Longterm attentuation AIDS virus?

[Martin]

there has been a preliminary result with only 24 petri-dish samples

Here is the popular media report of the result.

 

http://seattletimes.nwsource.com/html/nationworld/2002530417_hiv30.html

 

 

It suggests (but does not prove) evolutionary reduction in virulence.

 

This has been observed in other viral epidemics. If the virus weakens the host less then this makes the virus more able to reproduce and spread.

(A hypothetical virus that immediately killed the host would not be able to spread by contact at all.)

 

There is a professional-journal version of this report. I will try to get a link.

Sometimes the journal article gives extra detail, or more reliable info (what they actually said rather than what the journalist thought they said)

 

Hopefully something is online.

[Martin]

Here is one of the author's homepage

http://p450.case.edu/faculty/faculty.asp?arts

 

 

Here is an online medical research journal called AIDSonline

and the current table of contents shows this article by Eric Arts and others about the (possible) attentuation, or reduced virulence, of the virus

 

http://www.aidsonline.com/pt/re/aids/currenttoc.htm

 

 

Here is the abstract of the article

 

 

http://www.aidsonline.com/pt/re/aids/abstract.00002030-200510140-00001.htm

 

 

Replicative fitness of historical and recent HIV-1 isolates suggests HIV-1 attenuation over time.

AIDS. 19(15):1555-1564, October 14, 2005.

Arien, Kevin K a; Troyer, Ryan M b; Gali, Youssef a; Colebunders, Robert L c; Arts, Eric J b; Vanham, Guido a,d

 

Background: Changes in virulence during an epidemic are common among pathogens, but still unexplored in the case of HIV-1. Here we used primary human cells to study the replicative fitness of primary HIV-1 isolates from untreated patients, comparing historical (1986-1989) and recent samples (2002-2003).

 

Methods: Head-to-head dual virus infection/competition assays were performed in both peripheral blood mononuclear cells and human dendritic cell/T-cell co-cultures with pairs of 12 carefully matched historical and recent HIV-1 isolates from untreated patients. Sensitivity to inhibition by lamivudine (3TC) and TAK-779 of historical and recent R5 HIV-1 isolates was measured in a subset of samples.

 

Results: Overall, the historical HIV-1 out-competed the recent HIV-1 isolates in 176 of 238 competitions and in 9 of 12 competitions carefully matched for CD4 cell count. The mean relative replicative fitness (W) of all historical HIV-1 strains was significantly greater than that of recent HIV-1 isolates (W1986-1989 = 1.395 and W2002-2003 = 0.545, P < 0.001 (t test)). The more fit viruses (mean W > 1) from 1986-1989 appeared less sensitive to TAK-779 and 3TC than did the less fit (mean W < 1) 2002-2003 viruses.

 

Conclusions: These findings suggest that HIV-1 replicative fitness may have decreased in the human population since the start of the pandemic. This 'attenuation' could be the consequence of serial bottlenecks during transmission and result in adaptation of HIV-1 to the human host.

 

this study does not give any reason for optimism, I think, in any case change would be over a very long timeframe like 60 years. however it is an example of how a pathogen can evolve in the course of an epidemic