title: Clinical manifestations of human brucellosis: a systematic review and meta-analysis.
abstract: BACKGROUND
  The objectives of this systematic review, commissioned by WHO, were to assess the frequency and severity of clinical manifestations of human brucellosis, in view of specifying a disability weight for a DALY calculation.
  
  
  RESULTS
  Thirty three databases were searched, with 2,385 articles published between January 1990-June 2010 identified as relating to human brucellosis. Fifty-seven studies were of sufficient quality for data extraction. Pooled proportions of cases with specific clinical manifestations were stratified by age category and sex and analysed using generalized linear mixed models. Data relating to duration of illness and risk factors were also extracted. Severe complications of brucellosis infection were not rare, with 1 case of endocarditis and 4 neurological cases per 100 patients. One in 10 men suffered from epididymo-orchitis. Debilitating conditions such as arthralgia, myalgia and back pain affected around half of the patients (65%, 47% and 45%, respectively). Given that 78% patients had fever, brucellosis poses a diagnostic challenge in malaria-endemic areas. Significant delays in appropriate diagnosis and treatment were the result of health service inadequacies and socioeconomic factors. Based on disability weights from the 2004 Global Burden of Disease Study, a disability weight of 0.150 is proposed as the first informed estimate for chronic, localised brucellosis and 0.190 for acute brucellosis.
  
  
  CONCLUSIONS
  This systematic review adds to the understanding of the global burden of brucellosis, one of the most common zoonoses worldwide. The severe, debilitating, and chronic impact of brucellosis is highlighted. Well designed epidemiological studies from regions lacking in data would allow a more complete understanding of the clinical manifestations of disease and exposure risks, and provide further evidence for policy-makers. As this is the first informed estimate of a disability weight for brucellosis, there is a need for further debate amongst brucellosis experts and a consensus to be reached.
authors.affiliation: Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.
authors.forename: Anna S
authors.initials: AS
authors.lastname: Dean
authors.forename: Lisa
authors.initials: L
authors.lastname: Crump
authors.forename: Helena
authors.initials: H
authors.lastname: Greter
authors.forename: Jan
authors.initials: J
authors.lastname: Hattendorf
authors.forename: Esther
authors.initials: E
authors.lastname: Schelling
authors.forename: Jakob
authors.initials: J
authors.lastname: Zinsstag
mesh_terms: D002006:Brucellosis / Q000150:complications / Q000453:epidemiology* / Q000473:pathology*; D004697:Endocarditis, Bacterial / Q000453:epidemiology / Q000209:etiology; D004823:Epididymitis / Q000453:epidemiology / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D009422:Nervous System Diseases / Q000453:epidemiology / Q000209:etiology; D009920:Orchitis / Q000453:epidemiology / Q000209:etiology