Page 203 - Timeliness of Infectious Disease Notification & Response Systems - Corien Swaan

Background
Timeliness of response activities by public health authorities determines the effectiveness of infectious disease control measures. Timeliness as attribute for preparedness and response is broadly incorporated in WHO State Party annual self-assessment (SPAR) and Joint External Evaluation (JEE) tools, amongst others with regard to response to food safety events, laboratory testing, response to public health emergencies, and use of health services (8, 26). However, time- frames which define timeliness of response are missing. Performance indicators to evaluate foodborne outbreak detection and investigation procedures have been developed by FoodCORE, but indicators for control measures are missing (27). The latter also applies for the ‘hazard analysis of critical control points’ (HAC- CP) approach for evaluation of national pandemic preparedness policies (28).
Timeliness of response
We investigated the timeliness of two types of response measures in the Neth- erlands, during the pandemic influenza A(H1N1) outbreak in 2009 (Chapter 6), and during the Ebola outbreak in West Africa in 2014-2015 (Chapters 7 and 8). The first measure involved the provision of post-exposure prophylaxis (osel- tamivir) to passengers who had been in close contact with a patient with pan- demic influenza during an air flight. As we encountered considerable delay in PEP provision, we retrospectively investigated delays. Among in total 17 con- tact investigations, the average delay between flight arrival and contact details identified, a proxy for delivering PEP, was 3.9 days (median 4 days). In only 3/17 flights this delay was below 48 hours. We concluded that contact tracing among passengers was not effective. The main cause was patient, physician, and labo- ratory delay of the index case (mean 2.6 days, median 2 days). Contact tracing has led to the identification of infected passengers, as described for influen- za A(H1N1), tuberculosis and measles, although evidence is often lacking that transmission was flight related (29-31). Also, the proportion of infected passen- gers is considered to be very small. Constraints in tracing passengers resulting in delayed PEP are also described in case studies for measles (32, 33). There are too many steps, involving different organizations disciplines in the notification and response chain to achieve timely provision of PEP. Although the duration of certain steps can be reduced, for example by airlines providing information directly to passengers, timely PEP provision will be difficult to achieve, and the main achievement will be alerting exposed persons. Infected persons will seek medical care earlier, thereby reducing patient delay and potentially preventing tertiary cases. It is recommended to analyze contact tracing outcomes to decide
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