Contamination of irrigation systems of dental units with Cryptosporidium species in Alexandria, Egypt: a neglected disinfection pitfall

PURPOSE: To investigate the contamination of the dental irrigation systems with Cryptosporidium species in Alexandria, Egypt. METHODS: Forty water samples from all 20 working dental irrigation machines in a dental center in Alexandria were included in the study. Water samples were taken from the handpieces of dental irrigation machines in all studied units. After filtration through a membrane filter, water sample residues were stained using modified Ziehl–Neelsen staining and examined microscopically for Cryptosporidium spp. RESULTS: Cryptosporidium spp. was found as a contaminant in 27.5% of water samples taken from dental irrigation machines. CONCLUSION: This indicates a contamination by the public water supplies to which these dental irrigation machines are connected. This disinfection pitfall may pose an infection risk to those seeking dental care.