Human parvovirus B19 nosocomial outbreak in healthcare personnel in a paediatric ward at a national tertiary referral centre in Thailand

Background Nosocomial outbreaks of parvovirus B19 (pB19) have been reported, but they rarely occur among healthcare personnel (HCP). Susceptibility among pregnant HCP was the major concern. Methods An outbreak of pB19 among HCP is described in a paediatric ward with a cross-sectional serologic study in all HCP and patients exposed to the outbreak. Acute infection was diagnosed by polymerase chain reaction or positive anti-parvovirus B19 IgM. Findings Among 48 HCP (three pregnant) and 22 patients included in the outbreak serologic study, 11 (23%) HCP and two (9%) patients had acute infection. Of these, six HCP and no patients were symptomatic. Clinical manifestations included itchy rash (100%) and joint pain following resolution of rash (67%), with median rash duration of four days. Forty percent of HCP and 50% of patients had positive anti-parvovirus IgG, indicating previously immune status. HCP with acute infection and HCP who were susceptible without infection were younger than HCP with previous immunity (mean age 32.2 vs 40.5 years, respectively; P = 0.003). The attack rate was 38% among HCP and 18% among patients who were susceptible, respectively. The outbreak ended within two weeks following strict droplet precaution and segregation of symptomatic HCP. Conclusion Parvovirus B19 infection may cause nosocomial outbreak with high attack rate among HCP. Outbreak control with droplet precaution was highly effective.