Seroprevalence estimate and risk factors for Coxiella burnetii infections among humans in a highly urbanised Brazilian state

Trans R Soc Trop Med Hyg. 2022 Mar 2;116(3):261-269. doi: 10.1093/trstmh/trab113.

Abstract

Background: Q fever is among the top 13 global priority zoonoses, however, it is still neglected and under-reported in most of the world, including Brazil. Thus, we evaluated the seroprevalence of and the risk factors for Coxiella burnetii infections in humans from Minas Gerais, a highly urbanised Brazilian state.

Methods: Coxiella burnetii was searched for patient samples (n=437), which were suspected of then later confirmed as negative for dengue fever, by the indirect immunofluorescence technique and real-time PCR. Risk factors for infections and spatial clusters for both C. burnetii-seropositive individuals and livestock concentration were evaluated.

Results: We found that 21 samples (4.8%; 95% CI 3.0 to 7.2%) were reactive for at least one class of anti-C. burnetii antibodies (titer of ≥64), with rural residence (p=0.036) being a risk factor. Also, two spatial clusters of seropositivity were found within a significant area by Scan, and a probable relationship between the Scan result and the livestock concentration by area was found.

Conclusions: Seropositive individuals were associated with rural residence, with a likely relationship with the livestock concentration. Thus, this study establishes baseline figures for C. burnetii seroprevalence in humans in a state of Brazil, allowing the monitoring of trends and setting of control targets, as well as more representative longitudinal and risk analysis studies.

Keywords: Coxiella burnetii, public health; Q fever; seroprevalence; zoonosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Bacterial
  • Brazil / epidemiology
  • Coxiella burnetii*
  • Humans
  • Livestock
  • Q Fever* / epidemiology
  • Q Fever* / etiology
  • Risk Factors
  • Seroepidemiologic Studies
  • Zoonoses

Substances

  • Antibodies, Bacterial