摘要:

Objectives: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.Design: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 availableMycobacterium tuberculosisstrains 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.

ISSN:0269-9370    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Objective:To assess the economic benefits and costs of providing isoniazid preventive therapy for tuberculosis (TB) in HIV-infected persons in Zambia.Design:A spreadsheet model incorporating variables drawn from published studies and unpublished data.Subjects:Data drawn from a number of different studies and published literature involving a range of subjects.Setting:Zambia.Results:Using data primarily from Zambia we have modelled the costs and benefits of a TB preventive therapy programme using daily isoniazid for 6 months. The base-case scenario assumes recruitment at a voluntary testing and counselling site where HIV seroprevalence is 30%; persons with HIV have a 25% probability of developing active TB during their lifetime; two additional cases of TB would be prevented per person completing a course of preventive therapy; compliance would be 63%, and the efficacy of the isoniazid in preventing active TB of 60%. The costs under this scenario would exceed the benefits by a factor of 1.16 [benefit: cost ratio (BCR) of 0.86]. However, if preventing one case of TB prevented an additional five cases, the benefits would exceed the costs by a significant margin (BCR of 1.71). Other scenarios indicate that the targeted preventive therapy of persons with HIV whose occupation or living situation places them in contact with a large number of others (teachers and students, health personnel, military and police, miners, prisoners, etc.) would yield significant net benefits. The operational challenge for TB preventive therapy is thus to identify and target large numbers of such persons.

ISSN:0269-9370    

出版商:OVID    

年代:1997

数据来源: OVID