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

12th World AIDS Conference

Abstracts 43434-43438 931

3434 Individual case reporting (ICR) of HIV infection in Europe:
An evolving surveillance tool
Andrea Infuso, F.F. Hamers, J.B. Brunet. European Centre for Monitoring of
AIDS 14 Rue Val D'Osne, St. Maurice, Cedex, France
Background: AIDS reporting has been the basis of the epidemiological monitoring of HIV infection in Europe. Declining AIDS incidence in western Europe (partly
resulting from the introduction of new therapies) and emerging HIV epidemics in
eastern Europe (not yet detectable through AIDS surveillance) require an adaptation of surveillance strategies. We examined HIV ICR systems in European
countries.
Methods: A questionnaire, sent in September 1997 to HIV/AIDS surveillance
coordinators in 48 countries of the WHO European Region, was returned by 42
countries (including the 15 countries of European Union [EU]).
Results: Thirty-three countries (including eight EU countries) have national
HIV ICR systems, of which 29 started before 1990. HIV ICR is limited to some
regions in France, Italy and Spain (the three countries with the highest AIDS
incidence), and to a single city in Albania and The Netherlands. Austria, Ireland,
Luxembourg and Malta have no ICR. Among the 33 national systems, HIV ICR is
voluntary in Belgium, Greece, Lithuania, Poland, Portugal and United Kingdom,
and mandatory in other countries. Both laboratories and clinicians report in 19
countries. Cases are reported at national level with names in eight countries
(none in the EU) and through an identifying code in 18. Data completeness
differs markedly with, in 1996, up to 50% incomplete names in Ukraine, and 27%
unknown transmission group in Russia, 37% in Turkey and 58% in Germany.
Linkage with AIDS reporting is possible in 27 countries. System changes are
planned at short term in 16 countries, including coordinated expansion of regional
ICR (France, Italy, Spain), improved link with AIDS ICR (Denmark, Hungary),
coordination of laboratory and clinician reporting (Germany, Switzerland), switch
to non-nominative ICR (e.g. Poland, Russia). Ukraine, where the epidemic is
recent, is considering abandoning HIV ICR.
Conclusions: Different systems for HIV ICR exist since the 1980s in at least
38 European countries. Reorganization of HIV ICR is planned at short term in
16 countries, ranging from abandoning ICR in Ukraine (large recent epidemic) to
expanding regional systems in France, Italy and Spain (largest epidemics). Rising
interest in HIV ICR and changing epidemic trends represent a unique opportunity
to develop standardised HIV ICR at European level.
S43435 Status and trend of HIV infection in Vietnam
Tran Hien Nguyen1, Hoang Thuy Long2, Pham Kim Chi2. 'Department of
Epidemiology Hanoi Medical College 1 Ton That Tung Hanoi; 2National Institute
Hygiene Epidemiology 1 Yersin Hanoi, Vietnam
Objective: to measure prevalence and trends of HIV infections in defined populations
Design: Serial Cross-sectional study
Methods: Sentinel surveillance was stated in 1994 in 8 provinces, expanded
to 12 provinces in 1995 and to 20 provinces in 1996. Sentinel populations are
STD patients, IDUs, CSWs, Antenatal women, TB patients, and Army conscripts.
The sample size is 200 for high risk and 800 for low risk groups. Surveys was
repeated every 6 months for high risk groups and anually for low risk groups.
Unlinked and confidential methods and WHO recommended HIV testing strategy
II were used. Chi square test was used for the measure of linear trends.
Results: HIV prevalence varied greatly among provinces and populations, and
maily in southern provinces. The aggregated rates were increasing in all sentinel populations statistically from 1994-1997. The HIV prevalence among IDUs
increase from 0% in most provinces in 1993 to maximum 33% in 1994 and 44%
in 1995, and 51% in 1996, and 68.6% in 1997 in some provinces (mean: 5.6)
and the aggregated rate was 13%. The prevalence among CSWs ranged from
0-15% (median 0.4%) with the increase of aggregated rates from 0.6% in 1994
to 2.4% in 1997. The HIV prevalence among STDs remained quite low, ranging
from zero to 3.6% (median: 0) with the increase of aggregate rates from 0.12% in
1994 to to 0.66% in 1997. The HIV aggregated prevalence rates among low risk
population were less than 0.13%.
Conclusion: Vietnam HIV epidemic is predominantly and rapidly transmitted among IDUs. However the prevalence rates among CSWs and STD are
increasing. The HIV prevalence among low risk populations are still low.
43436 HIV surveillance system in Lazio region, Italy: Update
Daniela Porta, Angela Carboni, Marina Davoli, Elisabetta Rapiti, Carlo
Alberto Perucci. Department of Epidemiology, Lazio Region Health Authority, via
Santa Costanza, Rome, Italy
Background: The objective of the study is to describe the temporal distribution
of new diagnosis of HIV and the changing patterns of HIV transmission in Lazio,
an Italian region including Rome (about 5.5 million inhabitants).
Methods: A laboratory-based HIV Surveillance System (LHSS) has been active
in Lazio since 1985. Each individual HIV-positive test is anonymously reported

to the Regional Epidemiological Department, by public and private laboratories
and blood banks. The "new individual diagnosis" of HIV infections are identified
through a record-linkage procedure based on sex and date and place of birth. We
report an update of the data from LHSS.
Results: As of June 30 1997, 39674 HIV notifications of HIV-positive tests were
reported to the LHSS, corresponding to 15788 new diagnosis of HIV infection.
The incidence rose until 1992, reaching two peaks in 1987 (1725 new diagnosis)

