Abstract
Infection control in hospitals is the key strategy for prevention of nosocomial infections by breaking
down the transmission rout of infection from the source to susceptible patient by using of suitable
disinfectants. Chlorine Dioxide Gas and Chlorine Gas are promising alternative to other chlorinereleasing disinfectants. Sixty-five samples were collected from clinical and environmental sources of
Babylon Hospital for Pediatric and Gynecology and Al-Hilla General Teaching Hospital through a
period from September 2018 to March 2019. An antibacterial efficacy test of ClO2 and Cl2 was
performed against Streptococcus pneumoniae, Klebsiella pneumoniae, Enterobacter aerogenes,
methicillin resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Escherichia coli,
Bacillus sp. and Staphylococcus epidermidis. The results indicated that both of ClO2 and Cl2 revealed
a remarkable antibacterial potency against all of tested bacteria but ClO2 was more active compared
with Cl2. This antibacterial activity was a variable with the concentration and the type of bacteria.