Prolonged hypercalcaemia after industrial exposure to vitamin D3.

the study were grouped according to their length of stay in the unit. The prevalence of the outbreak strain among patients who spent less than three days in the unit was 085% (2/235 patients), compared with 54% (32/59) among those who stayed in the unit for more than three days. Among this second group, the 27 patients who never carried the outbreak strain spent an average of 8-6 days in the unit (total 233 days) whereas the 32 patients who did acquire the outbreak strain spent an average of 21 days in the unit (total 673 days). Thus there was a higher risk of colonisation by the outbreak strain for patients who remained in the unit for a long time. The average time between admission to the unit and colonisation with the outbreak strain was 6-6 days. This was consistent with a model of superinfection with an exogenous candidal strain. Four of the patients who subsequently died from infection with the outbreak strain were initially colonised by a different candidal phenotype. In two cases this was C tropicalis. These patients did not develop systemic disease from their original endogenous yeast but became superinfected by the endemic outbreak strain, which then disseminated. The outbreak was due to a particular strain of C albicans (serotype A, morphotype Al, biotype O/,5 5/7). This strain survived better on nurses' hands than control strains of C albicans and was considerably more resistant to washing with Hibiscrub, the disinfectant mainly in use at the time of the study. The lack of an environmental source agrees with earlier work20 21 and accords with the observation that the outbreak strain did not survive better on blocks of formica than the control strains. Of the 65 staff examined, four were oral carriers of the outbreak strain and one carried this strain on her hands. While nursing patients with systemic infections two out of 17 nurses acquired the outbreak strain. One nurse developed clinical vaginal candidosis 48 hours after nursing a patient (case 15). She had no history of the disease, and the isolate was the same as the outbreak strain. The data suggest that the cycle of infection lies between patients and staff. In conclusion, we found that one particular strain of C albicans was capable of causing systemic candidosis as a result of cross infection between patients and staff. It not only caused invasive infections but showed a propensity to spread, possibly due to its relative resistance to washing with Hibiscrub. Previously, chemoprophylaxis has concentrated on eradicating endogenous yeast flora from the gastrointestinal tract.3 This should perhaps be combined with isolation of patients with systemic infections and heavy colonisation as well as handwashing with disinfectants that are active against candida.