Objectives. To describe the qualitative aspects of the notifiable diseases surveillance system of the Gauteng Province, South Africa; to conduct a cross-sectional survey on knowledge and practices pertaining to disease notification among private sector primary health care providers in Gauteng Province; to measure the degree of underreporting of notifiable diseases versus positive laboratory diagnoses using malaria as a cases study; and to identify the correctible short-comings in the Gauteng Health Department’s diseases surveillance system and to recommend ways of addressing these to improve the system and its performance. Design. This is an evaluation study consisting of both the qualitative aspects and quantitative descriptive components of the notifiable disease system in Gauteng Province. The study designs used for the qualitative description were literature and policy review and a semi-structured interview with communicable disease coordinators. The quantitative research comprised of a telephonic questionnaire administered to a random sample of private general practioners and secondary data analysis comparing malaria cases notified to the Gauteng Provincial Department of Health with public and private sector laboratory data and clinical surveillance data. Setting. The study setting was the Gauteng Provincial Health Department and public and private health care service providers in Gauteng Province. The study period extended from 1 January to 30 June 2006. Subjects. The subjects of the study were the Gauteng Health Department’s disease surveillance system, public and private sector health care providers including private primary health care practitioners. Outcome measures. Outcome measures for the qualitative system description were the status of selected system attributes namely usefulness, simplicity, flexibility, data quality, acceptability, sensitivity, positive predictive value, representativeness and stability. Outcome measures for the knowledge and practice survey of private general practitioners were reporting compliance and knowledge of notifiable conditions. The primary outcome measure for the secondary data analysis was the proportion of laboratory diagnosed cases of malaria notified to the provincial health department. Results. The notifiable disease surveillance system in Gauteng is deemed useful by the public sector communicable disease coordinators but less so by the private sector general practitioners. Data quality as indicated by completeness of residential detail reporting on meningococcal notifications varied between 29% and 57% by district. Thirty seven percent of general practitioners report compliance with notifications and the mean score for knowledge on notification status of medical conditions was 56%. The sensitivity of notifications of malaria compared with laboratory notifications was 26% with relatively higher notification rates where cases occurred in children under 15 years of age. Conclusions. The notifiable disease surveillance system in Gauteng Province is relatively flexible and reasonably structured however this research suggests that there is suboptimal use of the information for local action in certain areas. Private General Practitioners self-report a low level of compliance citing time constraints and lack of motivation; knowledge of the notification status of selected medical conditions is lower than expected. The completeness and accuracy of notification data, as demonstrated in malaria notifications, is insufficient to gauge a true picture of burden of disease in the province. / Dissertation (MMed)--University of Pretoria, 2007. / School of Health Systems and Public Health (SHSPH) / Unrestricted