Coxiella burnetiiinfection in humans: to what extent do cattle in infected areas free from small ruminants play a role?

Abstract

Domestic ruminants (cattle, goats and sheep) are considered to be the main reservoirs for human Coxiella burnetii infection. However, there is still a need to assess the specific contribution of cattle. Indeed, most seroprevalence studies in humans were carried out in areas comprising both cattle and small ruminants, the latter being systematically implicated in human Q fever outbreaks. Therefore, we conducted a cross-sectional study in areas where C. burnetii infection in cattle was endemic, where the density of cattle and small ruminant farms were respectively high and very low. The aim was to estimate the seroprevalence rates among two occupational (cattle farmers and livestock veterinarians), and one non-occupational (general adult population) risk groups. Sera were collected in 176 cattle farmers, 45 veterinarians and 347 blood donors, and tested for phase I and II antibodies using immunofluorescence assay. Seroprevalence rates were 56.3% among cattle farmers, 88.9% among veterinarians and 12.7% among blood donors. This suggests that a specific risk for acquiring C. burnetii infection from cattle in endemically infected areas exists, mainly for occupational risk groups, but also for the general population. Further research is needed to identify risk factors for C. burnetii infection in humans in such areas.

Pilot Study of Risk Group Human Seroprevalence to Coxiella burnetii (Q Fever) in Latvia

“…The observed seroprevalence in Latvia and Estonia is significantly lower than in other countries. For example, in a recent study in France, the seroprevalence rate among veterinarians was 88.9%, among cattle farmers -56.3% and among blood donors -12.7% (Pouquet et al, 2020). In a risk group study of farm workers in Poland, the seroprevalence detected by ELISA was 39.07% (Szymañska-Czerwiñska et al, 2015).…”

Seroprevalence of vector-borne pathogens in outdoor workers from southern Italy and associated occupational risk factors

“…The high prevalence of C. burnetii exposure in farmers (67.7%) suggests the occurrence of a high risk of infection in the farming environment due to the contact with contaminated aerosols or infected animal products such as placentas [ 38 , 39 ]. In addition, this seroprevalence higher than that reported in other Italian areas (e.g.…”

Recent Advances on the Innate Immune Response to Coxiella burnetii

“…In addition, another important problem relating to affected animals is that they expel C. burnetii through milk, feces, vaginal mucus, and birth products, which are vehicles for spreading the infection between the livestock and to the humans. Cattle, goats, and sheep are indeed considered as the most important reservoirs for the human infection ( Georgiev et al., 2013 ; Pouquet et al., 2020 ).…”