[Coxiella burnetii endocarditis on a bioprosthetic valve: review of the literature apropos of a case]

Human-biting ticks and zoonotic tick-borne pathogens in North Africa: diversity, distribution, and trans-Mediterranean public health challenges

North Africa is home to more than 200 million people living across five developing economies (Egypt, Libya, Tunisia, Algeria, and Morocco) and two Spanish exclaves (Ceuta and Melilla), many of whom are impacted by ticks and tick-borne zoonoses. Populations in Europe are also increasingly vulnerable to North African ticks and tick-borne zoonoses due to a combination of climate change and the movement of ticks across the Mediterranean on migratory birds, human travellers, and trafficked wildlife. The human-biting ticks and tick-borne zoonoses in North Africa are reviewed along with their distribution in the region. We also assess present and future challenges associated with ticks and tick-borne zoonoses in North African and highlight opportunities for collaboration and coordination between governments in Europe and North Africa to address public health challenges posed by North African ticks and tick-borne zoonoses.

[Prosthetic valve endocarditis due to Coxiella burnetii: six cases]

PURPOSE

Prosthetic valve endocarditis is a dangerous complication of valvular surgery (3-6%). Among involved pathogens, Coxiella burnetii is an occasional agent, though isolated with increasing frequency. We report our experience with this peculiar endocarditis and lay stress on specific diagnostic and therapeutic difficulties.

METHODS

Between 1990 and 1995, six patients retrospectively met the diagnosis criteria for definite endocarditis due to Coxiella burnetii.

RESULTS

Five Algerian men and one French woman presented with prosthetic valve endocarditis with negative blood cultures (on bioprosthesis: four cases, on mechanical valve: two cases). The main clinical and biological feature was febrile congestive heart failure with hepatomegaly, splenomegaly, hepatic and renal abnormalities, inflammatory syndrome, hypergammaglobulinemia, anemia and lymphopenia. Serological testing for Coxiella burnetii provided diagnosis in all cases. Echocardiography displayed vegetations in all cases. Valvular replacement was performed in four patients. With antibiotic therapy including doxycycline or/and hydroxychloroquine, quinolones or rifampicine, all patients experienced complete clinical, biological and echographic remission.

CONCLUSION

Q fever prosthetic valve endocarditis presents as a systemic disorder occurring in patients with valvular heart disease. From now on, early diagnosis and efficient medical treatment may provide permanent prosthetic sterilization.

[Splenic abscess caused by Coxiella burnetti in the absence of endocarditis]

INTRODUCTION

The most frequent clinical expression of chronic Q fever is culture-negative endocarditis. Other localizations are rare.

EXEGESIS

We report a documented case of chronic Q fever that occurred in a 47-year-old immunocompetent man and was associated with spleen abscess, in the absence of detectable endocarditis. The spleen abscess was a complication of either a preexisting cyst or a calcified hematoma. Splenic infection with Coxiella burnetii was documented with cultures, polymerase chain reaction and immunohistochemistry. The outcome was favorable after splenectomy and a 21-month antibiotherapy.

CONCLUSION

Chronic Q fever may develop in the absence of endocarditis, when a preexisting vascular lesion such as aortic aneurysm exists. A splenic cyst may have played a similar role for this patient.