Introduction Oral candidiasis is the most common opportunistic infection seen in HIV-infected children around the world. The impact of highly active antiretroviral therapy (HAART) has resulted in a decline in the incidence of oral candidiasis in this population. This study aimed to estimate the incidence of oral candidiasis in HIV-infected children in pre-HAART and post-HAART eras.

Methods It was a cohort study. All HIV-infected children admitted in a Brazilian paediatric hospital were followed from 1985 to 2009. For analytical purpose, the patients were divided in two groups according to HIV diagnostic data: pre-HAART (from 1985 to 1998) and post-HAART (1999 to 2009). The incidence rate, incidence rate ratio and CIs were calculated respectively. The incidence rates through people-time were obtained by dividing the number of oral candidiasis episodes by the sum of the years that each subject contributed to the study. Only the first event per patient was considered for the incidence rate.

Results The study included 388 patients. The mean age at admission was 3.3 years and 48.2% of the children were female. The pre-HAART and post-HAART incidences of oral candidiasis were 6.4 and 2.7 cases per 100 children-years (p<0.000), resulting in an incidence rate ratio of 2.4 (CI 1.4 to 4.5).

Conclusion Oral candidiasis incidence was significantly reduced in the post-HAART era in this Brazilian cohort. Continued surveillance is important to assess the long term effect of HAART on the occurrence of opportunistic infections in children.