Molecular investigation of recurrent tuberculosis in patients from Rwanda.
METHODS
Pulmonary tuberculosis (TB) patients enrolled in four provinces of Rwanda.


OBJECTIVE
To determine the cause of recurrent TB.


METHODS
Serial Mycobacterium tuberculosis isolates obtained from patients with recurrent TB from January 2002 to September 2005 were genotyped by spoligotyping and mycobacterial interspersed repetitive unit-variable number of tandem repeat (MIRU-VNTR) typing. Drug resistance was determined by phenotypic susceptibility testing and sequencing of rpoB, katG, inhA and embB genes.


RESULTS
Among 710 culture-positive TB patients enrolled in the study, initial drug susceptibility testing results were available for 638. Sixty-nine of these had multidrug-resistant (MDR) TB and 569 were non-MDR-TB. Among the MDR-TB patients, 22 had follow-up isolates after cure (n = 12) or chronic infection (n = 10). The DNA patterns of sequential isolates from 4 of the 12 previously cured MDR-TB patients were different, indicating re-infection. DNA patterns of isolates from the remaining 8 previously cured and 10 chronic MDR-TB patients were identical, suggesting reactivation and treatment failure, respectively. Among the non-MDR-TB patients, disease recurrence was observed in one case; this was determined to be due to reactivation after initial mixed infection.


CONCLUSIONS
These results document a high treatment failure/reactivation rate for MDR-TB and suggest that re-infection within 2 years may not be a common cause of recurrent TB in this setting.
Umubyeyi
A N
AN
Mycobacteriology Unit, Institute of Tropical Medicine, Antwerp, Belgium. alainenyaruhirira@hotmail.com
Shamputa
I C
IC
Rigouts
L
L
Dediste
A
A
Karita
E
E
Struelens
M J
MJ
Portaels
F
F
D000995:Antitubercular Agents / Q000627:therapeutic use; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D012432:Rwanda; D014376:Tuberculosis / Q000382:microbiology; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy
D000995:Antitubercular Agents