title: Endogenous reactivation followed by exogenous re-infection with drug resistant strains, a new challenge for tuberculosis control in Saudi Arabia.
abstract: Endogenous reactivation and exogenous reinfection of tuberculosis were studied for the first time in Saudi Arabia after enrolling a total of 39 patients with multiple episodes of tuberculosis between 2009 and 2010. All of the primary and subsequent isolates enrolled were subjected to spoligotyping, 24 loci based MIRU-VNTR typing and first line anti-tuberculosis drug susceptibility testing. The primary episode isolates from patients born outside Saudi Arabia were dominated by lineages which are prevalent in their country of origin (e.g. Ghana, Cameroon, Uganda-I, among African patients/Delhi/CAS and EAI among Asian patients). On the other hand, in Saudi Arabian patients, (median age of 67 years) Delhi/CAS, TUR and S lineages were predominant. The second episode of infection was mainly caused by the lineages Delhi/CAS, EAI, Uganda-I, Haarlem, and LAM which are currently disseminating in the country. Surprisingly, all of the first episode isolates were pan-susceptible, while 35.9% of the re-infected cases were drug resistant. Reactivation of a remote infection eventually followed by an exogenous reinfection was confirmed among patients, particularly those of African origin. Immediate actions to break the cycle of transmission of drug resistant tuberculosis are greatly needed in Saudi Arabia.
authors: Mycobacteriology Research Section, Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, Takasussi Street, Riyadh 11211, PB No 3354, Saudi Arabia. bvarghese99@kfshrc.edu.sa
authors: Bright
authors: B
authors: Varghese
authors: Ruba
authors: R
authors: al-Omari
authors: Ceilidh
authors: C
authors: Grimshaw
authors: Sahal
authors: S
authors: Al-Hajoj
mesh_terms: D000293:Adolescent; D000328:Adult; D000349:Africa / Q000208:ethnology; D000368:Aged; D000369:Aged, 80 and over; D000995:Antitubercular Agents / Q000627:therapeutic use; D015373:Bacterial Typing Techniques / Q000379:methods; D024901:Drug Resistance, Multiple, Bacterial; D004641:Emigration and Immigration; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000145:classification / Q000187:drug effects; D010802:Phylogeny; D012008:Recurrence; D012529:Saudi Arabia / Q000453:epidemiology; D014376:Tuberculosis / Q000188:drug therapy / Q000208:ethnology / Q000382:microbiology; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy / Q000208:ethnology / Q000382:microbiology* / Q000635:transmission; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents