The timeliness of notification of clinically suspected cases of dengue imported into north Queensland

Objective: Evaluate the timeliness of notifications by medical practitioners of clinically suspected dengue importations into north Queensland (NQ). Describe the features the disease and determine the likely duration of viraemia prior to implementating public health measures. Method: Since December 1994, the Tropical Public Health Unit (TPHU) has maintained a register of all imported cases of dengue into NQ. Only confirmed viraemic cases were included in the study. Timeliness of notifications was defined as the interval between the first medical consultation in NQ and notification to TPHU. An Epi info database was developed and used to analyse data. Results: There were 31 confirmed dengue importations into NQ during the study period, including all four dengue serotypes. The largest source (39%) was Papua New Guinea. The median time for notifications was 5.5 days. Doctor notifications ranged from 0 to 21 days (median 2 days), remaining notifications range from 1 to 42 days (median 10 days) (p<0.05). The mean duration of viraemia of public health importance was 7 days (2-12 days). Conclusions: Of concern, doctors failed to notify >50% of suspected cases and only 26% of notifications were received within 48 hours. Notification delays led to prolonged viraemia of public health importance increasing the potential risk of secondary infections. Implications: General practitioners need to promptly notify all clinically suspected cases of dengue in travellers recently arrived in NQ. The TPHU intends to reemphasise to general practitioner the importance of timely notifications and develop an orientation package for new doctors.