Elimination of mother-to-child transmission of HIV in Oman: a success story from the Middle EastAli Elgalib, Fatma Al-Hinai, Jamila Al-Abri, Samir Shah, Zeyana Al-Habsi, Maha Al-Fouri, Richard Lau, Hanan Al-Kindi, Adil Al-Wahaibi, Amal Al-Maani, Bader Al-Rawahi, Said Al-Lamki and Seif Al-Abri