MigratoryBirds as a Potential Reservoirs of Cryptococcus Neoformans

Document Type : Original Research Paper


1 Department of Medical Laboratory Sciences, School of Paramedicine/ Infectious & Tropical Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

2 Department of Medical Mycology and Parasitology/Invasive Fungi Research Center (IFRC), School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran

3 Student Research Committee, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran


Migratory birds can become long-distance vectors for a wide range of microorganisms. The objective of the present study was to investigate the presence of Cryptococcus neoformans in the cloacae, crop and nasal cavity of migratory birds in order to assess their role as potential reservoirs and/or mechanical vectors of human and animal cryptococcosis. A total of 700 samples (cloacae, crops and nasal secretions) of 300 wild migratory birds (with the permission of the local Department of Environment) were collected and inoculated on Niger seed agar (NSA), incubated for two weeks at 30 ºC and daily observed for the presence of brown yeast colonies, which is presumptive for C. neoformans. The species identification was confirmed using conventional and molecular methods. Out of 700 samples, 4 samples (0.6%) from cloacae of 2 Anas crecca (2 cases), Anas platyrhychos (1 case) and Fulica atra (1 case) were positive for C. neoformans. To the best of our knowledge, due to low isolation rate of C. neoformans from cloacae, crops and nasal secretions, transmission from these samples could be as a minimal risk factor for human and animal cryptococcosis, unlike the dry excreta of wild pigeons.