A Cluster of Coxiella Burnetii Infections Associated with Exposure to Vaccinated Goats and their Unpasteurized Dairy Products

Is Q Fever an emerging or re-emerging zoonosis?

“…Drinking contaminated milk has induced seroconversion in human volunteers without clinical signs [13,83], but none of them presented aggravating risk factors. However some studies have reported clinical disease linked to the ingestion of cheese [41,54], but these results are sometimes contested since it is difficult to guarantee even for prisoners that the patients did not inhale contaminated dust or aerosols. Furthermore, nothing is known about the ingestion of massive doses of C. burnetii or of a moderate dose by persons at risk, such as pregnant women, immunocompromised patients, or patients with valvulopathy.…”

“…However, for several authors, phase I vaccines failed to prevent shedding in milk in naturally infected cows prior to vaccination [21,140], underlining that a vaccine can only protect uninfected animals but is not able to treat an infected one. In contrast, a phase II vaccine failed to protect livestock against the C. burnetii infection and to prevent the shedding of bacteria by the vaginal route and in milk [39,41]: the vaccine was not able to prevent abortions nor bacterial shedding in milk, vaginal secretions nor in feces [147]. Phase II vaccination, antibiotherapy, or a combination of both reduced but did not stop the milk excretion of Coxiella by cows [39,140] or by goats [41].…”

“…In contrast, a phase II vaccine failed to protect livestock against the C. burnetii infection and to prevent the shedding of bacteria by the vaginal route and in milk [39,41]: the vaccine was not able to prevent abortions nor bacterial shedding in milk, vaginal secretions nor in feces [147]. Phase II vaccination, antibiotherapy, or a combination of both reduced but did not stop the milk excretion of Coxiella by cows [39,140] or by goats [41]. Since contaminated aerosols are the main sources of animal and human contaminations, the control of fecal excretion and placental bacterial discharge is essential.…”

“…Since contaminated aerosols are the main sources of animal and human contaminations, the control of fecal excretion and placental bacterial discharge is essential. In France, vaccination of animals with an inactivated phase II vaccine is currently widely used when Q fever is diagnosed in a flock because it is the only available vaccine; however, this vaccination with a phase II vaccine fails to prevent human, animal and environmental contaminations [41].…”

Experimental Coxiella burnetii infection in pregnant goats: excretion routes

“…Nevertheless, the C. burnetii shedding kinetics is not well known. Oral transmission is less common, but the consumption of contaminated raw milk and dairy-products could be a source of infection [8,12,16]. Thus, most people could be contaminated by C. burnetii, but staffs working with ruminants appear to be the most exposed [17].…”