WHO global salm-surv external quality assurance system (EQAS): an important step toward improving the quality of Salmonella serotyping and antimicrobial susceptibility testing worldwide.

Initiated in 2000, WHO Global Salm-Surv is a global network of epidemiologists and microbiologists involved in Salmonella surveillance. WHO Global Salm-Surv seeks to enhance the capacity of national and regional reference laboratories to conduct Salmonella serotyping and antimicrobial susceptibility testing through international training courses and an External Quality Assurance System (EQAS). In 2000, 44 WHO Global Salm-Surv member laboratories from 35 countries determined the serotype and antimicrobial susceptibility pattern for eight "blinded" Salmonella isolates. For serotyping, 73% of the results were correct. For susceptibility testing, 92% of the results were in agreement with the expected results. However, only 78% of the performed tests with the E. coli ATCC 25922 reference strain were within the quality control range specified by National Committee for Clinical Laboratory Standards (NCCLS) guidelines. These EQAS results demonstrate the need for further training to improve the performance of some of the laboratories. WHO Global Salm-Surv activities, including international training courses and EQAS, represent an important step toward improving the quality of Salmonella serotyping and antimicrobial susceptibility testing worldwide, and improving the current reliability and comparability of Salmonella surveillance data obtained from different countries,