VIRUS PART 1

The smallest infectious agent that contains either RNA or DNA as its genome and can cause infections in humans, animals, plants, and bacteria.

Virus

A method of viral replication where the virus enters the host cell, takes over the cell's machinery to produce new virions, and eventually causes the host cell to burst and release the newly formed viruses.

Lytic replication

A method of viral replication where the virus integrates its DNA into the host cell's DNA and replicates along with the host cell's DNA, without causing immediate harm to the host cell.

Lysogenic replication

A disease characterized by the uncontrolled growth and spread of abnormal cells in the body, which can be caused by certain viruses.

Cancer

The genetic material of a virus, which can be either RNA or DNA.

Nucleic acid

The protein coat that surrounds the nucleic acid of a virus.

Capsid

The extracellular state of a virus, consisting of the nucleic acid and the protein coat (capsid).

Virion

A phospholipid bilayer and proteins that surround some viruses, acquired from the host cell during viral replication or release.

Envelope

The complete set of genetic material (DNA or RNA) of an organism or virus.

Genome

The organism or cell that a virus infects and uses for replication.

Host

Proteinaceous subunits that make up the capsid of a virus.

Capsomere

Proteins with attached carbohydrate molecules, often found on the envelope of viruses and involved in host recognition.

Glycoproteins

A virus that infects bacteria.

Bacteriophage

The process of making copies of the viral genome and producing new virions.

Replication

The membrane-bound organelle in eukaryotic cells where DNA replication and transcription occur.

Nucleus

The fluid-filled region of a cell, outside the nucleus, where many cellular processes take place.

Cytoplasm

The process by which a cell releases substances from the cell by fusing vesicles containing the substances with the cell membrane.

Exocytosis

The bursting or disintegration of a cell, often caused by the release of newly formed viruses.

Lysis

Single-stranded RNA with a negative sense

-ssRNA

Single-stranded RNA with a positive sense

+ssRNA

Double-stranded RNA

dsRNA

A complete virus particle

Virion

The outer membrane of a cell

Cytoplasmic membrane

The protein coat that surrounds the viral genome

Viral capsid

The process of making copies of the viral genome

Replication

When a virus remains dormant in host cells

Latency

Genes that have the potential to cause cancer

Oncogenes

Uncontrolled cell division in multicellular animals, resulting in a tumor

Neoplasia

The spread of cancer cells from one part of the body to another

Metastasis

Substances that can cause cancer

Carcinogens

A viral genome that has been incorporated into the host cell's DNA

Provirus

An organism that carries and transmits a virus or other pathogen

Vector

Viruses that infect bacteria

Phages

Extremely small, circular pieces of infectious RNA that can cause disease in plants

Viroids

Proteinaceous infectious agents that can cause neurological diseases

Prions

Bovine spongiform encephalopathy, also known as "mad cow disease"

BSE

Variant Creutzfeldt-Jakob disease, a human prion disease

vCJD

The categorization of viruses into different families based on their characteristics and genetic material

Classification of Viruses

A family of RNA viruses that have a single-stranded positive sense RNA genome. Representative genera include Enterovirus (polio), Hepatovirus (hepatitis A), and Rhinovirus (common cold).

Picornaviridae

A family of RNA viruses that have a single-stranded positive sense RNA genome. Representative genus is Norovirus, which causes gastroenteritis.

Caliciviridae

A family of RNA viruses that have a single-stranded positive sense RNA genome. Representative genus is Astrovirus, which causes gastroenteritis.

Astroviridae

A family of RNA viruses that have a single-stranded positive sense RNA genome. Representative genus is Hepevirus, which causes hepatitis E.

Hepeviridae

A family of RNA viruses that have a single-stranded positive sense RNA genome. Representative genera include Alphavirus (encephalitis) and Rubivirus (rubella).

Togaviridae

A family of RNA viruses that have a single-stranded positive sense RNA genome. Representative genera include Flavivirus (yellow fever), Japanese encephalitis virus (encephalitis), and Hepacivirus (hepatitis C).

Flaviviridae

A family of RNA viruses that have a single-stranded positive sense RNA genome. Representative genus is Coronavirus, which causes common cold and severe acute respiratory syndrome.

