Underascertainment, underreporting, representativeness and timeliness of the Iranian communicable disease surveillance system for tuberculosis.

OBJECTIVES: A well-functioning disease surveillance system is essential for effective control of diseases. Therefore, conducting evaluation studies on the performance of disease surveillance systems is necessary. This study was conducted to evaluate the performance of the Iranian syndrome-based surveillance system for tuberculosis (TB) in rural areas of Fars, the third largest province located in southern Iran. STUDY DESIGN: This was an evaluation study. METHODS: Two independent sources of information (data from a population-based survey and data from the surveillance system) were used in this evaluation. A group of trained female nurses used a specially designed interview-administered questionnaire to obtain data on the health status of family members from mothers or other adult women in rural houses. Subsequently, the nurses obtained data from individuals who reported a history of TB during a specified period and defined whether the patients presented themselves to a rural or urban health centre or clinic. RESULTS: A total of 48,771 individuals participated in this study. Of 156 cases who reported a history of TB, 137 (87.82%) presented themselves to at least one medical care provider seeking diagnosis and treatment services. Of patients who visited a health or medical centre, only 18 (13.14%) were reported to the highest level of the surveillance system. Accordingly, the rates of underascertainment and underreporting of the Iranian surveillance system for TB were 12.18% and 86.86%, respectively. Moreover, underascertainment was significantly higher for men (19.40%) than for women (6.74%). The mean time between the date at which TB was noticed and the date of diagnosis was 56.24 days, which was longer for men (79.29 days) than for women (40.10 days). The highest and lowest levels of underreporting were observed for private general practitioners (100%) and the health centres run by the government (87%), respectively. CONCLUSION: The quality of the communicable disease surveillance system for TB in Iran is facing important challenges, including underascertainment, underreporting and timeliness, in addition to different types of bias. Informing the general population and health workforce about TB and the importance of timely diagnosis is a good approach to improve the performance of Iran's national communicable disease surveillance system.

Under-ascertainment, under-reporting and timeliness of Iranian communicable disease surveillance system for zoonotic diseases.

OBJECTIVES: The important steps in controlling infectious diseases are fast detection, proper treatment and on-time reporting of cases to the appropriate authorities. This study was conducted to evaluate the quality of Iranian communicable diseases surveillance system (CDSS) for zoonotic diseases in rural areas of Fars province (Iran's third largest province). STUDY DESIGN: The three most important evaluation indices of CDSS, namely under-ascertainment, under-reporting and timeliness, for the three most common zoonotic diseases were measured using independent data source obtained from door-to-door interviews and patients' medical records. METHODS: Interviews were conducted with 48,771 households in rural areas of Fars province from April 2014 to March 2015. The medical and registration data were obtained from the CDSS and medical or health centres. RESULTS: Under-ascertainment, total under-reporting and timeliness (delay from the time of onset of symptoms to the time of visiting a medical or health centre, to the time of reporting visited cases to the highest level of CDSS) for leishmaniasis were 19.6%, 42.5% and 81.61 days (48.95 due to system delay), respectively. The corresponding indices for brucellosis were 0%, 41.8% and 56.5 days (22 due to system delay), respectively. For animal bite, the corresponding indices were 7.83%, 13.07% and less than 72 h, respectively (no system delay). CONCLUSIONS: Although the status of case reporting and timeliness of surveillance system in public sectors providing medical services are clearly better than those of the private sectors, the indices are far from the level needed by CDSS to be able to detect and handle epidemics on time. Training health personnel, especially physicians, from public and private sectors to secure their cooperation along with routine and indebt evaluation are necessary to improve CDSS in Iran.