Pre-exposure prophaylaxsis (Prep) is a treatment used worldwide and is given to at-risk groups to prevent them getting HIV. It requires taking an antiretroviral once a day.

Uptake in some countries has been fairly good but not so in Kenya.

Prep was given the green light for use last year but so far few have taken up the treatment.

Veronica Akinyi, a Kenyan sex worker, told the BBC's Newsday programme that when she found out about Prep it helped her do something positive to protect her health.