It is estimated that around one and a half million people in Kenya are living with HIV/Aids.
Part of the problem is in rural areas where fishermen trade their catch with poor women market-sellers for sex, rather than money.
Now local charities are trying to change the practice, known colloquially as ‘sex for fish’.
They are encouraging women to own boats and employ fishermen so that they are able to pay for the fish with money.
Mark Lowen reports from western Kenya.