Page 141 - Timeliness of Infectious Disease Notification & Response Systems - Corien Swaan

Timeliness of contact tracing among flight passengers 139
Figure 1. Routing of contact tracing for close passenger flight contacts during the in- fluenza A/H1N1 2009 pandemic. A request for contact tracing (CT) reaches the NFP of the RIVM (1). After checking the indication, the request is forwarded to the MHS/ GGD Kennemerland (2) who will submit the request at the appropriate airline (3). The airline collects contact details of the passengers and returns this to the GGD (4). Dutch contacts will be informed through the MHS of their region (5, 8), international contacts list are returned to the NFP/RIVM. The NFP requests the concerned public health autho- rities through the NFP or EWRS contact points to trace the contacts (6, 7)
During the pandemic, CT requests were turned down if more than 4 days had elapsed after flight arrival, as contact tracing was not considered to have addi- tional value. During the study period, passenger locator cards (PLC) only were used on direct flights from Mexico during the initial phase of the pandemic. These flights were all run by Dutch airlines.
For each contact investigation performed in the period April 29th until June 22nd 2009, the following data were collected: flight arrival date, first day of illness of index patient, date of laboratory diagnosis, date of contact tracing re- quest and the date passenger lists were obtained and contact details were com- pleted (‘contacts details identified’). From these data, time intervals (in days) between flight arrival and date of diagnosis (interval I), between diagnosis and request dates (interval II) and between request and contact details identified
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