Having HPV infection may double risk of becoming HIV positive.
The findings are important because more than 2 million people across the world--and about 50,000 people in the United States--get infected with HIV every year. There is no vaccine to prevent HIV infection, but there are several other approaches to preventing HIV. For example, avoiding and treating certain non-HIV infections could lower the new HIV rate because these other infections make it easier to pick up HIV.
HPV is a common sexually transmitted virus that may affect HIV risk (Figure 1). People can get infected cd with one or more of the 40 different types of HPV. Some HPV types--called high-risk types--can lead to cervical cancer, anal cancer, and other cancers in people with and without HIV. Cervical cancer is an AIDS cancer, and anal cancer poses an ongoing threat to gay and bisexual men, including those with HIV. Certain low-risk HPV types can lead to genital warts.
[FIGURE 1 OMITTED]
Learning more about how HPV affects the risk of HIV infection is important because two vaccines that prevent HPV infection are already available and a third vaccine is being developed. Researchers conducted this study to determine how having HPV infection affects chances of picking up -HIV infection. The researchers also estimated the proportion of HIV infections that can be attributed to HPV infection.
* How the study worked. The investigators searched online databases for studies involving HPV, genital warts (which HPV can cause), and HIV. They considered studies published in medical journals or presented at key HIV and sexually transmitted infection meetings.
All studies in the final analysis determined whether people had HPV infection then checked on these people over time to see ii they became infected with HIV. To determine the impact of HPV status on acquiring HIV, some studies considered the impact of other HIV risk factors and some studies did not. The analysis included studies published or presented up to July 29, 2011.
The researchers separately considered studies involving three groups: (1) women, (2) gay or bisexual men, and (3) heterosexual men. When possible, the investigators used standard statistical methods to combine findings from studies. Combining findings from several studies produces stronger, more reliable results. The researchers could not combine findings from different groups (for example, women and heterosexual men) because each group differs in how these individuals acquire HIV infection.
Finally, the researchers figured what proportion of new HIV infections could be explained by infection with HPV.
* What the study found. The researchers reviewed 1139 studies and found 8 that met their requirements for analysis. There were six studies of women (all in Africa), one study of gay or bisexual men (in the United States), and one study of heterosexual men (in Africa). Together the eight studies involved 12,750 people.
The study team was able to combine results of the six studies of women and thus to analyze the impact of HPV on HIV for a large group. This combined analysis produced strong evidence that infection with any HPV type raised the risk of becoming infected with HIV. The risk was calculated as a hazard ratio (HR), which was 2.06 in this analysis (Figure 2). That means being infected with any HPV type slightly more than doubled the risk that a woman in these studies would become infected with HIV.
Risk of HIV acquisition after infection with HPV Any HPV: Women 2.06 High-risk HPV: Women 1.99 Low-risk HPV: Women 2.01 2 or more HPV types: Gays 3.5 Any HPV: Other men 1.8 Figure 2. Analysis of six studies of women (first cone on left) determined that infection with any HPV type doubled the risk of HIV infection. In five studies of women (second cone from left), infection with a high-risk HPV type also doubled the risk of HIV infection. In two studies of women (third cone from left), infection with a low-risk HPV type again doubled the risk of HIV infection. In one study of gay or bisexual men (fourth cone from left), infection with two or more HPV types raised the risk of HIV infection 3.5 times. In one study of heterosexual men (fifth cone from left), detection of any HPV type on the head of the penis almost doubled the risk of HIV infection.
Five of the six studies in women examined the impact of high-risk HPV types (those most likely to lead to cancer) on becoming infected with HIV. Infection with a high-risk HPV type nearly doubled chances of HIV infection (HR 1.99). livo studies weighed the impact of low-risk HPV types on HIV acquisition, and once more being infected With one of these HPV types doubled chances of HIV infection (HR 2.01).
Two of six studies in women calculated the impact of persistent HPV infection (HPV detected over repeated visits) on HIV acquisition. This analysis did not show that persistent HPV affected chances of HIV infection. However, nonpersistent infection with a high-risk HPV type raised chances of HIV infection by two thirds (HR 1.67), nonpersistent infection with a low-risk HPV type more than doubled chances of HIV infection (HR 2.09), and nonpersistent infection with any HPV type raised chances of HIV infection more than 5 times (HR 5.4).
The one study of HPV in gay and bisexual men in the United States found that infection with one HPV type did not affect chances of picking up HIV infection. But infection of these men with two or more HPV types more than tripled chances of HIV acquisition ion (HR 3.5). The one study of HPV in heterosexual Kenyan men found that detection of any HPV type on the head of the penis almost doubled chances of picking up HIV infection (HR 1.8).
