Page 195 - Timeliness of Infectious Disease Notification & Response Systems - Corien Swaan

ture review showed that the outcome of 16 out of 39 studies with a timeframe was partly sufficient or had a mixed outcome. Interestingly, the authors appear generally to be satisfied with the outcome and are maybe not that concerned about achieving strict timeframes (9). As timeliness of notification systems is difficult to review as they are country and disease specific, using standardized thresholds for achieving country specific timeframes facilitates evaluation of a country’s preparedness system. International standardized thresholds would be a valuable indicator for measuring the surveillance capacity in the JEE which implies quantitative evaluation. We recommend ≥ 80% timely notifications as sufficient, ≥ 50% up to 80% as partly sufficient and < 50% as insufficient.
Based on these thresholds, we conclude that the notification delays of in- fectious diseases in the Netherlands in the period 2016-November 2017 was sufficient according to the legal timeframe. However, thresholds were not met for botulism, diphtheria, hantavirus, leptospirosis, malaria, MRSA CA, Q-fever, and STEC. These diseases have in common that they are rare, and some diseases require further laboratory testing such as serotyping or toxin producing deter- mination, in the case of hantavirus and diphtheria, respectively. Whether this is an administrative issue, as MHS might already have received a pre-notification and have started investigations, or whether it involves a real delay needs fur- ther exploration. Nowadays most notifications are made by laboratories, using a protected mail system, a form of electronic laboratory notification (personal communication regional consultants communicable disease control), irrespec- tive of specific disease. Obtaining results from another laboratory due to fur- ther testing might end up outside this automated system and explain the delay.
Although comparison of notification delays between studies is difficult as notifications systems and legal timeframes vary between countries, differences in notification delays between diseases within a country have been observed by others as well. Yoo et al. describe longer delays for diseases with a lower incidence, for example dengue and scrub typhus, and shorter delays for dis- eases associated with epidemics such as shigellosis and mumps (10). We also observed the latter phenomenon during the Q-fever epidemic. (Chapter 5)
We conclude that, even in a sophisticated notification system fulfilling the legal timeframe, inter-disease variation in notification delay exists. In this perspec- tive, we should be aware that our studies included 30 out of 43 group B and C diseases. Excluded were diseases with too little notifications, diseases with a different notification route, and chronic diseases that often miss a clear date of onset of disease, three aspects which may lead to prolonged notification delay. Excluding them may have positively influenced our delay results.
General discussion 193
9