EJMS

Abstract

The disinfection efficacy of vinegar and lemon juice against Giardia lamblia cysts was investigated in comparison to chlorine. Giardia lamblia cysts were obtained from human stool samples, purified and the cyst suspension was divided in half . One half was stored at 4˚C and the other half was left at room temperature for 2 hours before the experiment. The cysts were then exposed to different concentrations of the disinfecting solutions for 10, 30, 60 and 120 minutes at both 4˚C and room temperature. The viability of the cysts was determined by both eosin inclusion test and infectivity bioassay in laboratory mice. Cyst viability by eosin inclusion test after 120 minutes at 4˚C for control, chlorine, undiluted vinegar, diluted vinegar, undiluted lemon juice and diluted lemon juice was 96.333%, 0%, 0.667%, 5.667%, 65.333% and 72.667%, and at room temperature 95.333%, 0%, 0%, 1.667%, 62.333% and 71% respectively. No mice were infected in chlorine, undiluted vinegar and diluted vinegar groups (0% infectivity), while 66.6% of mice were infected in undiluted and diluted lemon juice groups. Results revealed that undiluted vinegar (5% acetic acid) was as effective as chlorine, and more effective than diluted vinegar, undiluted and diluted lemon juice in inactivating G. lamblia cysts. Also, undiluted vinegar was found to be more effective at room temperature and for an exposure time of 120 minutes. So, undiluted vinegar proved to be a safe and effective disinfecting agent against G. lamblia cysts that can be used for disinfecting vegetables at home.