Pediatric Pneumonia Death Caused by Community-acquired Methicillin-Resistant Staphylococcus aureus, Japan

To the Editor: Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA), which carries genes for Panton-Valentine leukocidin (PVL), has become a major concern worldwide (1–3). CA-MRSA is mainly associated with skin and soft tissue infections in young, otherwise healthy, persons in the community (3) and also with life-threatening sepsis and community-acquired pneumonia (preceded by infl uenza) (1,3,4). The role of PVL in the pathogenesis of staphylococcal infections is controversial. Whereas Labandeira-Rey et al. (5) provided data that PVL, in combination with staphylococcal protein A, destroys respiratory tissue and bacteria-engulfi ng immune cells, Voyich et al. (6) and Bubeck Warden-burg et al. (7) showed that PVL was not essential for the pathogenesis of skin disease, sepsis, or pneumonia in a mouse model. Several types of CA-MRSA clones exist, e.g., CA-MRSA belonging to multilocus sequence type (ST) 1 (called the USA400 clone) and ST8 (called the USA300 clone), which have been major clones in North America (recently, USA300 is becoming more prominent); CA-MRSA belonging to ST80, which has been a major clone in Europe; and CA-MRSA belonging to ST30, which is distributed worldwide, including Japan (2,8). MRSA carrying the PVL gene (a marker of CA-MRSA [ST30]) comprises 0.1% of MRSA isolated in hospitals in Japan (9).We describe a fatal case of pediatric pneumonia and septic shock from CA-MR-SA in Japan. A 16-month-old, previously healthy boy was admitted to the hospital for fever and shortness of breath on August 30, 2006. He had had cold-like symptoms for 14 days and fever for the 2 previous days. On examination , hordeolum of the right eyelid and cyanosis were observed; the patient's blood pressure was 106/ (undetectable) mm Hg, tachycardia 185 beats/ min, tachypnea 72 breaths/min, and temperature 39.8°C. He had bilateral coarse breath sounds, and broncho-vesicular breath sounds over the right lung. Chest radiography indicated lo-bar consolidation and pleural effusion on the right side. Laboratory analysis showed leukocytopenia, thrombocy-topenia, elevated C-reactive protein level, and hypoxemia. Intravenous administration of sulbactam/ampicillin and cefotaxime, and oxygen inhalation was started. Oxygen saturation did not improve, and laboratory values of disseminated intravascular coagulation (DIC) were observed: platelet count 121 K/mm 3 , fi brinogen level 528 mg/dL, fi brin degradation products 37.7 μg/mL, prothrombin time 1.86 international normalized ratio, and D-dimer 37.7 μg/mL. The condition was considered septic shock, and consequently the boy was transferred to the pediatric intensive care unit, where he required intu-bation and mechanical ventilation. Sulbactam/ampicillin was switched to …