In vivo response of acute Q fever to erythromycin

Azithromycin for acute Q fever in pregnancy

Q fever is a zoonosis caused by Coxiella burnetii. Although data on Q fever during pregnancy are limited, they indicate that infection with C. burnetii is associated with high morbidity and mortality. The infection is usually asymptomatic in pregnant women but may result in obstetric complications such as spontaneous abortion, intrauterine growth retardation, intrauterine fetal death and premature delivery; in addition, pregnant women are at higher risk of developing chronic Q fever. Treatment of Q fever during pregnancy is challenging not only because C. burnetii is an intracellular bacterium but also because of safety restrictions and limited information on the efficacy of treatment. We report a case of acute Q fever in pregnancy with a successful outcome for mother and child, describe our therapeutic approach to the management of this case, and suggest that treatment with azithromycin may have prevented possible obstetric complications and evolution toward a chronic serologic profile in our patient.

Newer macrolides as empiric treatment for acute Q fever infection

The effectiveness of newer macrolides in acute Q fever for 113 patients was recorded. The mean times to defervescence were 2.9 days for doxycycline and 3.3, 3.9, 3.9, and 6.4 days for clarithromycin, roxithromycin, erythromycin, and beta-lactams, respectively (P < 0.01 for macrolides versus beta-lactams). We conclude that macrolides may be an adequate empirical antibiotic therapy for acute Q fever.

In vitro susceptibilities of spotted fever group rickettsiae and Coxiella burnetti to clarithromycin

The in vitro bacteriostatic activity of clarithromycin, a new macrolide derivative, against Rickettsia rickettsii, Rickettsia conorii, and "Rickettsia israeli" was determined by the plaque assay and the dye uptake assay. Both bacteriostatic and bactericidal activities of clarithromycin against the Nine Mile, Q212, Priscilla, and ME9 strains of Coxiella burnetti were evaluated by using three cell culture systems. Clarithromycin showed improved antibacterial activity compared with that of erythromycin. A bacteriostatic activity was obtained at concentrations below the reported maximum concentration of clarithromycin in human serum (about 4 micrograms/ml) for all tested rickettsiae. MICs ranged from 1 to 2 micrograms/ml for the three Rickettsia species and from 1 to 4 micrograms/ml for the C. burnetti strains. No bactericidal activity against C. burnetti was obtained when clarithromycin was used at 4 micrograms/ml.

Antibiotic treatment in pneumonia due to Q fever

BACKGROUND

Whether Q fever responds better to doxycycline or erythromycin is unknown.

METHODS

The efficacy of doxycycline and erythromycin in the treatment of pneumonia due to Q fever was assessed in a prospective, randomised, double blind study of 82 patients with a diagnosis of pneumonia and features suggestive of Q fever infection; 48 proved to have Q fever. Of the 48, 23 received doxycycline 100 mg twice a day and 25 patients received erythromycin 500 mg six hourly, both for 10 days.

RESULTS

Both treatment groups had similar demographic characteristics. Fever showed a more rapid reduction in the doxycycline group (3(1.6) days versus 4.3(2) days). Side effects were observed in two patients receiving doxycycline compared with 11 patients receiving erythromycin (p less than 0.01). No differences were observed in other clinical or radiological measures. By day 40 the chest radiograph was normal in 47 of 48 patients.

CONCLUSION

The results demonstrate the self limiting and benign nature of most cases of pneumonia due to Q fever. Doxycycline was more effective than erythromycin.

Q fever in Plymouth, 1972-88. A review with particular reference to neurological manifestations

Between 1972 and 1988 we have serologically confirmed 103 Coxiella burnetii infections: 46 were acute, 5 were chronic, 52 represented past infections. Details of 61 cases are presented. Of acute cases 80% had respiratory involvement; at least 63% had pneumonias. The incidence (22%) of neurological complications was of particular interest; 40% of these patients had prolonged sequelae. One acutely ill patient died of fulminating hepatitis. Patients with pre-existing pathology or immunosuppression were especially susceptible to C. burnetii. In the absence of acute sera, the complement fixation test alone provided inadequate differentiation between recent and past Q fever: phase II titres persisted at greater than or equal to 80 for more than 1 year after the acute infection in 15 cases; maximum duration of persistence was 14 years. Three patients acquired high phase I titres. Only 5% of cases had chronic Q fever, but in view of the diverse sequelae observed in this series, we suggest that long-term serological and clinical follow-up of all cases of Q fever is fully justified.

Q fever - a review

Q or "query" fever is a zoonosis caused by the organism Coxiella burnetii. Cattle, sheep and goats are the most common reservoirs of this organism. The placenta of infected animals contains high numbers (up to 10(9)/g) of C. burnetii. Aerosols occur at the time of parturition and man becomes infected following inhalation of the microorganism. The spectrum of illness in man is wide and consists of acute and chronic forms. Acute Q fever is most often a self-limited flu-like illness but may include pneumonia, hepatitis, or meningoencephalitis. Chronic Q fever almost always means endocarditis and rarely osteomyelitis. Chronic Q fever is not known to occur in animals other than man. An increased abortion and stillbirth rate are seen in infected domestic ungulates.Four provinces (Nova Scotia, New Brunswick, Ontario and Alberta) reported cases of Q fever in 1989.A vaccine for Q fever has recently been licensed in Australia.

Encephalitis caused by Coxiella burnetii

Acute infection with Coxiella burnetii usually results in a self-limited illness, but it can occasionally cause chronic endocarditis or hepatitis. Headache is a common presenting symptom of acute infection with this agent, but specific neurological abnormalities are rare. We report the case of a patient with acute Q fever that caused frank encephalitis. We also review the literature on central nervous system disease attributable to C. burnetii.

Household outbreak of Q-fever pneumonia related to a parturient cat

An outbreak of febrile respiratory disease occurred over 11 days among thirteen adults in Nova Scotia, all members of an extended family and their friends. Signs of illness included bradycardia at the same time as fever, palatal petechiae, and rapidly enlarging bilateral pulmonary infiltrates. Ten of the patients had a four-fold rise in antibody to phase-2 Q-fever antigen as determined by complement fixation on acute and 4-week-convalescent serum samples. Six children of the extended family for whom a four-fold titre rise was shown had slight or no disease. Investigations showed that the illness related to having entered the home of four of the patients on 1 of 2 consecutive days. On the first day the family cat, subsequently found to have antibody to Q fever, gave birth to kittens which she nursed in a basket kept inside the entry way. Q fever has been associated with parturient cattle, sheep, and goats but family pets, particularly cats, have not previously been implicated in human illness.

[Coexistence of Legionnaires' disease and Q fever in a single patient]

A case of Legionnaires' disease associated with Q fever is presented; this is probably the first reported case of concomitant infections with Legionella pneumophila and Coxiella burnetii. The pulmonary features of the illness were not typical of either disease. The difficulties of making a diagnosis in such cases are discussed.