Severe Dengue
Dengue
Dengue Virus
Antibody-Dependent Enhancement
Indonesia
Thailand
Aedes
Severity of Illness Index
Dengue Vaccines
Brazil
Changing epidemiology of dengue hemorrhagic fever in Thailand. (1/325)
Dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) are reportable diseases, the third most common causes for hospitalization of children in Thailand. Data collected from the Ministry of Public Health were analysed for trends. Rates of DHF increased in Thailand until 1987 when the largest epidemic ever, 325/100000 population, was recorded. Whereas the disease used to be confined to large cities, the rate is now higher in rural (102.2 per 100000) than urban areas (95.4 per 100000 in 1997). The age of highest incidence has increased, and the age group most severely affected is now those 5-9 years old (679/100000 in 1997). The case fatality rate has decreased with improved treatment and is now only 0.28%. (+info)Impaired T cell proliferation in acute dengue infection. (2/325)
Decreased proliferative responses to mitogens and recall Ags have been observed in PBMC obtained during several acute human viral infections. To determine whether cell-mediated responses are altered during acute dengue infection, we examined the proliferative responses of PBMC from children enrolled in a prospective study of dengue infections in Thailand. All responses of PBMC during acute illness were compared with the same patients' PBMC obtained at least 6 mo after their infection. Proliferative responses to PHA, anti-CD3, tetanus toxoid, and dengue Ags were decreased significantly in PBMC obtained during the acute infection. The proliferative responses to PHA were restored by the addition of gamma-irradiated autologous convalescent or allogeneic PBMC. Cell contact with the irradiated PBMC was necessary to restore proliferation. Non-T cells from the acute PBMC of dengue patients did not support proliferation of T cells from control donors in response to PHA, but T cells from the PBMC of patients with acute dengue proliferated if accessory cells from a control donor were present. Addition of anti-CD28 Abs restored anti-CD3-induced proliferation of the PBMC of some patients. The percentage of monocytes was reduced in the acute sample of PBMC of the dengue patients. Addition of IL-2 or IL-7, but not IL-4 or IL-12, also restored proliferation of acute PBMC stimulated with anti-CD3. The results demonstrate that both quantitative and qualitative defects in the accessory cell population during acute dengue illness result in a depression of in vitro T cell proliferation. (+info)Evaluation of four methods for detection of immunoglobulin M antibodies to dengue virus. (3/325)
Dengue has become hyperendemic in many islands of the Caribbean region. The performance in a diagnostic laboratory of four commercial assays for detection of immunoglobulin M (IgM) antibodies was evaluated. Sera from 62 patients with dengue virus infection were studied. These included 18 patients from whom dengue virus type 2 was isolated in a 1997 outbreak (specimens collected a mean of 14 days after onset of symptoms), 8 patients with dengue hemorrhagic fever (mean time after onset, 11 days), and 36 patients in whom dengue was previously confirmed by serology (mean time after onset, 10 days). Thirty serum specimens from blood donors in a country where dengue is not endemic were used as negative controls. The methods evaluated were two IgM-capture enzyme-linked immunosorbent assays (ELISA) (MRL Diagnostics, Cypress, Calif., and PanBio, Queensland, Australia), a dot ELISA dipstick assay (Integrated Diagnostics, Baltimore, Md.), and a rapid immunochromatographic assay for dengue IgG and IgM (PanBio IC). IgG antibodies were also detected by an ELISA method (MRL Diagnostics). The sensitivities of the four assays were as follows: MRL Diagnostics IgM ELISA, 98.4%; PanBio IgM ELISA, 85.5%; Integrated Diagnostics IgM dot ELISA, 96. 8%; and PanBio IC, 83.9%. The specificities of all tests were 100%. Evidence of secondary dengue was found in all patients with dengue hemorrhagic fever and in 83% of the remaining patients. The MRL Diagnostics IgM ELISA appears to be more sensitive than the PanBio IgM ELISA, and this may be significant when IgM titers are low, particularly in patients with secondary dengue infections. The dot ELISA dipstick assay is equally sensitive and may be more appropriate for use in laboratories with lower workloads. (+info)Total immunoglobulin E levels and dengue infection on San Andres Island, Colombia. (4/325)
An evaluation of total immunoglobulin E (IgE) and dengue serostatus in 168 subjects from San Andres Island, Colombia, revealed altered levels of IgE in 89% of the population. IgE levels were higher in patients with a history of dengue or with a current secondary or current primary infection than in subjects with no exposure (P = 0. 01). Dengue infection accounted for 23% of the variation in IgE levels. (+info)Type-3 dengue viruses responsible for the dengue epidemic in Malaysia during 1993-1994. (5/325)
To characterize the dengue epidemic that recently occurred in Malaysia, we sequenced cDNAs from nine 1993-1994 dengue virus type-3 (DEN-3) isolates in Malaysia (DEN-3 was the most common type in Malaysia during this period). Nucleic acid sequences (720 nucleotides in length) from the nine isolates, encompassing the precursor of membrane protein (preM) and membrane (M) protein genes and part of the envelope (E) protein gene were aligned with various reference DEN-3 sequences to generate a neighbor-joining phylogenetic tree. According to the constructed tree, the nine Malaysian isolates were grouped into subtype II, which comprises Thai isolates from 1962 to 1987. Five earlier DEN-3 virus Malaysian isolates from 1974 to 1981 belonged to subtype I. The present data indicate that the recent dengue epidemic in Malaysia was due to the introduction of DEN-3 viruses previously endemic to Thailand. (+info)The first major outbreak of dengue hemorrhagic fever in Delhi, India. (6/325)
India An outbreak of dengue hemorrhagic fever/dengue shock syndrome (DHS/DSS) occurred in 1996 in India in and near Delhi. The cause was confirmed as dengue virus type 2, by virus cultivation and indirect immunofluorescence with type-specific monoclonal antibodies. This is the largest such outbreak reported from India, indicating a serious resurgence of dengue virus infection. (+info)Profile of transforming growth factor-beta 1 in patients with dengue haemorrhagic fever. (7/325)
The pathogenesis of dengue haemorrhagic fever (DHF) is incompletely understood but it has been suggested that various cytokines may have a role in the process. In this study the profile of the cytokine Transforming Growth Factor-beta 1 (TGF-beta1) was investigated in the sera of 79 patients with various grades of dengue illness and in 21 normal healthy controls. Also, TGF-beta1-specific mRNA was examined in their peripheral blood mononuclear cells (PBMC). The results showed that neither TGF-beta1 protein nor its mRNA were detected in healthy controls. In dengue patients, the TGF-beta1 protein and its mRNA were detected in 96%. However, among the patient groups, the levels of TGF-beta1 were lowest in patients with dengue fever (DF; mean value 315 +/- 95 pg/ml) and were highest in patients with DHF grade IV (mean value 1350 +/- 280 pg/ml; P = < 0. 001). The cytokine appeared during the first four days of illness (304 +/- 90 pg/ml) and gradually increased, reaching peak levels (1050 +/- 215 pg/ml) after the 9th day of the illness. Thus TGF-beta1 in the sera and TGF-beta1-mRNA in the PBMC were present in most of the patients with dengue (96%) but the cytokine levels were highest during the later periods of illness and in patients with DHF grade IV, suggesting a possible role of TGF-beta1 in the pathogenesis of DHF. (+info)A prospective seroepidemiologic study on dengue in children four to nine years of age in Yogyakarta, Indonesia I. studies in 1995-1996. (8/325)
A prospective study on dengue (DEN) viruses was initiated in October 1995 in Gondokusuman kecamatan, Yogyakarta, Indonesia. This report presents data from the first year of the study. The studied cohort included all children 4-9 years of age living in the kecamatan. Blood samples for serology were collected from 1,837 children in October 1995 and again in October 1996. Blood samples for virus isolation and serology were collected from cohort children who were seen in municipal health clinics with febrile syndromes or admitted to hospitals with a provisional diagnosis of dengue hemorrhagic fever. Dengue serotype antibody prevalence and 1995-1996 infection rates were calculated using a single dilution (1:60) 70% plaque reduction endpoint neutralization test. Prevalence of dengue antibody at the beginning of the study was DEN 1 = 12%, DEN 2 = 16%, DEN 3 = 2%, DEN 4 = 4%, and two or more dengue infections = 22%. Total dengue antibody prevalence increased from 38% in 4-year-old children to 69% in 9-year-old children. During the observation period, primary dengue infection rates were DEN 1 = 4.8%, DEN 2 = 7.7%, DEN 3 = 4.2%, and DEN 4 = 3.4%, while two or more dengue infections occurred in 6.7% of the study population. The secondary dengue infection rate was 19.0%. From febrile cases, all four dengue viruses were isolated with DEN 3 predominating. Seven children were hospitalized, including one fatal case with a hospital diagnosis of dengue shock syndrome. Based upon presence of antibody in the initial cohort bleeding and the serologic response both weeks and several months following illness, all had secondary dengue infections. Neutralizing antibody patterns in the initial cohort bleeding and in late convalescent serum samples permitted recognition of dengue infection sequence in five patients: DEN 2-DEN 1 (3), DEN 2-DEN 4 (1), DEN 1-DEN 3 (1), and none in the sequence DEN 1-DEN 2. In the total cohort 6.5% of the observed secondary infections were of the sequence DEN 2-DEN 1, while 4.9% were DEN 1-DEN 2, a highly pathogenic sequence in previous studies. Reduced pathogenic expression of secondary DEN 2 with enhanced pathogenic expression of secondary DEN 1 infections was an unexpected finding. Further studies will be required to understand the respective contributions to pathogenicity of antibody from initial dengue infections versus the biological attributes of the second infecting dengue viruses. (+info)Severe dengue, also known as dengue hemorrhagic fever, is a severe and potentially fatal complication of dengue virus infection. The World Health Organization (WHO) defines it as follows:
"Dengue hemorrhagic fever is characterized by a high fever (40°C/104°F) that lasts for 2-7 days, with generalized pain and severe headache, bleeding manifestations (e.g., nose or gum bleed, skin rash with bruising, internal bleeding), plasma leakage leading to accumulation of fluid in the lungs or abdomen, and a rapid decrease in platelet count."
