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

874 Abstracts 43134-43138

12th World AIDS Conference

Lessons Learned: Although HCTs appear to be increasing access to testing,
their impact will be limited unless barriers to their use are addressed. The experience of HCTs has important implications for the success or failure of other new
HIV tests.
43134 HIV screening of pregnant women: Is it cost-effective in
England? Study for the EU Concerted Action on
Multinational AIDS Scenarios
Maarten Postmal, E.J. Beck2, S. Mandalia2, M.D.S. Walters2, L. Sherr3,
H. Houweling1, J.C. Jager1. 1National Institute of Public health and the
Environment Bilthoven, the Netherlands; 2St Mary's Hospital, London; 3Royal
Free Hospital, London, UK
Objective: To estimate cost effectiveness of screening pregnant women for HIV
in England.
Data sources: (1) published literature on probabilities of mother-to-child-transmission (MTCT); (2) registration on childhood HIV/AIDS-related costs in St Mary's
Hospital, London; and (3) various sources for other costing parameters.
Methods used were: (1) decision-tree analysis; (2) cost-effectiveness analysis; and (3) Markov-modelling for progression of childhood HIV/AIDS. Plausible
assumptions were made for uptakes of AZT during pregnancy, elective caesarian
section (CS) and bottle feeding of the baby. Elaboration of results was done
for ranges of costs of pre-test counselling and testing (C&T) and prevalence of
pregnant women who are unaware of their serostatus.
Results: Lifetime costs of an HIV-infected baby were estimated at ~179 075
(cost level 1997; discount rate 3%). In the reference case HIV screening was cost
saving, for example, if costs of C&T are below ~25 and prevalence above 1/1000
pregnancies or at marginal costs of the test only (~4) and prevalence above 1/10
000 pregnancies. Considering ~25 for costs of C&T and plausible figures for
prevalence of unaware seropositive pregnant women, HIV screening of pregnant
women would cost ~300 per life-year gained in relatively high-prevalence areas,
such as London. In relatively low-prevalence areas in England costs might rise
up to ~3000 per life-year gained. Scenario and sensitivity analyses comprise
variation in the discount rate, MTCT probabilities, uptake of elective CS and bottle
feeding.
Conclusions: Although considerable variation in cost-effectiveness was estimated in the reference case and subsequent analysis, on balance and compared
with other health-care interventions, screening pregnant women for HIV appears
to be a cost-effective intervention. Integration in the daily routine of antenatal
care would lower costs of pre-test counselling and improve cost-effectiveness,
approaching cost saving in high-prevalence areas, such as London and below
~1000 per life-year gained in low-prevalence areas.
Study for the EU Concerted Action on Multinational AIDS Scenarios Contract
Number BMH1-CT-941723.
43135 High refusal rates for serological re-testing among drug
users in opiate substitution clinics: The Zurich
Prometheus study
Bertino Somaini1, J. Wang1, M. Perozo2, M. Olgiati3, D. Meili4, P. Grob5,
M. Flepp6. 1 nstitute F Social + Preventive Medicine, Sumaitrastr. 30, CH-8006,
Zurich; 1Zokl 2, Opiate Substitution Clinic, Zurich, ZH; 3Psychiatric University
Clinic, Zurich, ZH, 4Zokl 1, Methadone Substitution Clinic, Zurich, ZH; 5Dept.
Clin Immunology, Univ. Hospital, Zurich, ZH; 6Dept. Infectious Disease, Univ.
Hospital, Zurich, ZH, Switzerland
Objective: To acquire an up-to-date serological prevalence of HIV and hepatitis
testing among a heavily tested population of clients in opiate substitution clinics.
Methods: The Zurich Prometheus Study is a multi-centric project at four opiate
substitution clinics in Zurich, Switzerland. The study is multi-phase, with an initial
cross-sectional phase focusing on HIV and hepatitis serology among all clients
and a longitudinal phase focusing on combination therapy among HIV-positive
injecting drug users (IDUs). In the cross-sectional study, all clients were offered
serological testing for hepatitis and syphilis, with special criteria for HIV - i.e.,
all non-tested, all HIV-negatives with results older than 6 months, and all others
whose lab results cannot be verified.
Results: The results presented are based on provisional analyses of data on
482 drug users collected through December 17, 1997. The male-female ratio was
3:2, and the mean age was 31 years (SD = 6 years). All had a history of heroin
use, whereas 77% had reported ever injecting. Almost all (97%) of the drug users
recruited had previously been tested for HIV - 75% of whom within the past 2
years - with an overall lifetime average of 4.5 tests per person. Of the 15 who had
never been tested, 9 (60%) refused testing for this study, with "no interest" being
cited as the primary reason. Nearly a third of the additional 263 clients eligible for
HIV testing refused, citing a multitude of reasons - e.g., "no interest," "poor vein
access," "already tested," etc... All respondents were offered tests for hepatitis,
but only 49% accepted. Self-reported hepatitis prevalence was high - 62% HAV,
69% HBV, and 70% HCV - but previous infection status had no influence on
testing acceptance. Among those eligible for HIV-testing, 88% consented to both

HIV and hepatitis testing, whereas only 17% of those who refused the former
agreed to the latter. Of those ineligible for HIV-testing in this study, acceptance of
hepatitis testing was 80%. For those consenting to a hepatitis test, the prevalence
of anti-HCV antibody was 58%. HCV infection is spread evenly across all age
groups, including the youngest drug users. In contrast, HIV infection shows a pronounced age effect, concentrated among those born 1958-64, with a prevalence
of 44%. The HIV prevalence for people born before or after that period is 18%.

Conclusion: Although prior HIV testing and repeated testing were nearly universal, leading us to expect a high acceptance rate, a third of the people eligible
for a new test refused an HIV test within this study. The correlation between
consent to HIV and hepatitis tests suggest that acceptance has more to do with
being tested at all rather than what is actually being tested. The fact that poor
vein access was cited by refusers suggests that non-serum-based collection may
help boost participation rates. The consistently high prevalence of HCV among
all age groups and continued HIV infection among the youngest reinforce the
importance of effective prevention measures among IDUs.
[43136 A national survey of antenatal HIV screening policy and
practice in UK and Eire
Diana Gibb1, P. Tookey2, A. Nicoll3, L. Sherrr4, C. Hudson5, A. Gergenstr6m4.
1MRC HIV CTC Mortimer Market Centre, Capper Street, London WC1E GAU;
2Institute of Child Health, London; 3CDSC Public Health Laboratory Service,
London; 4Royal Free Hospital; 5Retired, London, UK
Background: The uptake of antenatal HIV testing and detection of previously
undiagnosed infected pregnant women are both low in the UK.
Objectives: To update the audit of antenatal HIV testing policy and practice in
UK and Eire (previous surveys were carried out in 1989, 1991 and 1995) and to
relate uptake of testing to the success of maternity units in identifying previously
undiagnosed HIV infected women.
Methods: A postal questionnaire was distributed to all 288 maternity units in UK
and Eire in 1997, through respondents to the National Study of HIV In Pregnancy.
Data on the number of women receiving antenatal care and the number having
an HIV test were collected for 1996 and the uptake of HIV testing calculated for
each unit. The proportion of pregnant women with previously undiagnosed HIV
infection (detection rate) was calculated from NSHIP data and data from unlinked
anonymous seroprevalence studies.
Results: 256 (90%) units responded. 25 (10%) reported a universal offer (U),
79 (31%) a selective offer (S) and 152 (59%) only tested women who requested
it (R). In London there were 17 (52%) U units, compared with 8% in Scotland, 3%
in the rest of UK and none in Eire. All 79 S units offered testing to IDU women,
but only 27 (21%) to women who had lived abroad. Among 80 units where uptake
and detection rates could both be calculated, uptake was over 10% in only 8 U
units. Only 103 of 726 previously undiagnosed women were detected in these
units, 72/461 (15.6%) in 19 U units, 13/126 (10.3%) in 24 S units and 18/139
(12.9%) in 37 R units. In U units, detection increased with uptake of testing (slope
0.53 (95% Cl 0.31-0.76, p < 0.001).
Conclusion: Although universal policies were more common in high prevalence areas, the survey suggests that particularly in London which has the highest
seroprevalence, antenatal HIV testing policies are failing. In most units less than
5% of women are tested, and the majority of undiagnosed HIV-infected pregnant
women remain unidentified. New policies and continuing audit are required to
urgently change this situation.
43137 HIV seroconversion rate in innercity inpatients 1995-1996
Irene Grant, N. Olivo, C. Ganea, I.G. Cerngul, Y. Hernandez, D.P. Strom,
J.A. Ernst. Bronx-Lebanon Hospital Center, 1650 Grand Bronx, New York, NY,
USA
Issue: HIV is highly endemic in the S. Bronx with an estimated 6.9% HIV
seroprevalence rate in patients without HIV related conditions.
Project: At Bronx-Lebanon Hospital Center, adult inpatient HIV counseling &
testing was begun in 1989, with universal approach initiated in 2/96. Between
1/94 & 11/96, 197 inpatients were retested: 84 males [4] Afro-American (AA), 37
Latino (Lat), 4 other], and 113 females [47 AA, 63 Lat, 3 other]. The age range
was 15-75 [mean 40.2].
Results: Twelve (6.1%) seroconverted: 7 males (8.3%), 5 females (4.4%). The
age range for male seropositives was 26-57, and female 27-57, [mean 40.1].
Of the seropositive males, 5 were AA, and 2 Lat. HIV exposure risks for the
males were: MSM as only risk in one, and hetersexual in 6 [5 with concommittant
alcohol, 3 with crack/cocaine, and 2 IDU]. Of the 5 female seroconvertors, 100%
were AA. Three had hetersexual risks [1 also with IDU/Crack & Cocaine], 1 had
only alcohol, another IDU.
Seroconversion rate per 100 person years was 6.5 [12 positives in 185 person
yrs]. The 5 males represented an HIV transmission rate of 4.85 per 100 person
yrs [5 per 103 yrs]. The 7 females represented a rate of 8.54 per 100 person yrs
[7 per 82 yrs].
Analysis of 1997 HIV seroconvertors is ongoing.
Conclusion: The HIV seroconversion rate was unexpectively high in a S. Bronx
inpatient population.
43138J Planning for marriage and HIV counseling and testing in
Uganda
James Turyagyenda, B. Agaba, J. Tumwine, J. Kalule, F. Baryarama, E.F. Aguti,

J.H. Namwebya. AIDS Information Centre, PO Box 10446, Kampala, Uganda
Background: The AIDS Information Centre (AIC) in Uganda has been providing
voluntary and anonymous HIV counseling and testing (CT) since 1990 and by the
end of 1997, over 350,000 clients had been served.
Methods: Routine data have been collected on all clients requesting CT
services, including the reasons why clients come for CT. Data for 1997 have