Pdf molecular mimicry between virus and host and its implications. Health experts have known about dengue fever for more than 200 years. It is transmitted by mosquitoes of the genus aedes, which are widely distributed in subtropical and tropical areas of the world see the image below. The high mutability of rna viruses such as flaviviruses leads to a. More than 40% of the worlds population lives in dengue endemic areas and as many as 100 million people a year become infected. Second dengue infection is worse than first, and what that. Animal models used for dengue tropism and pathogenesis studies. Pdf dengue viral infections affect up to 100 million individuals per year. Pathogenesis of viral infection sherris medical microbiology, 6e. Zika virus zikv is an emerging arbovirus of the flaviviridae family and is related to dengue, chikungunya, west nile, yellow fever, and japanese encephalitis viruses. Dengue fever is an infectious disease carried by mosquitoes and caused by any of four related dengue viruses.
Serum specimens were also tested by suckling mouse neutralization of denv2. Pathogens free fulltext sarscov2 and coronavirus disease. Dhf can occur in primary infection with certain genetic strains of virus. The viral genome is then translated and processed before replication commences 8. So what are the factors associated with the occurrence of dhf.
Dengue fever is found in the tropical and subtropical regions of the world, including southeast asia, the indian subcontinent, africa, and the americas. Dengue virus infection causes dengue fever df, dengue hemorrhagic fever dhf, and dengue shock syndrome dss, whose pathogeneses are not clearly understood. Dengue virus denv is a member of the flavivirus genus of singlestranded positivesense rna viruses that cause visceral and central nervous system disease in humans. Aside from being itchy and annoying, the bite of an infected female aedes aegypti or aedes albopictus mosquito can spread viral infections like dengue and chikungunya.
Each year, an estimated 390 million people are infected. It can be identified by the white bands or scale patterns on its legs and thorax. Beginning in the 1950s, at the time when four different denvs were discovered, a lethal variant. People get dengue from the bite of an infected mosquito. Transmission the transmission cycle of dengue virus by the mosquito aedes aegypti begins with a dengueinfected person. Multiple strains are known but most belong to a single serotype, emcv1. In the case of dengue virus infection which causes serious public health problems, the mechanisms regarding the pathogenesis of dengue hemorrhagic syndrome. Generally, dengue is classified as a blood infection and the. Dengue epidemics result in thousands of fatalities annually. Mar 27, 2017 during the last few decades, the global incidence of dengue virus denv has increased dramatically, and it is now endemic in more than 100 countries. Plasma leakage and intrinsic coagulopathy are the pathological hall marks in dengue haemorrhagic fever dhf. It is the idea that explains why the first brush with a dengue virus is less serious than the second.
Pathogenesis of dengue haemorrhagic fever and its impact. Summary much remains to be learned about the pathogenesis of the different manifestations of dengue virus denv infections in humans. Dengue virus 1 den1 was first discovered in japan in the 1940s. Current hypotheses of antibodydependent enhancement, virus virulence, and ifn. Explaining the heterogeneity between clinical presentations within a similar crosssection of the population remains a vital area of research. Rhesus monkeys develop viremia similar in pattern to humans after dengue virus challenge but do not develop clinical disease. As both cell tropism and tissue tropism of denv are considered major determinants in the pathogenesis of dengue, there is a.
The system relies on social actions of citizens reporting mosquito breeding sites and dengue cases, in which the reports are. This increase is believed to be to be due to multiple factors. Dengue research explorer universiteit van amsterdam. Cleaning and disinfection emcv is resistant to many environmental conditions and remains stable at ph 38.
Patients with resolved viral infection will have developed a specific antibody response which may be helpful in neutralizing viruses in newly infected individuals. Purchase pathology and pathogenesis of human viral disease 1st edition. The immune response against flaviviruses nature immunology. Recent evidence has provided further information of neutralizing versus enhancing monoclonal antibodies and their target epitopes on the. Despite this, usuv pathogenesis remains largely unexplored. This disease used to be called breakbone fever because it sometimes causes severe joint and muscle pain that feels like bones are breaking. The aim of this study was to evaluate usuv neuropathogenicity using in vivo and. In large part, this limitation is related to the lack of a suitable animal model of disease. Dengue fever is a virus, so it needs to run its course. Molecular insight into dengue virus pathogenesis and its implications for disease control. Anis karuniawati, andi yasmon department of microbilogy, fmui kochs postulates 1890 by robert koch the microbe must be present in every case of the disease the microbe must be isolated from the diseased host and grown in pure culture the disease must be reproduced when a pure culture is introduced into a nondiseased susceptible host the microbe must be.
