Evaluation of the national clinical sentinel surveillance system for sexually transmitted infections in South Africa: Analysis of provincial and district-level data. - Frank D; Kufa T; Dorrell P; Kularatne R; Maithufi R; Chidarikire T; Pillay Y; Mokgatle M (South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 2023)