Table 3.

Available data about rates of laboratory accidents and infections with specific parasitesa

Toxoplasma gondii
 Laboratory A in the United Kingdomb
  Rate of recognized laboratory accidents per person-hour of relevant work: one accident per 9,300 person-hours (three accidents in 27,750 person-hours of “performing the dye test or demonstrating viable T. gondii”)
  Total number of probable laboratory-acquired infections: one, which occurred in someone who had been symptomatic but had not noted an accident and whose case was detected through a serosurvey
 Laboratory B in the United States
  Number of person-years of work: ∼48 person-years (average of two to three persons working at a time, over a 19-year period; not limited to hours of relevant work)
  Rate of recognized laboratory accidents per person-year: one accident per 12 person-years (four accidents in 48 person-years)
  Rate of infections per person-year: one infection per 24 person-years (two symptomatic seroconversions in 48 person-years; testing done at baseline and after accidental exposures)
Trypanosoma cruzi
 State of São Paulo, Brazilc
  Number of person-years of work: 126.5 person-years over a period of ∼17 years, including 91.5 person-years of relatively high-risk work (e.g., working with needles, preparing viable parasites, working with tissue cultures with large numbers of parasites) by 21 persons
  Rate of recognized laboratory accidents per high-risk person-year: one accident per 15 person-years (six accidents in 91.5 person-years)
  Rate of infections per high-risk person-year: one infection per 46 person-years (two infections in 91.5 person-years)
 Laboratory C
  Rate of infections: four asymptomatic seroconversions, without recognized accidents, among ∼20 persons, during the period from the late 1970s through mid-1999 (number of person-years of work not available); two of the four persons had positive stool specimens
 Collective data from an unspecified number of laboratories that included “over 100 persons handling millions of cercariae for  over 20 years”d Number of symptomatic infections: none Number of asymptomatic seroconversions: two
  • a See the text for additional details. The extent to which these data are representative of research laboratories and laboratorians that work with these parasites is unknown.

  • b Data taken from reference 132.

  • c Data taken from M. Rabinovitch and R. de Cassia Ruiz, personal communication.

  • d Data taken from reference 58.