Dengue fever

About: Dengue fever is a research topic. Over the lifetime, 17463 publications have been published within this topic receiving 485745 citations. The topic is also known as: Dengue & dengue disease.

Reemergence of dengue in Cuba: A 1997 epidemic in Santiago de Cuba.

Abstract: After 15 years of absence dengue reemerged in 1997 in the municipality of Santiago de Cuba Cuba. After the 1981 epidemic in which there were 10312 cases of dengue hemorrhagic fever/dengue shock syndrome and 158 deaths a campaign to improve mosquito control and eradicate Aedes aegypti was launched and most of Cubas 169 municipalities were free of the vector. The municipality of Santiago de Cuba was reinfested in 1992 by A. aegypti transported in imported tires. Risk factors in the province include limited water supply inadequate eradication efforts high vector infestation and increasing migration of people from endemic countries of Latin America and the Caribbean. Establishment of an active dengue surveillance system in 1997 identified 205 cases of dengue hemorrhagic fever 12 of which were fatal. Secondary infection was implicated in 98% of these cases. No autochthonous transmission to other municipalities has been detected. As a result of the 1997 epidemic an epidemiological alert system has been established and antivector intervention and seroepidemiological surveillance have been strengthened throughout Cuba.

Race: a risk factor for dengue hemorrhagic fever.

Abstract: Cuban DHF/DSS outbreaks have provided evidence of a reduced risk of people of Negroid race for DHF/DSS compared to those of Caucasoid race. These observations from Cuban dengue outbreaks have significant epidemiological interest, as the differences in susceptibility to DHF/DSS among racial groups in Cuba coincide with that reported in African and Black Caribbean populations. In this article, we review the literature on race as a risk factor for DHF/DSS and discuss recent results from ongoing studies. Taking into consideration the origins of contemporary Cuban inhabitants, we propose that the Cuban, Caribbean Black and African populations share a common gene pool that could explain, at least partially, the low incidence of dengue hemorrhagic fever in Cuba and Caribbean and African countries. The central role played by immunological mechanisms in the pathogenesis of DHF/DSS has led us to consider that the polymorphic genes associated with the immune response must be carefully considered among those human genes regulating dengue disease severity that might be distributed unequally in Blacks and Whites.

Evaluation of two new commercial tests for the diagnosis of acute dengue virus infection using NS1 antigen detection in human serum.

Abstract: Background We compared the performance of two new commercial tests for the detection of dengue NS1 protein during the clinical phase of dengue virus (DENV) infection—an immunochromatographic test allowing rapid detection of the NS1 antigen, Dengue NS1 Ag STRIP (Bio-Rad Laboratories - Marnes La Coquette, France), and a two-step sandwich-format microplate enzyme-linked immunosorbent assay (ELISA), pan-E Dengue Early ELISA (Panbio - Brisbane, Australia)—with a one-step sandwich-format microplate ELISA, the Platelia Dengue NS1 Ag test (Bio-Rad). Methods We tested 272 serum samples from patients with dengue disease. Of these, 222 were from patients with acute infection of one of the four dengue serotypes, detected by RT-PCR and/or virus isolation. Forty-eight acute-phase serum samples from patients not infected with dengue virus were also included. Results The sensitivity of the Platelia Dengue NS1 Ag test on acute serum samples (n = 222) was 87.4% (95% confidence interval: 82.3% to 91.5%); that of Dengue NS1 Ag STRIP was 81.5% (95% CI: 75.8% to 86.4%) after 15 minutes and 82.4% (95% CI: 76.8% to 87.2%) after 30 minutes. Both tests had a specificity of 100% (97.5% CI, one-sided test: 92.6% to 100.0%). The pan-E Dengue Early ELISA had a sensitivity of 60.4% (95% CI: 53.4% to 66.8%) and a specificity of 97.9% (95% CI: 88.9% to 99.9%). Conclusion Our findings support the use of diagnostic tools based on the NS1 antigen detection for the diagnosis of acute DENV infection. The immunochromatographic test, Dengue NS1 Ag STRIP—the first rapid diagnostic test for DENV infection—was highly sensitive and specific, and would therefore be a suitable first-line test in the field. The pan-E Dengue Early ELISA was less sensitive than the Platelia test; this two-step ELISA should be combined with DENV IgM antibody detection for the diagnosis of DENV infection.

Detection of Dengue Virus RNA in Patients after Primary or Secondary Dengue Infection by Using the TaqMan Automated Amplification System

Abstract: In consecutive serum samples from 25 tourists with acute dengue fever, virus-specific RNA was detected by using fully automated TaqMan reverse transcriptase PCR. For this amplification technique new primers and special fluorochrome-labeled probes had to be synthesized. During amplification the increasing amount of viral DNA could simultaneously be measured in the tightly sealed tubes. Dengue virus RNA was found in almost all patients (17 of 18), if the samples had been taken soon after the onset of symptoms and before anti-dengue virus antibody had been produced. RNA was detectable in only one of five persons who had anti-dengue virus immunoglobulin M (IgM) antibodies but not yet IgG antibodies. In 30 late samples with both IgG and IgM antibodies viral RNA was no longer demonstrable. In two early samples from two frequent travelers obtained 1 and 2 days after the onset of symptoms significant IgG antibody titers were present but there were no anti-dengue virus IgM antibodies. In these samples a viral load of >5 x 10(6) dengue virus RNA copies (dengue types 1 and 2) was detectable. These findings of a high viral load in the presence of anti-dengue virus IgG antibody are suggestive of a secondary dengue virus infection. In the 20 tourists (17 plus 1 plus 2) in whom viral RNA was found, the dengue virus serotype could be related to the area where the infection had taken place. Most of our patients came from southeast Asia and most frequently had dengue virus type 1 infections (8 of 20).

A method for the isolation and identification of dengue viruses, using mosquito cell cultures

Abstract: An improved method for the isolation and identification of dengue viruses is described. Viruses were isolated in mosquito cell cultures (C6/36 or AP-61), identified by indirect fluorescent antibody technique, and typed by complement-fixation test, using the cell culture fluid as antigen. The sensitivity of this method was compared with mosquito inoculation in comparative titrations of 16 low passage dengue virus strains. Although lower virus titers were obtained by the mosquito cell culture technique, its decreased sensitivity was compensated for by the much larger volume (588×) which could be assayed. By incubating the mosquito cells at 32°C, dengue viruses can be identified and typed within 6 days after inoculation.