SEARCH · Search PubMed

Results for “DENGUE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources

PubMed1999

Detection of dengue virus RNA in patients after primary or secondary dengue infection by using the TaqMan automated amplification system.

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).

Base Sequence↗

PubMed1989

Antibody-dependent enhancement of dengue virus growth in human monocytes as a risk factor for dengue hemorrhagic fever.

Serum specimens collected during a prospective study of dengue infections among schoolchildren in Bangkok were tested for their ability to enhance dengue 2 (DEN-2) virus growth in human monocytes in vitro. Two groups of dengue-immune sera were compared: 32 dengue antibody positive serum specimens from children who subsequently developed asymptomatic secondary dengue infections; and 9 dengue antibody positive serum specimens from children who subsequently developed severe symptomatic secondary dengue infections, 8 of which were clinically diagnosed as dengue hemorrhagic fever. Antibody-dependent enhancement of virus growth was quantitated by measurement of virus yields in supernatant fluids of normal human monocyte cultures that were infected with DEN-2 virus in the presence of undiluted test serum. Only 4 of 32 (12%) preinfection sera from asymptomatic children, but 6 of 9 (67%) preinfection sera from symptomatic children, had significant enhancing activity (P less than 0.001). High serum DEN-2 antibody dependent enhancing activity is a significant (relative risk = 6.2) risk factor for severe illness among children in a dengue hemorrhagic fever endemic region. Dengue antibodies can be neutralizing and therefore protective, or they can be enhancing and increase the risk of dengue hemorrhagic fever.

Antibodies, Viral↗

PubMed1998

Changing clinical and biological manifestations of dengue during the dengue-2 epidemic in French Polynesia in 1996/97--description and analysis in a prospective study.

In August 1996 dengue-2 virus was detected in French Polynesia for the first time since 1976. A prospective study was conducted from November 1996 to April 1997. Each time one of 7 physicians suspected dengue, the patient was enrolled and epidemiological, clinical and biological data were recorded. Dengue diagnosis was confirmed by virus isolation and IgM detection. The aims of this study were to find clinical and biological predictive factors constituting a specific profile of dengue (DF) and dengue haemorrhagic fever (DHF/DSS) and to assess the possibility of diagnosing dengue at primary health care level using clinical criteria and basic laboratory parameters. Of 298 clinically suspect cases, 196 (66%) were confirmed as dengue. The association of macular rash, pruritus, low platelet count and leukopenia was statistically predictive of dengue but not clinically, since these four signs occur in many other viral infections. As the prevalence of clinical and biological manifestations varied over time in our study, a specific profile useful for dengue diagnosis cannot be defined. With six cases of DHF, the morbidity of this dengue-2 outbreak was very low despite the sequential infection scheme DEN-3/DEN-2. The clinical expression of dengue could depend on a specific virus strain circulating in a specific population in a particular place, with varying virulence over time.

Adolescent↗

PubMedDate not supplied

[Emergence of dengue hemorrhagic fever in the Americas. Reemergence of dengue].

Dengue is at present the most important human arbovirosis. It is the main cause of hospitalization and death among children from southeast Asia. Two fifth of the world population live in dengue risk areas. In 1997, over 100 countries reported epidemic and more than 50,000,000 cases and 25,000 deaths were estomated. Nowadays, the Americas is passing through the same situation Asia faced years ago. In 1997, 27 countries reported cases of dengue, and in 14 of them cases of dengue hemorrhagic fever were documented. In all, 387,459 cases of classic dengue and 11,645 of dengue hemorrhagic fever were registered. During the last 2 decades dengue has increased significantly in our region with ups and downs in the annual incidence since 1981. It should be remarked that every 3 or 4 years there is a cyclic decrease and a further increase of the incidence, though it trends to rise. As regards dengue hemorrhagic fever, the situation is not more favorable. The Cuban epidemic that appeared in 1981 was completely untimely in the region. In 1989, 8 years later, the second important dengue hemorrhagic fever epidemic emerged in Venezuela, and from that moment on there has been an increasing tendency of this clinical form of the disease. The factors of the emergence and reemergence are present and rise year after year. The neoliberal policies and the consequent privatization of the health services in most of the countries allow us to watch a gloomy future in relation to the development of dengue and its severe form, the dengue hemorrhagic fever/dengue shock syndrome.

