Q Fever in Humans and Animals in the United States

Abstract

Coxiella burnetii, the etiologic agent of Q fever, is a worldwide zoonotic pathogen. Although Q fever is present in the United States, little is known about its current incidence or geographic distribution in either humans or animals. Published reports of national disease surveillance, individual cases, outbreak investigations, and serologic surveys were reviewed to better characterize Q fever epidemiology in the United States. In national disease surveillance reports for 1948-1986, 1,396 human cases were reported from almost every state. Among published individual case reports and outbreak investigations, occupational exposures (research facilities, farm environments, slaughterhouses) were commonly reported, and sheep were most frequently implicated as a possible source of infection. In studies conducted on specific groups, livestock handlers had a significantly higher prevalence of antibodies to C. burnetii than did persons with no known risk. Animal studies showed wide variation in seroprevalence, with goats having a significantly higher average seroprevalence (41.6%) than sheep (16.5%) or cattle (3.4%). Evidence of antibody to C. burnetii was reported among various wild-animal species, including coyotes, foxes, rodents, skunks, raccoons, rabbits, deer, and birds. This literature review suggests that C. burnetii is enzootic among ruminants and wild animals throughout much of the United States and that there is widespread human exposure to this pathogen. Sheep and goats appear to be a more important risk for human infection in the United States than cattle or wild animals, and research studies examining the natural history and transmission risk of Q fever in sheep and goats in this country should be encouraged.

Is Q Fever an emerging or re-emerging zoonosis?

“…In the USA, C. burnetii is enzootic in ruminants and wild animals as in other parts of the world [105], but human infections due to C. burnetii are rare [48,105]. The most recent cases of Q fever have been described in Australia [50,148,186], Canada [87,94], France [125,165], Germany [58], Japan [160], Spain [34,135], Switzerland and the United Kingdom [117].…”

Q Fever in the United States: Summary of Case Reports from Two National Surveillance Systems, 2000–2012

“…[15][16][17][18][19][20][21] In humans in the United States, acute Q fever most commonly presents as a flu-like illness, more rarely as hepatitis or pneumonia; asymptomatic infections have also been documented. 22,23 In addition to the acute illness, Q fever can cause chronic infection. Chronic infection occurs rarely ( 5%) and may present months to years after an acute infection.…”

Association betweenCoxiella burnetii shedding in milkand subclinical mastitis in dairy cattle

“…Coxiella burnetii is an obligate intracellular zoonotic pathogen and the etiologic agent of Q fever in humans [1,[17][18][19]. Domestic ruminants (cattle, sheep, and goats) are described as the primary reservoir species for exposure of humans [1,[17][18][19].…”

“…Domestic ruminants (cattle, sheep, and goats) are described as the primary reservoir species for exposure of humans [1,[17][18][19]. In dairy cattle C. burnetii infections may be underrecognized [19,20] and there is incomplete understanding of infection dynamics and disease manifestations. In the United States there are currently no approved C. burnetii are inconsistent [8,15,24].…”