October 15, 2012
Britt S. Livak et al. Open AIDS J 2012; 6(Suppl 1: M6):142-8. Read the abstract.
The role of anal intercourse in HIV transmission among heterosexuals is understudied, despite evidence that many women, including those most at risk for HIV acquisition, engage in anal sex. According to one recent study, approximately 9% of women in the general U.S. population had anal sex within the past 12 months, and in a national probability sample, a third of the women aged 20 to 44 reported ever having anal sex.
Other data find that anal sex, particularly among injection drug users, was associated with additional risks for sexually transmitted infections (STIs). Less is known about specific sexual practices, such as anal sex, among non-injecting women, such as those living in inner cities in poverty.
This study from the Chicago Department of Health piggybacks on the recruitment of participants in a CDC study of people at risk for HIV in 21 cities across the U.S. To make sense of the study results, it is important to understand who exactly was recruited. The study involves identification of geographic areas considered higher-risk for heterosexual HIV transmission based on HIV prevalence and poverty level. People frequenting venues (convenience stores, laundromats, street corridors, etc.) within a selection of these areas were recruited and surveyed.
Of the 1,101 people approached, 851 consented; 48% were women. The mean age of women participating in the study was 31.7 years; the majority were black (82%) and had an annual income less than $10,000 (81%). Over the past year, 15% were homeless and 11% had been arrested and detained for over 24 hours. Excluding five who reported injection drug use, 87% reported unprotected vaginal sex and 17% reported anal sex (for 86% of those women, the anal sex was unprotected) in the past 12 months.
Rapid HIV testing was accepted by 381 (94%) of the women in the study; seven (1.86%) were positive, with no major difference in positivity rates between those with and without a history of anal sex.
In a multivariable analysis of factors associated with anal sex (adjusted for age and having had unprotected vaginal intercourse in the past 12 months), three variables were independently correlated with anal intercourse in the past 12 months: having three or more sex partners in the past 12 months (OR 3.27, 95% CI, 1.53-6.99), self-reported STI diagnosis in the past 12 months (OR 2.13, 95% CI, 1.06-4.26) and having had vaginal or anal intercourse for the first time before the age of 15 (OR 2.23, 95% CI, 1.28-3.89).
The prevalence of these and other STI risk factors in this sample -- including concurrency, prior diagnosis with STIs, illicit substance abuse and alcohol abuse -- was striking. Moreover, almost 90% of participants reported they had neither been exposed to nor utilized HIV prevention services over the previous year.
Importantly, the authors draw attention not only to the potential use of their data to profile women who may have higher risk of HIV acquisition via anal sex, but also to the structural factors they discovered that likely promote HIV/STI transmission in these women. Such structural factors include endemic homelessness, unemployment, low education attainment and incarceration.
Remedies for these social ills are a challenge to develop. Unlike interventions that target individual behavior, those addressing the structures that exist in a community may be difficult to apply and test. However, a greater obstacle to minimizing the effects of poverty, discrimination and similar forces is a failure to acknowledge their existence and a lack of willingness to take meaningful action to mitigate their toxic effects.
The current political debate on the role of government, which is uniquely able to intervene on a scale necessary to affect significant change, makes it clear that many in the U.S. do not believe we should be righting these wrongs. Until the scales tip more in favor of such action, we will continue to see grim reports such as this reminding us of the cost of inaction.
Van N. Selby et al. AIDS 2012, 26:1967-9. Read the abstract.
Pulmonary artery hypertension, a dangerous complication of HIV infection, is challenging to diagnose. Typically, the workup starts with a doppler echocardiogram. However, in a study from San Francisco, echocardiography was found to be insensitive for detection of pulmonary artery hypertension when compared to the gold standard of right heart catheterization.
The study was conducted among a cohort of 422 HIV-infected patients who underwent a research cardiac echo. Of these, 129 had an estimated pulmonary artery systolic pressure of 30 mmHg or more (an established upper limit of normal). They were all offered right heart catheterization; 76 accepted (80% male, median age 52 years).
While the pulmonary artery pressures estimated by the doppler echocardiography and the heart catheterization were generally correlated, the echo tended to overestimate pressures overall, but underestimate pressures when values were high. This meant that for 14 patients who were determined by right heart catheterization to have pulmonary artery hypertension (pressure >35 mmHg), five were missed by echocardiography.
These concerning results mirror those from studies of uninfected patients. HIV clinicians should take note of the limits of echocardiography and appreciate that when pulmonary artery hypertension is on the differential, a negative echo does not rule out the diagnosis. Only heart catheterization can be conclusive.
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