Featured Research

from universities, journals, and other organizations

Genetic variety of virus causing AIDS as a time indicator

Date:
January 21, 2011
Source:
Schweizerischer Nationalfonds zur Foerderung der wissenschaftlichen Forschung
Summary:
Researchers in Switzerland have identified a simple method to establish when a patient contracted the virus causing AIDS. The time of infection can be of importance for the treatment of the illness and it contributes to the understanding of the course of the epidemic.

Researchers of the Swiss HIV Cohort Study have identified a simple method to establish when a patient contracted the virus causing AIDS. The time of infection can be of importance for the treatment of the illness and it contributes to the understanding of the course of the epidemic.

Medical doctors rarely know when a patient contracted HIV. The exact point in time can only be established in the first eight weeks after infection -- during the so called acute phase. If the HIV test is taken later, it remains unclear if the infection took place three months or ten years ago. But this is about to change as researchers supported by the Swiss National Science Foundation (SNSF) have discovered a simple method to determine the approximate time of infection.

Relevant to understanding the spread of the illness

According to Huldrych Günthard from the university hospital in Zurich, information regarding the time of infection is beneficial in many ways. It allows doctors to establish how quick the illness is progressing and to determine the start of treatment accordingly. It will also inform epidemiological studies interested in how the disease is spreading.

In collaboration with colleagues from the ETH Zurich, researchers of the Swiss HIV Cohort Study analysed data that is obtained in routine resistance tests. These tests examine the genetics of the virus to establish its resistance to drugs. If a patient carries a variety of HIV strains, the test reveals ambiguous results with regard to certain points in the sequences of the virus' genetic code.

By-product of resistance testing

"For a long time, the ambiguous results of the viral sequencing were considered a by-product of the test," says Günthard. "We wondered if they were an indicator of the variety of viruses in the blood." Viral variety is a result of reproduction and evolution in the body, it increases with time and the ambiguity could therefore be an indicator for the time that has passed since infection. Günthard and his team tested this assumption by comparing the drug resistance data with an existing rudimentary method to calculate the time of infection. Additionally there are patients who know the exact time of HIV infection: e.g. patients who took the test during the acute phase or patients who took tests before and after the infection.

The study, that has now been published in the journal Clinical Infectious Diseases, was able to show that the proportion of ambiguous sequences is indeed increasing regularly during the first eight years after infection, afterwards the increase slows down. At the moment the new method is still too imprecise to establish the exact time of infection but the researchers were able to define a threshold level that indicates with 99 percent certainty if an infection happened more than a year ago.


Story Source:

The above story is based on materials provided by Schweizerischer Nationalfonds zur Foerderung der wissenschaftlichen Forschung. Note: Materials may be edited for content and length.


Journal Reference:

  1. R. D. Kouyos, V. von Wyl, S. Yerly, J. Boni, P. Rieder, B. Joos, P. Taffe, C. Shah, P. Burgisser, T. Klimkait, R. Weber, B. Hirschel, M. Cavassini, A. Rauch, M. Battegay, P. L. Vernazza, E. Bernasconi, B. Ledergerber, S. Bonhoeffer, H. F. Gunthard. Ambiguous Nucleotide Calls From Population-based Sequencing of HIV-1 are a Marker for Viral Diversity and the Age of Infection. Clinical Infectious Diseases, 2011; DOI: 10.1093/cid/ciq164

Cite This Page:

Schweizerischer Nationalfonds zur Foerderung der wissenschaftlichen Forschung. "Genetic variety of virus causing AIDS as a time indicator." ScienceDaily. ScienceDaily, 21 January 2011. <www.sciencedaily.com/releases/2011/01/110120073652.htm>.
Schweizerischer Nationalfonds zur Foerderung der wissenschaftlichen Forschung. (2011, January 21). Genetic variety of virus causing AIDS as a time indicator. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2011/01/110120073652.htm
Schweizerischer Nationalfonds zur Foerderung der wissenschaftlichen Forschung. "Genetic variety of virus causing AIDS as a time indicator." ScienceDaily. www.sciencedaily.com/releases/2011/01/110120073652.htm (accessed October 22, 2014).

Share This



More Health & Medicine News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Working Mother (Oct. 22, 2014) — Is your child ready? Video provided by Working Mother
Powered by NewsLook.com
U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

Newsy (Oct. 22, 2014) — Now that the U.S. is restricting travel from West Africa, some are dropping questions about a travel ban and instead asking about visa bans. Video provided by Newsy
Powered by NewsLook.com
US to Track Everyone Coming from Ebola Nations

US to Track Everyone Coming from Ebola Nations

AP (Oct. 22, 2014) — Stepping up their vigilance against Ebola, federal authorities said Wednesday that everyone traveling into the US from Ebola-stricken nations will be monitored for symptoms for 21 days. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Doctors Help Paralysed Man Walk Again, Patient in Disbelief

Doctors Help Paralysed Man Walk Again, Patient in Disbelief

AFP (Oct. 22, 2014) — Polish doctors describe how they helped a paralysed man walk again, with the patient in disbelief at the return of sensation to his legs. Duration: 1:04 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins