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

126 Abstracts 13202-13205

12th World AIDS Conference

Methods: Retrospective analysis of a range of demographic and clinical data
collected on patients diagnosed HIV positive in 1997 in all clinical areas of a
London Teaching Hospital.
Results: 104 patients were diagnosed HIV positive in 1997, 73 in the same
day testing clinic (SDTC) and 31 in other settings (OTHER). More women were
diagnosed outside the SDTC (61% of OTHER and 10% of SDTC). There was a
marked difference in ethnic origin (of OTHER, 61% were black African and 29%
white European c.f. 11% and 76% respectively of SDTC). In terms of risk factors,
heterosexual sex accounted for 77% of the OTHER group whilst homosexual
sex accounted for 84% of the SDTC group. The OTHER group had much more
advanced HIV disease as evidenced by CD4 count (< 100 in 35% of OTHER and
12% of SDTC), viral load (>100,000 in 62% of OTHER and 31% of SDTC) and
CDSC category (39% of OTHER and 6% of SDTC were Category C i.e. AIDS).
Conclusion: The majority of people diagnosed positive in a voluntary testing
clinic were white, European, gay men at an earlier stage of HIV infection. Patients
tested in other settings were more likely to be women, to be from Africa, have
a heterosexual risk factor and have advanced disease. The recent drive in the
United Kingdom to, encourage early HIV diagnosis, prompted by advances in
treatment, has been aimed at Gay men. We have not targeted other groups who
often present later and may miss out on the advantages of earlier diagnosis.
13202 Impact of highly active antiretroviral therapy (HAART) in
France: Is AIDS incidence still decreasing?
Francoise Cazein, R. Pinget, D. David, F. Lot, J. Pillonel. RNSP 14 Rue Du Val
D'Osne, 94415 Saint-Maurice, Cedex, France
Background: In France, HAART was introduced in the first half of 1996. The
study objective is to describe the impact of HAART on AIDS incidence over time.
Method: Adult AIDS cases reported through December 1997 were presented
by half-year of diagnosis, with adjustment for reporting delays (n = 47 659).
Trends were analysed by transmission group according to the use of antiretroviral
therapy (ART) for at least 3 months before AIDS diagnosis.
Results: AIDS incidence reached a plateau in 1993-1994, began to decline in
1995 and decreased dramatically between the 2 half-years of 1996 (-30%) and
between the 2nd half of 1996 and the 1st half of 1997 (-23%). This trend stopped
during the 2nd half of 1997.
Number of new AIDS cases according to knowledge
of HIV infection and use of ART before AIDS diagnosis
3000
3 0 total number of
2500 new AIDS
patients aware cases
2000 of their HIV infection
0 and treated before AIDS
1500
area I
1000 'patients aware of their HIV
i infection before AIDS but untreated area 2
0 -941 942 951 952 961 962 971 972
half-year of diagnosis
These abrupt decreases were observed in each of the 3 main transmission
groups, respectively -37% and -35% in IDU, -32% and -20% in homosexual
men and -23% and -18% in heterosexuals. Factors which could explain these
decreases were analysed (under-reporting, new AIDS case definition, HIV incidence) but the introduction of HAART has played the most important role. The
number of new AIDS cases having received ART before AIDS diagnosis (fig:
area 1) declined sharply during the 2nd half of 1996 and the 1st half of 1997
while the number of those who did not have access to ART remained relatively
stable (areas 2 + 3). The different decreases in AIDS incidence by transmission
group could be explained by the proportion of new AIDS cases not aware of their
HIV-infection prior to AIDS: 56% in heterosexuals, 45% in homosexual men and
20% in IDU in 1997.
Conclusion: AIDS incidence decreased dramatically since the second half
of 1996 coinciding with the introduction of HAART, but remained stable in the
second half of 1997. Early detection of HIV infection is essential to enable more
HIV-infected persons to benefit from HAART and to reduce the frequency of
progression to AIDS.
13203 Comparing RFLP IS6110 and PGRS fingerprinting in the
investigation of an outbreak of multidrug-resistant
tuberculosis in a central Lisbon hospital
Margaret Hannan1, H. Peres2, F. Lisbon2, M. Nelson3, B. Gazzard3. 17
Broughton Road, Fulham, UK; 2Curry Cabral Hospital Lisbon, Portugal;
3Chelsea and Westminster Hospital London, UK
Objective: To compare DNA fingerprinting patterns using RFLP IS6110 and RFLP

PGRS typing in the investigation of a nosocomial outbreak of multidrug-resistant
tuberculosis involving 101 patients over a period of four years 1993-1996 in
Lisbon, Portugal.
Methods: IS6110 RFLP and pTBN12 typing was performed on 101 isolates of
Mycobacterium tuberculosis isolated in 1993-1996 from HIV patients attending a
Lisbon Hospital. Epidemiological data was collected by reviewing patients notes
and outpatient records.