Humans↗

PubMed1998

Dengue and dengue hemorrhagic fever.

Dengue fever, a very old disease, has reemerged in the past 20 years with an expanded geographic distribution of both the viruses and the mosquito vectors, increased epidemic activity, the development of hyperendemicity (the cocirculation of multiple serotypes), and the emergence of dengue hemorrhagic fever in new geographic regions. In 1998 this mosquito-borne disease is the most important tropical infectious disease after malaria, with an estimated 100 million cases of dengue fever, 500,000 cases of dengue hemorrhagic fever, and 25,000 deaths annually. The reasons for this resurgence and emergence of dengue hemorrhagic fever in the waning years of the 20th century are complex and not fully understood, but demographic, societal, and public health infrastructure changes in the past 30 years have contributed greatly. This paper reviews the changing epidemiology of dengue and dengue hemorrhagic fever by geographic region, the natural history and transmission cycles, clinical diagnosis of both dengue fever and dengue hemorrhagic fever, serologic and virologic laboratory diagnoses, pathogenesis, surveillance, prevention, and control. A major challenge for public health officials in all tropical areas of the world is to develop and implement sustainable prevention and control programs that will reverse the trend of emergent dengue hemorrhagic fever.

Dengue↗

PubMed1989

An enzyme-linked immunosorbent assay to characterize dengue infections where dengue and Japanese encephalitis co-circulate.

The diagnostic sensitivity and specificity of detection of anti-dengue IgM by antibody capture enzyme-linked immunosorbent assay (ELISA) was investigated in dengue infections in a variety of clinical settings. Sera from uninfected controls were uniformly negative. Serial specimens from experimental and natural infections showed that viremia and fever terminated as anti-dengue IgM became detectable. Anti-dengue IgM appeared in most cases by the 3rd afebrile day of illness and declined to undetectable levels after 30-60 days. Assay sensitivity was 78% in admission sera (924/1,183; 95% CI = 75-81%) and 97% in paired sera (1,030/1,062; 95% CI = 96-98%) thus exceeding or matching the performance of the hemagglutination-inhibition assay. Measurement of the anti-dengue IgM to anti-Japanese encephalitis IgM ratio correctly identified all sera from 112 patients with strictly defined Japanese encephalitis and 98% (307/312; 95% CI = 96-99%) of sera from patients whose dengue infections were confirmed by virus isolation. Dengue infections could be classified as primary or secondary by determining the ratio of units of dengue IgM to IgG antibody. We propose that measurement of dengue and Japanese encephalitis IgM and IgG antibodies upon admission and discharge from hospital care should replace the hemagglutination inhibition assay as the standard dengue serologic technique in regions where these 2 viruses co-circulate.

Acute Disease↗

PubMedDate not supplied

Solomon Islands dengue seroprevalence study--previous circulation of dengue confirmed.

Since there were no confirmed outbreaks of dengue on record an extensive search of available records and a seroprevalence study were undertaken to determine if there was evidence of past dengue virus infections in the Solomon Islands. Hospital and Health Department records revealed a suspected dengue outbreak in 1982 and deaths attributed to dengue in 1995 and 1996. Serum samples from blood donors were analyzed for the presence of IgG antibodies specific for flavivirus and dengue virus. A total of 39% of the 515 samples, predominantly from adult males from Honiara, demonstrated IgG antibodies specific for dengue; 28% (26 of 93) were monotypically positive by plaque reduction neutralization test for dengue 2 antibody and the remaining samples had antibodies to more than one dengue serotype. A good correlation was found between the presence of flavivirus and dengue IgG confirming that dengue virus had circulated in the past in the Solomon Islands.

Antibodies, Viral↗

PubMed1991

Dot enzyme immunoassay: an alternative diagnostic aid for dengue fever and dengue haemorrhagic fever.

