Viral Infections: Dengue and Clinical Pathogenesis

Comprehensive vocabulary flashcards covering the virology, pathogenesis, clinical phases, and diagnostic methods for Dengue based on lecture notes.

Flaviviridae

The family of viruses to which Dengue belongs.

Dengue Serotypes

The four distinct, but closely related, virus types: DENV-1, DENV-2, DENV-3, and DENV-4.

Viral Genome

A single-stranded positive-sense RNA genome of approximately $10,700$ bases in length.

Hemagglutinin Activity

The function of the envelope glycoprotein spike responsible for the agglutination of RBCs and attachment to host cells.

Non-structural Proteins

Seven proteins including NS1, NS2b, NNS3, NS4a, NS4b, and NS5.

Aedes aegypti and Aedes albopictus

The primary mosquito species that spread Dengue, Zika, and Chikungunya viruses through bites during both day and night.

Extrinsic Incubation Period

The additional $8-12$ days required inside mosquitoes before the virus can be transmitted to healthy persons.

Autoinfection

The process by which a pregnant woman infected with dengue passes the virus to her fetus during pregnancy or birth.

Primary Viremia

The period within $24$ hours where the virus travels throughout the body and infects monocytes and macrophages.

Pyrogen

Fever-causing substances released during the infection process.

Capillary Leak Syndrome

Plasma leakage caused by endothelial cell dysfunction, leading to fluid diffusion into surrounding tissues.

Thrombocytopenia

A common clinical manifestation of all DENV infections characterized by a low platelet count, which is extreme in DHF.

Leukopenia

A low WBC count that makes the body less effective in combating foreign bodies in circulation.

Langerhans cells

The name for dendritic cells in the skin that are killed during the infection.

Acute Tubular Necrosis (ATN)

A deadly condition resulting from hypotension and decreased renal perfusion.

Hemoconcentration

A $201\%$ or greater increase in hematocrit level above baseline due to plasma leakage.

Breakbone Fever

A name for dengue derived from severe bone and muscle pain, especially in the legs and joints.

Retro-orbital pain

Pain behind the eyes, used alongside fever and rashes as a symptom of classical dengue.

Febrile Phase

The initial phase of dengue lasting $2-7$ days, characterized by high fever and potential biphasic patterns.

Critical Phase

The phase beginning at defervescence (no fever) lasting $24-48$ hours, where plasma leakage may lead to shock.

Convalescent Phase

The recovery phase where the body reabsorbs extravasated fluids and hemodynamic status stabilizes.

Hematemesis

A severe hemorrhagic manifestation involving the vomiting of blood.

Menorrhagia

Excessive bleeding during menstruation, which can occur in patients in prolonged shock.

Dengue Shock Syndrome (DSS)

A serious form of DHF characterized by circulatory failure, rapid pulse, and narrow pulse pressure (less than $20\,mm\,Hg$).

Antibody-Dependent Enhancement (ADE)

A phenomenon where heterotypic antibodies from a previous infection facilitate viral entry into macrophages, increasing viral load.

Metamorphopsia

A visual disturbance where images appear distorted, such as straight lines appearing wavy or objects appearing stretched.

Toxorhynchites

A very large mosquito species used in population control because its larvae eat the larvae of Aedes mosquitoes.

NS1 Antigen-capture ELISA

A diagnostic method targeting the non-structural protein 1 secreted into the blood of infected individuals.

MAC-ELISA

A test for the qualitative detection of dengue virus IgM antibodies, which become detectable $4-5$ days after symptom onset.

Plaque Reduction Neutralization Test (PRNT)

A biological assay used to detect and measure the titer of specific neutralizing antibodies against flaviviruses.