As both cell tropism and tissue tropism of denv are considered major determinants in the pathogenesis of dengue, there is a critical. Denv cycles in nature between its two principal mosquito vectors aedes albopictus or aedes aegypti and humans. Dengue haemorrhagic fever is a clinical form of disease characterised by intravascular fluid loss. Viruses known to cause hemorrhagic fever, such as viruses belonging to the families arenaviridae junin virus and lassa virus, filoviridae ebola virus and marburg virus, bunyaviridae hanta virus and rift valley virus, and flaviviridae yellow fever virus, are also not associated with ec damage 43, 70. Even during secondary infection, severe dengue is relatively rare, with only 0. Aspirin free fever reducers like acetaminophen, pain medications, rest. This book describes the molecular biology, pathogenesis, epidemiology, and potential. There are thousands of dengue cases across the world each year, making dengue viruses one of the most important mosquitoborne pathogens, explains professor pratit samdani, a renowned dengue expert in mumbai, india. Pdf numerous infectious agents may trigger autoimmunity or even result in. Current concepts in dengue pathogenesis pdf 92p download book. Immunopathogenesis of dengue virus infection springerlink. Although primary infection confers durable if not lifelong protection from reinfection by a homologous denv serotype, secondary infection by viruses of a heterologous denv serotype occurs frequently in endemic areas and is the single most important risk factor for severe disease halstead, 2007. Tourniquet test inflate blood pressure cuff to a point midway between systolic and diastolic pressure for 5 minutes positive test. Although dengue virus infections are usually selflimiting, dengue infection has.
Asia dengue viral strain is more virulent than american strain. Current epidemiology and pathogenesis in non endemic. Generally, dengue is classified as a blood infection and the main reaction of the human body to dengue virus. Dengue viral infections affect up to 100 million individuals per year. The other three viruses, den2, den3, and den4, are closely related to den1, but are not recognized as the same virus by. The relation of virus replication to interferon and antibody formation. Study of usutu virus neuropathogenicity in mice and human cellular. Viral virulence, infection enhancing antibodies, cytokines and chemical mediators in the setting of intense immune activation are the key players implicated in the pathogenesis of dhf. Aspirin free fever reducers like acetaminophen, pain medications, rest, and fluid for rehydration are typically prescribed.
Dengue a worldwide threat dengue, one of the most serious diseases affecting children in the tropics, is caused by a mosquitoborne virus related to those causing yellow fever and west nile. Jul 30, 2015 dengue virus epidemiology and clinical disease. Dengue is the most common and important arthropodborne viral arboviral illness in humans. Dengue and concurrent urinary infection in a tertiary care hospital in delhi. Pathogenesis of type 1 dengue virus infection in suckling, weaning and adult mice. The virus replicates in the salivary glands and when the mosquito bites another human, the cycle continues. Dengue is among the most important mosquitoborne viral disease in the world. A molecular mimicry pathogenesis for dengue disease which involves cross reactivity of dengue virus with human endothelial cells, platelets. The involvement of neuroinflammation in dengue viral disease.
This person will have virus circulating in the blooda viremia that lasts for about five days. Pathogenesis of dengue haemorrhagic fever and its impact on. During the last few decades, the global incidence of dengue virus denv has increased dramatically, and it is now endemic in more than 100 countries. A female mosquito will lay hundreds of eggs in her onemonth life. A risk to anyone traveling to a tropical or subtropical region of the world where dengue virus is found. The pathogenesis of spinal cord involvement in dengue virus infection. Pathogenesis of dhfdss risk factors reported for dhf most cases of dengue fever are selflimited in their course and never progress to dengue hemorrhagic fever. Help control mosquitoes that spread dengue and chikungunya b z z z z. Having known for its menace in tropical countries such as africa and asia, dengue fever is caused by a class of pathogens called as flavivirus that belongs to the family of flaviviridae and chikungunya, being caused by the alphavirus of family togaviridae buchen et al. Pathology and pathogenesis of human viral disease 1st edition. Rebeca ricohesses laboratory is studying the structural rna andor protein and transmission replication in aedes aegypti characteristics of dengue type 2 and type 3 virus variants that have produced dengue hemorrhagic fever in humans throughout the world. Anis karuniawati, andi yasmon department of microbilogy, fmui kochs postulates 1890 by robert koch the microbe must be present in every case of the disease the microbe must be isolated from the diseased host and grown in pure culture the disease must be reproduced when a pure culture is introduced into a nondiseased susceptible host the microbe must be recoverable.
