TY - JOUR
T1 - Characteristics of non-clustered tuberculosis in a low burden country
AU - Kamper-Jørgensen, Zaza
AU - Andersen, Aase Bengaard
AU - Kok-Jensen, Axel
AU - Bygbjerg, Ib Christian
AU - Thomsen, Vibeke Ostergaard
AU - Lillebaek, Troels
PY - 2012/5/1
Y1 - 2012/5/1
N2 - Molecular genotyping studies often focus on clustered tuberculosis and recent transmission. Less attention has been paid to non-clustered tuberculosis. However, non-clustered cases also contribute significantly to the tuberculosis burden, especially in low-incidence countries. The objective of this study is to characterize non-clustered tuberculosis cases in Denmark and point out potential implications for tuberculosis control. The study is based on nationwide IS6110-RFLP genotyping of tuberculosis cases from 1992 through 2004, corresponding to 98% of culture verified cases. Of 3988 cases, 45% were non-clustered. Both Danes and immigrants had a peak incidence of non-clustered tuberculosis at older ages, 80-89 years (4.3 cases/10 5 population/year) and 60-69 years (28.8 cases/10 5 population/year), respectively. In addition, immigrants had a peak at 20-29 years (43.2 cases/10 5 inhabitants/year). In Danes, the incidence of non-clustered tuberculosis decreased during the study period and was predominantly found in elderly persons, presumably reactivating infection acquired during 1910-40, when tuberculosis incidence was high. In immigrants, the incidence was high at all ages, presumably reflecting reactivation of imported infections. In the future, the number of non-clustered tuberculosis cases will decrease, as older Danes die, and as time since primary infection increases for immigrants residing in Denmark. TB control should include focus on non-clustered cases.
AB - Molecular genotyping studies often focus on clustered tuberculosis and recent transmission. Less attention has been paid to non-clustered tuberculosis. However, non-clustered cases also contribute significantly to the tuberculosis burden, especially in low-incidence countries. The objective of this study is to characterize non-clustered tuberculosis cases in Denmark and point out potential implications for tuberculosis control. The study is based on nationwide IS6110-RFLP genotyping of tuberculosis cases from 1992 through 2004, corresponding to 98% of culture verified cases. Of 3988 cases, 45% were non-clustered. Both Danes and immigrants had a peak incidence of non-clustered tuberculosis at older ages, 80-89 years (4.3 cases/10 5 population/year) and 60-69 years (28.8 cases/10 5 population/year), respectively. In addition, immigrants had a peak at 20-29 years (43.2 cases/10 5 inhabitants/year). In Danes, the incidence of non-clustered tuberculosis decreased during the study period and was predominantly found in elderly persons, presumably reactivating infection acquired during 1910-40, when tuberculosis incidence was high. In immigrants, the incidence was high at all ages, presumably reflecting reactivation of imported infections. In the future, the number of non-clustered tuberculosis cases will decrease, as older Danes die, and as time since primary infection increases for immigrants residing in Denmark. TB control should include focus on non-clustered cases.
KW - Genotyping
KW - IS6110-RFLP
KW - Non-clustered
KW - Reactivation
KW - Tuberculosis
UR - http://www.scopus.com/inward/record.url?scp=84859491769&partnerID=8YFLogxK
U2 - 10.1016/j.tube.2012.02.001
DO - 10.1016/j.tube.2012.02.001
M3 - Journal article
C2 - 22406154
AN - SCOPUS:84859491769
SN - 1472-9792
VL - 92
SP - 226
EP - 231
JO - Tuberculosis
JF - Tuberculosis
IS - 3
ER -
