Should Acute Q-Fever Patients be Screened for Valvulopathy to Prevent Endocarditis?

Long-term serological follow-up after primary Coxiella burnetii infection in patients with vascular risk factors for chronic Q fever

We evaluated the long-term serological follow-up of patients with vascular risk factors for chronic Q fever that were previously Coxiella burnetii seropositive. C. burnetii phase I IgG titers were reevaluated in patients that gave informed consent or retrospectively collected in patients already deceased or lost to follow-up. Of 107 patients, 25 (23.4%) became seronegative, 77 (72.0%) retained a profile of past resolved Q fever infection, and five (4.7%) developed chronic Q fever. We urge clinicians to stay vigilant for chronic Q fever beyond two years after primary infection and perform serological testing based on clinical presentation.

Acute Q Fever Endocarditis: A Paradigm Shift Following the Systematic Use of Transthoracic Echocardiography During Acute Q Fever

BACKGROUND

As Q fever, caused by Coxiella burnetii, is a major health challenge due to its cardiovascular complications, we aimed to detect acute Q fever valvular injury to improve therapeutic management.

METHODS

In the French national reference center for Q fever, we prospectively collected data from patients with acute Q fever and valvular injury. We identified a new clinical entity, acute Q fever endocarditis, defined as valvular lesion potentially caused by C. burnetii: vegetation, valvular nodular thickening, rupture of chorda tendinae, and valve or chorda tendinae thickness. To determine whether or not the disease was superimposed on an underlying valvulopathy, patients' physicians were contacted. Aortic bicuspidy, valvular stenosis, and insufficiency were considered as underlying valvulopathies.

RESULTS

Of the 2434 patients treated in our center, 1797 had acute Q fever and 48 had acute Q fever endocarditis. In 35 cases (72%), transthoracic echocardiography (TTE) identified a valvular lesion of acute Q fever endocarditis without underlying valvulopathy. Positive anticardiolipin antibodies (>22 immunoglobulin G-type phospholipid units [GPLU]) were independently associated with acute Q fever endocarditis (odds ratio [OR], 2.7 [95% confidence interval {CI}, 1.3-5.5]; P = .004). Acute Q fever endocarditis (OR, 5.2 [95% CI, 2.6-10.5]; P < .001) and age (OR, 1.7 [95% CI, 1.1-1.9]; P = .02) were independent predictors of progression toward persistent C. burnetii endocarditis.

CONCLUSIONS

Systematic TTE in acute Q fever patients offers a unique opportunity for early diagnosis of acute Q fever endocarditis and for the prevention of persistent endocarditis. Transesophageal echocardiography should be proposed in men, aged >40 years, with anticardiolipin antibodies >60 GPLU when TTE is inconclusive or negative.

Risk of chronic Q fever in patients with cardiac valvulopathy, seven years after a large epidemic in the Netherlands

BACKGROUND

From 2007 through 2010, a large epidemic of acute Q fever occurred in the Netherlands. Patients with cardiac valvulopathy are at high risk to develop chronic Q fever after an acute infection. This patient group was not routinely screened, so it is unknown whether all their chronic infections were diagnosed. This study aims to investigate how many chronic Q fever patients can be identified by routinely screening patients with valvulopathy and to establish whether the policy of not screening should be changed.

METHODS

In a cross-sectional study (2016-2017) in a hospital at the epicentre of the Q fever epidemic, a blood sample was taken from patients 18 years and older who presented with cardiac valvulopathy. The sample was tested for IgG antibodies against phase I and II of Coxiella burnetii using an immunofluorescence assay. An IgG phase II titre of ≥1:64 was considered serological evidence of a previous Q fever infection. An IgG phase I titre of ≥1:512 was considered suspicious for a chronic infection, and these patients were referred for medical examination.

RESULTS

Of the 904 included patients, 133 (15%) had evidence of a previous C. burnetii infection, of whom 6 (5%) had a chronic infection on medical examination.

CONCLUSIONS

In a group of high-risk patients with a heart valve defect, we diagnosed new chronic Q fever infections seven years after the epidemic, emphasizing the need for screening of this group to prevent complications in those not yet diagnosed in epidemic areas.

Ten-year experience of Q fever endocarditis in a tertiary cardiac center in Saudi Arabia

BACKGROUND

Q fever endocarditis (QFE) is considered rare in the Middle East, with only a few cases reported in Saudi Arabia. The aim of this study is to report on the experience of our centre on QFE.

METHODS

We searched the medical records for cases of QFE at our cardiac center from 2009-2018. Demographic data, clinical features, serology and echocardiography results, treatments, and outcomes were assessed.

RESULTS

Five hundred and two cases of infective endocarditis were detected over the 10 years period. Among the 234 patients with blood culture-negative endocarditis (BCNE), 19 (8.10%) had QFE. All patients had a previously diagnosed congenital heart disease except for one patient with rheumatic heart disease. Eleven patients had received a bovine jugular vein-related implant, e.g., a Melody valve (seven patients) or Contegra conduit (four patients). Coinfection was detected in three patients, and immunologic and embolic phenomena were observed in five patients. All patients received a combination of hydroxychloroquine and doxycycline, with good outcomes. Only two patients required surgery while on treatment. Two patients died several months after treatment; the cause of death was not identified.

CONCLUSION

This study indicates that Q fever exists in our population. The majority of the patients had congenital heart disease (CHD) and underwent bovine jugular vein implants. Patients with CHD are at increased risk of infective endocarditis. Bovine jugular vein implants increase the risk of infective and possibly QFE. Proper exclusion of Q fever is warranted in all BCNE and possibly in culture-positive endocarditis cases in areas endemic to Q fever.

KEY POINTS

We presented the largest series of Q fever endocarditis cases in Saudi Arabia. We showed that Q fever is not rare in the Middle East and suggest that it should be considered in all blood culture-negative endocarditis cases.