Because Dach probably won’t do it–and not that it will make the
slightest difference–here are some data.
George M. Carter
**
Allen S, Meinzen-Derr J, Kautzman M, Zulu I, Trask S, Fideli U,
Musonda R, Kasolo F, Gao F, Haworth A. Sexual behavior of HIV
discordant couples after HIV counseling and testing. AIDS. 2003 Mar
28;17(5):733-40.
Department of Epidemiology and International Health, School of Public
Health, University of Alabama in Birmingham, 35294, USA.
BACKGROUND AND OBJECTIVES: Sexual behavior following voluntary HIV
counseling and testing (VCT) is described in 963 cohabiting
heterosexual couples with one HIV positive and one HIV negative
partner (‘discordant couples’). Biological markers were used to assess
the validity of self-report. METHODS: Couples were recruited from a
same-day VCT center in Lusaka, Zambia. Sexual exposures with and
without condoms were recorded at 3-monthly intervals. Sperm detected
on vaginal smears, pregnancy, and sexually transmitted diseases (STD)
including HIV, gonorrhea, syphilis, and Trichomonas vaginalis were
assessed. RESULTS: Less than 3% of couples reported current condom use
prior to VCT. In the year after VCT, > 80% of reported acts of
intercourse in discordant couples included condom use. Reporting 100%
condom use was associated with 39-70% reductions in biological
markers; however most intervals with reported unprotected sex were
negative for all biological markers. Under-reporting was common: 50%
of sperm and 32% of pregnancies and HIV transmissions were detected
when couples had reported always using condoms. Positive laboratory
tests for STD and reported extramarital sex were relatively
infrequent. DNA sequencing confirmed that 87% of new HIV infections
were acquired from the spouse. CONCLUSIONS: Joint VCT prompted
sustained but imperfect condom use in HIV discordant couples.
Biological markers were insensitive but provided evidence for a
significant under-reporting of unprotected sex. Strategies that
encourage truthful reporting of sexual behavior and sensitive
biological markers of exposure are urgently needed. The impact of
prevention programs should be assessed with both behavioral and
biological measures.
PMID: 12646797 [PubMed - indexed for MEDLINE]
***
Fideli US, Allen SA, Musonda R, Trask S, Hahn BH, Weiss H, Mulenga J,
Kasolo F, Vermund SH, Aldrovandi GM. Virologic and immunologic
determinants of heterosexual transmission of human immunodeficiency
virus type 1 in Africa. AIDS Res Hum Retroviruses. 2001 Jul
1;17(10):901-10.
Department of Epidemiology and International Health, School of Public
Health, University of Alabama at Birmingham, Birmingham, Alabama
35294, USA.
More than 80% of the world’s HIV-infected adults live in sub-Saharan
Africa, where heterosexual transmission is the predominant mode of
spread. The virologic and immunologic correlates of female-to-male
(FTM) and male-to-female (MTF) transmission are not well understood. A
total of 1022 heterosexual couples with discordant HIV-1 serology
results (one partner HIV infected, the other HIV uninfected) were
enrolled in a prospective study in Lusaka, Zambia and monitored at
3-month intervals. A nested case-control design was used to compare
109 transmitters and 208 nontransmitting controls with respect to
plasma HIV-1 RNA (viral load, VL), virus isolation, and CD4(+) cell
levels. Median plasma VL was significantly higher in transmitters than
nontransmitters (123,507 vs. 51,310 copies/ml, p < 0.001). In
stratified multivariate Cox regression analyses, the risk ratio (RR)
for FTM transmission was 7.6 (95% CI: 2.3, 25.5) for VL > or = 100,000
copies/ml and 4.1 (95% CI: 1.2, 14.1) for VL between 10,000 and
100,000 copies/ml compared with the reference group of <10,000
copies/ml. Corresponding RRs for MTF transmission were 2.1 and 1.2,
respectively, with 95% CI both bounding 1. Only 3 of 41 (7%) female
transmitters had VL < 10,000 copies/ml compared with 32 of 93 (34%) of
female nontransmitters (p < 0.001). The transmission rate within
couples was 7.7/100 person-years and did not differ from FTM (61/862
person-years) and MTF (81/978 person-years) transmission. We conclude
that the association between increasing plasma viral load was strong
for female to male transmission, but was only weakly predictive of
male to female transmission in Zambian heterosexual couples. FTM and
MTF transmission rates were similar. These data suggest
gender-specific differences in the biology of heterosexual
transmission.
