Patterns of fungal colonization in preterm infants weighing less than 1000 grams at birth

Background: Colonization with Candida spp. is an important risk factor for systemic infection in very low birth weight (VLBW; < 1500 g) and extremely low birth weight (ELBW, < 1000 g) infants. ELBW infants are at a higher risk than VLBW infants for fungal sepsis and its associated mortality, but few studies have examined fungal colonization exclusively in ELBW infants. Methods: Fungal colonization data were analyzed retrospectively in 50 high risk ELBW infants. Weekly surveillance fungal cultures of the skin, gastrointestinal tract, respiratory tract and umbilicus had been performed from birth through the first 6 weeks of life. Colonization was analyzed for time of initial colonization, site, species and spread of Candida from one site to another. Results: Candida was isolated from surveillance cultures in 31 of 50 (62%) infants. Colonization was inversely proportional to gestational age. Initial week of both the fungal colonization of the skin [1 (0-6) week, median (range)] and gastrointestinal tract [2 (0-6)] preceded colonization of the respiratory tract [3 (1-6)] (P = 0.0001). Among infants colonized by only 1 of the species, colonization at 2 or more sites occurred similarly with Candida albicans (77%) and Candida parapsilosis (85%), whereas colonization at 3 or more sites occurred more frequently with C. albicans (69%) compared with C. parapsilosis (23%) (P = 0.047). Conclusions: Fungal colonization occurs on the skin and gastrointestinal tract before the respiratory tract. In addition, C. albicans is more likely than C. parapsilosis to colonize multiple sites.