One-year follow-up of patients of the ongoing Dutch Q fever outbreak: clinical, serological and echocardiographic findings

Abstract

PurposeIn 2007, a large goat-farming-associated Q fever outbreak occurred in the Netherlands. Data on the clinical outcome of Dutch Q fever patients are lacking. The current advocated follow-up strategy includes serological follow-up to detect evolution to chronic disease and cardiac screening at baseline to identify and prophylactically treat Q fever patients in case of valvulopathy. However, serological follow-up using commercially available tests is complicated by the lack of validated cut-off values. Furthermore, cardiac screening in the setting of a large outbreak has not been implemented previously. Therefore, we report here the clinical outcome, serological follow-up and cardiac screening data of the Q fever patients of the current ongoing outbreak.MethodsThe implementation of a protocol including clinical and serological follow-up at baseline and 3, 6 and 12 months after acute Q fever and screening echocardiography at baseline.ResultsEighty-five patients with acute Q fever were identified (male 62%, female 38%). An aspecific, flu-like illness was the most common clinical presentation. Persistent symptoms after acute Q fever were reported by 59% of patients at 6 months and 30% at 12 months follow-up. We observed a typical serological response to Coxiella burnetii infection in both anti-phase I and anti-phase II IgG antibodies, with an increase in antibody titres up to 3 months and a subsequent decrease in the following 9 months. Screening echocardiography was available for 66 (78%) out of 85 Q fever patients. Cardiac valvulopathy was present in 39 (59%) patients. None of the 85 patients developed chronic Q fever.ConclusionsClinical, serological and echocardiographic data of the current ongoing Dutch Q fever outbreak cohort are presented. Screening echocardiography is no longer part of the standard work-up of Q fever patients in the Netherlands.

Chronic Q Fever in the Netherlands 5 Years after the Start of the Q Fever Epidemic: Results from the Dutch Chronic Q Fever Database

“…This is in contrast with earlier reports from France, where endocarditis predominates (1, 7). It might be that this disparity is caused by strain-specific differences, leading to distinct clinical presentations (24). Another explanation might be increased awareness in the Netherlands of this previously relatively unacknowledged manifestation of chronic Q fever.…”

“…Moreover, active case finding in a Q fever epidemic area could be initiated by screening for Q fever in high-risk groups, including patients with aneurysms, vascular prostheses, or heart valve prostheses (12). In our current analysis, minor heart valve lesions (for example, grade I aortic valve insufficiency) were also included as risk factors for chronic Q fever, although the influence of minor valvulopathies on chronic Q fever development is debated (13,24,25). This could have led to overestimation of the amount of risk factors in all chronic Q fever cases.…”

Effectiveness of Long-term Doxycycline Treatment and Cognitive-Behavioral Therapy on Fatigue Severity in Patients with Q Fever Fatigue Syndrome (Qure Study): A Randomized Controlled Trial

“…Besides chronic Q fever (ie, persistent C. burnetii infection), which occurs in 1%-5% of cases [1], a debilitating fatigue syndrome has been described [2][3][4][5][6][7][8][9][10][11]. This Q fever fatigue syndrome (QFS) persists for years in approximately 20% of cases following acute Q fever [2][3][4][5][6][9][10][11]. Many QFS patients fulfill the case definition of chronic fatigue syndrome (CFS) [2,8,10,12].…”

Prevalence of Chronic Q Fever in Patients with a History of Cardiac Valve Surgery in an Area Where Coxiella burnetii Is Epidemic

“…These titers can also be caused by antibodies cross-reacting to other pathogens or by aspecific reactions (18). Yet, it is also known that, following C. burnetii infection, antibodies to C. burnetii can disappear over time or titers can become very low, leading to an underestimation of the infection rate (12,25). This was illustrated in our study by one case who had a confirmed acute Q fever episode in 2009 and demonstrated a phase II IgG titer of 1:32 in our screening.…”