Page 130 - Timeliness of Infectious Disease Notification & Response Systems - Corien Swaan

128 Chapter 5
This was probably a consequence of the outbreak in 2013–2014, when the dis- ease identification delay was reduced by, among other things, the RIVM alert systems. Performance thresholds of measles and mumps were close to the threshold of 80%. Therefore, we advise to further decrease patient, doctor and laboratory testing delays, especially for bacterial gastroenteritis and measles. Given the current measles outbreaks in Europe and regular imported cases in the Netherlands, we recommend enhancing doctors’ awareness and optimising laboratory confirmation procedures to achieve early detection of measles cases for optimal outbreak control [18]. As we have demonstrated in this study, the RIVM alert systems can contribute to achieve this.
Strengths
This is the first study in the Netherlands analysing timeliness of notifications, describing the effect of the law change and of alerts and guidance provided dur- ing an outbreak, and including notifications of almost 15 years. To our knowl- edge, studies systematically analysing the effect of alerts and guidance have not been performed before.
Limitations
Our study did not investigate the way these changes in delays were achieved on local level. Although notification is mandatory for both physicians and heads of laboratories, according MHSs mainly laboratories perform notifications. This study did not provide best practices to achieve legal thresholds.
Although delay of disease identification is the longest delay in the notifi- cation and reporting chain, we cannot determine patient, doctor or laboratory delay because information on the first date of consultation (TC) or of requesting laboratory testing (TL) is not available, as this is not legally required. We expect that the ratios between these delays differ by disease, as some diseases de- velop gradually (resulting in patient delay), are nonspecific (resulting in doctor delay) or may need laboratory tests which are not available at every laboratory, or two-point serology testing (resulting in laboratory delay). During outbreaks, public health professionals need real-time information on new cases to monitor the effect of control measures. Insight in patients, doctors and laboratory delays is necessary to decide whether and how these delays in the notification chain can be reduced. The importance of this information has been emphasised be- fore for pertussis surveillance and control in the Netherlands [19].
In some countries such as Sweden, the UK and the United States, speci- men collection dates are recorded in the laboratory surveillance system, which