Abstract
HIV and AIDS
Rates of Primary Infection and Superinfection Equivalent
A study among a general population in Uganda revealed a surprising finding: the rate of HIV superinfection—acquisition of a new viral strain by an already HIV-infected individual—was essentially that same as the rate of primary HIV infections. In this non-high–risk heterosexual population, the rate of HIV superinfection was 1.44 per 010 person years (PYs), compared to a primary HIV incidence among more than 20,000 initial HIV-negative individuals in the general population of 1.15 per 100 PYs. Propensity score matching to control for differences in sociodemographic and behavioral characteristics between the HIV-positive individuals at risk for superinfection and the HIV-negative population at baseline and follow-up led to adjusted estimated rates of primary HIV incidence of 3.28 per 100 PYs (controlling for baseline differences) and 2.51 per 100 PYs (controlling for follow up differences). The authors point out that many models of the HIV epidemic and viral evolution assume that superinfection is not occurring. These findings refute that assumption and demonstrate that superinfection is common and occurs both within and between HIV subtypes, suggesting that the immune response elicited by primary infection confers limited protection. This calls into question the potential effectiveness of vaccine strategies intended to replicate the natural anti-HIV immune response.
Source: Redd Ad, Mullis CE, Serwadda D. The rates of HIV superinfection and primary HIV incidence in a general population in Rakai, Uganda. J Infect Dis 2012;206:267–274.
Southern U.S.: Plenty of AIDS, Few HIV Experts
Nine southern U.S. states account for about half of all new AIDS diagnoses, yet access to care is limited in that region by a paucity of HIV medical specialists. Whereas there are 411 HIV specialists in California and 275 concentrated in New York State, according to the American Academy of HIV medicine, only 243 HIV specialists are available to treat patients in the 9-state region encompassing Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, and Tennessee. The Washington, D.C.-based group AIDS United, which provides grants to community organizations, helped to highlight the need for better control of AIDS in the South at a congressional roundtable held recently on Capitol Hill. High AIDS incidence rates in the South may be attributable to factors such as poverty, racism, cultural conservatism, and the stigma associated with high-risk behaviors. The Alabama-based group Montgomery AIDS Outreach recently launched a program in which HIV specialists can extend their reach by providing patient consults via a video link with patients and nurses at a satellite care center.
Source: Copeland L. Many AIDS cases, few HIV specialists in South. USA Today June 17, 2012.
Women in Argentina Infected by Stable Partners
A study conducted jointly by the national organization Argentine Network of Women Living with HIV and the Buenos Aires Network of People Living with HIV found that 92% of HIV-infected women were infected as a result of unprotected sex and 73% were infected while in a stable relationship. In some cases, the women had been with their partner for many years. It is estimated that as many as half the people living with HIV in Argentina do not know they are HIV infected. All of the women interviewed had been diagnosed since January 1, 2009. The study also revealed an expanding age range of HIV-infected women with an increasing number older than 60 years. Another reported finding was that 44% of the women interviewed had experienced conflict or tension at some point with their partners over the use of condoms.
Source: Valente M. HIV-positive women in Argentina mainly infected by stable partners. Inter Press Service May 28, 2012.
Do MSM's Sexual Behavior Patterns Differ?
Different sexual behavior patterns by men who have sex with men (MSM) compared to heterosexual men and women may explain why MSM have higher rates of HIV and other sexually transmitted infections despite reporting more consistent condom use during anal sex than is reported by heterosexuals with vaginal sex. The main differences included sexual activity beginning at a younger age among MSM, longer cumulative lifetime periods of new partner acquisition, and a more gradual decline in forming new partnerships with advancing age. MSM were also 2 to 3 times more likely as heterosexuals to report recent concurrent partners.
Source: Glick SN, Morris M, Foxman B, et al. A comparison of sexual behavior patterns among men who have sex with men and heterosexual men and women. J Acquir Immune Defic Syndrome 2012;60:83–90.
Higher Risk of Sudden Cardiac Death
Most cardiac and many non-AIDS–related natural deaths among HIV-infected individuals are due to sudden cardiac death (SCD). HIV-related risk factors may include inflammation and antiretroviral regimens and therapy interruptions. A retrospective study of nearly 3000 patients over approximately 3.5 years in a public HIV clinic led to the following findings: of 230 deaths, 13% met SCD criteria; 57% were due to AIDS; 11% were due to other natural diseases; and 19% were due to overdoses, suicides, or unknown causes. Among the cardiac-related deaths, 86% were due to SCD, for a SCD rate 4.5-fold higher than expected.
Source: Tseng ZH, Secemsky EA, Dowdy D, et al. Sudden cardiac death in patients with human immunodeficiency virus infection. J Am Coll Cardiol 2012;59:1891–1896.
