Variable number tandem repeat polymorphism of the interleukin-1 receptor antagonist gene in meningococcal disease.

Sir—The experience reported by Myoken et al. [1] of superinfection with fungal organisms resistant to itraconazole in patients who are receiving the drug as prophylaxis is of interest. We have not seen superinfections with resistant organisms in immunocompromised HIV-infected patients receiving prophylactic itraconazole. In our experience [2] and in that of others who have reported in vitro testing results [3–5], Penicillium marneffei strains have been uniformly susceptible to itraconazole. However, resistance to fluconazole is not uncommon. In our doubleblind trial [6], 1 (1.6%) of 63 subjects assigned to receive itraconazole developed a disseminated P. marneffei infection, and 11 (16.7%) of the 66 persons who received placebo developed a systemic fungal infection (7 of these patients developed cryptococcal meningitis, and 4 developed P. marneffei infection). We have not done in vitro testing of isolates from these patients. Because the study was blinded, we were not aware of which regimen the patients were receiving at the time that infection was diagnosed. However, the lower rates of P. marneffei infection seen among patients receiving itraconazole suggest that the drug may have been effective. Whether the breakthrough infection that occurred in the single patient who became infected with P. marneffei could have been due to dosing or pharmacokinetic issues, rather than to resistance of the organism to itraconazole, is unclear. We agree with Myoken et al. [1] that monitoring of patients receiving itraconazole who develop fungal infections and susceptibility testing of isolates from these patients could be important. Kenrad E. Nelson, Suwat Chariyalertsak, Khuanchai Supparatpinyo, and Thira Sisisanthana Department of Epidemiology, Johns Hopkins University, Baltimore, Maryland; and Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand