Recent transmission of tuberculosis in a cohort of HIV-1-infected female sex workers in Nairobi, Kenya.
OBJECTIVE
To describe the epidemiological and clinical characteristics of HIV-related tuberculosis in a female cohort, and to investigate the relative importance of recently transmitted infection and reactivation in the pathogenesis of adult HIV-related tuberculosis.


METHODS
Members of an established cohort of female sex workers in Nairobi were enrolled in a prospective study. Women were followed up regularly and seen on demand when sick.


METHODS
Between October 1989 and September 1992 we followed 587 HIV-infected and 132 HIV-seronegative women. Standard protocols were used to investigate common presentations. Cases of tuberculosis were identified clinically or by culture. All available Mycobacterium tuberculosis strains underwent DNA fingerprint analysis.


RESULTS
Forty-nine incident and four recurrent episodes of tuberculosis were seen in HIV-infected women; no disease was seen in seronegative sex workers (P = 0.0003). The overall incidence rate of tuberculosis was 34.5 per 1000 person-years amongst HIV-infected participants. In purified protein derivative (PPD) skin test-positive women the rate was 66.7 per 1000 person-years versus 18.1 per 1000 person-years in PPD-negative women. Twenty incident cases (41%) were clinically compatible with primary disease. DNA fingerprint analysis of strains from 32 incident cases identified two clusters comprising two and nine patients; allowing for index cases, 10 patients (28%) may have had recently transmitted disease. Three out of 10 (30%) patients who were initially PPD skin test-negative became PPD-positive. Taken together, 26 incident cases (53%) may have been recently infected. DNA fingerprint analysis also identified two (50%) of the four recurrent tuberculosis episodes as reinfection.


CONCLUSIONS
Substantial recent transmission of tuberculosis appears to be occurring in Nairobi amongst HIV-infected sex workers. It may be incorrect to assume in other regions of high tuberculosis transmission that active HIV-related tuberculosis usually represents reactivation of latent infection.
Gilks
C F
CF
Clinical Research Centre, Kenya Medical Research Institute, Nairobi, Kenya.
Godfrey-Faussett
P
P
Batchelor
B I
BI
Ojoo
J C
JC
Ojoo
S J
SJ
Brindle
R J
RJ
Paul
J
J
Kimari
J
J
Bruce
M C
MC
Bwayo
J
J
Plummer
F A
FA
Warrell
D A
DA
D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D000328:Adult; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D015497:HIV-1 / Q000302:isolation & purification; D006801:Humans; D007630:Kenya / Q000453:epidemiology; D009169:Mycobacterium tuberculosis / Q000145:classification / Q000302:isolation & purification; D011446:Prospective Studies; D011477:Sex Work; D014374:Tuberculin Test; D014376:Tuberculosis / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*