Commercial sex workers in sub-Saharan Africa have one of the highest rates of HIV infections in the world, an international study has established.The research findings also recommend that prostitution should be legalised to make working conditions for sex workers more tolerable and reduce their rate of HIV infections.The study, which was released last week, was funded by the World Bank and the UN and carried out by the US, based John Hopkins School of Public Health.It recommended an urgent scale up of HIV programmes. The researchers sampled about 100,000 prostitutes from 50 countries in Africa, Asia, Eastern Europe, Latin America, the Caribbean and Middle East.They found that of all the prostitutes in the 50 countries, those in sub-Saharan Africa had the highest HIV prevalence.The survey which covered between January 1, 2007 and June 25, 2011, ranked prostitutes in Kenya, Uganda, Madagascar, South Africa, Malawi and Zimbabwe as having the highest rates of HIV infections.In Africa, Kenya had the highest number of sampled prostitutes at 7,000 with Senegal having the second largest sample at 1,656.According to a recent City Council of Nairobi report, there were an estimated 7,000 prostitutes in Nairobi who service an average of three to four clients each night.The study, published by The Lancet, a medical journal, argues that such high levels of HIV infection were not good for the general population.