Severe dengue can be life-threatening if not diagnosed and treated promptly. It is important to seek medical attention immediately if you suspect you have dengue fever and are experiencing any of the symptoms associated with severe dengue.
Dengue is a mosquito-borne viral infection that is primarily transmitted by the Aedes aegypti and Aedes albopictus species of mosquitoes. It is caused by one of four closely related dengue viruses (DENV 1, DENV 2, DENV 3, or DENV 4). The infection can cause a wide range of symptoms, ranging from mild fever and headache to severe flu-like illness, which is often characterized by the sudden onset of high fever, severe headache, muscle and joint pain, nausea, vomiting, and skin rash. In some cases, dengue can progress to more severe forms, such as dengue hemorrhagic fever or dengue shock syndrome, which can be life-threatening if not treated promptly and appropriately.
Dengue is prevalent in many tropical and subtropical regions around the world, particularly in urban and semi-urban areas with poor sanitation and inadequate mosquito control. There is no specific treatment for dengue, and prevention efforts focus on reducing mosquito populations and avoiding mosquito bites. Vaccines are available in some countries to prevent dengue infection, but they are not widely used due to limitations in their effectiveness and safety.
Dengue virus (DENV) is a single-stranded, positive-sense RNA virus that belongs to the genus Flavivirus in the family Flaviviridae. It is primarily transmitted to humans through the bites of infected female mosquitoes, mainly Aedes aegypti and Aedes albopictus.
The DENV genome contains approximately 11,000 nucleotides and encodes three structural proteins (capsid, pre-membrane/membrane, and envelope) and seven non-structural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5). There are four distinct serotypes of DENV (DENV-1, DENV-2, DENV-3, and DENV-4), each of which can cause dengue fever, a mosquito-borne viral disease.
Infection with one serotype provides lifelong immunity against that particular serotype but only temporary and partial protection against the other three serotypes. Subsequent infections with different serotypes can increase the risk of developing severe dengue, such as dengue hemorrhagic fever or dengue shock syndrome, due to antibody-dependent enhancement (ADE) and original antigenic sin phenomena.
DENV is a significant public health concern in tropical and subtropical regions worldwide, with an estimated 390 million annual infections and approximately 100-400 million clinical cases. Preventive measures include vector control strategies to reduce mosquito populations and the development of effective vaccines against all four serotypes.
Antibody-Dependent Enhancement (ADE) is a phenomenon in which the presence of antibodies against a particular virus actually enhances the ability of the virus to infect and replicate within host cells, leading to increased severity of infection. This occurs when the antibodies bind to the virus but do not neutralize it, instead facilitating uptake of the virus into immune cells expressing Fc receptors, such as macrophages. The virus can then use these cells as a site for replication and evasion of the host's immune response. ADE has been observed in various viral infections, including dengue fever and respiratory syncytial virus (RSV) infection. It is a concern in the development of vaccines against these viruses, as non-neutralizing antibodies induced by vaccination could potentially enhance subsequent infection with a heterologous strain of the virus.
I'm sorry for any confusion, but "Indonesia" is not a medical term. It is a country located in Southeast Asia and Oceania, between the Indian and Pacific oceans. It is the world's largest island country, with more than thirteen thousand islands. If you have any questions about medical terms or concepts, I would be happy to help with those!
