Lecture 8 - Medically Important Virus 1

It is a method used to grow viruses by inoculating them into the embryonic tissues of a chick, allowing for the replication and study of the virus.

An Envelope is a lipid layer that surrounds some viruses, containing part of the host's protein and derived from the nuclear or cytoplasmic membrane of the host. It is sensitive to ether and bile and features spikes or projections of viral origin.

The cold chain refers to the process of transporting specimens in a temperature-controlled environment, typically using ice, to preserve the viability of viruses for isolation.

Ingestion is a mode of transmission where viruses are introduced into the body through the consumption of contaminated food or water.

Viral Transport Medium is a solution used to preserve and transport viral specimens, ensuring the viability of viruses during transport to a laboratory for testing.

The process of safely moving biological samples from one location to another for testing or analysis, ensuring that the integrity and viability of the specimens are maintained during transit.

Viral transport medium (VTM) is a specialized solution used to preserve viral specimens during transportation, ensuring the stability and viability of the viruses for subsequent testing.

Viroids are single molecules of circular RNA that lack a protein coat or envelope and are known to cause diseases in plants.

Polio viruses, Hepatitis A virus (HAV), Hepatitis E virus (HEV), and Reo/Rota viruses are transmitted through ingestion.

Antiviral chemotherapy is a treatment that selectively inhibits viral function without damaging the host.

The nucleic acid in viruses can be either DNA or RNA, and it can be single-stranded or double-stranded.

A cytoplasmic inclusion body caused by rabies virus in brain tissue is known as a Negri body, which is a characteristic histopathological finding in rabies infection.

A virus is a very small infectious agent that can infect bacteria and other living cells, often damaging the host cell.

Cubic symmetry is a type of viral structure characterized by a symmetrical arrangement of protein subunits that form a cube-like shape, commonly seen in many viruses.

The target of antiviral drugs is the stage of viral replication.

Helical Symmetry refers to the structural arrangement of viral capsids where the protein subunits are arranged in a spiral or helical formation around the viral nucleic acid. An example of a virus exhibiting helical symmetry is the Rabies virus.

Enveloped viruses are viruses that have an outer lipid membrane, derived from the host cell membrane, which surrounds their protein coat (capsid). This envelope is crucial for the virus's ability to infect host cells.

The stages of maturation of an enveloped virus include assembly of viral components, budding from the host cell membrane, and acquisition of the viral envelope.

Changes in host cells caused by viral infections can be seen using a microscope.

Capsid proteins in viruses can be classified as cubic, helical, or complex.

Adenovirus is a type of virus that can cause a range of illnesses, including respiratory infections, conjunctivitis, and gastroenteritis, and is known for its cubic symmetry.

AZT is the antiviral drug used for the treatment of HIV.

A capsid is a protein shell that encases and protects the viral nucleic acid, serving as a structural component of the virus.

Complex structure refers to a type of viral architecture that is more intricate than simple helical or icosahedral forms, exemplified by the pox virus.

Acyclovir is the antiviral drug used for the treatment of Herpes.

When some viruses lyse the host cell, they cause the cell to break open, releasing new viral particles into the surrounding environment.

The envelope in viruses can be present or absent and may contain glycoprotein spikes that aid in attachment to host cells.

HIV can be transmitted through transfusion, sexual contact, and from mother to child.

A naked virus is a type of virus that lacks an envelope and consists only of a capsid and nucleic acid.

Polio virus is an enterovirus that causes poliomyelitis, a highly infectious disease that can lead to paralysis, and is characterized by its icosahedral shape.

Oseltamivir is the antiviral drug used for the treatment of Influenza.

Pox virus is an example of a virus that has a complex structure.

HBV can be transmitted through transfusion, sexual contact, and from mother to child.

Prions are proteinaceous infectious agents that contain only protein and no nucleic acid, causing slow diseases in animals and humans.

An obligate intracellular parasite is an organism that can only reproduce within the living cells of a host, such as viruses.

The process of viral replication involves the production of millions of copies of viruses that exit the host cell through budding or lysis.

No, chicken pox is caused by the herpes virus, not the pox virus.

HCV can be transmitted through transfusion, sexual contact, and from mother to child.

