Investigation and management of an imipenem-resistant oxa-23 Acinetobacter baumannii outbreak in an intensive care unit

OBJECTIVES

The study objectives were to describe the investigation and management of an imipenem-resistant Acinetobacter baumannii outbreak that occurred in the 15-bed ICU of a tertiary care teaching hospital (Brest, France), during the summer 2008.

PATIENTS AND METHODS

Patients harboring an imipenem-resistant A. baumannii strain were defined as case patients. We described case occurrence and steps taken to control the outbreak: contact isolation, reinforcement of hygiene procedures, unit shutdown decision, unit disinfection, and reopening. We also made a case control study and a cost analysis of the outbreak management.

RESULTS

During a 10-day period, five patients were positive for a single clone of imipenem-resistant oxa-23 A. baumannii. Four patients presented with ventilation-acquired pneumonia and one was asymptomatic. The first two patients died one day after the first swab which led to the identification of A. baumannii. No additional case was noted in the ICU or in other hospital units after deciding to close the ICU. The cost of outbreak management was estimated at 264,553 euros. The case control study identified several factors associated with infection or colonization: length of stay in the ICU, chronic respiratory disease, number of previous antibiotic classes used, duration of ventilation, prone position, echocardiography, and presence of a nasogastric tube.

CONCLUSION

This outbreak occurred during the summer period requiring the shutdown of the ICU and inducing a considerable cost. Rapid reactions of the ICU staff during the outbreak enabled to limit the epidemic.

Juvenile relapsing periarteritis nodosa and streptococcal infection

Classic polyarteritis nodosa is a multisystem inflammatory disease associated with necrotizing vasculitis of small and medium arteries. In most cases, the causes of polyarteritis nodosa remain unknown, but viruses (HBV, HCV, HIV) and microbes (especially streptococcus) have been considered as etiologic or contributing factors. A 13-year-old boy was admitted with fever, skin lesions, polyarthritis and muscle involvement. A muscle biopsy demonstrated a necrotizing vasculitis and antistreptolysin titre was tremendously increased. His condition improved following the administration of oral steroids but he experienced relapses 5 and 12 years later when penicillin withdrawal was attempted. The flares were accompanied by a major increase of antistreptolysin titre and response to corticosteroid was obtained. He is currently 38 years old and he remains well on prophylactic penicillin. Polyarteritis nodosa in children may occur after a streptococcal infection. It may be prudent to consider penicillin prophylaxis in patients with periarteritis nodosa when a streptococcal etiology is documented or highly suspected.

[Idiopathic orbital myositis]

INTRODUCTION

Orbital myositis is a subtype of nonspecific orbital inflammation confined to one or more of the extraocular muscles.

EXEGESIS

Three female patients presented presumed orbital myositis, in each of whom the diagnosis was suspected clinically and confirmed by the computed tomography (CT) scan appearances. All presented with orbital pain, diplopia and periorbital edema. All patients responded to systemic corticosteroid with prompt resolution of symptoms and signs, but one patient had recurrent episodes of myositis, leading to the prescription of azathioprine. The clinical and radiological constellation of findings allowing a definitive diagnosis of the nonspecific orbital inflammatory syndrome in most cases is discussed.

CONCLUSION

The nonspecific orbital inflammatory syndromes are a heterogenous group of conditions and the CT scan is a valuable tool in differentiating these conditions. Most cases of idiopathic orbital myositis require corticosteroids, but therapeutic alternatives to corticosteroids in refractory diseases are warranted.