Reversely,the immune response of dengue does not resist to the next infection, but promote the severity of the disease from dengue fever to dengue hemorrhagic fever. Molecular diagnosis of chikungunya virus chikv and. Viral pathogenesis comprises of several stages, including 1 transmission and entry of the virus into the host, 2 spread in the host, 3 tropism. The images also appear when selecting from individual virus names. Virus transmitted 1 to human in mosquito saliva 22. Viral hepatitis is a systemic disease with primary inflammation of the liver by any one of a heterogeneous group of hepatotropic viruses.
Atera is an it management interface that provides the summit of solutions for msps. The incidence of dengue has increased dramatically in recent decades, with estimates of 40%50% of the worlds population at risk for the. Dengue has been around since the 1780s and has caused numerous global pandemics throughout these regions. The more dengue virus, the more target cell infection. Virus infects white 3 blood cells and lymphatic tissues4. Pdf autoimmune pathogenesis in dengue virus infection. Most of these images are 1200 x 784 pixels and saved qith quality 12 maximum from photoshop. Once someone becomes infected with it, his or her symptoms are treated. It takes a week or more for the dengue virus to replicate in the mosquito. Antibiotics are ineffective at treating this disease. Dengue is a syndrome and its pathogenesis an interplay between virus and host factors that remains incompletely understood.
Dengue is believed to infect 50 to 100 million people worldwide in a year. Recent findings the pathogenesis of severe dengue is thought to be immunemediated due to the timing of the clinical manifestations and higher incidence in secondary infections with a heterologous serotype. The disease is caused by four serologically and genetically distinct viruses termed dengue virus denv 1, 2, 3 and 4. Chikungunya virus advances in biology, pathogenesis, and. Focusing on the pathogenesis of dengue, a pattern of acute viral infection can be seen. Textbook of pathology, 6th edition mosc medical college hospital. Figure 1 depicts a diagramatic representation of the pathogenesis of dengue. Dengue is a disease caused by any one of four closely related dengue viruses denv1, denv2, denv3, and denv4. Aedes aegypti the most common epidemic vector of dengue in the world is the aedes aegypti mosquito. Encephalomyocarditis virus emcv is a nonenveloped rna virus in the family picornaviridae. Dengue virus denv belongs to the family flaviviridae. A molecular mimicry pathogenesis for dengue disease which involves. The pathology of dengue hemorrhagic fever sciencedirect. The first record of a disease clinically resembling dengue fever df can be found in a chinese medical encyclopedia dated 992.
Robust and balanced immune responses to all 4 dengue virus serotypes following administration of a single dose of a. Dengue virus denv infections of humans were long thought to be selflimited and of low mortality. Both diseases are transmitted to humans by daybiting aedes aegypti and aedes albopictus mosquitoes. They may range from subclinical infection to dengue fever, dengue hemorrhagic fever dhf, and eventually dengue shock syndrome dss. The mosquito becomes infected when it bites a person who has dengue virus in their blood. In the case of dengue virus infection which causes serious public health problems, the mechanisms regarding the pathogenesis of dengue. Clinical manifestations of denv infection and disease severity vary according to different factors. Molecular mimicry between virus and host and its implications for. Molecular insight into dengue virus pathogenesis and its. Many studies have focused on the adaptive response, as antibodies and t cells play a crucial role in protection against infection, as well as in the pathogenesis of dengue disease 4 5 6. Frontiers books allows users to browse, free of charge, through the pages of frontiers ebooks and emagazines or download the entire pdf. Dengue virus ns2b protein targets cgas for degradation and. Much remains to be learned about the pathogenesis of the different manifestations of dengue virus denv infections in humans. Dengue is transmitted by an infected female mosquito.
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