Page 49 - Timeliness of Infectious Disease Notification & Response Systems - Corien Swaan

Timeliness of infectious disease reporting, the Netherlands, 2003-2009 47
their parents’ home countries [19]. The effectiveness of active or passive immu- nisation of contacts in preventing illness depends on the time elapsed after HAV exposure. Since HAV infections have a long incubation period, it is acceptable that 90.3% of cases are reported within one incubation period. However, the percentage of cases reported within one Ic should be improved.
Given that direct laboratory reporting can reduce delays, Dutch legislation was introduced in December 2008 to make laboratory reporting mandatory in addition to the mandatory reporting by physicians. This could considerably im- prove the reporting speed for MHS lacking physician agreements, an assump- tion that we will analyse in the coming years.
The findings of the present study are subject to some limitations. Several MHS merged during the study period, causing some loss of data from former MHS. Also, many MHS, especially those serving large cities, receive reports from several laboratories but do not have physician agreements covering all of them, impeding a comparison of laboratories. However, our findings are supported by other studies in the Netherlands that deal with physician-laboratory-MHS agreements [14].
Many cases of measles are reported solely on the basis of epidemiological criteria (i.e. a clinical case definition combined with known exposure to some- one with a laboratory confirmed diagnosis) and need no laboratory confirma- tion. As there is no laboratory-related delay in such cases, the over all median Po may be shorter for measles. For the other diseases we studied, the proportion of cases reported solely on the basis of epidemiological criteria, is negligible.
In assessing the report cards posted by physicians to their MHS, we used the absolute number of cards and did not correct for variation in MHS region size.However, the MHS that received the most cards is not situated in one of the largest regions, and its total number of notifications is in the mid-range.
For all six of the infectious diseases considered , we have demonstrated how much timeliness in notification could be improved if MHS were to receive reports from physicians on the day of laboratory diagnosis (assuming that Pd is zero), thereby shortening Po. Although the Pd will not be zero for cases diag- nosed on weekend days, this does not detract from the possible improvement during working days, when most cases are diagnosed. Agreements between physicians and laboratories that allow direct laboratory reporting can reduce delay by several days, and fast communication methods such as fax or tele- phone are preferable to post.
However, the results of the means of the Po per year, did not show an improvement for shigellosis or HAV infection, while the means of the Pd de-
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