Is PVL positive S. aureus dangerous?
S. aureus strains that are positive for PVL, and especially epidemic strains of PVL CA-MRSA, have an increased ability to cause spontaneous infection and recurrent disease as compared to toxin negative S. aureus strains. Most of these infections are superficial skin infection such as a boil or skin abscess. These tend to heal spontaneously or heal after incision and drainage. Thus, most infections caused by PVL S. aureus are not dangerous. However, a correct diagnosis is important since (i) recurrence of infection and spread between members of a household or close contacts is a common feature of epidemic PVL CA-MRSA, (ii) the recurrent boils are unpleasant, and (iii) the identification of MRSA would help to avoid the use of ineffective antibiotics. Rarely, PVL positive S. aureus causes severe and life-threatening infection such as pneumonia in previously healthy adults and children. Once such a severe infection has developed, the fatality rate is high. Fatalities in previously healthy