Background
Panton Valentine Leukocidin S. aureus  (PVL-SA) has repeatedly been associated with more severe disease than PVL negative S. aureus infections, although controversy exists as to whether PVL-toxin is the major virulence determinant. Surveillance studies in England found PVL-SA in less than 5% of S. aureus related disease, and less than 2% of S. aureus bacteraemias.

Case Presentation Summary
A previously well two-years-old girl presented in poor clinical conditions with a 5 days history of fever and swollen left eye. She was diagnosed with periorbital cellulitis and was started on intravenous ceftriaxone and metronidazole. A brain MRI was also performed confirming the diagnosis. Her blood culture grew fully sensitive S. aureus.  A cardiac ultrasound revealed no abnormalities. However, she developed sixth nerve palsy after five days of treatment and an urgent brain CT showed a small extra-axial collection in the posterior fossa, and septic emboli in both lungs. Repeated brain MRI reported a cavernous sinus thrombosis. Therapy was switched to flucloxacillin, and when PVL was reported, rifampicin was added. Once stable, using an elastomeric device for flucloxacillin delivery, the patient was discharged under the supervision of our paediatric outpatient parenteral antimicrobial therapy team (p-OPAT); she required a prolonged intravenous treatment course of three months and completed her antimicrobial treatment with a further month of oral amoxicillin-clavulanate. The patient made a full recovery.

Learning Points/Discussion
This case illustrates that PVL-MSSA can cause very severe invasive disease in children. Clinicians and laboratories should routinely submit isolates for PVL from children with invasive MSSA disease, because this would improve the knowledge of the epidemiology of the disease. Optimal antimicrobial combination and length of therapy is not well established.

SEVERE PANTON VALENTINE LEUKOCIDIN METiCILLIN-SENSITIVE STAPHYLOCOCCUS AUREUS INFECTION: A CASE REPORT