A mathematical model shows that a new wave of drug-resistant HIV is rising among among men in San Francisco who have sex with men and that this trend will continue over the next few years, according to a new study from the UCLA AIDS Institute.
At the same time, the evolution of drug-resistant HIV may have actually reduced the severity of the city's epidemic, saving many men from becoming infected.
The model and its results were unveiled today by UCLA biomathematics professor Sally Blower, director of the Biomedical Modeling Center at the David Geffen School of Medicine at UCLA, during a session on drug-resistant diseases at the annual American Association for the Advancement of Science conference in Boston.
"Our amplification cascade model has been validated by our reconstructions and can now be used to design novel and effective health policies for controlling single-, dual- and triple-class resistant strains of HIV in both resource-rich and resource-constrained countries," said Blower, who is also a member of the UCLA AIDS Institute.
The model enabled the researchers to reconstruct the epidemic's past and predict its future by calculating the evolution of several classes of drug-resistant HIV strains in San Francisco.
The research relied on a novel multi-strain mathematical model called the Amplification Cascade Model to examine the rise between 1987 and 2007 of HIV strains resistant to the three major classes of drugs -- nucleosides (NRTIs), nonnucleosides (NNRTIs) and protease inhibitors (PIs). The model took into account three interacting processes -- transmitted, acquired and amplified resistance -- the last of which refers to amplification of drug-resistant strains in HIV-positive people due to the repeated use of multiple-treatment drug regimens.
The study tracked uninfected individuals; newly infected people in the primary stage of infection; chronically infected individuals who were not yet eligible for treatment; chronically infected people who remained untreated, though eligible for it; and patients under treatment.
Researchers found complex waves of rising and falling single-, dual- and triple-class drug-resistant HIV strains over 20 years, with more complex patterns continuing to evolve.
The model predicts that resistance to NRTIs will decline substantially and PI resistance will fall slightly through 2012, and that resistance to NNRTIs will rise over the next five years and then begin falling.
Although strains with dual- and triple-class resistance will be transmitted, they will be far less potent than wild-type HIV strains -- those strains that have not developed drug-resistant mutations and remain sensitive to all classes of drugs.
Most surprising of all, the evolution of drug-resistant HIV strains has substantially reduced the severity of the San Francisco AIDS epidemic because the strains that have emerged have become less infectious than the wild-type strains.
Enrique Rivero | EurekAlert!
Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung
High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
26.10.2016 | Power and Electrical Engineering
26.10.2016 | Health and Medicine
26.10.2016 | Materials Sciences