Page 57 - Timeliness of Infectious Disease Notification & Response Systems - Corien Swaan

Timeliness of notification systems: a systematic literature review 55
Introduction
Monitoring infectious diseases is essential for detecting outbreaks that demand public health response and control measures. Therefore, efficient and reliable surveillance and notification systems are vital for monitoring public health trends and early detection of disease outbreaks [1]. Timeliness is an important indicator for evaluation of surveillance systems, and defined as ‘reflecting the speed between steps in a public health surveillance system’ [2].
Public health response relies amongst others on notification of infectious diseases; a notifiable disease is a disease that is reportable either by law or by regulation [3]. Notification is the result of a chain of events from infection until report at the public health services, either local, regional or national [4]. Figure 1 illustrates the reporting timeline of infectious diseases. Delays in this chain are disease specific and the result of 1) patient delay, i.e. time elapsed from onset of disease until consultation of a physician (DOC), 2) doctors delay, time elapsed between consultation and ordering a laboratory confirmation test (DCL), and 3) laboratory delay, i.e. time elapsed until confirmation test result, depending on duration and frequency of testing (DLX). Lastly, there is a notification delay, from either laboratory or physician to the local health department (D3X and D3P, respectively), and reporting delay to regional and/or national health insti- tutes (D4, D5 respectively). Most countries have installed legal obligations for physicians and diagnosing laboratories to notify certain infectious diseases to public health authorities according to a designated timeframe to ensure timely response, and in order to comply with international regulations [5, 6].
Notification systems traditionally involved conventional methods using postal mail, telephone, fax and/or electronic mail. Over the last two decades, electronic software systems for laboratory test recording and patient file re- cords facilitated the development of electronic reporting systems, as electronic laboratory reporting (ELR), and automated ELR. [7] These electronic software systems have improved timeless of notification to public health services, both on local level as regional or national level [8-13]. Nowadays, inter-operable, interconnected, electronic real-time reporting systems have become the stan- dard, and included as indicator for real time surveillance in the 2016 Joint Ex- ternal Evaluation (JEE) Tool of the WHO [14]. These systems however, are costly and evaluations of the surveillance systems reveal that also electronic reporting systems do not always meet the designated (‘predefined’) notification time- frames [15, 16].
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