How does dengue virus enters a cell?
To infect a cell, the dengue virus initially binds to the cell surface. It gains entry into the cell when it becomes enveloped by the cell membrane during the creation of a pouch-like structure known as an endosome.
What surface proteins does dengue virus use?
The virus uses ribosomes on the host’s rough endoplasmic reticulum (ER) to translate the viral RNA and produce the viral polypeptide. This polypeptide is then cut to form the ten dengue proteins. The newly synthesized viral RNA is enclosed in the C proteins, forming a nucleocapid.
What is the pathogenesis of dengue fever?
The pathogenesis of dengue was attributed to various viral and host factors such as non-structural protein 1 (NS1) viral antigen, DENV genome variation, subgenomic RNA, antibody-dependent enhancement (ADE), memory cross-reactive T cells, anti-DENV NS1 antibodies and autoimmunity.
What is the host of the dengue virus?
Humans serve as the primary reservoir for dengue. Certain nonhuman primates in Africa and Asia also serve as hosts but do not develop dengue hemorrhagic fever. Mosquitoes acquire the virus when they feed on a carrier of the virus.
What type of cells does dengue virus infect?
The virus infects nearby skin cells called keratinocytes, the most common cell type in the skin. The dengue virus also infects and replicates inside a specialized immune cell located in the skin, a type of dendritic cell called a Langerhans cell.
What do viral particles use from the host cell to enter the cell?
To enter the cell, a virus needs to bind a receptor and sometimes a coreceptor before delivering its genome into the cytosol by crossing either the plasma membrane or the membrane of an endocytic vesicle.
Which type of receptors do dengue viruses use for entry into host cells in primary infection?
Dengue virus uses human mannose-binding receptor (MR) and DC-SIGN on macrophages as primary receptors, and CLEC5A as signaling receptor to sense the dengue virus invasion and then to signal and stimulate macrophages to secrete cytokines.
WHO dengue diagnosis criteria?
To meet a case definition of DHF, all 4 criteria are required: (1) fever, (2) hemorrhagic manifestations, (3) thrombocytopenia (platelet count, ≤100000 platelets/mm3), and (4) evidence of plasma leakage. Diagnosis of DHF does not require laboratory support.
What are the portals of entry of a dengue fever?
The dengue virus gains entry via the bite of an infected Aedes mosquito and initially infects immature Langerhans cells. Infected cells disseminate through the lymphatic system, where myeloid dendritic cells, blood-derived monocytes, and splenic and hepatic macrophages are subsequently infected.
Which blood cells are affected in dengue fever?
Dengue fever can result in a drop in your white blood cell and platelet counts. The normal platelet count in the body ranges from 1.5 to 4 lacs, this can go down to as low as 20,000 to 40,000 in the case of dengue patients.
Does lymphocytes increase in dengue?
Dengue patients had higher neutrophil percentage predominately in the first 5 days of the fever then this was reversed and the percentage of lymphocytes increased.
Why do platelets decrease in dengue?
The number of platelets in dengue fever decreases as it suppresses the bone marrow (which is the site of platelet production). The platelet count in dengue fever decreases because the blood cells are affected by the virus that causes platelet damage.
How do viruses enter the cell membrane?
Viruses initially stick to cell membranes through interactions unrelated to fusion proteins. The virus surfs along the fluid surface of the cell and eventually the viral fusion proteins bind to receptor molecules on the cell membrane (4). If only binding occurred, the two membranes would remain distinct.
Which are the three main criteria used in classifying viruses into families?
The criteria used for classifying viruses into families and genera are primarily based on three structural considerations: (1) the type and size of their nucleic acid, (2) the shape and size of the capsids, and (3) the presence of a lipid envelope, derived from the host cell, surrounding the viral nucleocapsid.
WHO dengue latest guidelines?
There is no specific treatment for dengue fever. Patients should rest, stay hydrated and seek medical advice. Depending on the clinical manifestations and other circumstances, patients may be sent home, be referred for in-hospital management, or require emergency treatment and urgent referral.
Why is CBC important in dengue?
The clinical presentation of dengue patients is acute febrile illness with no localizing signs and symptoms which may mimic other infections. Therefore the laboratory tests such as a complete blood count (CBC), serological test or blood culture need to be used to differential and confirm the diagnosis.