Bridging the Gap: Conference Record [Abstract book, International Conference on AIDS (12th: 1998: Geneva, Switzerland)]

12th World AIDS Conference

Abstracts 22144-22148 291

r22144 Application of molecular methods for detection and
transmission analysis of drug resistance to M.
tuberculosis in a HIV population
Antonella Cingolani1, A. Antinori2, M. Sanguinetti3, A. de Luca2, F. Ardito3,
G. Fadda3, L. Ortona2. Department of Infectious Diseases Catholic
University-L. Go A. Gemelli-8-Rome; 2Depart. Infect. Dis.-Catholic University
Rome, 3 Depart. Microbiology-Catholic University Rome, Italy
Background of the Study: Transmission of drug-resistant tuberculosis (DR-TB)
represents a crucial problem for TB control, mainly in the context of HIV infection.
Molecular tools can detect DR-TB, but whether these techniques are applicable
for clinical use and for rapidly appropriate therapy is unclear.
Objectives: 1) To assess pattern and frequency of genotypic mutations associated to phenotypical DR-TB in a population with high HIV prevalence; 2) To
study possible chains of transmission of DR-TB. 3) To analyse the impact of rapid
detection of DR directly on clinical samples.
Design: 71 consecutive pts (81% HIV+) hospitalized in a 2-years period had
M. tuberculosis isolates (phenotypic resistance patterns: 25% INH, 11% RMP, 7%
SM, 6% EMB; 22% single DR and 11% MDR) from respiratory samples. Genotypic
DR was determined using PCR-SSCP and DNA sequencing of 13 regions sites
of mutations associated to DR in INH, SM, RMP and EMB in the isolates and
directly in sputum, induced sputum and broncho-alveolar lavage fluid. For DNA
fingerprinting we used Pvull-IS6110 RFLP.
Results: Mutations in katG were observed in 78% (33% R463L, -H, -stop;
7% each of A172V, S315T, Q294H and 17% 122-125 deletion of 12 bp) and in
inhA in 5% (1304V) of INH resistant isolates. In 80% of RMP resistant isolates
mutations were detected in rpoB (60%H526Y and H526Q, 20% S531T, 20%
L511R). Mutations in rpsL were observed in 50% of SM-resistant isolates (K43R)
and SSCP altered patterns of embB were found in all EMB resistance isolates.
RFLP analysis revealed three clusters of 2, 3 and 3 pts each. In one cluster 2
out 3 pts had INH-resistant isolates. Analysis of clinical samples is in progress.
Results of complete pattern of genotipic resistance were obtained in 6 days for
each patient.
Conclusions: The high degree of correlation between phenotypic and genotypic resistance as well as the reduction of processing time suggest these
techniques as useful tool for rapidly appropriate therapy. The high phenotipic DR
rates and the widespread unique patterns at RFLP among DR strains indicate
therapeutical intervention as a priority, mainly in terms of rapid detection of DR.
The efficiency of genetic detection of DR may depend on TB burden in respiratory
samples.
Supported by National Tuberculosis Project; Istituto Superiore di Sanita - Ministero della Sanita, Roma, Italy.

S22146 A simple, effective algorithm for the diagnosis of
pulmonary tuberculosis (TB) in a resource-poor setting
with high HIV prevalence
Alasdair Reid1 2, W.J. Newman1, D. Wilkinson3, S.B. Squire2, A.W. Sturm4,
C.F. Gilks2. 1Hlabisa Hospital, Private Bag X5001, Hlabisa 3937, Kwazulu Natal;
3Cersa (Hlabisa) and MRC South Africa, Mtubatuba; 4Natal University Medical
Microbiology Durban, South Africa; 2Liverpool School of Tropical Medicine,
Liverpool, UK
Objectives: To evaluate a diagnostic algorithm using sputum smear microscopy
and objective response to a trial of antibiotics among adults with suspected
pulmonary TB in Hlabisa, South Africa, 1996-7, where HIV prevalence is 26%.
Methods: Adults with chronic chest symptoms and an abnormal chest x-ray
compatible with TB had sputum examined for acid-fast bacilli (AFB) by microscopy.
Those with negative smears were given amoxycillin for 5 days and objectively
assessed for response: cough ceased or markedly reduced, sputum production
ceased or markedly reduced, apyrexial for 48 hours and significant clinical improvement. Those that did not improve were given erythromycin for 5 days and
reassessed. All sputa were cultured for M. tuberculosis and response to therapy
was compared with culture results. Algorithm performance was compared by HIV
status.
Results: 280 patients (139 male, 141 female) were enrolled and completed the
algorithm. 160 (57%) had at least one positive sputum smear (sensitivity against
culture, 70%; specificity, 96%; positive predictive value (PPV), 99% negative
predictive value (NPV), 46%). The remaining 120 smear negative cases were
reassessed after receiving antibiotics. The overall algorithm was highly sensitive
(89%) and specific (84%) with correspondingly high PPV (95%) and NPV (70%).
Among all 280 patients, 11 (4%) were unnecessarily treated for tuberculosis
while 24 (9%) patients with tuberculosis were misdiagnosed. Predictive values
were marginally improved by addition of low haemoglobin concentration to the
algorithm. HIV prevalence was 70% among TB cases and the algorithm was not
affected by HIV status.
Conclusion: The use of a diagnostic algorithm for TB in adults with chronic
cough and an abnormal chest x-ray based on sputum smear microscopy, objective response to a trial of antibiotics and haemoglobin may prove to be highly
predictive of pulmonary TB. This simple algorithm which utilises inexpensive
laboratory investigations and clinical response may be effective in resource poor
settings with a high HIV prevalence to improve the diagnosis of pulmonary TB.
22147 Tuberculous lymphadenitis in patients infected and not
infected with the human immunodeficiency virus (HIV)
Christian C. Hofling, A.M. Oliveira, M. Jacques de Moraes. Campinas State
University, R. Fernao de Magalhaes, N. 1017, Parque Taquaral, Campinas, SP,
Brazil
Background: Tuberculous lymphadenitis is one of the most common forms of
extrapulmonary tuberculosis. Its incidence has increased in association with the
HIV epidemy, as tuberculosis as a whole. In addition to this higher incidence in
the recent years, we have noticed in our facility an apparent increase of the well
known "paradoxical worsening" during the treatment of tuberculous lymphadenitis. The objective of this study is to review the cases of tuberculous lymphadenitis
diagnosed in the last three years in the State University of Campinas (UNICAMP)
regarding clinical course and the HIV-status.
Methods: Demographic, clinical and laboratorial data of all cases of tuberculous lymphadenitis diagnosed between January 1995 and December 1997 were
reviewed. The patients were classified according to the HIV-status and a statistical
comparison was performed.
Results: Tuberculous lymphadenitis was diagnosed in 89 patients in the 3-year
period studied. 81 (79.7%) were tested for HIV-infection and 47 (52.8%) were
infected. HIV infection was diagnosed after tuberculous lymphadenitis in most
patients (64%). The partial analysis showed a tendency to more frequent paradoxical worsening and treatment interruption in the HIV-infected group. More
complete statistical study is being performed.
Conclusions: The majority of the patients presenting with tuberculous lymphadenitis in this university clinic in Campinas, Brazil are coinfected with HIV and
are unaware of it. Every patient diagnosed with tuberculous lymphadenitis should
undergo HIV-serologic test. The partial analysis of our data points to a modifying
role of HIV in the course of tuberculous lymphadenitis.
22148 Active mycobacterium tuberculosis infection in HIV
infected patients, a radiological evaluation
Elena Seminari, L. Rizzi, L. Scudeller, P. Marone, L. Bono, L. Cocchi. Infect Dis
Dept-Policlinico San Matteo Via Taramelli 5 Pavia, Italy
Background: Tuberculosis (TB) has been increasingly reported in our country
and a substantial proportion of these cases is represented by HIV+ patients.
Methods: Culture-positive (sputum/BAL) TB cases admitted to our Centre between the 1990 and 1997 have been included in this retrospective analysis. Chest

