Determination Of Legionella Spp Prevalence In Hot Springs Lakes Hospitals And Drinking Water Distribution Systems In Ethiopia

Legionnaires’ disease is an emerging atypical pneumonia type of illness caused by inhalation of aerosols contaminated by Legionella Spp. There is limited information about the prevalence of Legionella Spp., from Ethiopian water systems. A cross-sectional descriptive study which entails the quantitative investigation of Legionella spp from Hot Springs, Lakes, hospitals and drinking water distribution Systems was conducted from Dec 14, 2016, to June 20, 2018. Representative water and biofilm samples collected and analyzed following standard procedures. 1L of water samples was concentrated by membrane filtration techniques by using 47 mm diameter cellulose membranes with a pore size of 0.2μm, microbes retained by the filter transferred to a sterile test tube containing distilled water and further eluted from the filter by vortex-mixing for 5-10 minutes. Biofilm samples were collected from water distribution system by sterilized Dacron Tipped swabs by rubbing three to four times inside water pipe. For Legionella isolation, about 0.1 ml of filtered and biofilm samples were spread plated on Buffered Charcoal Yeast Extract Agar, while Plate count agar were used for Heterotrophic plate Count and standard microbial procedures were followed. physicochemical qualities of water samples analyzed by portable digital photometer instruments following instrument instructions. Among a total of 220 water samples 46(43.3%) of hot spring samples; 22(38.6%) of hospital water samples; 8(30.7%) of Addis Ababa water distribution system and 19(61.3%) of natural water samples were positive to Legionella spp. The Legionella colonies of hot springs range from Log10 2.60 ±0.69 to 3.22±0.78; natural water bodies 1.66±0.8 to 3.29±0.3; Addis Ababa water distribution samples 1 to 1.41±0.8 and Hospital water samples 1.22±0.46 to 2.8±1.41 Log10 cfu/l. Meanwhile 23(21.7%), 12(21.05%) and 3(11.5%) of hot springs, hospital water samples and Addis Ababa water distribution system had HPC >300cfu/ml respectively, while 23(74.2%) natural water bodies had HPC>2500cfu/ml. Temperature (OC) range were 35.3±1.4 to 48.3±5.5 in hot springs IV rnwhile from 18.6±1.1-25.2±0.4 in natural water bodies; pH varies 6.5-7.5 in hot springs; 6.9-7.4 in hospital water; 6.6 to 8.5 in natural water bodies; mean Fluoride and Iron levels range 2.6-30.4 and 6.1-23.1mg/l in hot springs; 0.2-0.4 and 0.6-0.6mg/l in hospital water samples; 0.2-7.1 and 0.4-8.4mg/l in natural water bodies but range from 0.21-30.4 and 0.34-23.1mg/l respectively. The mean free residual chlorine from the sampled hospital and Addis Ababa water distribution system was below 0.2mg/l. The minimum and maximum concentration of elements all samples ranged, Potassium 1.9-44.8mg/L; Phosphate 4.95-48.3mg/L; Sulfate 2.2-59.7mg/L; Total alkalinity 61.7-4752.0mg/L; Total Dissolved Solids 88.7-2569mg/L; Electrical Conductivity 130-1813.7(μS/cm). Significant level of correlation was observed between microbial parameters of Legionella and heterotrophic plate count. HPC correlated with Legionella at P

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