A dot enzyme immunoassay (DEIA) for the detection of antibodies to dengue virus was tested for use as a tool in the presumptive diagnosis of dengue fever and dengue haemorrhagic fever. Paired sera from the following groups of patients were tested using the DEIA and the haemagglutination inhibition (HI) test: those with primary dengue fever; those experiencing a second dengue infection; and febrile patients who did not have dengue. The data obtained show that the DEIA can be effectively used at a serum dilution of 1:1000 to confirm presumptive recent dengue in patients with a second dengue infection. However, demonstration of seroconversion proved necessary for patients with primary dengue. At a serum dilution of 1:1000 the DEIA has a specificity of 97.3%. The role of this simple and rapid test in improving the effectivity of programmes for the control of dengue virus infection is discussed.

Adult↗

PubMed1977

Infections with two dengue viruses in Greece in the 20th century. Did dengue hemorrhagic fever occur in the 1928 epidemic?

From contemporary clinical accounts we hypothesized that the 1928 dengue epidemic in Greece may have been an earlier occurrence of dengue hemorrhagic fiver/dengue shock syndrome (DHF/DSS). To study the possibility that two different dengue viruses may have been involved, serums from 62 Athenians alive during the epidemic were examined for dengue antibodies; 73 per cent showed evidence of prior dengue infection. Monotypic neutralizing antibodies were found to two different dengue viruses, types 1 and 2. A large proportion of the sampled population had evidence of two or more past dengue infections. Since there is no evidence that dengue viruses have been transmitted in Greece since 1928, during the epidemic a very large number of persons immune to one dengue type must have acquired infections with a secon type. The virological criteria for secondary infection DHF/DSS are thus satisfied. Although DHF/DSS is currently restricted to Asia and the Pacific, the Greek oubreak suggests a biological potential for fatal consequences of dengue infections in Caucasians, particularly the elderly.

Adolescent↗

PubMed2003

Policymakers' views on dengue fever/dengue haemorrhagic fever and the need for dengue vaccines in four southeast Asian countries.

A survey of policymakers and other influential professionals in four southeast Asian countries (Cambodia, Indonesia, Philippines and Vietnam) was conducted to determine policymakers' views on the public health importance of dengue fever and dengue haemorrhagic fever (DHF), the need for a vaccine and the determinants influencing its potential introduction. The survey, which involved face-to-face interviews with policymakers, health programme managers, researchers, opinion leaders and other key informants, revealed an almost uniformly high level of concern about dengue fever/DHF and a high perceived need for a dengue vaccine. Several characteristics of the disease contribute to this high sense of priority, including its geographic spread, occurrence in outbreaks, the recurrent risk of infection each dengue season, its severity and the difficulty in diagnosis and management, its urban predominance, its burden on hospitals, and its economic toll on governments and families. Research felt to be key to future decision-making regarding dengue vaccine introduction include: disease surveillance studies, in-country vaccine trials or pilot projects, and studies on the economic burden of dengue and the cost-effectiveness of dengue vaccines. The results suggest favourable conditions for public and private sector markets for dengue vaccines and the need for creative financing strategies to ensure their accessibility to poor children in dengue-endemic countries.

Asia, Southeastern↗

PubMed2005

The differences of dengue vectors and human behavior between families with and without members having dengue fever/dengue hemorrhagic fever.

Dengue vectors, human knowledge and behavior have been reported to play an important role in the transmission of dengue. This study was designed to understand the differences of dengue vectors and the behavior between families with (target group) and without (control group) members having dengue fever/dengue hemorrhagic fever. Population density of dengue vectors were determined by ovitrap index. The living conditions, knowledge, and behavior related to dengue were investigated by questionnaire survey. Long-term ovitrap indices obtained in the target group was significantly higher than those obtained in the control. Most of the respondents had sufficient knowledge about the transmission and prevention of dengue. However, only low percentages of the families frequently cleaned water-filled containers and ditches around their residence, especially in the target group. These findings indicate that higher indices of dengue vectors and dengue-related behavior are important in the transmission of indigenous dengue.

Adult↗

PubMed1976

Replication of dengue viruses in cultures of peripheral blood leukocytes from dengue-immune rhesus monkeys.

