Mycobacterium tuberculosisdetected in Shanghai Port: prevalence, typing and drug resistance profile
MENG Chen-Yan1, FANG Yun1, WANG Jian1, SHEN Yao-Jie2, LU Ye1, YE Wei1, ZHANG Qi1, ZHANG Xiao-Hang1, ZHOU Xian1
1. Shanghai International Travel Healthcare Center, Shanghai 200335, China; 2. Department of Infectious Diseases, Hua Shan Hospital, Fudan University, Shanghai 200040, China
Abstract:The present paper aims to determine the prevalence of Beijing strains of Mycobacteriumtuberculosis isolated from visa applicants in Shanghai Port, to define the probability of drug resistance and to evaluate the underlying risks of dissemination of Mycobacteriumtuberculosis and tuberculosis burden for Chinese tuberculosis surveillance system. From January 2009 to May 2013, a total of 193 visa applicants who received medical examinations in Shanghai Port were suspected of infectious tuberculosis by detected abnormalities in the chest radiology. Smear and culture examination from 3 consecutive early morning sputum specimens collected from them were performed. Isolated Mycobacteriumtuberculosis complex strains were subjected for genotyping using deletiontargeted multiplex polymerase chain reaction (DTMPCR). Fifty of them were positive for Mycobacteriumtuberculosis complex. Forty isolates were genotyped by DTMPCR, 23 of the isolates (57.5%) belonged to Beijing genotype. The ratio was significantly lower than that in the local people going abroad (37/41, 90.2%). In all imported cases with Beijing genotype, 5 were from SouthEast Asia Region and 16 were from Western Pacific Region. Of 23 Beijing strains, 7 (30.4%) were resistant to at least one firstline antituberculosis drug, which was similar to the drug resistance rate (34.1%) in the local people going abroad. No multidrugresistant Beijing strain was found. The drug resistance rate to pyrazinamide was much higher in visa applicants (16.7%) than that in the local people going abroad (2.4%).