Tuberculosis risk varies with the duration of HIV infection: a prospective study of European drug users with known date of HIV seroconversion.
BACKGROUND
It is not known whether the risk of active tuberculosis disease varies with the length of time that individuals are infected with HIV.


OBJECTIVE
To study how, independently of CD4 T cell count, the risk of tuberculosis varies with the duration of HIV infection.


METHODS
Using Poisson regression analysis, the incidence of and risk factors for tuberculosis were studied in 683 injecting drug users (IDU) with a documented date of HIV seroconversion followed in seven cohorts in six European countries until 1998.


RESULTS
Overall incidence was 11.5/1000 person-years. Adjusted for CD4 T cell count and geographic region, the risk ratio (RR) for tuberculosis (both pulmonary and extrapulmonary), compared with the first 3 years of HIV infection, was 2.8 for years 4 to 6 of HIV infection [95% confidence interval (CI), 1.3-6.3], 1.2 for year 7 to 9 (95% CI, 0.3-4.2) and 4.6 after 9 years (95% CI, 1.4-15.0). The adjusted RR for geographic region was 13.1 (95% CI, 4.3-40.0) for Amsterdam and 15.8 (95% CI, 4.8-52.0) for the Valencian region of Spain compared with all other sites combined.


CONCLUSIONS
The risk of tuberculosis is increased relatively early in HIV infection (year 4 to 6) and also later (after year 9) with possibly a relatively silent period between. As expected, IDU in Southern Europe have a substantially higher risk of tuberculosis than IDU in Northern and Central Europe. Amsterdam forms an exception for Northern Europe, with very high incidence rates.
van Asten
Liselotte
L
Municipal Health Service, Cluster Infectious Diseases, Amsterdam, The Netherlands.
Langendam
Miranda
M
Zangerle
Robert
R
Hernández Aguado
Ildefonso
I
Boufassa
Faroudy
F
Schiffer
Veronique
V
Brettle
Raymond P
RP
Robertson
J Roy
JR
Fontanet
Arnaud
A
Coutinho
Roel A
RA
Prins
Maria
M
D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology / Q000209:etiology*; D000328:Adult; D018791:CD4 Lymphocyte Count; D005060:Europe / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006679:HIV Seropositivity / Q000150:complications; D006801:Humans; D015994:Incidence; D008297:Male; D016012:Poisson Distribution; D011446:Prospective Studies; D012307:Risk Factors; D013223:Statistics as Topic; D015819:Substance Abuse, Intravenous / Q000150:complications*; D013997:Time Factors; D014376:Tuberculosis / Q000453:epidemiology / Q000209:etiology*