Malignant Boutonneuse fever with multiple organ failure: a three-case series

Introduction

Rickettsia conorii infection, the agent of Boutonneuse fever, presents usually in a form considered benign, with serious complications in less than 10% of patients. Its mechanism of infection consists of vascular endothelial invasion by the microorganism and subsequent vasculitis and tissue necrosis. The process is usually localized or limited to the skin but can progress with malignant severe systemic involvement [1,2].

Methods

A series of three cases of patients with multiple organ failure admitted to an ICU with confirmed diagnosis of Boutonneuse fever is presented (positive serology or tissue PCR).

Results

Common to all the patients was the rapid development of the disease (average: 3 days) from the initial complaints of fever after a bite by an unidentified agent and development of generalized rash, and the diagnosis of multiple organ failure (average Simplified Acute Physiology Score II: 59; average Sequential Organ Failure Assessment score on admission: 12.6). All developed respiratory failure requiring invasive mechanical ventilation, haematological failure with haemolytic anaemia and acute renal failure suggestive of serious widespread vasculitis. One of the cases developed lethal refractory septic shock within 6 hours of admission. Tetracycline antibiotic therapy was started early in all patients, based on clinical and epidemiological data, since initial microbiological results were negative.

Conclusion

This series of cases illustrates the most severe form of Boutonneuse fever, usually associated with comorbidities such as diabetes, malignant disease, immunodeficiency or delay in the diagnosis and appropriate antibiotic therapy, which was not the case in these patients.