Vertical transmission refers to the transfer of a virus from mother to child, which can occur during pregnancy, childbirth, or breastfeeding. Examples include HIV, HBV, CMV, and Rubella.

Hepatitis B infection is a viral infection that attacks the liver, potentially leading to chronic liver disease, cirrhosis, and liver cancer.

Normal proteins convert to pathogenic prion forms due to post-translational modification.

Viruses cannot grow in cell-free media because they require a living host cell to replicate and carry out their life cycle.

A viral vaccine is a preparation used to stimulate the body's immune response against viral infections, providing immunoprophylaxis.

During replication, the virus copies itself from one to many, resulting in a significant increase in viral particles.

CMV can be transmitted through transfusion, sexual contact, and from mother to child.

Vector-borne viral infections are diseases transmitted to humans through the bite of infected arthropods, such as mosquitoes. Examples include dengue, yellow fever, and Japanese B encephalitis (JBE).

Chronic Hepatitis B infection can lead to cirrhosis, liver cancer, and can ultimately result in death.

Prions cause slow diseases characterized by a long incubation period, primarily affecting the brain and are often fatal.

HIV is primarily transmitted through sexual contact, as well as through blood and from mother to child during childbirth or breastfeeding.

A killed vaccine is made from viruses that have been inactivated or killed, such as the rabies vaccine and the Salk polio vaccine (IPV).

Lysis refers to the destruction and death of host cells caused by viruses, resulting in a cytopathic effect (CPE), as seen with polioviruses that destroy anterior horn cells.

Viruses can be cultivated in living animals, developing chick embryos, and tissue or cell cultures.

'Blocking not binding' refers to the mechanism by which certain antiviral strategies prevent the virus from attaching to or entering the host cell, rather than interfering with the binding process itself.

A host is an organism, such as a human, animal, plant, or bacteria, that can be infected by a virus.

An enveloped virus is a type of virus that has an outer lipid membrane, which is derived from the host cell membrane, and contains glycoprotein spikes that facilitate attachment to host cells.

Inhalation is the primary mode of transmission for the Influenza virus.

A complete infectious virus particle.

Hepatitis B can integrate into the host's liver cells, allowing the virus to persist in the body indefinitely, which can lead to reactivation.

Zoonotic viral infections are diseases that are transmitted from animals to humans. Examples include rabies and Middle East Respiratory Syndrome (MERS).

A preventive treatment administered after potential exposure to a pathogen to reduce the risk of infection.

A defective virus is functionally deficient in some aspect of replication and requires the help of another virus to infect host cells.

The incubation period is the time from the point of infection to when symptoms start to appear.

A live attenuated vaccine contains live viruses that have been weakened so they cannot cause disease, such as the Sabin polio vaccine (OPV) and the MMR vaccine.

Immuno-pathogenesis refers to the immune response causing damage to liver cells in hepatitis B infections, despite the absence of a cytopathic effect (CPE) on those cells.

Using a fertilized egg for virus culture is considered tricky due to the complexities involved in handling and maintaining the embryo for viral growth.

Surface proteins are responsible for attachment to host cell receptors, determining tissue specificity and host specificity.

HBV is transmitted through sexual contact, exposure to infected blood, and from mother to child during childbirth.

Taking out the viral coat is crucial for the release of viral genomic materials, allowing the virus to replicate and assemble new viral particles.

Neurotropic viruses are viruses that have a preference for infecting nervous tissue, examples include Rabies and polioviruses.

Surface proteins are responsible for attachment to host cell receptors, influencing tissue specificity and host specificity, which are critical for pathogenesis.

Inhalation is the primary mode of transmission for the Measles virus.

The envelope protects the viral capsid and nucleic acid, and aids in the virus's ability to infect host cells.

A structure consisting of the viral nucleic acid and the protein coat, found in viruses such as adenoviruses and polioviruses.

Clinical features can include eye diseases at delivery, cataracts in newborns, learning difficulties, low IQ, and congenital heart disease.

A preparation of antibodies used to provide immediate passive immunity against Hepatitis B virus after exposure.

The hiding period refers to the time during which the virus remains dormant in the liver cells before potentially reactivating.

Parvoviruses are a group of small, single-stranded DNA viruses that are unique among DNA viruses as they are not double-stranded.