Three studies had enough details to let the researchers calculate the proportion of new HIV infections that could be attributed to infection with one or more of the 40 HPV types. These rates were:
* 21% in women in Zimbabwe
* 37% in women in South Africa
* 28% in heterosexual men in Kenya
Overall, these three studies indicated that infection with HPV may have accounted for more than one quarter of new HIV infections in these groups.
* What the results mean for you. The six-study analysis of HPV in African women produced strong evidence to support the theory that being infected with HPV in creases the risk of becoming infected with HIV. Individual studies of HPV in gay and bisexual men and in heterosexual men also showed that HPV infection may make becoming infected with HIV more likely.
HPV can pass from one person to another during sex. Getting infected with HPV usually causes no illness, so infected people do not realize they have picked up HPV. Most people will get rid of HPV infection on their own, even the high-risk HPV types, without any treatment. Over many years, however, infection with high-risk HPV types can lead to cervical cancer, anal cancer, cancer of the penis, cancer of the vagina, and other cancers. And HPV is especially important to HIV-positive people because rates of cancers associated with HPV are higher in people with HIV.
Two available vaccines, Cervarix and Gardasil, can protect against genital warts and cancers caused by HPV in both women and men. A study of 16- to 23-year-old HIV-positive women in the United States found that about half of them did not test positive for any of the four HPV types that Gardasil protects against (HPV-6, HPV-11, PV-16, and HPV-18) (2) (see preceding report in this issue of Hit' Treatment Alerts!). These researchers also found evidence that Gardasil may produce a protective response against these HPV types in HIV-positive women. (3) A trial of the same vaccine in healthy boys and men in 18 countries found that it protects against infection with these four HPV types and prevents development of HPV-related genital sores. (4)
In the United States the Centers for Disease Control and Prevention (CDC) recommends one or the other HPV vaccine for (1) all teen girls and women through age 26 who did not get all three doses of the vaccine when they were younger, and (2) all teen boys and men through age 21 who did not get all three doses of the vaccine when they were younger. (5) The CDC also recommends an HPV vaccine for gay and bisexual men through age 26 and for any man with HIV infection through age 26.
The researchers were careful to point out the study's limitations and to clarify the potential impact of HPV vaccines on HIV. The current HPV vaccines protect against only two or four of the known HPV types; and those vaccines are protective only if they are given before a person becomes infected with those HPV types. Most of the studies in this analysis were carried out in countries with high rates of HPV and HIV. The researchers believe the HPV vaccines are unlikely to help protect against HIV in countries like the United States. But the vaccines can protect people from HPV in the United States.
The overall study findings suggest that preventing HPV infection lowers the risk of HIV infection in some populations. But the types of studies analyzed here leave open the possibility that other factors led to HIV infection in these HPV-positive people. For example, none of the studies tested people for herpes simplex virus type 2 infection or bacterial vaginosis, both of which may raise the risk of HIV infection.
For these reasons, this study cannot say definitely whether preventing HPV infection with an HPV vaccine will lower the rate of HIV infection. But avoiding HPV infection makes sense for many other reasons, including preventing genital warts and several cancers in women and men. The CDC notes that using a condom during sex may lower the risk of HPV infection and may prevent HPV-related diseases, such as genital warts and cervical cancer. (6)
(1.) Houlihan CF Larke NL., Watson-Jones D, et al. Human papillomavirus infection and increased risk of HIV acquisition. A systematic review and mcta-analysis. AIDS. 2012;26:2211-2222.
(2.) Kahn IN, Burk RD, Squires KE, et al. Prevalence and risk factors for HPV in HIV-positive young women receiving their first Li PV vaccination.J Arquir Immune, Defit Syndr. 2012;61:390-399.
(3.) Kahn J, Xu J, Kapogiannis B, et al. Immunogenicity of the HPV-6, -11, -16, -18 vaccine in HIV-positive young women. XIX International AIDS Conference. Washington, DC. July 22-27, 2012. Abstract WEA130202.
(4.) Giuliano AR, Palefsky JM, Goldstone S, et al. Efficacy of quadrivalent HPV vaccine against HPV infection and disease in males. N Engl.J Med. 2011;364:401-411.
(5.) Centers for Disease Control and Prevention. Human papillomavirus (HPV). HPV vaccines. http:/www.cdc.gov/hpv/vaccine.htm1
(6.) Centers for Disease Control and Prevention. Human papilloniavirus (HPV). Prevention. http://www.cdc.gov/hpv/Prevention.html
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|Title Annotation:||Article 3|
|Publication:||HIV Treatment: ALERTS!|
|Date:||Mar 1, 2013|
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