Use of simple clinical and laboratory predictors to differentiate influenza from dengue and other febrile illnesses in the emergency room

Abstract

BackgroundClinical differentiation of influenza from dengue and other febrile illnesses (OFI) is difficult, and available rapid diagnostic tests have limited sensitivity.MethodsWe conducted a retrospective study to compare clinical and laboratory findings between (i) influenza and dengue and (ii) influenza and OFI.ResultsOf 849 enrolled patients, the mean time between illness onset and hospital presentation was 1.7, 3.7, and 3 days for influenza, dengue, and OFI, respectively. Among pediatric patients (≤18 years) (445 influenza, 24 dengue, and 130 OFI), we identified absence of rashes, no leukopenia, and no marked thrombocytopenia (platelet counts <100 × 109 cells/L) as predictors to distinguish influenza from dengue, whereas rhinorrhea, malaise, sore throat, and mild thrombocytopenia (platelet counts 100-149 × 109/L) were predictors that differentiated influenza from OFI. Among adults (>18 years) (81 influenza, 124 dengue, and 45 OFI), no leukopenia and no marked thrombocytopenia distinguished influenza from dengue, while rhinorrhea and malaise differentiated influenza from OFI. A diagnostic algorithm developed to distinguish influenza from dengue using rash, leukopenia, and marked thrombocytopenia showed >90% sensitivity to identify influenza in pediatric patients.ConclusionsThis study identified simple clinical and laboratory parameters that can assist clinicians to distinguish influenza from dengue and OFI. These findings may help clinicians diagnose influenza and facilitate appropriate management of affected patients, particularly in resource-poor settings.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-014-0623-z) contains supplementary material, which is available to authorized users.

Pitfalls in acute febrile illness diagnosis: Interobserver agreement of signs and symptoms during a dengue outbreak

“…Coryza, sore throat and cough, signs and symptoms cited by Huang et al (2014) as suggestive of other febrile illnesses such as influenza presented almost perfect to substantial agreement. Dyspnoea was an exception.…”

Accuracy of clinical criteria and an immunochromatographic strip test for dengue diagnosis in a DENV-4 epidemic

“…We found that leukopenia was more frequent in D4 than in ND, although the overlapping range between the two groups prevented an adequate discrimination between them. The relevance of leukopenia as a discriminant feature of dengue infection has been previously documented, although the cutoff values may vary [ 13 , 31 – 34 ].…”

“…Similar to findings in other studies [ 22 , 35 ], there was no significant difference in hematocrit between groups. This may be because both hemoconcentration and platelet drop are usually not seen in the first days of disease [ 34 ]. Repeated monitoring of the platelet count and hematocrit is recommended, as an abrupt fall in platelet count is proposed as a warning sign, and a significant hematocrit increase is an indirect sign of plasma leakage [ 10 , 34 ].…”

Influenza Illness among Case-Patients Hospitalized for Suspected Dengue, El Salvador, 2012

“…We found a higher prevalence of cough, rhinorrhea and nasal congestion, in patients hospitalized for suspected dengue tested positive for influenza; this respiratory symptomatology could guide to test for influenza in those cases hospitalized for suspected dengue. This sign is described in the literature to differentiate influenza other acute febrile infections [ 17 ]. As has been described in the literature, the tourniquet test can be useful to differentiate dengue from other acute febrile illnesses [ 18 ].…”