Under-recognition and under-reporting marks the epidemiological profile of CA-MRSA (community acquired methicillin resistant Staphylococcus aureus) in India. We present the first case report with Panton-Valentine leukocidin (PVL) gene isolation.

The index case, a 13 year male, previously well, developed a boil in left elbow followed by fever, rapidly progressive tender swelling of left leg, respiratory distress and septic shock within next 12 hours warranting intubation, mechanical ventilation and use of pressors. Thrombotic and vasculitis work-up, coagulation, hematological, metabolic para-meters were normal with polymorphonuclear leucocytosis. Limb Doppler showed femoropopliteal deep venous thrombosis (DVT). CT chest revealed patchy consolidation in both lungs CT limb and echocardiogram were normal. Blood culture sent on day 1 of illness grew MRSA.

The patient was started on linezolid and low molecular weight heparin. Despite 7 days of IV linezolid therapy, blood cultures remained positive for MRSA. We switched to clindamycin (initially intravenous and later oral), given for a total of 4 weeks. Genetic studies confirmed presence of PVL gene.

CA-MRSA infections differ from hospital acquired MRSA by predominantly presenting as minor skin and soft tissue infections in risk free healthy hosts(1). Infection often carries PVL toxin that kills leucocytes and is associated with severe course of disease(1,2). Our patient had DVT, a well recognized association in patients with CA-MRSA. "PVL syndrome" includes osteomyelitis, skin infections, pneumonia and DVT(3).

The recommended antibiotic therapy for severe infections with CA-MRSA include vancomycin, linezolid and clindamycin(2,4,5). Vancomycin is used to treat sensitive (MIC <1µg/mL) strains. Data of resistance to this drug in India is lacking. Vancomycin MIC was of intermediate range here (2-4 µg/mL) and hence was not prescribed. Linezolid (IV or oral) is recommended as standard ICU therapy for suspected CA-MRSA pneumonia due to good lung penetration.

2.4% to 10% of CA-MRSA isolates initially reported susceptible to clindamycin (but resistant to erythromycin) may develop clindamycin resistance (detected by the D-zone disk diffusion test) resulting in treatment failure. Our patient’s D test was negative. Unlike vancomycin, linezolid and clindamycin have excellent anti-toxin activity.

The PVL toxin and CA–MRSA are under-recognized entities in India. In very sick patients with risk factors for MRSA, possibility of CA-MRSA infection must be entertained and vancomycin/clindamycin empirically used with de-escalation later. However, it is vital to avoid indiscriminate misuse of higher and antibiotics in the management of methicillin sensitive staphylococcal infections where cloxacillin is the drug of choice.

Kerry Williams, Clinical Scientist, Royal Free Hospital London isolated the PVL gene from the strain; Dr Abdul Gafur for helping us send the strain for genetic analysis.