Over-the-Counter Rapid HIV Test Approved
The U.S. Food and Drug Administration (FDA) granted approval to OraSure Technologies' (Bethlehem, PA) for over-the-counter sales of its OraQuick® In-Home HIV Test. The test uses an oral swab for sample collection and detects antibodies to HIV-1 and HIV-2, providing results within about 20 min. OraSure expects the test to be available for purchase by October 2012. The test direct to consumers rapid test is similar to the company's OraQuick ADVANCE® HIV 1/2 Antibody Test. The FDA has recommended that a positive result be followed up by testing by a medical professional. The home test has been shown to be accurate 99.98% of the time in HIV-negative individuals and 92% of the time in HIV-infected persons. Antibody-based testing will yield false-negative results during the 3-month window between infection and when HIV antibodies are first produced.
Each OraQuick test kit will include information on HIV and HIV testing, and step-by-step directions on how to use the test, as well as providing access to a toll-free customer support center and a consumer website. The support center will be staffed 24 h a day, 7 days a week by bilingual (English/Spanish) representatives who can answer questions about HIV/AIDS, describe how to use the test and interpret the results, and provide direct referral to care.
Source: OraSure
AIDS Funding Does Not Compromise Care
In light of criticism that donor funding for HIV/AIDS undermines general health care, a group of researchers from Brandeis University (Waltham, MA) and Abt Associates (Bethesda, MD) carried out a 6-year empirical study to evaluate the impact of HIV/AIDS funding on the primary health care system in Rwanda. They compared randomly selected rural health centers that offered comprehensive HIV/AIDS services to those with no HIV/AIDS services in terms of growth in overall inputs (staff, drugs, and other resources) and outputs (services provided, including visits and vaccinations). The results indicated that the centers with HIV/AIDS services performed better in seven of nine services evaluated, although only one—Bacille Calmette-Guérin vaccination—reached or neared statistical significance. The authors concluded that the expansion of HIV/AIDS services made possible by donor funding had no adverse effects on the provision of non-HIV services and, in fact, may contribute to enhanced preventive care.
Source: Shepard DS, Zeng W, Amico P, et al. A controlled study of funding for human immunodeficiency virus/acquired immunodeficiency syndrome as resource capacity building in the health system in Rwanda. Am J Trop Med Hygiene 2012;86:902–907.
Human Papilloma Virus
Cellular Origin of Cervical Cancer Identified
Researchers may have identified the elusive cells targeted by human papilloma virus (HPV) that lead to the development of precancerous cervical intraepithelial neoplasia (CIN) and, ultimately, cervical cancer. A discrete population of ectoendocervical squamocolumnar junctional cells with a unique morphology and gene expression profile appears to be the target cell population for HPV. The researchers showed that selected SC biomarkers were expressed by a high percentage of high-grade CIN and cervical cancers associated with carcinogenic HPVs, but were rarely expressed in ectocervical CINs or those associated with noncarcinogenic HPVs. They suggest that these findings “uncover a potential target for cervical cancer prevention, provide insight into the risk assessment of cervical lesions, and establish a model for elucidating the pathway to cervical cancer following carcinogenic HPV infection.
Source: Herfs M, Yamamoto Y, Laury A, et al. A discrete population of squamocolumnar junction cells implicated in the pathogenesis of cervical cancer. PNAS 2012;109:10516–10521.
Hepatitis B Virus
Higher than Expected Chronic HBV Prevalence in the United States Attributable to Infected Immigrants
The prevalence of chronic HBV infection (CHB) in the United States may be substantially higher than recent estimates, as high as 2.2 million. Accounting for this discrepancy is the high contribution of foreign-born persons in the United States. The authors of a recent study estimated the number of foreign-born persons in the United States in 2009 living with CHB by their country of origin. Of the 1.32 million person total, they determined that 58% had emigrated from Asia, 11% from Africa, and 7% from Central America.
Source: Kowdley KV, Wang CC, Welch S, et al. Prevalence of chronic hepatitis B among foreign-born persons living in the United States by country of origin. Hepatology 2012;doi:10.1002/hep.24804.
Chronic HBV Cases Largely Untreated
A survey of Asian Canadians indicates that most individuals who are aware they have chronic hepatitis B virus (HBV) infection are not receiving medical treatment. Of the 1000 people surveyed by the Chinese advocacy group S.U.C.C.E.S.S., 49% of respondents had been tested for HBV, but only 70% of those with a positive diagnosis were not under a doctor's care and 88% were not taking any medication for the infection. HBV is disproportionately high among Asian immigrants to Canada, affecting about 15% of the Asian Canadian community, compared to 1% of Canadians. Estimates of chronic HBV cases in the city of Vancouver exceed 60,000.
Source: Ellis E. Most hepatitis B arriers aren't being treated, survey finds. Vancouver Sun May 30, 2012.