The strain of HIV found in four women alleged to have been infected by an asylum seeker is most commonly found in the area of Africa where he is from, a court was told today.
Musician Feston Konzani, 28, of Albany Street, Middlesbrough, denies four counts of grievous bodily harm to women by infecting them through sexual intercourse between November 2000 and August 2003.
Dr William Lynn, a specialist in infectious diseases who has worked with HIV patients since the 1980s, appeared at Teesside Crown Court earlier today.
He said the type of HIV in this case was most strongly associated with sub-Saharan Africa, including Malawi, where Konzani is from.
He added the type was rare in the UK until the past few years, and the proportion of cases here was still "substantially less than 10pc", he added.
Partners from sub-Saharan Africa were considered to present a higher risk than others.
He said most cases would become infectious after six to eight weeks, but individuals would not know that.
But added that it was not possible to state how soon after sleeping with an infected person the virus would begin to contaminate them.
He said most people would not realise they had HIV, which kills patients by seriously weakening their immune systems, until they see advanced signs - which could be up to seven years later - or if they found out they might be at risk and had tests.
The court heard that when someone is diagnosed, they would be given counselling. It would be explained how the disease was transmitted, and how to avoid risks.
He said highly accurate tests could determine how advanced the condition was.
The highest risk of infection was through unprotected penetrative sex without the use of condoms. There were variations depending on the people and the sex act itself.
Alison Hardy, who works for the Viral Evolution Group at Edinburgh University, said samples taken from the defendant and five women showed a "common variant" between them, though not identical, between mutations in the virus.
