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Background: WHO has identified Dengue as the fastest spreading mosquito-borne disease in the world. Approximately 96 million
people develop clinical Dengue annually, of which 1 in every 200
proceeds to develop potentially fatal Dengue haemorrhagic fever
and/or shock syndrome (DHF/DSS). Depending on the availability
of appropriate supportive treatment, the case-fatality rate varies
from 3.5% to 50%. The debilitating and painful nature of the disease,
together with the lack of an accurate method to predict DHF/DSS,
resulted in unnecessary over-hospitalisation. The situation is worsened during epidemic years, in both developed (e.g. Singapore in
2004/2005) and developing countries (e.g. India in 2015) alike. Elective surgeries and non-emergency admissions had to be cancelled
to release health resources for Dengue inpatients. Our laboratory
previously discovered a panel of novel serum biomarkers that
can predict DHF/DSS with a sensitivity and specificity of 90% and
91%, respectively. As majority of Dengue-endemic countries are
developing countries, we sought to evaluate how test performance
would be affected by using only one biomarker (BM1), so as to make
the test more affordable.
Methods & Materials: 109 Dengue patients were enrolled from
the Colombo South Teaching Hospital and National Hospital of Sri
Lanka. The study was approved by the Ethics Review Committee
of the University of Sri Jayawardanapura, and all patients provided
informed consent. Blood samples were collected when subjects first
presented themselves at the hospitals. Serum BM1 concentration
was measured using a quantitative ELISA developed in-house. All
statistical analyses were performed using R version 3.1.2.
Results: 60 subjects were diagnosed with DHF while 49 had
classical Dengue fever. Based on only serum BM1 concentration,
the performance of the test to predict DHF/DSS was as follows: sensitivity – 73.3%, specificity – 77.6%, positive predictive value (PPV)
– 80.0%, and negative predictive value (NPV) – 70.4%.
Conclusion: While performance of the BM1 prognostic test (on
Sri Lankan patients) could not match that of the panel prognostic
test (on Singapore patients), there were considerable improvements in specificity and PPV over current clinical practices used
(in Singapore) to determine which Dengue patients to hospitalise
(specificity: ≤55%; PPV: ≤34%).