Mad cow disease is a prion disease that can be transmitted from animals to humans.

The helper virus provides the necessary functions that the defective virus lacks, allowing it to replicate and infect host cells.

A recombinant vaccine is produced using recombinant DNA technology, such as the Hepatitis B vaccine.

No, viruses cannot be cultured in blood culture as this medium is specifically designed for bacteria.

HSV 2 is primarily transmitted through sexual contact, particularly through genital contact.

Transformation is the process by which certain viruses, such as human papillomaviruses and hepatitis B, can lead to cancer and malignancy, including genital cancers and hepatocellular carcinoma.

Hepatotropic viruses are viruses that primarily infect liver tissue, including Hepatitis A virus (HAV), Hepatitis B virus (HBV), Hepatitis C virus (HCV), Hepatitis D virus (HDV), and Hepatitis E virus (HEV).

Inhalation is the primary mode of transmission for the Mumps virus.

Nucleic acid can be detected by PCR or RT-PCR, which can be qualitative or quantitative, aiding in the diagnosis of viral infections.

Viruses are composed of genetic material (either DNA or RNA) encased in a protein coat called a capsid, and some have an outer lipid envelope.

A technique used to visualize viral particles or infected cells under a microscope after applying specific stains.

The structure of viruses typically includes a core of genetic material (either DNA or RNA) surrounded by a protein coat called a capsid, and in some cases, an outer lipid envelope.

Glycoprotein spikes are protein structures on the surface of enveloped viruses, such as HIV and COVID, that allow the virus to adhere to and enter host cells.

Herpes viruses and orthomyxoviruses.

A method used to visualize viruses in samples by applying stains and examining them under a microscope.

An antibody preparation used in conjunction with rabies vaccination to provide immediate protection against rabies after exposure.

Horizontal transmission refers to the spread of viruses between individuals through direct or indirect contact, such as sneezing, as seen in COVID-19.

The process by which a virus causes disease in a host, including entry, replication, spread, and effects on the host.

Viruses are small infectious agents that are obligate intracellular parasites, ranging in size from 30 to 300 nm in diameter. They contain one kind of nucleic acid (RNA or DNA) encased in a protein coat called a capsid, which may be surrounded by a lipid-containing membrane known as an envelope in some viruses.

All RNA viruses are typically single-stranded, except for reoviruses and rotaviruses, which are double-stranded.

Hepatitis D Virus (HDV) is an example of a defective virus that requires Hepatitis B Virus (HBV) as a helper virus for replication.

Viruses can be classified based on whether they contain DNA or RNA as their genetic material, and whether it is single-stranded or double-stranded.

A bacteriophage is a type of virus that specifically infects bacteria.

HPV is transmitted through direct skin-to-skin contact during sexual activity.

Inhalation is the primary mode of transmission for the Rubella virus.

Serological tests can detect capsid proteins, envelope proteins, or surface glycoprotein spikes, which are important for diagnosis.

Viruses are classified based on various criteria including their type of genetic material, shape, size, and mode of replication.

Viruses are classified based on their type of nucleic acid, symmetry of their capsid, presence or absence of an envelope, and their mode of replication.

It can cause infection.

The process of growing viruses in controlled environments using host cells to identify and isolate the virus.

Viruses can have either DNA or RNA as their genetic material, but they do not possess both simultaneously.

A technique that involves growing viruses in controlled environments to identify and study them.

The initial phase where a virus enters the host and begins to replicate within cells.

Blood serum containing antibodies against specific antigens, used for immunotherapy to provide passive immunity.

Obligate intracellular parasites are organisms that cannot reproduce outside of a host cell and rely on the host's cellular machinery for replication and survival.

PCR (Polymerase Chain Reaction) is used to detect nucleic acids in viruses, allowing for both qualitative and quantitative analysis.

Reverse transcriptase is an enzyme that allows RNA to be transcribed back into DNA, a characteristic feature of retroviruses.

The morphology of the protein capsid refers to the shape and structure of the protein shell that encases the viral genome, which can be icosahedral, helical, or complex.

The Hepatitis B vaccine can provide immunity to Hepatitis B, which in turn prevents the replication of Hepatitis D, as HDV cannot replicate without HBV.

