Association between oral candidiasis and immunity level in a population of drug addicts in a centre for prevention and treatment of drug addictions in Rome, Italy

Abstract number: 1733_783

Rocchi L., D'Alessandro D., Fabiani M., Osborn J.F., Leonardi C., Tarsitani G., Grillot R., Vescia N.

Objectives: To evaluate the prevalence of Candida infections in the oral cavity of a population of drug addicts, in order: (1) to test the susceptibility of Candida isolates to antifungal compounds; (2) to evaluate the relationship between history of drug abuse, Candida infection and CD4 levels.

Methods: Fifty-seven drug addicts were enrolled in the prospective study: oral samples were collected from each one and cultured for yeast detection on selective medium. The Candida isolates were identified by API 20C AUX^® (bioMérieux, France) and C. dubliniensis by BICROMO-DUBLI^® (Fumouze Diagnostic, France). Using E-test (AB Biodisk, Sweeden), the strains' susceptibility to fluconazole was determined. Regression analysis and significance test were used to compare means and distributions.

Results: Heroin (55 subjects, 96.5%) and/or cocaine (31 subjects, 54.4%) were the drugs most used, and 51 subjects (89.5%) were addict to more than one drug. The duration of the drug addiction varied from 1 to 26 years (mean 13.4). Nine subjects (15.8%) were HIV-infected. The prevalence of oro-pharyngeal candidiasis was 31.6% (18 subjects): 11 cases >250 CFU and 7 cases 50–250 CFU. C. albicans was the most common species (n = 16, 88.8%) and infection due to C. dubliniensis was identified in 4 subjects (22.2%). 87% of C. albicans and 86% of C. dubliniensis isolates were susceptible to fluconazole (MIC ≤ 8 micro-g/mL). The CD4 count was less than 500/mL in 8 subjects (14.03%) and for 3 of them, HIV positive, it was less than 200/mL. The difference between the mean values of PMNs was statistically significant (mean difference 1,479.3; P = 0.04) in subjects with >150 CFU of Candida in oral cavity. There was no evidence of an association between CD4 count and years of use of heroin. However the percentage level of CD4 reduced on average by 0.033 for each additional year of heroin use (P = 0.03). The difference between the mean years of use of heroin in subjects infected or not by C. dubliniensis (difference: 6.35 years) was statistically significant (P < 0.05).

Conclusion: This work shows an association between oral candidiasis (>150 CFU) and reduction in the level of PMNs. The percentage of CD4 is lower in patients who abuse heroin together with other drugs, and the reduction is proportional to the number of years of drug use. The finding of C. dubliniensis in the oral cavity is associated with the duration of heroin abuse.