Incidence of tuberculosis and survival after its diagnosis in patients infected with HIV-1 and HIV-2.
BACKGROUND
In sub-Saharan Africa, tuberculosis (TB) is the most frequently diagnosed opportunistic infection and cause of death among HIV-infected patients. HIV-2 has been associated with less immune suppression, slower disease progression and longer survival.


OBJECTIVE
To examine whether the incidence of TB and survival after TB are associated with CD4 cell count rather than HIV type.


METHODS
Clinical and immunological data were retrospectively evaluated among an open clinic-based cohort of HIV-1- and HIV-2-infected patients to determine incidence of TB (first diagnosis > 28 days after HIV diagnosis) and subsequent mortality. Patients were grouped by CD4 cell count into those with < 200, 200-500 and > 500 x 10 cells/l.


RESULTS
Incident TB was diagnosed among 159 of 2012 patients, with 4973 person-years of observation time. In 105/159 (66.0%), the diagnosis was confirmed by direct microscopy or culture. Incidence of TB was highest in the group with < 200 x 10 cells/l (9.1/100 and 8.8/100 person-years in HIV-1 and HIV-2, respectively). Adjusted for CD4 cell count, there was no significant difference in incidence or mortality following TB between HIV-1- and HIV-2-infected patients. Mortality rate was higher in those with incident TB and HIV infection, most markedly in the group with the highest CD4 cell count (hazard ratio, 10.0; 95% confidence interval, 5.1-19.7).


CONCLUSIONS
Adjusted for CD4 cell count, incidence of TB was similar among HIV-1- and HIV-2-infected patients. Mortality rates after TB diagnosis were similar in both groups and high compared with those without TB.
van der Sande
Marianne A B
MA
London School of Hygiene and Tropical Medicine, London, UK. mvdsande@mrc.gm
Schim van der Loeff
Maarten F
MF
Bennett
Rachel C
RC
Dowling
Mary
M
Aveika
Akum A
AA
Togun
Toyin O
TO
Sabally
Saihou
S
Jeffries
David
D
Adegbola
Richard A
RA
Sarge-Njie
Ramu
R
Jaye
Assan
A
Corrah
Tumani
T
McConkey
Samuel
S
Whittle
Hilton C
HC
D017088:AIDS-Related Opportunistic Infections / Q000150:complications / Q000401:mortality*; D000328:Adult; D017954:Africa South of the Sahara / Q000453:epidemiology; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D005260:Female; D015497:HIV-1; D015498:HIV-2; D006801:Humans; D015994:Incidence; D008297:Male; D011446:Prospective Studies; D012189:Retrospective Studies; D016019:Survival Analysis; D014376:Tuberculosis / Q000150:complications / Q000401:mortality*