title: Epidemiology of imported malaria give support to the hypothesis of 'long-term' semi-immunity to malaria in sub-Saharan African migrants living in France.
abstract: BACKGROUND
  Short-term semi-immunity to malaria in sub-Saharan African migrants who have recently arrived in non-endemic countries results in less severe imported malaria. Our aim was to investigate the factors associated with imported malaria that would favour the hypothesis of a 'long-term' semi-immunity to malaria in adult travellers of sub-Saharan origin living in France and visiting family or relatives in their country of origin (VFR group).
  
  
  METHODS
  The epidemiological, clinical and biological characteristics of imported Plasmodium falciparum malaria in VFR were compared with those of travellers of European origin (TEO). Newly arrived African migrants and European expatriates were excluded.
  
  
  RESULTS
  This retrospective study included 106 adult VFR (30%) and 240 adult TEO (70%) with imported P. falciparum malaria treated at the University Hospital Center of Bordeaux between 2000 and 2007. The main regions visited were West Africa (58%) and Central Africa (34%). P. falciparum was associated with severe malaria in 8% of patients (VFR 3% vs. TEO 11%), of which two TEO died. In univariate analysis, the factors associated with P. falciparum malaria in VFR vs. TEO were: female sex, younger age, less frequent use of mosquito nets, poor compliance with chemoprophylaxis, less severe malaria without death, less severe thrombocytopenia and a tendency towards a lower level of parasitaemia and higher haemoglobinaemia. In multivariate analysis, the only factor to be independently associated with P. falciparum malaria in VFR compared to TEO was less frequent severe malaria.
  
  
  CONCLUSIONS
  Our results give support to the hypothesis of 'long-term' semi-immunity to malaria in VFR living in France.
authors.affiliation: Travel Clinic and Division of Clinical Tropical Medicine, Department of Tropical Diseases, University Hospital Center of Bordeaux, France; Centre René Labusquière, Centre for Tropical Medicine, Université Victor Segalen, Bordeaux, France. Electronic address: thierry.pistone@chu-bordeaux.fr.
authors.forename: T
authors.initials: T
authors.lastname: Pistone
authors.affiliation: Centre René Labusquière, Centre for Tropical Medicine, Université Victor Segalen, Bordeaux, France.
authors.forename: A
authors.initials: A
authors.lastname: Diallo
authors.affiliation: Travel Clinic and Division of Clinical Tropical Medicine, Department of Tropical Diseases, University Hospital Center of Bordeaux, France.
authors.forename: M
authors.initials: M
authors.lastname: Mechain
authors.affiliation: Travel Clinic and Division of Clinical Tropical Medicine, Department of Tropical Diseases, University Hospital Center of Bordeaux, France; Centre René Labusquière, Centre for Tropical Medicine, Université Victor Segalen, Bordeaux, France.
authors.forename: M-C
authors.initials: MC
authors.lastname: Receveur
authors.affiliation: Travel Clinic and Division of Clinical Tropical Medicine, Department of Tropical Diseases, University Hospital Center of Bordeaux, France; Centre René Labusquière, Centre for Tropical Medicine, Université Victor Segalen, Bordeaux, France.
authors.forename: D
authors.initials: D
authors.lastname: Malvy
mesh_terms: D000328:Adult; D017954:Africa South of the Sahara / Q000208:ethnology; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data*; D005260:Female; D005602:France / Q000453:epidemiology; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008288:Malaria / Q000097:blood / Q000453:epidemiology* / Q000208:ethnology / Q000276:immunology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018512:Parasitemia / Q000097:blood; D012189:Retrospective Studies; D057236:Travel Medicine
chemical_list: D006454:Hemoglobins
keywords: Africa; France; Immunity; Malaria; Traveller