroconverted, becoming anti-circumsporozoite antibody-positive. All four had been adherent to chemoprophylaxis; two visited Africa, one Suriname, one India. Ten subjects with fever were tested for malaria while abroad and of these, three received treatment. All three were adherent to chemoprophylaxis and tested negative for anti-circumsporozoite antibodies.
  
  
  CONCLUSIONS
  Travel to Africa, using mefloquine, travel duration of 14-29 days in endemic areas, and use of DEET were associated with good adherence to chemoprophylaxis. The combination of chemoprophylaxis and other preventive measures were sufficient to protect seroconverting travelers from clinical malaria. Travelers who were treated for malaria abroad did not seroconvert.
authors: Department of Infectious Diseases, Public Health Service, GGD, Amsterdam, The Netherlands. sbelderok@ggd.amsterdam.nl
authors: Sanne-Meike
authors: SM
authors: Belderok
authors: Anneke
authors: A
authors: van den Hoek
authors: Will
authors: W
authors: Roeffen
authors: Robert
authors: R
authors: Sauerwein
authors: Gerard J B
authors: GJ
authors: Sonder
mesh_terms: D000293:Adolescent; D000328:Adult; D000913:Antibodies, Protozoan / Q000097:blood; D000962:Antimalarials / Q000627:therapeutic use*; D018890:Chemoprevention; D005260:Female; D006801:Humans; D016778:Malaria, Falciparum / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000276:immunology / Q000472:pathogenicity*; D011446:Prospective Studies; D014195:Travel; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan; D000962:Antimalarials