The incidence of HIV in Romania is actually lower than the UK, 1.1 per 1000 of 15-49yos as compared to 3.3 per 1000 on average in the UK, these are estimated figures, so would likely take into account any lack in detection and of course would include homosexual & bi- males.
External Link/Members OnlyLondon is even higher with some boroughs up to 15 per 1000.
External Link/Members OnlyMy local GUM nurse reckons that in the UK some Black African nationalities, Thais, Brazilians and Russians have the highest risk of carrying HIV. Looking through the prevalence rates in those countries, I can see what she's saying. It is rampant in South Africa, Zimbabwe, Botswana, Swaziland, Lesotho, Zambia, etc This article confirms this particular risk in the UK.
External Link/Members OnlyThough she did seem more concerned with transmission of the various strains of Hepatitis, which are equally deadly, but very difficult to treat.