An outbreak of hospital-acquired Staphylococcus aureus skin infection among newborns, Nan Province, Thailand, January 2008.

In January 2008, we investigated a cluster of neonates with bullous impetigo in a hospital of northern Thailand in order to control the outbreak and identify a potential source of the infection. We reviewed medical records and working timetables of healthcare workers (HCWs) and conducted a case-control study. We performed an environmental study and took bacteriological samples from HCWs and equipments. According to our case definitions, we identified 16 confirmed cases and 14 probable cases. The attack rate was 42%. Most cases had skin blisters (28 cases) followed by pustules (five cases) and exfoliation (three cases). The location of the lesion was the trunk (17 cases), neck (14 cases) or armpits (nine cases). Nineteen cases had symptoms onset after discharge from hospital. Median age at onset was 4 days. The strain isolated from an infected newborn shared the same phage type as the contaminated equipment. Insufficient hand hygiene was an observed risk behaviour of HCWs and visitors. Exposure to a nasal carrier of Staphylococcus aureus (adjusted OR: 80.3, 95% CI: 4.8 - 1350.3) and ward sharing with a symptomatic case (adjusted OR: 35.6, 95% CI: 1.9 - 654.7) increased the risk of acquiring the infection. The outbreak ended abruptly after implementation of hand hygiene practices and equipment cleaning.