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

130 Abstracts 13222-13225

12th World AIDS Conference

at the time of childbirth. To determine trends over time of a number of factors
including region in Canada, maternal HIV risk factors, country of origin and race.
Methods: All HIV paediatric centres in Canada provide a yearly update on the
status of all perinatal cases that they follow. Any child diagnosed as HIV infected
with an HIV+ mother was considered to have become infected through vertical
transmission unless there was reason to believe otherwise.
Results: The identified number of children born to HIV+ women in Canada
has steadily risen since 1985. This is true both for women whose risk was IDU
or heterosexual contact. The course of the epidemic varies geographically with
IDU's driving the epidemic in British Columbia and sexual contact in Ontario. The
population rate of children born to HIV+ mothers is highest in British Columbia.
Women who are black or first nation are over represented relative to their proportion in the population. Based on an expected rate of vertical transmission of
25% in untreated mothers, many cases of HIV-children born to HIV+ mothers
were missed. Even before zidovudine therapy was introduced to prevent vertical
transmission, there was an decreasing ratio of HIV+ to - infants born each year,
which indicates that the identification rate for infants with perinatal HIV exposure
was improving.
Conclusions: The Canadian perinatal HIV surveillance program has been
successful in collecting national statistics on known perinatal HIV exposure. The
database is now large enough to begin to allow meaningful analysis of trends
over time.
S13222 1 Trends in HIV incidence among adolescents and young
adults in the United States
Philip Rosenberg, R.T. Biggar. National Cancer Institute, 6130 Executive Blvd,
EPN-403, USA
Context: Behaviors that result in potential exposure to HIV usually begin in adolescence or young adulthood, but trends in HIV incidence among young people
remain unclear.
Objective: To estimate trends in HIV incidence among teenagers and young
adults.
Design and Setting: Back-calculation of past HIV incidence in persons born
from 1960 to 1974 using United States national AIDS incidence data and estimates
of the distribution of times between HIV infection and AIDS.
Main Outcome Measures: HIV incidence and prevalence in 1988 and 1993
among persons 20 and 25 years of age, respectively, in each of those years.
Results: As of January 1993, approximately 22,000 men and 11,000 women
aged 20 years were living with HIV infection in the United States. Homosexual contact was the leading route of infection among young men. Heterosexual
contact was the leading route of infection among young women. HIV incidence
attributed to homosexual contact or injection drug use decreased among 20 and
25 year-olds between 1988 and 1993, but HIV incidence attributed to heterosexual contact was stable or increasing. Notably, among both 20 and 25 year
old men, HIV prevalence declined by almost 50% in whites but was stable or
increasing in blacks and Hispanics. In contrast, HIV prevalence in women rose
by 26% because of increasing heterosexual transmission.
Conclusions: Among young persons, HIV incidence in homosexual men and
injection drug users was slowing by 1993; this favorable trend was offset by
increasing heterosexual transmission, especially to minority teenagers. Overall,
HIV prevalence in 20 and 25 year olds declined only 14% between 1988 and
1993.
13223 Bordetella bronchiseptica infection in HIV-infected
persons
Mark S. Dworkin, P.S. Sullivan. Centers for Disease Control and Prevention
Mailstop E-47, 1600 Clifton Road, Atlanta, Georgia, USA
Background: Bordetella bronchiseptica is a pleomorphic gram negative coccobacillus which is a common cause of respiratory tract infections in dogs and
may also infect cats. Case reports of B. bronchiseptica pneumonia, septicemia,
and wound infections in immunosuppressed people have been recognized.
Methods: To identify persons with culture-confirmed B. bronchiseptica infections, we searched computerized records of persons observed in over 100 medical
clinics in 11 US cities from January 1990-July 1997 in the Adult and Adolescent
Spectrum of HIV disease project For identified cases of B. bronchiseptica infection, we abstracted medical records to determine the nature of the illness, CD4
count at the time of the illness, outcome, concurrent bacteriologic culture isolates,
and pet ownership.
Results: Among 41,336 persons with a median of 13 months of follow time, 9
cases of B. bronchiseptica infection were identified, with no geographic clustering.
Seven cases occurred in males; median age was 33 years (range, 24-37 years).
Most (5/9) had B. bronchiseptica pneumonia, 2/9 had sinusitis, 1/9 had bronchitis,
and 1/9 had sinusitis and pneumonia. CD4 count at the time of diagnosis ranged
from 1-207 (median, 15 cells/pl); 7 patients recovered from the illness during
which B. bronchiseptica infection was diagnosed, and 2 died during the illness.
Among 6 isolates with antibiotic resistance testing available, all were resistant to

cefazolin and 5/6 were resistant to ceftriaxone; all were sensitive to gentamicin,
5/5 tested were sensitive to tobramycin, and 4/4 tested were sensitive to trimethoprim/sulfamethoxazole. For 5 patients, B. bronchiseptica was the only organism
isolated from the culture sample; 4 others had co-isolates including Pneumocystis
carinii, viridans Streptococcus, Candida albicans, and Staphylococcus aureus.
Two of the patients reported contact with pet dogs and one with pet cats before the
illness; history of contact with pets was unavailable for the remaining 6 patients.

Conclusions: Bordetella bronchiseptica in HIV infected persons may cause a
range of illness from mild to severe sinusitis, bronchitis, and pneumonia. Most
infections occurred in persons with severe imunosuppression, and half of the
persons had co-pathogens in the culture sample which yielded B. bronchiseptica.
No clear association with contact with dogs or cats was evident, although data
on contact with animals was missing from medical records of most patients.
[ 13224 1Age-specific trends in seroprevalence of HIV and
hepatitis B and C virus among injecting drug users
admitted to drug treatment in six US cities
Christopher Murill, H.R. Weeks, S. Lambert, H. Weinstock, C.L. Spruill,
M. Gwinn. CDC 1600 Clifton Road E46 Atlanta Georgia 30333, USA
Objective: To describe trends in prevalence of hepatitis B virus (HBV), hepatitis
C virus (HCV) and HIV infection among injecting drug users admitted to drug
treatment in six US metropolitan areas.
Methods: Unlinked remnant specimens (n = 1,716) from injecting drug users
entering drug treatment in 1993-1994 were screened for antibodies to hepatitis
B core antigen (anti-HBc) and HCV (anti-HCV). Specimens had been previously tested for anti-HIV, and demographic and drug use information had been
abstracted from client intake records. US cities represented were Baltimore,
Newark, San Francisco, Seattle, Denver, and Detroit.
Results: Overall, prevalence of HIV, anti-HBc and HCV increased with age:

Age:
# Tested
HIV
Anti-HBc
Anti-HCV

20-24
103
6%
27%
49%

25-29
220
8%
40%
58%

30-34
288
14%
57%
75%

35-39
437
12%
65%
85%

40-44 45+
402 239
15% 11%
81% 82%
88% 90%

Age-adjusted HIV seroprevalence varied by city: Baltimore (25%), Newark
(24%), San Francisco (7%), Seattle (5%), Denver (2%), and Detroit (1%). All
cities had high age-adjusted prevalence of anti-HBc (48% to 73%) and anti-HCV
(58% to 90%). Although injecting drug users were more likely to be positive for
anti-HCV than anti-HBV, HIV was more highly associated with anti-HBc (MantelHaenzel OR = 6.0, 3.9-9.4) than with HCV (OR = 1.3, 0.8-2.0).
Conclusion: Although the prevalence of HBV and HCV infection among injecting drug users was high in all six cities, the prevalence of HIV varied greatly.
A stronger association of HIV with HBV than with HCV suggests that both sexual and percutaneous exposure may be important in HIV transmission among
injecting drug users.
S13225 Prevalence of HIV-1 group M, non-B subtypes in a Bronx,
New York community: A sentinel site for monitoring HIV
genetic diversity in the United States
Paul J. Weidle1, C.E. Ganea2, D. Pienniazek1, A. Ramos1, C.A. Schable1,
J. Enst2, J. McGowan2. Centers for Disease Control & Prevention, Atlanta, GA;
2Bronx Lebanon Hospital Center, Bronx, NY USA
Background: The predominant HIV-1 isolates in the United States are classified
as group M, subtype B. A nonblinded survey in 1992-1994 at the Bronx-Lebanon
Hospital Center (BLHC) found HIV-1 subtype A in 2 of 43 (5%) patients, indicating
introduction of non-B subtypes in the US (J Infect Dis 1997; 176:1629-33).
Objectives: To evaluate the prevalence of non-B HIV-1 and potential recombinants among HIV-infected patients at BLHC who have resided in the US since
age 15 and to compare HIV risk behaviors to determine whether non-B subtype
infections were acquired locally or from contacts outside the US.
Methods: We are recruiting 300 HIV-infected BLHC patients who have resided
in the US since the age of 15 years and who had different durations of HIV
infection and types of sex or needle-sharing contact with foreign nationals or foreign travelers. The subtype analysis was done by subtype-specific peptide-based
enzyme immunoassays. All non-B serotype specimens were subtyped by DNA
sequencing and phylogenetic. analysis of the gp41 region. Potential recombinants
were further tested by RFLP or sequence analysis of the protease gene region.
Results: Of the first 91 patients, 88 have been identified as subtype B (63 by
serotype, 25 by sequence analysis), one as subtype A, one as subtype F, and
one as a recombinant with subtype F in the protease region and subtype B in the
gp41 region. Phylogenetic analysis of the protease region from both specimens
with subtype F clustered with Puerto Rican F rather than Brazilian F. All three
persons (two men) with non-B subtypes were born in the US and tested HIV
positive between 1988 and 1997 while living in the Bronx. All denied travel to
other countries. The man with subtype A and the woman with subtype F reported
heterosexual sex but denied knowledge of foreign birthplace or foreign travel of
partners. The man with the recombinant isolate reported unprotected sex with
women and men (including a man from Puerto Rico in the 1980s). All denied
receipt of blood products or injection drug use.
Conclusion: This study provides evidence of diverse non-B HIV-1 subtypes,
including subtype A and F (Puerto-Rico) and a recombinant isolate, in the US
The occurrence of non-B HIV -1 subtypes in long-term US residents without
foreign contact may have implications for the evaluation and development of HIV
diagnostics and vaccines.