Inhalation is the primary mode of transmission for SARS CoV.

Viral proteins are often targeted for antiviral therapy, which aims to inhibit viral replication and spread.

The 4 F's refer to food, finger, fly, and feces, which are key factors in preventing foodborne viral diseases such as polio, rotavirus, norovirus, HAV, and HEV.

Viruses can be transmitted through various modes including direct contact, respiratory droplets, vector-borne transmission, and contaminated surfaces.

A method used to identify viral proteins in a sample, indicating the presence of a virus.

Modes of transmission for viruses include direct contact, airborne transmission, vector-borne transmission, and fomite transmission.

Smeared, staining, and microscopy are techniques used to visualize viral particles or infected cells, aiding in the identification of viral infections.

Viruses that have DNA as their genetic material, which can be either single-stranded (ssDNA) or double-stranded (dsDNA).

A method used to identify viral proteins in a sample, indicating the presence of a virus.

The capsid is a protein shell that encases and protects the viral nucleic acid, playing a crucial role in the virus's structure and function.

The dissemination of the virus throughout the host and its preference for infecting specific cell types.

Antigens that can trigger an immune response, potentially leading to the production of antibodies.

Viruses typically range in size from 30 to 300 nanometers in diameter.

Serological tests can detect capsid proteins, envelope proteins, or surface glycoprotein spikes.

The central dogma describes the flow of genetic information from DNA to RNA to protein.

Modes of transmission for viruses include direct contact, respiratory droplets, vector-borne transmission, and fomites.

Viral proteins can be used as vaccine antigens, helping to stimulate an immune response and prevent viral infections.

Viral replication involves attachment to a host cell, entry, uncoating, replication of viral nucleic acid, assembly of new virions, and release from the host cell.

Sterilization and disinfection are crucial for preventing the transmission of viruses such as HIV, HBV, and HCV.

Replication of viruses involves the attachment to a host cell, entry, uncoating, replication of viral genetic material, assembly of new virions, and release from the host cell.

DNA viruses that have a lipid membrane surrounding their capsid, which can help them evade the host's immune system.

A diagnostic method that identifies antibodies produced by the immune system in response to a viral infection.

Culture involves growing viruses in controlled laboratory conditions to isolate and identify them, which is crucial for diagnosis.

The damage caused to host cells by the virus, leading to symptoms and disease manifestations.

A technique that measures the immune response to a virus by detecting specific antibodies in the patient's serum.

To neutralize the rabies virus and prevent the onset of the disease after exposure.

A capsid is a protein coat that encases the nucleic acid of a virus, providing protection and aiding in the delivery of the viral genome into host cells.

Viral proteins can be used as vaccine antigens, providing a target for immune response.

A protein capsid is a protective protein shell that encases the viral genome, providing structural integrity and facilitating the delivery of the viral genetic material into host cells.

Host tissue and cell tropisms refer to the specific types of cells and tissues that a virus can infect, which is determined by the virus's ability to attach to and enter those cells.

Hepatitis viruses and HIV are examples of viruses that possess reverse transcriptase, allowing them to convert RNA into DNA.

Pathogenesis refers to the mechanisms by which viruses cause disease, including cell damage, immune response evasion, and the effects of viral replication on host tissues.

Pathogenesis of viral infections refers to the mechanisms by which viruses cause disease, including cell damage, immune response evasion, and the resulting clinical manifestations.

Condoms are effective in preventing sexually transmitted infections (STIs) such as HIV, HBV, HSV-2, and HPV.

Antigen detection is a method used to identify viral proteins in a sample, indicating the presence of a virus.

A method that identifies viral genetic material (DNA or RNA) in a sample, often using techniques like PCR.

DNA viruses that lack a lipid membrane, making them generally more resistant to environmental conditions.

The process by which the host's immune system eliminates the virus and restores health.

A technique used to identify the genetic material of a virus, such as DNA or RNA, in a sample.

The three types of symmetry in viruses are cubical (icosahedral) symmetry, helical symmetry, and complex symmetry.

Symptomatology refers to the study and classification of symptoms associated with viral infections, which can vary widely depending on the virus and the host.

The viral envelope, which is a lipid-containing membrane surrounding some viruses, plays a role in protecting the virus and facilitating entry into host cells.

