Coxiella burnetii Antibody Prevalence and Risk Factors of Infection in the Human Population of Estonia.

Kädi Neare,Marilin Janson,Arvo Viltrop,Brian Lassen,Pirje Hütt

doi:10.3390/microorganisms7120629

Kädi Neare, Marilin Janson + Show 3 more

Open Access

https://doi.org/10.3390/microorganisms7120629

Copy DOI

Abstract

Q fever is an emerging health problem in both humans and animals. To estimate the prevalence of Coxiella burnetii (C. burnetii) antibodies in the Estonian population, we analyzed plasma samples from 1000 individuals representing the general population and 556 individual serum samples from five population groups potentially at a higher risk (veterinary professionals, dairy cattle, beef cattle, and small ruminant stockbreeders and hunters). Additionally, 118 dairy cow bulk tank milk samples were analyzed to establish the infection status of the dairy cattle herds and the participating dairy cattle keepers. Questionnaires were used to find the potential risk factors of exposure. The effects of different variables were evaluated using binary logistic regression analysis and mixed-effects logistic analysis. The prevalence in veterinary professionals (9.62%; p = 0.003) and dairy cattle farmers (7.73%; p = 0.047) was significantly higher than in the general population (3.9%). Contact with production animals in veterinary practice and being a dairy stockbreeder in C. burnetii positive farms were risk factors for testing C. burnetii seropositive (p = 0.038 and p = 0.019, respectively). Results suggest that C. burnetii is present in Estonia and the increased risk of infection in humans is associated with farm animal contact.

Highlights

Q fever is a widespread zoonosis with pandemic potential caused by the intracellular bacterial pathogen Coxiella burnetii (C. burnetii) [1]
The estimates for C. burnetii antibody-positive humans in Europe varies between geographical regions and population groups, ranging from 2.4% in the Netherlands (2006–2007) [4] and 5.35% in France (1995) [5] to 38% in Bulgaria (1995) [6]
One positive enzyme-linked immunosorbent assay (ELISA) result was found to be negative with immunofluorescent assay (IFA)

Summary

Introduction

Q fever is a widespread zoonosis with pandemic potential caused by the intracellular bacterial pathogen Coxiella burnetii (C. burnetii) [1]. The estimates for C. burnetii antibody-positive humans in Europe varies between geographical regions and population groups, ranging from 2.4% in the Netherlands (2006–2007) [4] and 5.35% in France (1995) [5] to 38% in Bulgaria (1995) [6]. In some countries, such as Bulgaria and Spain, the number of reported cases increased. Low numbers might not reflect the real situation, as some European Union/European Economic Area countries do not report the presence of C. burnetii infection [12]. These prevalence estimates should be compared with caution as different approaches to determine seropositivity for Coxiella burnetii infection have been used in these studies. The IFA has been shown to be the most sensitive and specific test for C. burnetii antibody detection, but since IFA testing is more laborious, combining ELISA as a primary screening test and IFA as a confirmatory test has been suggested for large-scale population studies [14]

Objectives

Methods

Results

Discussion

Conclusion