title: Human brucellosis in northwest Ecuador: typifying Brucella spp., seroprevalence, and associated risk factors.
abstract: Human brucellosis in Ecuador is underreported and based only on passive surveillance. Since 2008, brucellosis was removed from the list of communicable diseases in the country. Until now, the true human brucellosis picture has not yet been determined. The aim of this study was to determine the seroprevalence of the disease, identify risk factors associated with brucellosis seropositivity in humans, and isolate circulating strains of Brucella spp. in the northwestern part of Ecuador. Between 2006 and 2008, a large transect survey was conducted, based on blood sampling of people from the northwestern part of Ecuador (n=3733) together with an epidemiological inquiry. On the basis of three diagnostic tests used in parallel, the overall seroprevalence was estimated as 1.88% (95% confidence interval [CI] 1.48-2.38). Based on a multivariable random effects logistic regression analysis, the main risk factors associated with human brucellosis seropositivity were contact with livestock (odds ratio [OR]=3.0; CI 1.25-7.08), consumption of fetus and placenta (OR=2.5; CI 1.18-5.22), and involvement in activities at risk for brucellosis infection (OR=1.8; CI 1.00-3.35). Noticeable variation in brucellosis seropositivity among humans within cantons was observed. The circulating strain was Brucella abortus biotype 4. This study emphasized that contact with livestock, consumption of fetus and placenta, and occupational hazard group were all significant risk factors for the transmission of brucellosis among individuals in the northwestern part of Ecuador. Alongside encouraging the launching of educational campaigns against brucellosis, especially in rural areas where 36% of the population lives, controlling this zoonotic disease in animals will directly benefit its prevention in humans, especially because there is no safe and efficacious vaccine against brucellosis in humans.
authors.affiliation: 1 Centro Internacional de Zoonosis (CIZ), Universidad Central del Ecuador , Quito, Ecuador .
authors.forename: Jorge
authors.initials: J
authors.lastname: Ron-Román
authors.forename: Lenin
authors.initials: L
authors.lastname: Ron-Garrido
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Abatih
authors.forename: Maritza
authors.initials: M
authors.lastname: Celi-Erazo
authors.forename: Laura
authors.initials: L
authors.lastname: Vizcaíno-Ordóñez
authors.forename: Jaime
authors.initials: J
authors.lastname: Calva-Pacheco
authors.forename: Pablo
authors.initials: P
authors.lastname: González-Andrade
authors.forename: Dirk
authors.initials: D
authors.lastname: Berkvens
authors.forename: Washington
authors.initials: W
authors.lastname: Benítez-Ortíz
authors.forename: Jef
authors.initials: J
authors.lastname: Brandt
authors.forename: David
authors.initials: D
authors.lastname: Fretin
authors.forename: Claude
authors.initials: C
authors.lastname: Saegerman
mesh_terms: D000003:Abattoirs; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002006:Brucellosis / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D004484:Ecuador / Q000453:epidemiology; D005260:Female; D006801:Humans; D058751:Livestock; D008297:Male; D008461:Meat Products / Q000382:microbiology / Q000706:statistics & numerical data; D008875:Middle Aged; D008892:Milk / Q000382:microbiology / Q000706:statistics & numerical data; D016273:Occupational Exposure / Q000706:statistics & numerical data; D011247:Pregnancy; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D017678:Sex Distribution; D055815:Young Adult