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Pulmonary tuberculosis and HIV interaction in a setting with a high prevalence of HIV : clinical, diagnostic and epidemiological aspects

thesis
posted on 2024-09-03, 04:58 authored by Judith Bruchfeld

The overall aim of this study was to elucidate the influence of HIV infection on the occurrence, clinical presentation, diagnostic yield and transmission of M tuberculosis among consecutive out-patients with symptoms suggestive of PTB in a high TB and HIV endemic area.

Among 509 consecutive out-patients attending a university hospital in Ethiopia, 33.0% were culture-verified as having PTB. PTB patients, non-TB patients and controls were HIV-1 positive in 57.1%, 38.5% and 8.3% of cases, respectively. Independent predictors for culture-verified PTB were age <25 years, male gender and the presence of HIV and fever, whereas profound weight loss indicated HIV infection Diagnosis of PM based on clinical symptoms, direct sputum microscopy for acid-fast bacilli (AFB) and chest radiography (CXR) was significantly less sensitive and specific in HIV-positive patients Our findings indicate that, although M is more often under-diagnosed in HIV-positive patients, other HIV-related pulmonary infections am often misinterpreted as smear-negative PM in this setting. HIV screening is warranted as part of the diagnostic work-up m patients with respiratory symptoms suggestive of PM. Also, increased awareness of, and improved diagnostic tools and algorithms for, HIV-related pulmonary infections, including PTB, are required.

A high proportion of direct smear-negative culture-proven PTB (61.5%) was found in HIV-positive patients. In this patient group, sputum concentration after digestion with sodium hypochlorite significantly increased the yield for AFB, suggesting did this method has a place m routine diagnosis of PTB m HIV endemic countries. Molecular strain typing of the IS6110 and direct repeat genetic markets and drug sensitivity testing were performed in 121 M tuberculosis isolates.

In a multivariate logistic regression model HIV-positive serostatus was significantly associated with clustering in both sexes. There was a trend towards increased clustering with isolates obtained from tuberculous women residing in Addis Ababa (OR 2.10; 95% CI 0.85-5.25). In total, 17 bit of 121 isolates (14.0%) were, resistant to one or more of the standard anti-tuberculous drugs. Inpatients 35-44 years old the high rate of drug resistant isolates (29.6%) coincided with the peak HIV prevalence (77.8%). The majority (62.5%) of resistant isolates in this group were found within clusters. Simultaneous accumulation of certain bacterial clones in a patient population is likely to reflect recent transmission. Hence, we conclude that in Ethiopian HIV-positive patients tuberculosis is commonly caused by recent infection. Furthermore, drug resistant tuberculosis is likely to increase Strengthening of classical TB control measures by promoting active case-finding among HIV-positive adults with TB is warranted to reduce transmission.

The highest prevalence of Pneumocystis carinii (P carinii) in expectorated sputum. samples was 10.9% by immunofluorescence assay (IF) and 30.3% by nested polymerase chain reaction (nPCR) among HIV-positive non-TB patients. In HIV-negative non-TB patients, the prevalence of P carinii by nPCR was significantly lower In the IF positive and nPCR positive HIV-positive non-TB patients more than third were interpreted as PTB by CXR whereas only one patient was diagnosed with clinical PCP. The frequent occurrence of P carinii by nPCR suggests that PCP may be an important but not well recognised, differential diagnosis m HIV-positive patients with symptoms suggestive of PTB, implicating the need for treatment and primary prophylaxis for PCP in Ethiopia.

List of scientific papers

I. Bruchfeld J, Aderaye G, Bergren Palme I, Bjortvatn B, Britton S, Feleke Y, Kallenius G, Lindquist L (2002). Evaluation of out-patients with suspected pulmonary tuberculosis in a high HIV prvealence setting in Ethiopia: clinical, diagnostic and epidemiological characteristics. Scandinavian Journal of Infectious Diseases. 34: 331-7.

II. Bruchfeld J, Aderaye G, Palme IB, Bjorvatn B, Kallenius G, Lindquist L (2000). Sputum concentration improves diagnosis of tuberculosis in a setting with a high prevalence of HIV. Trans R Soc Trop Med Hyg. 94(6): 677-80.
https://pubmed.ncbi.nlm.nih.gov/11198655

III. Bruchfeld J, Aderaye G, Palme IB, Bjorvatn B, Ghebremichael S, Hoffner S, Lindquist L (2002). Molecular epidemiology and drug resistance of Mycobacterium tuberculosis isolates from Ethiopian pulmonary tuberculosis patients with and without human immunodeficiency virus infection. J Clin Microbiol. 40(5): 1636-43.
https://pubmed.ncbi.nlm.nih.gov/11980933

IV. Aderaye G, Bruchfeld J, Olsson M, Lindquist L (2002). Occurrence of Pneumocystis carinii in HIV-positive patients with suspected pulmonary tuberculosis in Ethiopia. [Submitted]

History

Defence date

2002-06-07

Department

  • Department of Medicine, Huddinge

Publication year

2002

Thesis type

  • Doctoral thesis

ISBN-10

91-7349-249-3

Number of supporting papers

4

Language

  • eng

Original publication date

2002-05-17

Author name in thesis

Bruchfeld, Judith

Original department name

Department of Medicine at Huddinge University Hospital

Place of publication

Stockholm

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