Narrow host range viruses, like chickenpox and smallpox, infect specific hosts, while wide host range viruses, like influenza, can infect a variety of hosts including humans and animals.

Laboratory diagnosis of viral infections typically includes techniques such as PCR, serology, viral culture, and antigen detection.

Laboratory diagnosis of viral infections typically involves techniques such as PCR, serology, and viral culture to detect the presence of the virus or the immune response to it.

Health education is essential for raising awareness and promoting preventive measures against all viral infections.

Antibody detection is a method used to identify antibodies produced in response to a viral infection, indicating past or current infection.

A family of large, complex, enveloped DNA viruses known for causing diseases such as smallpox.

The release of virus particles from an infected host, which can lead to transmission to other individuals.

Malaria is not classified as a viral disease because it is caused by protozoan parasites of the genus Plasmodium, not by viruses.

Cubical (icosahedral) symmetry is a type of viral structure characterized by a spherical shape composed of equilateral triangles, forming a symmetrical arrangement.

PCR machines cannot detect RNA viruses directly; instead, RT-PCR (Reverse Transcription PCR) is used for RNA viruses.

It indicates that the available diagnostic methods may not be comprehensive and often require specific samples like tissue or cells.

Treatment of viral infections may include antiviral medications, supportive care, and in some cases, vaccines for prevention.

Immunoprophylaxis refers to the use of vaccines to prevent viral infections.

Viruses that have a lipid membrane surrounding their capsid, which can affect their transmission and stability.

Treatment, prevention, and control of viral infections may include antiviral medications, vaccines, public health measures, and hygiene practices to reduce transmission.

Nucleic acid detection involves using techniques like PCR to identify viral genetic material, allowing for precise diagnosis of viral infections.

A family of enveloped DNA viruses that cause infections such as herpes simplex and varicella-zoster.

Helical symmetry refers to a viral structure where the protein subunits are arranged in a spiral around the viral nucleic acid, forming a rod-like shape.

An inflammation of the liver often caused by viral infections, leading to liver dysfunction.

Chemoprophylaxis involves the use of antiviral drugs to prevent viral infections.

Prevention and control measures include vaccination, good hygiene practices, isolation of infected individuals, and public health interventions.

Single-stranded RNA, a type of viral genomic material that can be either positive or negative sense.

Quantitative viral load measurement assesses the amount of virus present in a sample, which can inform treatment decisions and disease progression.

A family of enveloped DNA viruses that primarily infect the liver, including Hepatitis B virus.

It refers to the occurrence of viral infections without a known cause or predisposing factor, often arising unexpectedly.

Complex symmetry is a type of viral structure that does not fit into the categories of icosahedral or helical symmetry, often featuring a combination of both or additional structures.

Immunotherapy involves the use of immunoglobulin or antibodies to treat or prevent viral infections.

Positive-sense single-stranded RNA that can be directly translated into proteins by the host cell's ribosomes.

The presence of antibodies and absence of antigens typically indicates a past infection or successful immune response, while the presence of antigens suggests an active infection.

Nonenveloped DNA viruses that can cause respiratory infections and conjunctivitis.

Enveloped viruses are considered fragile because their lipid membrane can be easily disrupted by environmental factors, making them sensitive to heat, detergents, and acids.

Double-stranded RNA, a type of viral genomic material that consists of two complementary strands.

Nonenveloped DNA viruses that are known to cause warts and are associated with cervical cancer.

Naked viruses are more resistant because they lack a lipid envelope, making them less susceptible to environmental factors such as heat and acids.

Viruses that have their RNA genome divided into separate segments, allowing for genetic reassortment.

Nonenveloped DNA viruses that can cause diseases in immunocompromised individuals, such as JC virus.

There is currently no vaccine available for Hepatitis E.

A family of small, non-enveloped viruses that contain positive-sense single-stranded RNA.

Small, nonenveloped DNA viruses that can cause infections like fifth disease in children.

A family of non-enveloped viruses that contain positive-sense single-stranded RNA and are associated with gastroenteritis.

A viral infection caused by Hepadnavirus that affects the liver and can lead to chronic disease.

A family of segmented double-stranded RNA viruses that are non-enveloped and can cause respiratory and gastrointestinal infections.