A sour business

The number of new HIV infections continue to rise, particularly in sub-Saharan Africa, but also in south-east Asia and elsewhere in developing countries. Condom promotion has not stemmed the tide, nor abstinence, nor faithfulness. There is no HIV vaccine in the immediate future. So there is understandably a great deal of interest in novel approaches to HIV prevention.

One interesting line of research leads to ... lemons. For some time, lemon juice -- applied to the female genitalia -- has been used as a relatively cheap, natural contraceptive. Sex workers in Nigeria and elsewhere in Africa use lemon juice as a way of killing potential HIV virus in the semen of their male clients, particularly those who pay more for the privilege of not using a condom. The safety and efficacy of lemon juice for this particular purpose is unknown: for the moment it seems that the concentration of lemon juice that might be effective may be unsafe for women. Findings presented at this month's Microbicides 2006 Conference in Cape Town may provide more answers. Those trading in lemons should take note.