Management of Coxiella burnetii infection in livestock populations and the associated zoonotic risk: A consensus statement

Abstract

Infections caused by Coxiella burnetii, commonly referred to as coxiellosis when occurring in animals and Query fever when occurring in humans, are an important cause of abortions, decreased reproductive efficiency, and subclinical infections in ruminants. The organism also represents an important zoonotic concern associated with its ability to aerosolize easily and its low infectious dose. Available diagnostic tests have limited sensitivity, which combined with the absence of treatment options in animals and limited approaches to prevention, result in difficulty managing this agent for optimal animal health and zoonotic disease outcomes. The purpose of this consensus statement is to provide veterinarians and public health officials with a summary of the available information regarding management of C. burnetii infection in livestock populations. A discussion of currently available testing options and their interpretation is provided, along with recommendations on management practices that can be implemented on‐farm in the face of an outbreak to mitigate losses. Emphasis is placed on biosecurity measures that can be considered for minimizing the zoonotic transmission risk in both field and veterinary facilities.

Monitoring Coxiella burnetii Infection in Naturally Infected Dairy Sheep Flocks Throughout Four Lambing Seasons and Investigation of Viable Bacteria

“…The marked differences in seroprevalence observed in ewes and yearlings throughout the four lambing seasons among flocks were probably associated to the exposure of animals to different loads of viable bacteria. However, as seen in this study and others ( 16 ), seroprevalence is not correlated with bacterial shedding.…”

“…This study shows the patterns of C. burnetii infection in four naturally infected dairy sheep flocks throughout four lambing seasons. The presence of animal shedders in the previous milking season and high seroprevalence in yearlings suggested at the beginning of the study that infection was active in all flocks ( 1 , 16 ). It is known that shedding of C. burnetii by vaginal fluids, feces, and milk can persist in the breeding season that follows infection onset in small ruminant farms, even when vaccination has been implemented ( 20 ).…”

“…However, cattle and goats in the farm were managed under a year-round extensive system and did not share pastures with sheep, thus minimizing opportunities for sheep cross-infection. In any case, inappropriate implementation of biosafety measures is a risk factor for flock infections that cannot be ruled out ( 1 , 16 , 36 ).…”

“…In a recent study carried out in dairy sheep flocks, C. burnetii shedding through milk was still observed in several flocks 10 years after first detection (13). This suggests that flock management practices together with lack of control measures implemented can cause periodical reactivation of C. burnetii infection (14)(15)(16)(17).…”

Sero-Epidemiological Study of Selected Zoonotic and Abortifacient Pathogens in Cattle at a Wildlife-Livestock Interface in South Africa

“…April to September 2013, the location and management of cattle farms (Transvaal province vs. Mpumalanga province), and most importantly, serological tests used (Complement Fixation Test vs. ELISA). These factors have the potential to affect exposure and detection of C. burnetii (Muleme et al 2016, Plummer et al 2018, Larson et al 2019.…”