title: High seroprevalence for spotted fever group rickettsiae, is associated with higher temperatures and rural environment in Mbeya region, Southwestern Tanzania.
abstract: BACKGROUND
  Rickettsioses are endemic in sub-Sahara Africa. Burden of disease, risk factors and transmission are hitherto sparsely described.
  
  
  METHODS
  From the EMINI (Evaluating and Monitoring the Impact of New Interventions) population cohort, we randomly selected 1,228 persons above the age of 5 years from the nine participating communities in Mbeya region, Southwestern Tanzania, stratified by age, altitude of residence and ownership of domestic mammals, to conduct a cross-sectional seroprevalence study in. The aim was to estimate the seroprevalence of IgG antibodies against Spotted Fever Group (SFG) rickettsiae and to assess socioeconomic and environmental risk factors. Serology (indirect immunofluorescence) was performed at a dilution of 1:64.
  
  
  RESULTS
  SFG-seropositivity in the cohort was found to be 67.9% (range among nine sites: 42.8-91.4%). Multivariable analysis revealed an association with age (prevalence ratio, PR per 10 years: 1.08; 95% CI 1.06-1.10), warmer temperatures (PR per °C: 1.38; 1.11-1.71), male gender (PR 1.08; 1.00-1.16), and low population density (PR per 1.000 persons/km²increase 0.96; 0.94-0.99). At higher elevations, higher cattle density was associated with higher seroprevalence.
  
  
  CONCLUSIONS
  SFG rickettsial infection seems to be common in the more rural population of Mbeya Region. Spread seems to be further limited by temperature and higher elevation. Examination of the contribution of SFG to febrile illnesses seems warranted in a prospective study to estimate the disease burden in the population. This will also allow determination of the causative pathogens.
authors: Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany; German Center for Infection Research (DZIF), Munich partner site, Munich, Germany.
authors: Norbert
authors: N
authors: Heinrich
authors: Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany.
authors: Tatjana
authors: T
authors: Dill
authors: Bundeswehr Institute of Microbiology, Munich, Germany; DZIF German Center for Infection Research, Munich partner site, Munich, Germany; German Partnership Program for Excellence in Biological and Health Security, Munich, Germany.
authors: Gerhard
authors: G
authors: Dobler
authors: Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany; NIMR-Mbeya Medical Research Centre, Mbeya, Tanzania.
authors: Petra
authors: P
authors: Clowes
authors: Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany; NIMR-Mbeya Medical Research Centre, Mbeya, Tanzania.
authors: Inge
authors: I
authors: Kroidl
authors: German Center for Infection Research (DZIF), Munich partner site, Munich, Germany; Bundeswehr Institute of Microbiology, Munich, Germany; DZIF German Center for Infection Research, Munich partner site, Munich, Germany; German Partnership Program for Excellence in Biological and Health Security, Munich, Germany.
authors: Mandy
authors: M
authors: Starke
authors: NIMR-Mbeya Medical Research Centre, Mbeya, Tanzania.
authors: Nyanda Elias
authors: NE
authors: Ntinginya
authors: NIMR-Mbeya Medical Research Centre, Mbeya, Tanzania.
authors: Leonard
authors: L
authors: Maboko
authors: Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany.
authors: Thomas
authors: T
authors: Löscher
authors: Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany; German Center for Infection Research (DZIF), Munich partner site, Munich, Germany; NIMR-Mbeya Medical Research Centre, Mbeya, Tanzania.
authors: Michael
authors: M
authors: Hoelscher
authors: Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany; German Center for Infection Research (DZIF), Munich partner site, Munich, Germany.
authors: Elmar
authors: E
authors: Saathoff
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D002417:Cattle; D003430:Cross-Sectional Studies; D004777:Environment; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D012282:Rickettsia Infections / Q000097:blood / Q000453:epidemiology*; D012307:Risk Factors; D012424:Rural Population; D016036:Seroepidemiologic Studies; D012959:Socioeconomic Factors; D013636:Tanzania / Q000453:epidemiology; D013696:Temperature; D017282:Tick-Borne Diseases / Q000097:blood / Q000453:epidemiology*
chemical_list: D007074:Immunoglobulin G