Nav: Home

HIV therapy could be contributing to syphilis outbreak: UBC study

January 16, 2017

Drugs used to treat HIV could affect how the body responds to syphilis, inadvertently contributing to a current outbreak, a new study suggests.

Syphilis cases in several countries have risen sharply in recent years, primarily affecting men who have sex with men. In this study, researchers investigating the outbreak hypothesize that medications used in highly active antiretroviral therapy (HAART), the gold standard for treating HIV infection, could reduce the body's immune responses to particular diseases, including syphilis.

"After reading about the astounding increase in syphilis cases, I also noticed a huge gap between syphilis and other sexually transmitted infections like chlamydia and gonorrhea," said Michael Rekart, lead author and clinical professor in UBC's school of population and public health. "That led me to believe there must be something else going on."

Until now, research and clinical communities have suggested that the outbreak could be a result of more risky sexual behaviour, such as people having sex without condoms, springing from the perception that the risk of HIV infection is low due to the availability and effectiveness of HAART.

However, the study points to evidence showing that many men with HIV do not practice high-risk sexual behaviour and that new syphilis cases are commonly observed in people on HAART. It also suggests there are plausible biological explanations for HAART effects on the body's immune response to certain diseases, says Caroline Cameron, a microbiologist at the University of Victoria who was part of the study team.

Rekart and his colleagues used mathematical modeling to predict syphilis rates based on the premise that risky sexual behaviour was the sole cause, and calculated a rate of increase lower than today's actual rate. When they considered both behaviour changes and possible immunity effects, their model predicted a rate that closely approximated the actual incidence of syphilis in B.C. and several other countries. Researchers have not yet compared data of people on HAART who contract syphilis with those not on HAART who contract the infection to establish a link.

While the findings suggest that researchers and health-care professionals should look more closely at this issue, Rekart said it is vital for people to continue to take their HAART. He said people can use information from this study to make behaviour decisions such as always using condoms and reducing the number of sexual partners.

"HAART drugs are life-saving; syphilis is curable," he said. "HAART drugs bring people with HIV back to a normal state of immunity, they can have a normal life, they don't get most opportunistic infections such as tuberculosis."

As a next step, researchers will need to look more closely at the relationship between HAART and infectious and non-infectious diseases and whether there are specific drugs in the HAART medication cocktail that impair immunity.
-end-
The research was published today in Sexually Transmitted Infections: http://sti.bmj.com/lookup/doi/10.1136/sextrans-2016-052870.

An editorial accompanying the new research was also published today by researchers at Johns Hopkins University School of Medicine, Baltimore: http://sti.bmj.com/lookup/doi/10.1136/sextrans-2016-052940

Note: Michael Rekart is in Beijing and can conduct interviews by Skype but has limited availability because of the time difference; he is available at michael.rekart@ubc.ca. University of Victoria's Caroline Cameron is available at: 250-853-3189 or caroc@uvic.ca.

University of British Columbia

Related Hiv Articles:

Defective HIV proviruses reduce effective immune system response, interfere with HIV cure
A new study finds defective HIV proviruses, long thought to be harmless, produce viral proteins and distract the immune system from killing intact proviruses needed to reduce the HIV reservoir and cure HIV.
1 in 7 people living with HIV in the EU/EEA are not aware of their HIV status
Almost 30,000 newly diagnosed HIV infections were reported by the 31 European Union and European Economic Area (EU/EEA) countries in 2015, according to data published today by ECDC and the WHO Regional Office for Europe.
Smoking may shorten the lifespan of people living with HIV more than HIV itself
A new study led by researchers at Massachusetts General Hospital finds that cigarette smoking substantially reduces the lifespan of people living with HIV in the US, potentially even more than HIV itself.
For smokers with HIV, smoking may now be more harmful than HIV itself
HIV-positive individuals who smoke cigarettes may be more likely to die from smoking-related disease than the infection itself, according to a new study published in the Journal of Infectious Diseases.
Patients diagnosed late with HIV infection are more likely to transmit HIV to others
An estimated 1.2 million people live with HIV in the United States, with nearly 13 percent being unaware of their infection.
The Lancet HIV: New HIV infections stagnating at 2.5 million a year worldwide
A major new analysis from the Global Burden of Disease 2015 study, published today in The Lancet HIV journal, reveals that although deaths from HIV/AIDS have been steadily declining from a peak in 2005, 2.5 million people worldwide became newly infected with HIV in 2015, a number that hasn't changed substantially in the past 10 years.
NIH scientists discover that defective HIV DNA can encode HIV-related proteins
Investigators from the National Institutes of Health have discovered that cells from HIV-infected people whose virus is suppressed with treatment harbor defective HIV DNA that can nevertheless be transcribed into a template for producing HIV-related proteins.
Study examines risk of HIV transmission from condomless sex with virologically suppressed HIV infection
Among nearly 900 serodifferent (one partner is HIV-positive, one is HIV-negative) heterosexual and men who have sex with men couples in which the HIV-positive partner was using suppressive antiretroviral therapy and who reported condomless sex, during a median follow-up of 1.3 years per couple, there were no documented cases of within-couple HIV transmission, according to a study appearing in the July 12 issue of JAMA, an HIV/AIDS theme issue.
HIV vaccine design should adapt as HIV virus mutates
Researchers from UAB, Emory and Microsoft demonstrate that HIV has evolved to be pre-adapted to the immune response, worsening clinical outcomes in newly infected patients.
Charlie Sheen's HIV disclosure may reinvigorate awareness, prevention of HIV
Actor Charlie Sheen's public disclosure in November 2015 that he has the human immunodeficiency virus (HIV) corresponded with the greatest number of HIV-related Google searches ever recorded in the United States, according to an article published online by JAMA Internal Medicine.

Related Hiv Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Changing The World
What does it take to change the world for the better? This hour, TED speakers explore ideas on activism—what motivates it, why it matters, and how each of us can make a difference. Guests include civil rights activist Ruby Sales, labor leader and civil rights activist Dolores Huerta, author Jeremy Heimans, "craftivist" Sarah Corbett, and designer and futurist Angela Oguntala.
Now Playing: Science for the People

#521 The Curious Life of Krill
Krill may be one of the most abundant forms of life on our planet... but it turns out we don't know that much about them. For a create that underpins a massive ocean ecosystem and lives in our oceans in massive numbers, they're surprisingly difficult to study. We sit down and shine some light on these underappreciated crustaceans with Stephen Nicol, Adjunct Professor at the University of Tasmania, Scientific Advisor to the Association of Responsible Krill Harvesting Companies, and author of the book "The Curious Life of Krill: A Conservation Story from the Bottom of the World".