Q fever — a forgotten disease?
By Linda on Jan 22, 2011 in Infections | comments(0)
Excerpt:
“Q fever epidemic in the Chamonix valley” (France), is a recent headline from ProMed-mail.1 To date, 79 clinical cases have been identified with a further 22 seropositive individuals. This report has been followed by an outbreak affecting up to 86 people from Newport, South Wales.2 The causative organism, Coxiella burnetii has its reservoir in a broad range of vertebrates and arthropods.3 It is typically transmitted by the aerosol route, where it causes a zoonotic infection, but the source of this current outbreak remains elusive, as is often the case in retrospective epidemiological investigations.
Primary infection in human beings is symptomless in more than half of those infected.4,5 Signs of acute disease have no typical presentation, but tend to manifest as a self-limiting debilitating febrile illness for 2—14 days, non-typical pneumonia, or hepatitis.3 It is estimated that less than 5% of those with acute Q fever will develop chronic disease, the most common presentation of which is endocarditis. C burnetii accounts for 35% of all cases of infective endocarditis after infection with slow-growing or fastidious bacterial species (3% of total endocarditis cases), especially in those with prosthetic valves, previous valve injury, or rheumatic heart disease.6 Other cases are associated with immuno-suppression through corticosteroid use, cancer, AIDS, or lymphoma.6Manifestation of chronic disease may be delayed for several years possibly requiring C burnetii reactivation from a persistent latent form.