***
Gray RH, Wawer MJ, Brookmeyer R, Sewankambo NK, Serwadda D,
Wabwire-Mangen F, Lutalo T, Li X, vanCott T, Quinn TC; Rakai Project
Team. Probability of HIV-1 transmission per coital act in monogamous,
heterosexual, HIV-1-discordant couples in Rakai, Uganda. Lancet. 2001
Apr 14;357(9263):1149-53.
Departments of Population and Family Health Sciences, School of
Hygiene and Public Health, Johns Hopkins University, Baltimore, MD
21205, USA. rg…@jhsph.edu
BACKGROUND: The probability of HIV-1 transmission per coital act in
representative African populations is unknown. We aimed to calculate
this probability overall, and to estimate how it is affected by
various factors thought to influence infectivity. METHODS: 174
monogamous couples, in which one partner was HIV-1 positive, were
retrospectively identified from a population cohort in Rakai, Uganda.
Frequency of intercourse and reliability of reporting within couples
was assessed prospectively. HIV-1 seroconversion was determined in the
uninfected partners, and HIV-1 viral load was measured in the infected
partners. Adjusted rate ratios of transmission per coital act were
estimated by Poisson regression. Probabilities of transmission per act
were estimated by log-log binomial regression for quartiles of age and
HIV-1 viral load, and for symptoms or diagnoses of sexually
transmitted diseases (STDs) in the HIV-1-infected partners. RESULTS:
The mean frequency of intercourse was 8.9 per month, which declined
with age and HIV-1 viral load. Members of couples reported similar
frequencies of intercourse. The overall unadjusted probability of
HIV-1 transmission per coital act was 0.0011 (95% CI 0.0008-0.0015).
Transmission probabilities increased from 0.0001 per act at viral
loads of less than 1700 copies/mL to 0.0023 per act at 38 500
copies/mL or more (p=0.002), and were 0.0041 with genital ulceration
versus 0.0011 without (p=0.02). Transmission probabilities per act did
not differ significantly by HIV-1 subtypes A and D, sex, STDs, or
symptoms of discharge or dysuria in the HIV-1-positive partner.
INTERPRETATION: Higher viral load and genital ulceration are the main
determinants of HIV-1 transmission per coital act in this Ugandan
population.
***
Johnson AM, Laga M. Heterosexual transmission of HIV. ]AIDS. 1988;2
Suppl 1:S49-56.
\Academic Department of Genito-Urinary Medicine, University College
and Middlesex School of Medicine, London.
PIP: Recent developments concerning heterosexual transmission of HIV
(review of 1988 literature only) suggest improved understanding of the
pattern of spread and role of risk behaviors and biological cofactors
in its transmission. 3 distinct patterns if HIV infection are known:
heterosexual spread in sub-Saharan Africa and the Caribbean, spread
primarily among homosexuals and injecting drug users in Europe, North
American and much of Latin America and Australia, and both homosexual
and heterosexual transmission in Asia, the Pacific, the Middle East
and Eastern Europe, where prevalence is low. In Africa an estimated
80% of cases are acquired heterosexually. Important risk factors are
number of sex partners, sex with prostitutes, being a prostitute,
being a sex partner of an infected person, and having a history of
other sexually transmitted diseases. Prevalence rates have risen
rapidly in Zaire and Kenya. In Africa, acquisition of HIV is related
to sexual activity only. In contrast, in the U.S., heterosexual cases
make up only 4% of all cases, and in Europe only 6%. Data on types of
sexual transmission of HIV are mounting, in aggregate suggestive of a
marked heterogeneity in infectivity and possibly susceptibility
between individuals. Among couples where the man is positive, in some
places individuals appear to be highly infective, notably those from
Kinshasa, Zaire and Haiti, while other series of discordant couples
the receptive partner remained seronegative for several years.
Transmission from women to men appears to be less efficient than from
men to women, as has been observed with other STDs such as gonorrhea.
Biological cofactors implicated in enhanced HIV transmission appear to
be advanced CDC Stage IV AIDS disease, with low T-helper lymphocyte
counts and high antigenemia; concomitant STDS, especially those with
genital ulceration; lack of circumcision; oral contraceptive use;
practice of anal intercourse; inconsistent or no use of condoms.
Theoretical models for future heterosexual spread emphasize number of
partners, use of condoms, and treatment of STDs