Coronaviridae

A family of RNA viruses that have a single-stranded positive sense RNA genome. Representative genera include Human T cell leukemia virus (leukemia) and Lentivirus (AIDS).

Retroviridae

A family of RNA viruses that have a single-stranded negative sense RNA genome. Representative genus is Influenzavirus, which causes flu.

Orthomyxoviridae

A family of RNA viruses that have a single-stranded negative sense RNA genome. Representative genera include Paramyxovirus (common cold, respiratory infections), Pneumovirus (pneumonia, common cold), Morbillivirus (measles), and Rubulavirus (mumps).

Paramyxoviridae

A family of RNA viruses that have a single-stranded negative sense RNA genome. Representative genus is Lyssavirus, which causes rabies.

Rhabdoviridae

A family of RNA viruses that have a single-stranded negative sense RNA genome. Representative genera include Bunyavirus (California encephalitis virus) and Hantavirus (pneumonia).

Bunyaviridae

A family of RNA viruses that have a single-stranded negative sense RNA genome. Representative genus is Filovirus, which causes Ebola hemorrhagic fever.

Filoviridae

A family of RNA viruses that have a single-stranded negative sense RNA genome. Representative genus is Lassavirus, which causes hemorrhagic fever.

Arenaviridae

A family of double-stranded segmented RNA viruses. Representative genera include Orbivirus (encephalitis), Rotavirus (diarrhea), and Coltivirus (Colorado tick fever).

Reoviridae

Positive-sense RNA, which is equivalent to mRNA and can be directly translated by ribosomes.

(+RNA)

Negative-sense RNA, which is complementary to mRNA and cannot be directly translated.

(-RNA)

A DNA virus that is associated with cervical dysplasia, carcinoma, and genital warts. It is primarily transmitted through sexual activity and previous exposure to certain strains.

Human Papillomavirus (HPV)

A DNA virus that infects humans and early apes. There are two types:BK polyoma virus, which causes asymptomatic infection in children, and JC polyoma virus, which causes an opportunistic infection called Multifocal leukoencephalopathy (PML) in patients with JC.

Polyomavirus

A DNA virus that causes upper respiratory tract infections in children, characterized by symptoms such as rhinitis, conjunctivitis, sore throat, and cough.

Adenoviridae

The smallest icosahedral virus that contains single-stranded DNA. It causes childhood diseases known as erythema infectiosum (5th disease), which is characterized by fever and a "slapped face" rash on the cheeks.

Parvoviridae

A family of DNA viruses that can develop a latent state in the sensory ganglia and cause cell destruction, resulting in blisters or vesicles.

Herpesviridae

A type of Herpesviridae that is mainly transmitted through oral-to-oral contact, causing oral herpes (cold sores). It can also lead to genital herpes and is associated with conditions such as gingivostomatitis, herpetic keratitis, and encephalitis.

Herpes Simplex Virus-1

Another type of Herpesviridae that commonly causes genital disease as a sexually transmitted infection. It can cause vesicles on the vagina, cervix, vulva, perineum, glans, and shaft of the penis, and is associated with symptoms such as pain, burning, itching, and urination discomfort.

Herpes Simplex Virus-2

The causative agent of Chickenpox and Shingles. It is a DNA virus that causes a highly contagious disease characterized by a generalized vesicular eruption of the skin and mucous membranes. In adults and immunocompromised individuals, it can cause severe disease and be reactivated as Shingles.

Varicella-Zoster Virus (VZV)

A common herpesvirus that can cause human disease, including congenital infection, genital disease, and mononucleosis syndrome. It is also a cofactor in the development of cervical cancer and can cause severe complications in immunocompromised patients.

Cytomegalovirus (CMV)

A ubiquitous herpesvirus that is associated with acute infectious mononucleosis and various types of cancer, including nasopharyngeal carcinoma, Burkitt lymphoma, Hodgkin and non-Hodgkin lymphomas, and gastric carcinoma. It is also associated with tumors.

Epstein-Barr Virus (EBV)

A DNA virus that infects human B cells and is associated with mononucleosis in young adults.

Epstein-Barr Virus (EBV)

A family of DNA viruses that cause viral hepatitis infection of liver hepatocytes.