I'm sorry for any confusion, but "Thailand" is not a medical term. It is a country located in Southeast Asia. If you have any questions about medical terms or concepts, I would be happy to help answer those for you!
"Aedes" is a genus of mosquitoes that are known to transmit various diseases, including Zika virus, dengue fever, chikungunya, and yellow fever. These mosquitoes are typically found in tropical and subtropical regions around the world. They are distinguished by their black and white striped legs and thorax. Aedes aegypti is the most common species associated with disease transmission, although other species such as Aedes albopictus can also transmit diseases. It's important to note that only female mosquitoes bite and feed on blood, while males feed solely on nectar and plant juices.
A Severity of Illness Index is a measurement tool used in healthcare to assess the severity of a patient's condition and the risk of mortality or other adverse outcomes. These indices typically take into account various physiological and clinical variables, such as vital signs, laboratory values, and co-morbidities, to generate a score that reflects the patient's overall illness severity.
Examples of Severity of Illness Indices include the Acute Physiology and Chronic Health Evaluation (APACHE) system, the Simplified Acute Physiology Score (SAPS), and the Mortality Probability Model (MPM). These indices are often used in critical care settings to guide clinical decision-making, inform prognosis, and compare outcomes across different patient populations.
It is important to note that while these indices can provide valuable information about a patient's condition, they should not be used as the sole basis for clinical decision-making. Rather, they should be considered in conjunction with other factors, such as the patient's overall clinical presentation, treatment preferences, and goals of care.
Antibodies, viral are proteins produced by the immune system in response to an infection with a virus. These antibodies are capable of recognizing and binding to specific antigens on the surface of the virus, which helps to neutralize or destroy the virus and prevent its replication. Once produced, these antibodies can provide immunity against future infections with the same virus.
Viral antibodies are typically composed of four polypeptide chains - two heavy chains and two light chains - that are held together by disulfide bonds. The binding site for the antigen is located at the tip of the Y-shaped structure, formed by the variable regions of the heavy and light chains.
There are five classes of antibodies in humans: IgA, IgD, IgE, IgG, and IgM. Each class has a different function and is distributed differently throughout the body. For example, IgG is the most common type of antibody found in the bloodstream and provides long-term immunity against viruses, while IgA is found primarily in mucous membranes and helps to protect against respiratory and gastrointestinal infections.
In addition to their role in the immune response, viral antibodies can also be used as diagnostic tools to detect the presence of a specific virus in a patient's blood or other bodily fluids.
Dengue vaccines are designed to protect against dengue fever, a mosquito-borne viral disease that can cause severe flu-like symptoms and potentially life-threatening complications. Dengue is caused by four distinct serotypes of the virus (DENV-1, DENV-2, DENV-3, and DENV-4), and infection with one serotype does not provide immunity against the others.
The first licensed dengue vaccine, Dengvaxia (CYD-TDV), is a chimeric yellow fever-dengue tetravalent vaccine developed by Sanofi Pasteur. It is approved for use in several countries and has demonstrated efficacy against dengue fever caused by all four serotypes in clinical trials. However, the vaccine has raised concerns about the risk of severe disease in individuals who have not been previously exposed to dengue. As a result, it is recommended primarily for people with a documented past dengue infection or living in areas with high dengue prevalence and where the benefits outweigh the risks.
Another dengue vaccine candidate, Takeda's TAK-003 (also known as TDV), is a live attenuated tetravalent dengue vaccine that has shown efficacy against all four serotypes in clinical trials. It was granted approval by the European Medicines Agency (EMA) and several other countries for use in individuals aged 4-16 years old, living in endemic areas.
Research and development of additional dengue vaccine candidates are ongoing to address concerns about safety, efficacy, and accessibility, particularly for at-risk populations in low- and middle-income countries where dengue is most prevalent.
I apologize, but "Brazil" is not a medical term or condition. It is the largest country in both South America and Latin America by land area and population. If you have any questions related to medical terminology or health concerns, please provide more information and I will do my best to help.
Insect vectors are insects that transmit disease-causing pathogens (such as viruses, bacteria, parasites) from one host to another. They do this while feeding on the host's blood or tissues. The insects themselves are not infected by the pathogen but act as mechanical carriers that pass it on during their bite. Examples of diseases spread by insect vectors include malaria (transmitted by mosquitoes), Lyme disease (transmitted by ticks), and plague (transmitted by fleas). Proper prevention measures, such as using insect repellent and reducing standing water where mosquitoes breed, can help reduce the risk of contracting these diseases.