Page 207 - Timeliness of Infectious Disease Notification & Response Systems - Corien Swaan

Furthermore, the model only includes group B and C diseases with enough quantitative notifications in the period 2003-2011, not addressing introduc- tion of more rare diseases with higher morbidity and mortality, such as coro- naviruses (MERS CoV, SARS) and viral hemorrhagic fevers. As these diseases are notifiable upon clinical suspicion, the positive predictive value of symptoms in combination with epidemiological criteria needs to be weighed against the time gained by notification before laboratory confirmation. In other words, the pro- portion of false positive notifications, leading to unnecessary response by the MHS needs to be limited to justify the timely response in true positive notifi- cations. For this purpose Yoo el al. introduced a ‘ time-accuracy trade-off ratio’, applied to four gastro-enteral diseases (43). Trade-off between timeliness of clinical suspicion and accuracy was better with public awareness and clinical sensitivity. Despite not providing a timeframe for timeliness, it gives direction for the development of a model for notifications upon clinical suspicion. Also, our model is not applicable for non-person-to-person transmissible diseases, as vector-borne and zoonotic diseases, or diseases caused by a common food or environmental exposure. Monitoring and modelling of drivers of infectious disease health threats, such as environment, food and water quality, contribute to anticipation of these health threats (44, 45). Although intervening in these drivers is preferable, early detection of human cases through clinical awareness and availability of appropriate laboratory tests is necessary as well to identify out-breaks, to perform outbreak investigation and provide decision makers with timely information (46, 47). In absence of an outbreak control timeframe for these non-person-to-person transmissible diseases, we recommend incubation periods as disease specific timeframes instead.
A limitation of this thesis is that we did not determine the consequences of delayed notification or reporting of infectious diseases. Although studies ana- lyzing notification timeliness seldom incorporate consequences of these specif- ic delays, examples do exist on consequences of delays in patient identification. As mentioned earlier in this thesis, delayed disease identification led to a sec- ondary case of Lassa fever due to incomplete personal protection equipment among contacts in Germany in 2017 (48). Plipat et al describe a 48-hour labo- ratory test delay of MERS CoV confirmation in a patient from Oman in Thailand, during which the patient abusively was released from isolation, not leading to secondary cases fortunately.(49). Van den Wijngaard et al retrospectively iden- tified seven clusters of lower respiratory tract infections and one hepatitis clus- ter in hospitalized patients in the Netherlands during 2005-2007, with Q fever as plausible cause. Better syndromic surveillance might have detected Q fever
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