Emergence of Coxiella burnetii in Ruminants on Reunion Island? Prevalence and Risk Factors

Abstract

Q fever is a widespread zoonosis that is caused by Coxiella burnetii (C. burnetii), and ruminants are identified as the main sources of human infections. Some human cases have been described, but very limited information was available about Q fever in ruminants on Reunion Island, a tropical island in the Indian Ocean. A cross-sectional study was undertaken from March 2011 to August 2012 to assess the Q fever prevalence and to identify the major risk factors of C. burnetii infection in ruminants. A total of 516 ruminants (245 cattle, 137 sheep and 134 goats) belonging to 71 farms and localized in different ecosystems of the island were randomly selected. Samples of blood, vaginal mucus and milk were concomitantly collected from females, and a questionnaire was submitted to the farmers. Ticks from positively detected farms were also collected. The overall seropositivity was 11.8% in cattle, 1.4% in sheep and 13.4% in goats. C. burnetii DNA was detected by PCR in 0.81%, 4.4% and 20.1% in cow, sheep and goat vaginal swabs, respectively. C. burnetii shedding in milk was observed in 1% of cows, 0% in sheep and 4.7% in goats. None of the ticks were detected to be positive for C. burnetii. C. burnetii infection increased when the farm was exposed to prevailing winds and when there were no specific precautions for a visitor before entering the farm, and they decreased when a proper quarantine was set up for any introduction of a new ruminant and when the animals returned to the farm at night. MLVA genotyping confirmed the role of these risk factors in infection.

Coxiella burnetii(Q Fever) Infection in Farmed Ruminants in Three Northeastern Provinces and Inner Mongolia Autonomous Region, China

“…The antigen is a sheep strain (phase 1-2). Sensitivity and specificity of this ELISA test were 87% and 100%, respectively (manufacturer's data) (Cardinale et al 2014). Positive samples were retested.…”

“…Q fever is a zoonosis occurring worldwide caused by the Gram-negative bacterium Coxiella burnetii (Rodríguez et al 2010, Cardinale et al 2014. Humans are infected primarily by inhaling an aerosol contaminated with material from the urine or feces of infected animals (Esmaeili et al 2014, Schimmer et al 2014.…”

“…This is because of the massive shedding by small ruminants of C. burnetii during abortions. Thus, detecting the shedders of C. burnetii and investigating the prevalence of the infection are important for controlling the transmission of C. burnetii among animals and from animals to humans (Maurin and Raoult 1999, Cardinale et al 2014, Klaasen et al 2014.…”

A systematic knowledge synthesis on the spatial dimensions of Q fever epidemics

“…Studies performed in other countries on inter-herd transmission of ruminants also showed relevance of transmission via direct contact as well as indirect transmission. Direct transmission was mainly studied by assessing trade data (Nusinovici et al, 2014;Nusinovici, Hoch, Brahim, Joly, & Beaudeau, 2015) and by assessing proxies like proper quarantine procedures (Cardinale, Esnault, Beral, Naze, & Michault, 2014). Indirect transmission was suggested by identified crude risk factors like animal density (Lambton, Smith, Gillard, & Horigan, 2016;Nusinovici et al, 2015Nusinovici et al, , 2014 and spatial clustering (Alvarez et al, 2012;Nogareda et al, 2013).…”

Molecular characterization of Coxiella burnetii in the slaughtered animals of Southern Iran

“…The reports have implied that farm animals including cattle, sheep, and goats, play a major role as reservoir of the infection, with high risk to the vulnerable populations including ranchers, veterinarian, butchers and personnel of slaughterhouses [5][6][7]. Transmission routes of the infection to human are including infected ticks, aerosols, direct contact with the infected animal fluids such as milk, urine, seminal fluid, contaminated tissues such as kidneys, mammary glands and lymph nodes [2,[8][9][10][11][12].…”