Dengue virus of types 1, 2, and 4 replicated reproducibly in cultures of peripheral blood leukocytes from 18 dengue-immune rhesus monkeys but failed to multiple in peripheral blood leukocytes from 25 nonimmune monkeys. Replication was observed at input multiplicity of infection of 0.1 and 0.01 but irregularly at less than or equal to 0.001. Dengue viruses in permissive leukocytes achieved maximal titers on days 2-4 of culture. Viral replication in peripheral blood leukocytes from animals immune to a different type of dengue virus and in animals immune to two or more types of dengue virus was quantitatively similar to that in peripheral blood leukocytes from homotypically immune donors. Dengue virus permissiveness developed between two and three weeks after primary dengue infections. Leukocytes of animals that developed immunity to dengue virus remained permissive to in vitro infection by dengue virus of types 1 and 2 for prolonged periods, but within six months permissiveness to type 4 decreased. Thus an immunological dependence of in vitro dengue virus replication in simian peripheral blood leukocytes was demonstrated.

Animals↗

PubMed2003

Serotype-specific dengue virus circulation and dengue disease in Bangkok, Thailand from 1973 to 1999.

Dengue virus circulation and association with epidemics and severe dengue disease were studied in hospitalized children with suspected dengue at the Queen Sirikit National Institute of Child Health in Bangkok, Thailand, from 1973 to 1999. Dengue serology was performed on all patients and viral isolation attempted on laboratory-confirmed patients. Acute dengue was diagnosed in 15,569 children and virus isolated from 4,846. DEN-3 was the most frequent serotype in primary dengue (49% of all isolates), DEN-2 in secondary and in dengue hemorrhagic fever (37% and 35%, respectively). The predominant dengue serotype varied by year: DEN-1 from 1990-92, DEN-2 from 1973-86 and 1988-89; DEN-3 in 1987 and 1995-99; and DEN-4 from 1993-94. Only DEN-3 was associated with severe outbreak years. Our findings illustrate the uniqueness of each serotype in producing epidemics and severe disease and underscore the importance of long-term surveillance of dengue serotypes in understanding the epidemiology of these viruses.

Adolescent↗

PubMed2006

Dengue virus infections in the first 2 years of life and the kinetics of transplacentally transferred dengue neutralizing antibodies in thai children.

BACKGROUND: Understanding dengue virus infection in children and the kinetics of maternal dengue neutralizing antibodies is essential for effective dengue immunization of children in endemic areas. METHODS: Serum samples from 219 mother-child pairs and 140 children at 3, 6, 9, 12, 18, and 24 months of age from Bangkok, Thailand, were tested for serotype-specific dengue antibodies. Febrile episodes in the children were recorded. RESULTS: Antibodies were found in 97% of cord serum samples and disappeared in 27%, 80%, and 95% of the children by the age of 6, 9, and 12 months, respectively. Geometric mean titers (GMTs) of the antibodies to 4 dengue serotypes decreased to 5.4-15.5 in 6-month-old infants. Eleven of 12 children acquired dengue virus infection at 6 months of age and beyond; 1 had the infection at 3 months of age. Two exhibited undifferentiated febrile illnesses, and 10 had subclinical infections. CONCLUSIONS: Evidence of dengue virus infection and very low GMTs against all dengue serotypes in children at 6 months of age and beyond was demonstrated. There was no evidence that maternal antibodies were harmful to infants. Dengue virus infection rates increase from 12 months of age onward. These data provide information for supporting the optimal age at vaccination.

Antibodies, Viral↗

PubMed1978

The defined antigen substrate sphere system with direct immunohistoperoxidase for detection of soluble dengue antigen in sera of patients with dengue hemorrhagic fever.

The defined antigen substrate sphere system is a simple method for detecting antigen or antibody in the circulation. The technic is based on the coupling of antigen or antibody with Sepharose 4B beads that have been activated by cyanogen bromide. In this study the activated beads were exposed to dengue antigen in the serum from a patient with dengue hemorrhagic fever and then stained with antidengue antibody conjugated with horseradish peroxidase. The positive reaction showed brown beads by light microscopy, whereas the negative reaction gave colorless beads. The authors examined 134 specimens from 91 cases. The results were positive in 53.85%. The dengue antigen appeared in the sera on the day before shock or subsidence of fever. The percentages of sera containing soluble dengue antigen were greatest on the day of shock or subsidence of fever (33.33%) and on the fifth day of fever (28.07%). The highest titers of soluble dengue antigen (1:40 to 1:80) appeared in the sera of patients who had Grade III disease on the day of shock. The dengue antigen appeared most often in sera that had high titers of dengue antibody. It is postulated that this detected dengue antigen may be a part of soluble immune complexes formed during the hyperimmune stage of the immune response, and plays a significant role in the pathogenesis of dengue hemorrhagic fever and shock syndrome.

