ABSTRACT
To characterize the immunophenotypes of lymphocytes in patients with dengue infection, we performed flow cytometric analysis of peripheral blood mononuclear cells collected from 49 dengue hemorrhagic fever (DHF), 25 dengue fever (DF), and 26 dengue-like syndrome (DLS) cases. The mean total atypical lymphocytes in DHF (916.1 +/- 685.6 cells/microl) and DF (876.2 +/- 801.9 cells/microl) were higher than those of DLS (310.5 +/- 181.4 cells/microl). An atypical lymphocyte count of 10% or higher was a good indicator of dengue infection (sensitivity 50% and specificity 86%). Flow cytometric studies showed that the percentages of atypical lymphocytes correlated with those of CD19+ B lymphocytes and inversely correlated with the percentages of CD69+ lymphocytes. The mean absolute counts of atypical lymphocytes and CD19+ cells on the discharge day were significantly higher than those on the admission day. Low percentages of TdT+ cells were found in all groups of patients. We concluded that atypical lymphocyte and CD19+ cell counts may be a useful diagnostic tool for dengue infection and the recovery from the disease could be judged when numbers of both cell types are significantly elevated.
Subject(s)
Adolescent , Adult , Antigens, CD , Child , Child, Preschool , Dengue/immunology , Severe Dengue/diagnosis , Dengue Virus , Humans , Immunophenotyping , Leukocyte Count , Lymphocyte Activation , Lymphocyte Count , Lymphocyte Subsets/immunology , MaleABSTRACT
RNA amplification by nucleic acid sequence-based amplification (NASBA) was used to detect serotype specific dengue viruses in artificially-infected female Aedes mosquitoes, in comparison with RT-PCR technique. NASBA could detect dengue virus serotype 2 and 4 below 0.1 PFU, which was more sensitive than RT-PCR, but this technique was as sensitive as RT-PCR when detecting dengue virus serotype 1 and 3. Dengue viruses could be detected at the thorax of mosquitoes at 0, 7, and 14 days after inoculation with dengue virus serotype 2. This method should be useful for virological surveillance of dengue infected Aedes mosquitoes, as an early warning system to predict outbreaks of dengue viruses.
Subject(s)
Animals , Dengue/epidemiology , Dengue Virus/classification , Nucleic Acid Amplification Techniques , RNA/blood , RNA, Viral/analysis , Sequence Analysis, DNA , Serotyping , ThailandABSTRACT
The objective of this study was to compare the clinical spectra of the dengue serotypes proven by the PCR technique. This retrospective study reviewed the clinical information of dengue-infected patients who were admitted to northeastern provincial hospitals in Thailand from June to September 2002. Dengue infection and viral serotypes were confirmed by polymerase chain reaction (PCR). Paired anti-dengue immunoglobulin G (IgG) and IgM from paired sera were analyzed by enzyme-linked immunosorbent assay (ELISA). Ninety-nine PCR-proven dengue-infected Thai patients were studied. Their ages ranged from 3-30 years. They were infected with DEN1, DEN2, DEN3 and DEN4 in 21, 55, 12, and 12%, respectively. Twenty-two percent had primary and 78% had secondary infections. Dengue fever was the most common presentation for both primary (77.2%) and secondary infections (46.7%). The ratios of dengue fever:dengue hemorrhagic fever (DF:DHF) and non-dengue shock syndrome:dengue shock syndrome (non-DSS:DSS) for DEN2 was the lowest of the dengue serotypes. There was no difference in the duration of fever, percentage of hepatomegaly and bleeding among the serotypes in both DF and DHF. The trends in the white blood cells, lymphocyte and atypical lymphocyte counts in DEN3 were the highest, while those of DEN1 were the lowest of the dengue serotypes.