Fatal Human Co-infection with Leptospira spp. and Dengue Virus, Puerto Rico, 2010

was identifi ed in 1 sample. These results enabled us to compare DHPS genotypes for 6 pairs of samples. A full match was found for these 6 pairs. DHPS and ITS genotype matches were found for 4 pairs. Several lines of evidence suggest that P. jirovecii is exhaled by infected patients and transmitted by the airborne route to susceptible persons (4). In the study reported here, ITS or DHPS genotype matches between pairs of pulmonary and air samples are consistent with the possibility that P. jirovecii organisms in the air originated from patients. DHPS mutants were detected in 6 (40%) of the 15 pulmonary samples; none of the15 patients had received sulfonamide treatment at the time of PCP diagnosis. These results were not unexpected because frequency of fi nding DHPS mutants in PCP patients in Paris who had no prior sulfonamide treatment is high (8). The exhalation of DHPS mutants from infected patients can spread potentially sulfonamideresistant organisms. Matches of P. jirovecii genotypes in pairs of pulmonary and room air samples argue in favor of P. jirovecii exhalation by infected patients. The exhalation of P. jirovecii organisms emphasizes the risk for their nosocomial transmission. Our data provide additional arguments in favor of the application of measures to prevent the airborne transmission of P. jirovecii in hospitals.