Optimum sampling time for detection of dental bacteraemia in children

A total of 458 blood cultures were taken from 229 children aged 2 to 16 yr. Each 6 ml sample was taken starting at one of the following times after the extraction of a single tooth: 10 s, 30 s, 60 s, 90 s, 120 s, 180 s, 600 s and continuously over 2.5 min. The samples were cultured in the BACTEC radiometric culture system and when positive the bacteria isolated were speciated. At 30 s 56% of the samples were positive, the highest proportion, in contrast to only 38% of positive samples at 90 s and 28% at 600 s. Over 50% of the organisms found were Viridans streptococci.