Simultaneous Diagnosis of Dengue and Prognosis of Severe Dengue with a Single Point-of-Care Test

Dengue is the most common mosquito-borne viral disease and the cause of tremendous morbidity, mortality and economic burden. Yearly, there are an estimated 390 million (M) Dengue virus (DENV) infections, 96M symptomatic cases of Dengue Fever, and 0.5M cases of Severe Dengue. Untreated Severe Dengue has a fatality rate of 20-40%, but the fatality rate drops to less than 1% with timely in-hospital care. Unfortunately, Severe Dengue is now detected only by skillful observation of clinical warning signs, and progression to severe disease can occur within hours, making effective care difficult. Therefore, there is an urgent need for prognostic tests that can identify patients most likely to progress to Severe Dengue. There are four serotypes of DENV and infection with any one serotype generates strong, potentially life-long immunity to reinfection by that same serotype, due to development of neutralizing antibodies against serotype-specific epitopes. However, most antibodies induced by first infections are cross-reactive and non-neutralizing, and paradoxically can increase the risk of Severe Dengue in patients who suffer a later infection with a different serotype, due to a phenomenon termed Antibody-Dependent Enhancement (ADE). Heterotypic secondary infection is the major accepted risk factor for Severe Dengue but heterotypic secondary infections cannot now be identified within the time available for decision making to impact clinical care and outcome. We propose to create a simple, inexpensive, Point-of-Care (POC) test with visual plus/minus readout that will not only diagnose DENV infections early, but also be prognostic for Severe Dengue by quickly identifying patients who have secondary heterotypic infections. Phase I will create key biomarker detection reagents and incorporate them into two sets of serotype-specific Lateral Flow Assays (LFAs): 1) antigen LFAs to diagnose and serotype current infections (by detecting DENV- NS1 made during active infections), and 2) antibody LFAs to diagnose and serotype past infections (by detecting anti-DENV-antibodies made by patients in response to previous infections). Phase II will combine the individual assays in a single dual reporter LFA and then generate analytical and clinical performance data to support applications for CE Mark and FDA 510(k) clearance as a POC IVD. Innovation: The proposal creatively combines a well-established clinical observation (heterotypic secondary infection is the major risk factor for Severe Dengue), with two significant technical advances:1) rapid serotyping of current infections, and 2) rapid serotyping of past infections. With this combination we will develop a first-in- class POC test for DENV diagnosis and Severe Dengue prognosis that will change clinical practice. Impact: A simple, inexpensive POC test that provides timely prognostic results even in resource-limited settings would enable dramatic reductions in Dengue morbidity and mortality while reducing health care costs by allowing clinicians to focus resources effectively and efficiently on patients who may need them most.