X-ray (CXR) of patients were correlated to the CD4+ cell count and classified into
a) typical pattern, i.e. lymphadenopathy, parenchymal opacities with or without
cavitation b) atypical pattern, i.e. diffuse reticular or nodular infiltrates, diffuse
opacities, or a normal chest. Previous use of antiretrovirals has been evaluated.
Results: Pulmonary TB was documented in 31 (13.9%) out of 235 patients
admitted with bacterial pneumonia; of these, 25 qualified for the study. Twenty-two
were male and 3 female with a mean age of 32 years. Sixteen were IVDA, 2

22145

Risk of mycobacterial disease in patients with advanced
AIDS is decreased among those with prior BCG
vaccination or prior tuberculosis

David Jamil Hadad1 2, A.C.C. Pignatari2, D.S. Lewi2, M.C. Martins3,
S.Y. Mueki3, C.F. Von Reyn4, R.D. Arbeit5. 'Rua DR Didgo de Faria 666 35, Vila
Clemente-CEP 04037-222, Sao Paulo-SP; 2Universidade Federal de Sao Paulo,
Sao Paulo SP; 3 nstituto Adolpho Lutz, Sao Paulo SPR Brazil;
4Dartmouth-Hitchcock Medical Center, Lebanon NH; 5Boston VA Medical
Center, Boston MA, USA
The risk of disseminated M. tuberculosis (dMTB) in HIV-infected patients in
Trinidad has been reported to be decreased in those with prior childhood immunization with BCG and in the United States the risk of disseminated M. vium
complex (dMAC) has been reported to be decreased in those with prior pulmonary tuberculosis (pTbc). We evaluated these associations among patients
with advanced AIDS in Sao Paulo State, Brazil. HIV-infected patients with CD4 <
100/mm3 or lymphocyte count - 1000/mm3 and fever 32 weeks were prospectively
evaluated including mycobacterial blood cultures using Bactec 13A (Becton Dickenson, Sparks, MD) and Isolator 10 (Wampole, Cranbury, NJ). Medical records of
all patients were reviewed for prior diagnosis of Tbc and a subset of 92 patients
were examined for BCG scar on their right arms. Disseminated mycobacterial
disease was defined as the isolation of mycobacteria from blood. Among patients
with negative blood cultures, extra-pulmonary tuberculosis (epTbc) was the isolation of MTB from at least one extra-pulmonary site; pTbc was the isolation of
MTB only from respiratory specimens.
Results: Among 172 patients, 87 (51%) had mycobacterial infection (53 dMAC,
17 dMTB, 6 epTbc, 8 pTbc, 3 infection due to other mycobacteria). 50 (29%)
patients had a history of prior Tbc; 53 (58% of evaluated patients) had a BCG
scar. Neither factor alone influenced the risk of mycobacterial disease. However,
mycobacterial infection during advanced AIDS was present significantly less frequently among patients with prior mycobacterial experience (BCG scar OR prior
Tbc) than among those with neither factor: 40/87 (46%) vs. 17/24 (71%), p <.04,
Fisher's exact test.
These epidemiologic data confirm prior studies and indicate that in a single
population of patients with advanced AIDS, prior BCG and prior tuberculosis
each contribute to protection against mycobacterial infection due to MAC or
MTB. These data support the hypothesis that active immunization may also be
protective.