and 1989 (1774 new diagnosis). From 1992 it continuously decreased to the end
of 1996 (931 new diagnosis). Data show an increasing number of new diagnosis
among women (male/female ratio from 3.5 in 1985 to 2.4 in 1997) and higher
mean age at diagnosis. Data also show an increasing proportion of both men
and women reporting heterosexual contacts as risk factor and a corresponding
decrease in the proportion of injection drug users. Sexual exposure overtook
injection drug use among women and men, respectively in 1992 and in 1995 and
still remains the main modality of transmission reported.
Conclusions: Data from the LHSS suggest a slow but consistent decrease
of incidence of new diagnosis of HIV reported. There are evidences of a shift
in the incidence of new infections from a "high risk" population to the "general"
population, exposed through heterosexual transmission. However, the incidence
in the general heterosexual population is lower than predicted by mathematical
models developed in Lazio region.
S434317 Towards real-time HIV surveillance using HIV testing data
Margaret Fearon1, C. Swantee2, R. Galli2, R. Remis3, T. Degazio2, K. Wu2,
C. Major2. 'Ontario Ministry of Health, HIV Laboratory, 81 Resources Road,
Etobicoke, Ontario; 2Ministry of Health PHL, Toronto, ON; 3University of Toronto,
Toronto, ON, Canada
Objective: To carry out real-time HIV surveillance using laboratory testing data
in a province where all HIV diagnostic testing is carried out at the Public Health
Laboratory (PHL) System.
Methods: An Informix-based laboratory information system (LAByrinth, CoCam
Pty, Australia) developed for the Australian National HIV Reference Laboratory
was implemented at the Ontario central and regional PHLs. Existing testing data
(1.6 million records) was converted from a specimen-centered to a patient-centered database. New records were collected directly through on-line data entry,
testing and reporting. Data quality assurance using data enhancement, data integrity and duplicate checking procedures is an integral component of the system.
Using SAS, an epidemiologic module was incorporated into the system. Automated regular data extraction created data sets and tables and maps reporting:
new cases, positivity rates (eliminating duplicate positive and negative tests),
incidence density among repeat testers (Kitayaporn et al), and testing patterns,
by age, sex, exposure category and geographical region.
Results: From 1992 to end 1997, 1,548,638 tests were done on 1,486,117
persons. Testing patterns appeared stable except for an increase in transfusion
related testing in 1993-94. Overall positivity rates steadily declined among MSM
(5.8% in 1993, 3.0% in 1997), were relatively stable in IDUs (1.5% in 1993, 1.3% in
1997) and those from HIV endemic areas (2.6% in 1993; 2.4% in 1997). However,
we observed regional variations in testing patterns and repeat testers; positivity
rates in some geographic regions were higher than provincial means (MSM:
Toronto 8.3%, Niagara 5.0%; IDU: Ottawa 3.7% Thunder Bay 3.4%, Sudbury
3.0%; HIV endemic: Toronto 5.5%). Incidence density (per 100 person-years) in
1996 was 3.2 (CL 2.3-4.1) for MSM and 0.8 (CL 0.2-1.3) for IDU.
Conclusions: The complex and dynamic nature of the HIV epidemic can
be tracked with a real-time surveillance system using laboratory testing data.
This data is especially important for identifying potential "hotspots" or outbreaks.
Surveillance data is critical in resource allocation and health care and intervention planning. Additional information on HIV test-seeking behaviour would further
enhance the value of the data.
43438 How common is secondary transmission of HIV in the
US?
R. Monina Klevens1, P.L. Fleming1, J.J. Neal2, J. Li3. 1Center For Disease
Control, 1600 Clifton Rd Mailstop E-47 Atlanta GA 30333; 2CSTE Atlanta GA;
3 TRWAtlanta GA, USA
Background: Of all AIDS cases in the US, 9% have been reported as heterosexual transmission (HT); however, the proportion of HT cases is increasing. We
evaluated the frequency with which persons with heterosexually acquired AIDS
knew their sexual partners' HIV risk behaviors.
Methods: Six US reporting sites (Alabama, California, Florida, New Jersey,
New York City, and Texas) interviewed 598 adults to elicit their knowledge of
their sexual partners' HIV risk behaviors. Persons were selected from a random
sample of AIDS cases, initially reported as HT or unspecified risk. We defined
primary HT as heterosexual activity with a partner with any of the following
risks: male-to-male sex, injection drug use, receipt of contaminated blood, blood
products, organ, or tissue; secondary HT was heterosexual activity with a partner
with no primary risk behavior. Analysis was restricted to the 466 adults reporting
heterosexual activity.
Results: Persons interviewed were similar to those not interviewed by gender
and age, but interviewees were more likely to be black (p = 0.04). Of persons
interviewed, 370 (79%) reported primary HT. Women (n = 62, 65%) were more
likely than men (n = 34, 35%) to report secondary HT (p = 0.03). Persons reporting
secondary HT were less likely than those reporting primary HT to have a history
of sexually transmitted diseases (45% and 60%; p < 0.01) and less frequently

reported use of non-injecting drugs (45% and 50%; p = 0.34). Persons reporting
secondary HT were not significantly different than those reporting primary HT by
race (73% and 62% were black, respectively; p = 0.07), education (51% and 41%
had less than a high school education, respectively; p = 0.08), or marital status
(45% and 36% had never been married, respectively; p = 0.13). Adults reporting
secondary HT had a similar median age, and median numbers of male or female
sexual partners compared with those reporting primary HT.