Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gladstone study finds no evidence of superinfection among highly exposed HIV+ couples

15.07.2004


In a study of 33 HIV+ couples who engaged in frequent, unprotected sex, Gladstone Institute of Virology and Immunology researchers found no evidence of superinfection, the sequential acquisition of multiple HIV variants.



HIV is a highly mutable virus encompassing two quite different types around the world, HIV-1 and HIV-2. Within those types there are variations known as "subclades" that are typically subdivided further into genetically differentiated strains. The epidemic in the U.S. consists almost entirely of a single subclade, HIV-1B, while HIV epidemics in other parts of the world involve a mix of subclades. In the study, researchers investigated potential superinfection involving variations within HIV-1B. In 28 of the 33 couples, each participant was infected with a strain of HIV-1B that was genetically different than that of the person’s partner, and the 28 couples were particularly relevant for these preliminary results.

The findings, presented at the XV International AIDS Conference in Bangkok on July 15, call into question the widely held perception that people with HIV-1 are highly susceptible to additional infection by HIV-1 variants that may be drug-resistant or more virulent, says lead investigator Robert Grant, MD, MPH, a Gladstone Institute of Virology and Immunology scientist. The study presentation was titled, "No superinfection among seroconcordant couples after well-defined exposure."


The ongoing investigation, known as the Positive Partners study, began in 2001 and will eventually involve up to 200 HIV-1-infected couples. It is designed to investigate the incidence of superinfection in the HIV+ population.

In addition to the couples cited in these preliminary findings, 30 individuals reporting multiple partners were included in the study. One of them, a participant who had recently developed HIV-1, presented with a highly divergent variation of the virus at a follow-up visit. "This one case demonstrates that people who have recently developed HIV-1 can harbor multiple viruses," notes Grant, who also holds appointment as assistant professor of medicine, at the University of California, San Francisco. "In contrast, superinfection has not appeared in people who have had the disease for many years, as our couples have."

The possibility that superinfection may be restricted to a short window period after the development of HIV has been suggested by experimental studies in non-human primates. In addition, a recent mathematical analysis demonstrated that superinfection restricted to a short window period after seroconversion could account for the high prevalence of recombinant and dual infections observed in some parts of the world. This analysis has just been published in the July 23, 2004, issue of AIDS, the journal of the International AIDS Society, as a paper titled "HIV-1 Superinfection and Viral Diversity," by Grant and investigators Kimber L. Gross and Travis C. Porco of the San Francisco Department of Public Health.

"Studies are warranted to better understand why superinfection among patients who have had HIV for a long time is rare," Grant explains. "The mechanisms preventing superinfection may include specific or non-specific anti-viral immune responses or viral interference. If there is indeed an immune response at play, it’s reasonable to investigate the possibility of inducing that response with a vaccine that can be made available to high-risk HIV-negative individuals."

Couples in the Positive Partners study share a variety of characteristics: their infections predate their relationships with their current partners; they practice unprotected anal or vaginal sex with each other; and all live in the San Francisco Bay Area. The 30 singles reported unprotected intercourse with multiple HIV-positive partners. During the one-year course of participation in the study, all participants taken together reported a total of 3,725 episodes of unprotected intercourse with partners known to be HIV-positive.

One theme has become apparent to Grant over the course of the study. "It’s clear that, to some degree, HIV-positive individuals prefer fellow HIV-positive partners, a phenomenon known as serosorting," he observes. "In this way, they avoid the risk of infecting HIV-negative partners."

The study was supported by grants from the UCSF AIDS Research Institute Breakthrough Fund, UCSF-Gladstone Centers for AIDS Research, Universitywide AIDS Research Program, Gladstone Institute of Virology and Immunology (GIVI), and Centers for Disease Control and Prevention. Continuing research through 2007 is funded by the National Institutes of Health.

The presentation was co-authored by Grant and J. Jeff McConnell, Annie Boutelle, Eric Hunt and Teri Liegler, all of GIVI; Rose Tsui of Blood Systems Research Institute (BRSI); and Belinda Herring and Eric Delwart of BSRI and University of California, San Francisco.

John Watson | EurekAlert!
Further information:
http://www.ucsf.edu
http://www.gladstone.ucsf.edu

More articles from Studies and Analyses:

nachricht The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft

nachricht Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Molecular Force Sensors

20.09.2017 | Life Sciences

Producing electricity during flight

20.09.2017 | Power and Electrical Engineering

Tiny lasers from a gallery of whispers

20.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>