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

12th World AIDS Conference

Abstracts 13118-13122 109

113118 HIV/AIDS morbidity and mortality in Kampala/Uganda:
1988 vs 1996
Olaf Mueller', M. Abbas2. 1Schaefergasse, Heildelberg, Germany; 2Red Cross
Society, Kampala, Uganda
Objective: To measure the impact of the HIV/AIDS epidemic in urban Uganda.
Design: Repeated cross-sectional household survey.
Methods: In early 1997 a standardized questionnaire was completed by trained
volunteers, visiting all households covering two villages in the central Kampala
parish Kibuye I. The questionnaire focused on demographic data, on morbidity
and mortality data, and on socioeconomic aspects of disease and death in households. A similar household survey had been carried out in this community in early
1989.
Results: In 1997, there were 12,339 persons living in 1998 households (5809
adults and 6530 children), compared to 5345 persons living in 1133 households
eight years ago. Of the 1153 deaths reported to have occurred in these households since the last survey, the mortality fraction attributable to AIDS was 82%
Forty-two percent of Kibuye I households had experienced at least one death due
to AIDS. In 1997, 18% of households reported at least one member living with a
severe disease which is not HIV/AIDS, while 41% reported at least one member
currently living with HIV disease or AIDS in the household.
Conclusions: Within 8 years, the number of inhabitants in the study area has
more than doubled. At the same time, HIV/AIDS has become by far the leading
cause of morbidity and mortality in this urban African community.

13119

Geographical variations in the prevalence of HIV and
other sexually transmitted infections: Lower risk in
lake-island communities in Mwanza region, Tanzania

Richard Hayes', H. Jansen1, F. Mosha2, L. Williams1, J. Changalucha2,
J. Todd2, A. Obasi3. 1London Sch. of Hygiene and Tropical Medicine Keppel
Street London Wcie 7HT England; 2NIMR, Mwanza;3AMREF Mwanza, Tanzania
Objectives: (i) To compare island communities in Lake Victoria with rural mainland
communities in the same Region, with respect to the prevalence and incidence of
HIV and other STDs; (ii) To assess whether identified differences in prevalence
and incidence are explained by differences in sexual behaviour or other risk
factors.
Methods: As part of an HIV/STD intervention trial, data on the prevalence and
incidence of HIV and other STDs in the general population were collected from
2 island communities and 8 rural communities on the mainland. In each of the
8 communities, HIV and syphilis serology were available for a random sample
of about 1,000 adults aged 15-54 years, and HSV2 serology for a sub-sample
of these. Data were also available on the prevalence of male urethritis from the
same cohort. In women, prevalences of gonorrhoea (NG), chlamydia (CT) and
trichomoniasis (TV) were measured in 100 antenatal clinic attenders from each
community.
Results: HIV prevalences were significantly lower on the islands than in the
rural mainland communities (M: 1.8% vs 3.3%; F: 1.6% vs 4.1%). Similar findings
were observed for past/current syphilis (TPHA+: M: 7.7% vs 15.1%; F: 9.2% vs
16.4%), and active syphilis (TPHA+/RPR+: M: 2.5% vs 8.7%; F: 3.8% vs 9.7%).
In contrast, no significant differences were observed for HSV2 (M: 22% vs 16%;
F: 42% vs 44%) or male urethritis (10.9% vs 10.3%); or for antenatal prevalences
of NG/CT (10.6% vs 8.3%) or TV (23% vs 28%). Island men and women did
not differ significantly from rural-dwellers in age at first sex, age at first marriage
or age difference between spouses. However island men had significantly fewer
lifetime sex partners (-5 partners: 59% vs 75%, P < 0.001), and sex partners
during the past year (- 2 partners: 40% vs 54%, P = 0.01).
Conclusions: This study has shown a lower prevalence of HIV and syphilis
on lake-island communities than in rural mainland villages, while there was little
difference in other STDs. HIV and syphilis are possibly more closely associated
with "core-group" patterns of sexual networking, while HSV2 and non-ulcerative
STDs are more widely dispersed and less dependent on high risk behaviour. This
hypothesis is supported by data showing that men on the islands are less likely
to engage in multiple sexual partnerships.
I13120 Seroepidemiology of HIV-1/2 infections among patients
attending the tuberculosis unit, Douala Central Hospital
Jean Najomou1, E. Nyankiye2, L. Zekeng1, L. Kaptue1.
SHaematology-Immunology Laboratory University Centre Hospital Yadunae;
2Douala Central Hospital Douala, Cameroon
Background: HIV infection has been increasing in subsaharan African countries.
Respiratory Diseases are frequently found among HIV infected individuals. The
objectives were 1) to determine the prevalence of HIV1/2 and 2) to evaluate the
rate of HIV1/O among the HIV infected patients.
Methods: A cluster sampling survey was conducted among patients attending
the chest unit of the Douala Central Hospital. After verbal information, a questionnaire was completed and 10 ml of blood was collected in EDTA tubes. Plasma
was screened for the presence of HIV1/2 antibodies using a third generation EIA
containing MVP5180 gp41 antigen (Enzygnost ant-HIV1/2 plus, berhing Marburg,
Germany). Reactive samples were then tested using a competitive EIA (Wellcozyme HIV1, Murex). Samples having a ratio (cut-off/OD) >5 on competitive EIA
were considered as HIV1 group M positive whereas those having a ratio <5 were
further tested using 1) a western blot assay (HIV1 immunoblot Biorad, Munich,

