Belgium's Princess Astrid is to visit Riyadh at the end of this month to raise awareness about the threat malaria poses to the region, the United Nations' Roll Back Malaria (RBM) campaign announced yesterday. Princess Astrid, who is RBM's special representative, along with RBM Executive Director Awa Marie Coll-Seck will be in Saudi Arabia from March 28-30 before heading to the United Arab Emirates as part of their Gulf tour. Malaria is the biggest killer of children under five in Africa.