Antibodies, Viral↗

PubMed1979

Absence of leukocytes permissive to dengue 2 virus in the acute phase of dengue hemorrhagic fever.

Patients with primary dengue infection developed dengue 2 virus (D2V) permissive peripheral blood leukocytes (PBL) 2--3 weeks after infection. PBL from healthy individuals with dengue antibody were permissive to D2V in vitro, suggesting that immunologically mediated in vitro D2V permissiveness persists for a relatively long time after recovery from dengue infection. However, PBL obtained from second infection dengue hemorrhagic fever patients did not support D2V growth during the acute phase of illness but did so during convalescence. Leukocytes from dengue-immune patients with typhoid fever or non-dengue viral illness were permissive throughout both acute and convalescent phases of illness although there was tendency for increased permissiveness during convalescence. Acute phase PBL from DHF patients synthesized and secreted dengue neutralizing antibody in culture. Absence of D2V replication in these cultures was strongly, but not completely, correlated with antibody production. Other immunological mechanisms, in addition to antibody, may be operating in vitro or in vivo during acute phase dengue hemorrhagic fever to alter the permissiveness of PBL to D2V infection.

Adolescent↗

PubMed1992

Envelope protein sequences of dengue virus isolates TH-36 and TH-Sman, and identification of a type-specific genetic marker for dengue and tick-borne flaviviruses.

Complementary DNAs were synthesized from the envelope protein genes of two isolates of dengue virus (TH-36 and TH-Sman, previously suggested as possible dengue virus type 5 and dengue virus type 6 respectively) and amplified by the polymerase chain reaction using sense and antisense primers designed from conserved dengue virus gene sequences. The amplified cDNA clones were sequenced in both directions by double-stranded dideoxynucleotide sequencing. Alignment with published dengue virus sequences enabled us to assign these viruses accurately to classified serotypes, confirming that TH-36 and TH-Sman are strains of dengue virus type 2 and dengue virus type 1 respectively. Amino acid changes between the proteins encoded by these two isolates and strains of their respective serotypes may account for the significant antigenic differences observed during previous serological typing of these viruses. Moreover, sequence alignment of flavivirus envelope proteins revealed a hypervariable region, within which members of the dengue and tick-borne virus antigenic complexes show unique peptide sequences. This type-specific hypervariable domain may be useful as a genetic marker for typing dengue and tick-borne flaviviruses.

Amino Acid Sequence↗

PubMed2004

Serotype-specific entry of dengue virus into liver cells: identification of the 37-kilodalton/67-kilodalton high-affinity laminin receptor as a dengue virus serotype 1 receptor.

Dengue virus, the causative agent of dengue fever, dengue shock syndrome, and dengue hemorrhagic fever, infects susceptible cells by initially binding to a receptor(s) located on the host cell surface. Evidence to date suggests that receptor usage may be cell and serotype specific, and this study sought to identify dengue virus serotype 1 binding proteins on the surface of liver cells, a known target organ. By using a virus overlay protein binding assay (VOPBA), in both nondenaturing and denaturing gel systems, a putative dengue virus serotype 1 binding protein of approximately 37 kDa expressed on the surface of liver (HepG2) cells was identified. Mass spectrometry analysis identified a candidate protein, the 37/67-kDa high-affinity laminin receptor. Entry of the dengue virus serotype 1 was significantly inhibited in a dose-dependent manner by both antibodies directed against the 37/67-kDa high-affinity laminin receptor and soluble laminin. No inhibition of virus entry was seen with dengue virus serotypes 2, 3, or 4, demonstrating that the 37/67-kDa high-affinity laminin receptor is a serotype-specific receptor for dengue virus entry into liver cells.

Animals↗