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

12th World AIDS Conference

Abstracts 42130-42136 799

42130 Prevalence of HIV-2 infection in Calcutta (India) with a
special reference to blood donors
Dhruba Neogi1, T. Chakrabarti2, N. Bhattacharya2. 'Dept of Virology School of
Tropical Medicine, Calcutta; 2School of Tropical Medicine, Calcutta, India
Objectives: To know the HIV-2 prevalence and its major routes of transmission
in Calcutta.
Design: Controlled study.
Methods: Between May 1994 and December 1997, 18,814 serum samples
collected from persons of different high risk groups, in the Department of Virology,
School of Tropical Medicine, Calcutta. The sera showing HIV-seropositivity by
rapid test were subjected to reader based ELISAS with Inno test (HIV-1/HIV-2 Ab.,
s.p. Innogenetics N.V. Belgium).The ELISA positive sera were than tested for confirmation by Western Blot assay with HIV Blot 22 Kit, Diagnostic Bio-technology
(pvt.) Ltd, Singapore, which could detect HIV-land also indicate HIV-2.
Result: Overall HIV-2 infection could be detected in 6.6% (N = 45) cases
whereas HIV-2 lone infection was noted in 1.92% (N = 13) and consistent HIV
1&2 infections were observed in 4.7% (N = 32) cases. Highest HIV-2 seropositivity could be detected among blood donors 13.8% followed by 13.3% and 11.1%
among patients of AIDS/ARC and recipients of blood and/or blood products
respectively.
Conclusion: HIV-2 infection being prevalent amongst different high risk groups
including blood donors. Findings of this study demand strictimposition of screening of donors for both HIV-1 and HIV-2 and more study to detect any change in
the epidemiology of HIV-2 in Calcutta and India as a whole.
42131 Detection and enumeration of HIV-1-producing cells by
ELISPOT (Enzyme-Linked ImmunoSpot) assay
Jean-Pierre Vendrell', P. Corne2, M.F. Huguet2, L. Brian2, M. Segondy2,
J. Reynes3. 1Departement De Virologie Chu Lapeyronie371 Av. Giraud 34295
Montpellier Cedex5; 2Laboratoire Des Infections Retrovirales, Montpellier;
3Service Des Daladies Infectievses, Montpellier, France
Objectives: The enzyme-linked immunospot (ELISPOT) assay was adapted to
detect and enumerate human immunodeficiency virus type 1 (HIV-1) producing
cells at the single cell level.
Methods and Results: With CEM cells or peripheral blood mononuclear cells
(PBMC) infected in vitro with HIV-1, the ELISPOT assay detected cells that produced HIV-1 antigens and showed that 5.4% to 9.5% of the p24 antigen-positive
CEM cells and 11.1% to 23.6% of the p24 antigen-positive PBMC were productively infected. In HIV-1-infected patients in early stage of the disease and
without antiretroviral therapy, up to 4.5 HIV-1-producing cells per 106 CD4+ T
lymphocytes were detected in peripheral blood and up to 340 HIV-1-producing
cells per 106 CD4+ T lymphocytes were detected in splenic lymphoid tissue.
Conclusion: Our results indicate that the ELISPOT assay could represent a
new tool to study HIV-1 replication in vivo.
42132 Evaluation of microplate ELISA reader for quality control
of anti-HIV test
Surapol Kohreanudom. AIDS Division Dept. CDC Tivanon Rd., Nonthaburi
11000, Thailand
Issue: Once installed, microplate enzyme linked immunosorbent assay (ELISA)
readers are rarely evaluated for their performance. Reagent control cannot detect
instrument errors.
Project: Hospitals under supervision of the Ministry of Public Health are inquired for their quality control routines and interesting in external quality check.
Microplate ELISA readers were evaluated using MedTec Linear Validation Plate
and judged for their performances with standard curve for either 450 or 405
nanometer absorbance according to US Food and Drug Administration (FDA)
and Clinical Laboratory Improvement Amendment (CLIA).
Results: Among 10 central hospitals in Thailand with ELISA readers, 4 (40%)
did not pass the test.

Methods: 3 rural hospitals participated in the study. 250 consecutive baseline
enrollment were recorded for each hospital HIV testing practices. Data generated was compared with subsequent 250 consecutive clients using the Dipstick
algorithm. Quality Controls was done at reference hospital in Lusaka.
Findings: 1500 clients entered the study. Costs of HIV testing included laboratory costs, such as technician time spent per test and required supplies were
favourable to the Dipstick HIV test. The Dipstick algorithm accuracy was greater
than 98%.
The accuracy of HIV testing at rural hospitals is acceptable The algorithm
used in this study can be recommended as the most effective rapid HIV testing
technology available at present.
42134 Screening of HIV in 740 Brazilian blood donors by
multi-target reverse transcription (RT)-linked polymerase
chain reaction (PCR)
Luiz Claudio Arreas', S. Barreto1, W. Lu2, J.M. Andrieu2. 1Laboratorio De
Serologia, Funda go Hemope Rua Joaquim Nabuco, 171 Gracas, Recife, Pe,
Brazil; 2Unite De Virologie Molecularie, Hopital Laennec Paris, France
Objective: To compare the results of conventional HIV serology with a recently
developed ultrasensitive multi-target RT-PCR (detection threshold: 10 HIV RNA
equivalent copies/mi) (see Abstract by Lu W, et al) in Brazilian blood donors.
Methods: A prospective study was conducted in serum samples taken from
740 new blood donors in Recife. Anti-HIV antibody status was evaluated by a
commercial kit (Vironostika HIV Uniform II, Organon Teknika, Boxtel, Belgium)
and confirmed by LIA HIV Confirmation K1036 (Innogenetics, Zwijndrecht, Belgium). In parallel, the same 740 serum samples were tested for HIV RNA by
multi-target RT-PCR using multiple primers pairs for high-sensitivity detection, an
internal control for intra-tube quality control, and an automated ELISA system for
high-efficiency post-PCR reading.
Results: Results of the serological test and the multi-target RT-PCR are
summarised in the table.

