Page 117 - Timeliness of Infectious Disease Notification & Response Systems - Corien Swaan

Timeliness of infectious disease reporting, the Netherlands, 2003-2017 115
lated by Bonačić et al. for six person-to-person transmissible diseases based on the proportion (= PIR2) of expected new infections produced by each secondary case at the time of notification of the index case to the MHS [2]. An outbreak is controlled, in other words the prevalence begins to decline, if the average num- ber of cases produced by an infected person is<1. The number of cases pro- duced by each secondary case is PIR2 multiplied by the reproduction number. Therefore, outbreak control can be achieved if PIR2 × R < 1. The following total local delays (D1) were determined to achieve the outbreak control timeframe: 17 days for hepatitis A, 42 days for hepatitis B, 5 days for measles, 8 days for mumps, 4.5 days for pertussis and 3 days for shigellosis.
As performance threshold indicator, reporting was considered timely when at least 80% of cases were notified within the specific timeframe in a spe- cific period, in line with the World Health Organization (WHO) Joint External Evaluation Tool which recommends at least 80% of all reporting units report in time [11]. In addition, RIVM uses 80% as the threshold for minimal timely reporting of D6 in feedback to the MHS.
Increased awareness and guidance
To determine the effect of increased awareness and guidance for local health professionals on disease identification and notification delays, we identified the following outbreaks in our study period (2013–2017) which were addressed in the signalling reports and (laboratory) inf@cts ((lab)inf@cts): two large local outbreaks, namely legionella (Amsterdam, July 2006) and Q fever (West-Bra- bant province, outbreak period 2007–2009), and six national outbreaks, name- ly rubella (October 2004–January 2006), measles (March 2013–March 2014), meningococcosis W (March 2016–November 2017), hepatitis A (October 2016– November 2017) and mumps (two outbreaks periods: December 2009–January 2014 and April 2015–January 2016). In addition, specific guidance messages ((lab)inf@ct alerts) on laboratory diagnostic tests for psittacosis and notification criteria for invasive group A streptococcal disease, were identified in our study period and included.
Medians and means of these delays during the outbreak periods were cal- culated and compared with the delays for identical time periods before and after the outbreak period, using the permutation test. We observed a large in- crease in patient identification delay of 42 days during the first year of the Q fever outbreak. We excluded this delay from our analysis because this was an exceptional situation where the disease and diagnostic confirmation method- ology was unknown to physicians and medical microbiologists at the time and
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