Introduction of a rapid diagnostic dengue NS1 antigen–IgM/IgG combination assay associated with a reduced inpatient length of stay

It is estimated that 2–12% of travellers from tropical areas will suffer from a febrile illness either during their trip or upon their return, accounting for a significant number of hospital presentations and admissions. Data from other published studies reveals up to 25% of returned travellers require hospitalisation, and of these, average length of stay was 5 days, with a range of 1 to 11 days. Though malaria still remains the most common cause of fever in travellers worldwide, dengue fever is more common in travellers returning from Asia, accounting for a significant number of Australian hospital presentations. A proportion of patients with dengue fever require hospitalisation, but many can be discharged into home care once a definitive diagnosis has been made, as the spectrum of disease in dengue fever varies. Most clinical dengue fever infections are mild to moderate in severity, although a small proportion of patients develop dengue haemorrhagic fever (DHF) or dengue shock syndrome (DSS). Case fatality rate varies across World Health Organization (WHO) regions, estimates ranging around 1–2%. Accurate and rapid diagnosis aids appropriate management as hospitals now aim to reduce emergency department overcrowding and inpatient length of stay; both of which are associated with adverse outcomes. We chose to review the impact on length of stay after the introduction of a NS1 antigen (NS1Ag)–IgM/IgG combination rapid diagnostic assay (RDT), for patients presenting with dengue fever at Royal Darwin Hospital.