RESUMO
Large-scale epidemiological surveillance of dengue in the field and dengue patient management require simple methods for sample collection, storage, and transportation as well as effective diagnostic tools. We evaluated the kinetics of three biological markers of dengue infection-non-structural protein 1 (NS1) antigen, immunoglobulin M (IgM), and IgA-in sequential capillary blood samples collected from fingertips of confirmed dengue patients. The overall sensitivities and specificities of the tests were 96% and 100%, respectively, for NS1, 58.1% and 100%, respectively, for IgM, and 33% and 100%, respectively, for IgA. During the acute phase of the disease, NS1 was the best marker of dengue infection, with a sensitivity of 98.7%, whereas from day 5, all three markers exhibited relevant levels of sensitivity. This first descriptive study of the kinetics of biological markers of dengue in capillary blood samples confirms the usefulness of this biological compartment for dengue diagnosis and argues for its exploitation in community-level and remote settings.
Assuntos
Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Vírus da Dengue/imunologia , Dengue/sangue , Imunoglobulina A/imunologia , Imunoglobulina M/imunologia , Proteínas não Estruturais Virais/imunologia , Adolescente , Adulto , Biomarcadores/sangue , Coleta de Amostras Sanguíneas/métodos , Capilares , Dengue/imunologia , Progressão da Doença , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Testes Sorológicos , Fatores de Tempo , Vietnã , Adulto JovemRESUMO
To strengthen active dengue surveillance in Saint Martin and Saint Barthélemy, two French Caribbean islands, we evaluated the epidemiological usefulness of collecting blood samples from NS1-positive dengue patients on filter paper to identify the dengue serotypes circulating in these regions during a 27-month period. This approach allowed dengue serotypes to be identified by reverse transcriptase-polymerase chain reaction in 90.1% of the total set of 666 samples analyzed and, in 95.5% of the samples collected during the acute phase of the disease. This prospective virological surveillance using blood samples absorbed onto filter paper, which were stored at 4°C and shipped at ambient temperature to a specialized laboratory for analysis, allowed us to avoid the logistic and financial costs associated with shipping frozen venous blood samples. This surveillance system offers a low-cost alternative for reinforcing dengue prevention in areas where specialized laboratories do not exist, notably by facilitating the early detection of potentially new dengue serotypes.