Results: RFLP IS6110:Forty six (48%) isolates clustered in group A and 34
(33%) isolates clustered in Group B using IS6110. Strains clustered within A were
uniformly indistinguishable (>80% homology) except for an additional band in 10
isolates. These were considered the same strain. All isolates typed in cluster A
had been isolated in either 1995 or 1996 whereas isolates in cluster B represented
1993-96. When we regrouped the clusters using the >70% homology cut off the
two clusters became one differing by only one band or two bands. RFLP PGRS:
Cluster A and Cluster B were indistinguishable on PGRS typing suggesting that
these two clusters have evolved from the same strain gaining extra IS6110 bands
with time. Epidemiological data: there were no differences observed between
clusters A and B.
Conclusion: Accurate identification of strains and the resulting conclusions
about the epidemiological relatedness of isolates, requires appropriate application of RFLP analysis, possibly using multiple probes.
This project was supported by Wellcome Trust
13204 Increasing diversity of HIV-1 serotypes in French blood
donors (1985-1996)
Francis Barin1 2, J. Pillonel3, L. Buzelay2, A.M. Courouce4. Members of
Retrovirus Study Group; 'Lab. Virologie, 2CHU Bretonneau Tours, Tours;
3RNSP, St. Maurice; 41NTS, Paris, France
Objective: To study the prevalence and the dynamics of diffusion of HIV-1
subtypes in French blood donors.
Methods: A retrospective and then prospective study was conducted in 508
blood donors, identified as positive for antibody to HIV-1, by 12 blood banks
between 1985 and 1996. Results for 1997 will be available and included for
presentation. Serological subtyping was performed with a subtype-specific ELISA
(SSEIA), the reliability for genotyping of which has been demonstrated previously.
Results: 55 of the 467 SSEIA-typable samples were reactive to non-B subtypes (11.8%): 18 to subtype A, 32 to subtype C, 2 to subtype D and 3 were
equally reactive to 2 subtypes (2 A/B and 1 A/C). The distribution of the subtypes
was clearly associated with origin of the donors: 91.7% of European donors were
infected by subtype B viruses whereas 80% of African donors were infected by
non-B variants. However, 34 of the non-B samples were from European donors,
most of them infected through heterosexual route but some of them being homosexual men. A statistically significant increasing prevalence of non-B samples
was observed: from 4.4% in 85-89, to 12.4% in 90-93, and 26.0% in 94-96. A
subgroup of 103 SSEIA-typable samples from donors with known date of seroconversion was identified. The data observed in these seroconverters confirmed
the increasing prevalence of non-B subtypes: from 5.7% in 86-91 to 21.2% in
92-96.
Conclusion: These results-stress the necessity to broaden the surveillance of
HIV-1 diversity in blood donors in order to keep adapted the screening assays to
the diffusing strains.
S13205 Sero- and genotyping of HIV-1 variants circulating on the
territory of the former USSR
Edward V. Karamov', M.Yu. Shekanuv', N.G. Yaroslavtseva1,
S.V. Verevochkin', A.P. Kozlov2, V.Ph. Eremin3, L.P. Titov3. 'lvanovsky Institute
of Virology, Gamaley 16, 123098 Moscow; 2Research Institute of Biochemicals,
St. Petersburg; 3lnstitute Epidemiology and Microbiology, Minsk, Russia
Objectives: To get a more precise molecular profile of HIV-1 epidemic on the
territory of the former USSR.
Methods: Sera from 465 HIV-1 infected patients were tested in ELISA with a
set of V3 synthetic peptides. RNA- and DNA-PCR-amplified samples of V3-loop
gp120 HIV-1 were sequenced. Nucleic acid sequences were classified with the
help of agglomerative cluster-analysis, multidimensional scaling and factor analysis.
Results: Phylogenetic analysis clustered the V3 sequences recovered with
subtypes A, B, C, D, F and G. All sequences from the homosexual men were
shown to belong to subtype B and most of the heterosexually infected individuals
were of subtypes A, B and C. Sequences from the parenterally infected individuals
were more heterogeneous. In the peptide ELISA three reactivity patterns were
found. Serum samples from most homosexual men (78%) showed reactivity to
peptides derived from B subtype. Serum samples from heterosexual patients were
reactive to peptide derived from A subtype (26% in St.-Petersburg, about 13% in
Moscow and Minsk), B subtype (about 24% in Moscow and St.-Petersburg, 41%
in Minsk), C subtype (50% in Moscow, 14% in Minsk, 7% in St.-Petersburg), other
subtypes are not significant. Serum samples from St.-Petersburg and Minsk often
(up to 35%) have complicated immunoreactive profile. Multidimensional scaling
and factor analysis allowing to visualize results of V3 serotyping show great
heterogeneity of subtype B found in homosexual population and a high level of
serological homogeneity among IVDUs from Svetlogorsk epidemic source.
Conclusions: Before 1995 serum samples from IVDUs have mainly B subtype
whereas after 1995 serotype A/C exists. There is a great heterogeneity of subtype
B found in homosexual population.