Anti-HIV antibody test
(Vironostika HIV Uniform II)
Positive
Negative

Multi-target RT-PCR for HIV
Positive Negative

734

The patient with a positive RT-PCR was the only one who had a positive result
on the confirmation test (gp41, +++; p31, +++; p24, ++++; p17, +++) among the
6 antibody positive samples.
Conclusion: This ultrasensitive multi-target RT-PCR assay system is more
specific and accurate than conventional anti-HIV antibody test. It could become
a powerful mean for early diagnosis in countries with a high incidence of HIV
infection.
421351 HIV RNA in oral washes of Senegalese men and women
Charlotte Ndiaye Faty', A. Gaye Fall', M.A. Faye Niang2, A.M. Coil Seck2,
C. Critchlow3. Centre Dentaire C.H.U. de Fann, B.P 5035, Dakar Fann, Dakkar,
2Service Des Maladies Infectieuses, CHU de Fann, B.P 5035 Dakar Fann,
Dakar, Senegal; 3University of Washington, Seattle, USA
The objective of this study was to determine the prevalence and quantity of
HIV-RNA shedding in oral washings from HIV-1 seropositive senegalese men
and women. Since march 1995, individuals presenting to the infectious disease
service at the university of Dakar have undergone standardized oral screening
examinations and collection of HIV RNA in the oral cavity. Sera were tested for
antibody to HIV-1 and HIV-2 by an ELISA test (Genetic Systems, Seattle) with
confirmation by a peptide based assay (Multispot, Diagnostics Pasteur, Paris).
Plasma HIV RNA was detected and qualified in RNA samples purified from 200
microliters (pI1) of both saliva and plasma using Monitor and women screened, 367
(10.5%), 75 (2.2%) and 42 (1.2%) were infected with HIV-1, HIV-2 and both HIV-1
and HIV-2, respectively. Preliminary studies of these methods on oral washes
from 45 HIV-1 infected persons showed HIV-1 RNA detectable in 13, with 8 having
RNA levels below and 5 with levels above 1000 copies per ll. Those with versus
those without HIV RNA detected in the oral washes did not significantly differ with
respect to male gender (54% vs. 63%), age (35 vs. 37 years), oral candidiasis
(38% vs. 53%) or HIV-associated periodontal lesions (23% vs, 19%) and mean
CD4 count (276 vs. 234). However, HIV RNA in the oral washes was associated
with levels of HIV RNA in plasma.
This study was supported by grants from the National Institutes of Health (DE
08547, DE 11372, CA 62801, Al-37466).
42136 Advanced stage of HIV infection among newly
established Bulgarian seropositives
Danail A. Beshkov, V. Georgieva, S. Raleva, R.M. Argirova. 44A Stoletov STR
1233 Sofia National AIDS reference laboratory, Bulgaria
Objective: To evaluate the stage of HIV infection by a proposed complex of markers of HIV infection in newly established Bulgarian sropositives as an evaluation
of HIV epidemic in Bulgaria
Methods: During one year period twenty one (11 male and 10 female) out of
30 newly established Bulgarian seropositives were tested at the moment of HIV
diagnosis by a complex of the following three markers: CD4 T-cell count, free p24

ID No.
1
2
4
5

BCV
3.5750
15.558
6.6235
8.0121

SicV
1.8181
9.1551
3.5563
3.7363

S2CV
0.5676
6.9988
1.2980
0.8192

S3CV
1.2388
3.9982
1.2295
1.2151

S4CV S5CV
0.8779 3.1225
1.8688 1.4970
0.7030 0.6100
0.5626 0.3964

r2
0.9996
0.9996
0.9995
0.9992

Slope
1.4585
1.5473
1.6073
1.5523

Lessen Learned: A surprisingly high proportion of ELISA readers did not pass
quality check. There should be regular quality evaluation among these ELISA
readers for their best performances. Also, there should be a mechanism to control
quality of the quality control plate to reassure qualified quality control.
42133 Evaluation of the introduction of low-cost HIV testing
technologies into rural hospitals in Zambia
Simon Mphuka', B. Mazuwa', G. Muyinda2, P. Plourde3, A. Ronald3,
K. SichingaL, D. Chama2. 1 Cmaz RO. Box 34511, Lusaka; 2University Teaching
Hospital, Lusaka, Zambia; 3 University of Manitoba, Winnipeg, Canada
Objective: To evaluate the introduction of Dipstick, in a testing algorithm with
capillus HIV confirmatory testing in rural Zambia
Design: Prospective, Controlled Study.