Hepadnaviridae

A DNA virus belonging to the Hepadnaviridae family that causes hepatitis B infection.

Hepatitis B virus (HBV)

A sudden illness with a mild to severe course followed by complete resolution, characterized by symptoms like flu, low-grade fever, cough, fatigue, muscle aches, runny nose, and pharyngitis.

Acute viral hepatitis

A test that measures the levels of liver function enzymes, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), and alkaline phosphatase.

Liver Function Test

The intact virus of Hepatitis B, which has an envelope, an icosahedral capsid with protein spikes, and a core containing double-stranded DNA and associated DNA polymerase enzyme.

Dane particle

A viral antigen present on the surface of Hepatitis B virus, used as a marker for active disease and highly infectious state.

Hepatitis B surface antigen (HBsAg)

A viral antigen found in the core of Hepatitis B virus, used to understand the duration of infection.

Hepatitis B core antigen (HBcAg)

A long-lasting inflammation of the liver caused by Hepatitis B virus, which can be asymptomatic, chronic persistent, chronic active, or co-infection with hepatitis delta virus (HDV).

Chronic hepatitis

A method of prevention and control of Hepatitis B infection through the administration of a recombinant vaccine containing HBsAg.

Active immunization

Medications used for the treatment of chronic active or persistent HBV infection, including lamivudine and interferon alpha.

Anti-viral agents

A family of RNA viruses that includes Norovirus (gastroenteritis).

Caliciviridae

A family of RNA viruses that includes Astrovirus (gastroenteritis).

Astroviridae

A family of RNA viruses that includes Hepevirus (hepatitis E).

Hepeviridae

A family of RNA viruses that includes Alphavirus (encephalitis) and Rubivirus (rubella).

Togaviridae

A family of RNA viruses that includes Flavivirus (yellow fever), Japanese encephalitis virus (encephalitis), and Hepacivirus (hepatitis C).

Flaviviridae

A family of RNA viruses that includes Coronavirus (common cold, severe acute respiratory syndrome).

Coronaviridae

A family of RNA viruses that includes Human T cell leukemia virus (leukemia) and Lentivirus (AIDS).

Retroviridae

A family of RNA viruses that includes Influenzavirus (flu).

Orthomyxoviridae

A family of RNA viruses that includes Lyssavirus (rabies).

Rhabdoviridae

A family of RNA viruses that includes Bunyavirus (California encephalitis virus) and Hantavirus (pneumonia).

Bunyaviridae

A family of RNA viruses that includes Filovirus (Ebola hemorrhagic fever) and Marburg virus (hemorrhagic fever).

Filoviridae

A family of RNA viruses that includes Lassavirus (hemorrhagic fever).

Arenaviridae

A family of double-stranded RNA viruses that includes Orbivirus (encephalitis), Rotavirus (diarrhea), and Coltivirus (Colorado tick fever).

Reoviridae

RNA that is equivalent to mRNA and can be directly translated by ribosomes.

Positive-sense (+RNA)

RNA that is complementary to mRNA and cannot be directly translated.

Negative-sense (RNA)

A family of RNA viruses that includes Influenza virus, which causes flu and pneumonia.

Orthomyxoviridae

A protein found on the surface of Influenza virus that can attach to host sialic acid receptors, causing heme-agglutination reaction.

Hemagglutinin (HA)

A protein found on the surface of Influenza virus that cleaves neuraminic acid and disrupts the mucin barrier.

Neuraminidase (NA)

Mutation that occurs during viral replication, leading to changes in the antigenic nature of glycoproteins such as HA and NA.

Antigenic drift

Complete change of HA and NA or both, which can occur with Influenza type A and involves the trading of RNA segment between animal and humans.

Antigenic shift

Influenza A virus that infects birds and can cause severe pneumonia and death in humans.

Avian influenza

Vaccines are given to prevent outbreaks, especially in elderly, immunocompromised patients, and healthcare providers.

Control of Influenza

A family of RNA viruses that includes Parainfluenza virus, Respiratory syncytial virus, Mumps virus, and Measles virus.

Paramyxoviridae

A protein found in Paramyxoviridae that causes infected host cells to fuse together into multinucleated giant cells.

Fusion protein (F)