I mentioned today in class that the HIV found in semen is far more virulent than HIV alone. Well, I went back to the article and it turns out it is 100,000 times more virulent!!
Researchers "found that fragments of prostatic acidic phosphatase isolated from human semen form tiny fibres known as amyloid fibrils, which they call Semen-derived Enhancer of Virus Infection or SEVI. Those fibrils capture HIV particles and help them to penetrate target cells, thereby increasing the infection rate by up to several orders of magnitude."
Powerful stuff! Talk about viral evolution adapting to its environment. :)