Germany) 2) a specific western blot assay (MVP5180 immunoblot, research tool
from Max von pottenkofer institute, Germany) and 3) a V3 loop peptide EIA.
Results: Between february to september 1997, 1,281 samples were collected.
There were 750 (58.6%) males and 531 (41.4%) females. The mean age was
32.40 varying between 2 and 79 years. The overall prevalence of HIV1/2 was
24.12%; HIV1/M accounting for 98.4% and HIV1/0 for 1.6%. The 5 cases of
HIV1/0 were distributed among tuberculosis (1), bronchitis (2) and pleurisy (2)
patients. A statistically significant difference, (p < 0.05) was observed between
the different pathologies and the HIV seropositivity. There was no significant sex
difference (p > 0.05) on HIV seropositivity. No case of HIV2 was found, therefore
confirms the fact that HIV2 is not indigenous to Cameroon.
Conclusion: HIV infection is spreading among patients attending the Chest
unit. Continuous monitoring of HIV infection among these patients is needed and
new strategies of control and care of TB and HIV/AIDS in the African regions
should be envisaged.
S13121 Improved specificity for serotyping HIV-1 in Uganda by
use of V3 and gp41 env peptides
Pontiano Kaleebu1, D. Yirrel2, F. Lyaboga3, R. Cheingsong Popov4, N. French3
C. Gilks5, J. Whitworth3. 1MRC/UVRI PO. Box 49 Entebre; 3MRC/UVRI Entebre,
Uganda; 2Centre For HIV Research Edinburgh; 4ICSM At St Mary's London;
5Liverpool School Of Tropical Medicine Liverpool, UK
Background: Peptide serology has been a useful tool for serotyping HIV-1 in
regions where the epidemic is recent, such as Thailand. However, this approach
has been difficult in East Africa due to high cross-reactivity. We have evaluated a
combination of V3 and gp41 envelope peptides followed by heteroduplex mobility
assay (HMA) for subtyping HIV-1 in comparison with DNA env sequencing.
Method: Samples were obtained from an adult HIV+ cohort in a Ugandan town.
DNA was amplified in the V3 region for HMA and sequencing. Antigen limiting
dilution assay was used for the V3 peptide ELISA. The gp41 peptides of HIV-1 LAI
and ELI were used at 5ug/ml in an indirect ELISA assay. For analysis, subtypes
A/C and B/D were taken as the same serotypes. Samples were also subtyped by
HMA.
Results: Using V3 peptides alone, out of 109 sequenced samples, 6% could
not be subtyped, 72% were correctly identified and 22% were wrongly identified.
A combination of V3 and gp41 peptides could not subtype 18% of samples, 72%
were correctly identified and only 10% were wrongly identified. Using these two
peptides, followed by HMA for the untypable samples, we correctly identified
88%.
A combination of V3 and gp41 peptides followed by HMA can be a useful tool
for subtyping HIV-1 for epidemiological purposes in areas where subtypes A
and D are predominant. The added gp4l peptides improve the specificity of the
algorithm.
| 13122 Genotypic and phenotypic characterization of HIV-1 from
migrant workers on three South African gold mines
Helba Bredell12, C. Williamson3, P. Sonnenberg4, G.M. Hunt2, S.F. Lyons2,
C.T. Tiemessen2, L. Morris2. 1National Institute for Virology Private Bag X4
Sandringham 2131; 2MRC AIDS Virus Research Unit (NIV), Johannesburg;
3Dept Medical Microbiol & SAIMR Virology Capetown; 4Dept of Community
Health, Univ of Witwatersrand, Johannesburg, South Africa
Objectives: To determine the extent of HIV-1 genetic variation and phenotypic
characteristics of isolates from infected subjects employed by three adjacent
South African gold mines.
Design: Fifty-two samples were obtained from 51 HIV-1 seropositive male patients who were admitted to a mine hospital. The patients were migrant workers
originating from rural areas of South Africa and the neighbouring countries of
Lesotho, Botswana, Swaziland and Mozambique.
Methods: Proviral HIV-1 DNA was subtyped using a heteroduplex mobility
assay (HMA) based on the 700 bp V3-V5 region of the env gene. DNA sequence
analysis confirmed the subtype designation and was used to determine phylogenetic relationships between isolates. Virus was isolated from 8 patients and
characterized phenotypically using conventional culture methods.
Results: All 52 HIV-1 isolates were identified as envsubtype C using both HMA
and phylogenetic analysis. These isolates did not show a distinct phylogenetic
relatedness based on the geographic origins of the migrant workers or show close
homology to other subtype C sequences from southern Africa or India. However,
five clusters of closely related sequences were identified mainly involving miners from disparate geographic origins. The characteristic tetrapeptide sequence,
GPGQ, at the tip of the V3 loop of subtype C viruses was conserved in the
predicted amino acid sequences of most isolates. Phenotypic characterization
of the subtype C isolates has shown that they are predominantly non-syncytium
inducing.
Conclusion: The heterogeneity of HIV-1 sequences among migrant workers in a mining cohort suggest multiple introductions of HIV-1 subtype C into
the population. The presence of a few closely related cluster suggest possible

epidemiological linkage in a few cases. There was no correlation between the
geographic origins of the miners and the genetic relatedness of HIV-1 isolates.