[Outbreak of skin infections due to Staphylococcus aureus carrying Panton-Valentine leukocidin genes in pupils and their relatives].

Objectives: The study objectives were to describe an outbreak of skin infections in school settings, caused by Staphylococcus aureus carrying Panton-Valentine leukocidin genes (Sa PVL(+)), over a 2-year period. Nasal colonization prevalence was assessed in families where new skin infections occurred, despite a prevention and control strategy.
Patients and Methods: A retrospective investigation of skin infections likely to be related to Sa and prospective monitoring and treatment of new infections occurring in pupils and their family members were implemented in October 2006, following the reporting of Sa PVL(+) abscesses and furuncles in a primary school. Additional nasal screening was performed in families where new skin infections occurred, after an initial systematic screening of Sa PVL(+) nasal carriers.
Results: On October 31, 2008, 53 patients, accounting for 30 households, had developed 69 skin infections, in four decreasing outbreaks. The cumulative incidence of a first skin infection was 34.6% in primary classes, 21.3% in nursery schools, and 6.5% in the pupils' family households. Several skin infections were reported in 13 households, and in one of them, all of the seven family members had developed at least one skin infection during follow-up. The estimated frequency of nasal colonization ranged from 14.1% to 19.5% according to successive nasal screenings.
Conclusion: Early reporting of skin infection clusters is necessary to reinforce the effectiveness of hygiene and prevention measures, and thus limit the risk of a long-lasting outbreak.
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