Changes in the oral microflora during cytotoxic chemotherapy in children being treated for acute leukemia.

Thirty-four children with diagnosed cases of acute leukemias and being treated with cytotoxic chemotherapy at St James' Hospital, Leeds, were followed for between 6 months and 1 year to determine the changes in their oral microflora. They were examined before treatment commenced and then at monthly intervals. Swabs were taken from the oral cavity to test for the presence or absence of bacteria and Candida. Saliva samples were also used to assess the levels of Streptococcus mutans in the mouth. Sensitivity tests were carried out to assess the effect of the cytotoxic agents on the oral flora. All children received prophylactic nystatin and chlorhexidine gluconate mouthrinses four times daily for the whole period of the study. There was significant difference (p < 0.0001) for counts of S. mutans at different treatment stages. Sensitivity tests showed that S. mutans was sensitive to the cytotoxic drug daunorubicin, and this drug was probably responsible for the fall in S. mutans counts. A significant difference was also found in the types of bacteria isolated between the study and reference groups, but there was no change in the composition of the flora in the study group during treatment. These bacteria were also found to mirror those cultured from routine blood samples in children with acute leukemia.