Introduction of the US Centers for Disease Control and Prevention’s Standard Method for the Detecting Legionella in Water Samples from the Environment into the Routine Laboratory Program of Regional Medical Sciences Center 11, Surat Thani

Abstract

Legionellosis, a bacterial disease caused by Legionella, is a health problem among foreign tourists. In Thailand, the laboratory test for Legionella bacteria was developed by Department of Medical Sciences, Ministry of Public Health. The objective of this study was to assess the standard procedure for the recovery of Legionella spp. in water samples from the environment developed by the US Centers for Disease Control and Prevention (CDC). The study was conducted in the laboratory of the Regional Medical Sciences Center 11 (RMSC 11), Surat Thani province during January – August 2013. In the process, the reference strain of Legionella pneumophila ATCC 33152 was added to sterilized deionized water samples and diluted to become 3 sets of samples with the concentrations of 10-100, 100- 1,000 and 1,000-10,000 CFU/L, respectively. All three water samples were subsequently tested for Legionella spp., using the CDC method. It was found that Legionella pneumophila was detected in all 3 sets of samples. The detection rate was 99.29% (95% confidence interval, p=0.05) and the standard deviation was 0.0721. Thus, it is justifiable for the RMSC 11 to utilize the standard CDC procedure for testing Legionella spp. on a routine basis as this process could upgrade the competency of the Center to meet international standard and build confidence of foreign tourists and other clients, as well as ensure the utilization of the test results at the international level.