LE 6 Flashcards

Question

The herpes virus transmitted thru bites of old world monkeys or macaques A. B Virus B. Adenovirus C. HIV D. Influenza virus

Answer 1

A. B Virus

Answer 2

C. Alpha interferon

Answer 3

D. Herpesvirus

Answer 4

a. Rotavirus

Answer 5

a. DNA integration

Answer 6

a. Reovirus Reoviridae Rotavirus Birnaviridae

Answer 7

a. Cytomegalovirus

Answer 8

c. The diagnosis is usually made by isolating the virus in a cell culture

Answer 9

c. Enteroviruses

Answer 10

d. All of the choices are correct

Answer 11

c. Coxsackie B

Answer 12

b. Polioviruses

Answer 13

A. Genetic reassortment amongst 8 genes The influenza virus is known for its segmented genome, which allows for genetic reassortment among its 8 RNA segments. This process contributes to the emergence of new viral strains and is a significant factor in the virus's ability to cause pandemics.

Answer 14

a. Single-stranded RNA

Answer 15

b. Vaccination

Answer 16

b. rotavirus Here are the primary families of dsRNA viruses known to have segmented genomes: Reoviridae: This family includes rotaviruses, which are a common cause of acute gastroenteritis in children, as well as orbiviruses and coltiviruses, which can cause disease in animals and sometimes humans. Members of this family infect a wide range of hosts, including humans, animals, plants, and insects. Birnaviridae: This family includes viruses such as Infectious bursal disease virus (IBDV) that affects chickens, and Infectious pancreatic necrosis virus (IPNV) that affects fish. These viruses typically have a bipartite (two-segment) genome.

Answer 17

a. Picornavirus Icosahedral Naked Resistant ● Picornaviridae ● Astroviridae ● Caliciviridae ● Reoviridae

Answer 18

c. Henipavirus

Answer 19

a. Parainfluenza virus

Answer 20

c. Adenoviruses dsDNA viruses Poxviridae Asfaviridae Iridoviridae Herpesviridae Adenoviridae Polyomaviridae Papillomaviridae

Answer 21

a. F. glycoprotein

Answer 22

c. Household bleach

Answer 23

c. Progressive multifocal leukoencephalopathy

Answer 24

d. Dead relatives

Answer 25

a. Bunyavirus (Hantavirus)

Answer 26

a. Togavirus

Answer 27

a. Arenaviridae

Answer 28

c. Paramyxovirus

Answer 29

d. Adenovirus

Answer 30

c. Retroviruses DNA TUMOR VIRUSES ● Polyomavirus ● Papillomavirus ● Poxviruses ● Adenovirus ● Herpesviruses

Answer 31

a. Congenital heart disease

Answer 32

a. picornavirus

Answer 33

a. picornavirus

Answer 34

d. reovirus

Answer 35

a. EB virus

Answer 36

b. parvovirus

Answer 37

a. Transmitted by arthropods Rubella, also known as German measles or three-day measles, is not transmitted by arthropods but rather through respiratory droplets.

Answer 38

a. EB Virus

Answer 39

b. Human Papillomavirus

Answer 40

c. Rubella virus

Answer 41

c. Cancer producing viruses

Answer 42

a. EB virus

Answer 43

b. Human papillomavirus

Answer 44

a. EB virus

Answer 45

d. HTL virus

Answer 46

b. Retroviridae

Answer 47

a. Flaviviridae

Answer 48

b. Retroviridae

Answer 49

a. Flaviviridae

Answer 50

a. Viruses are always complete carcinogen

Answer 51

a. Enveloped symmetrical RNA virus

Answer 52

D. All of the choices are correct A viral capsid provides binding sites that enable the virus to attach to specific receptor sites on the host cell, serves as a vehicle of transmission from one host to another, and protects the viral genome from physical and enzymatic destruction.

Answer 53

A. HSV 1 Herpes Simplex Virus 1 (HSV-1) is known to establish latency in the trigeminal ganglia after the primary infection.

Answer 54

B. Viral Hepatitis A Hepatitis A virus (HAV) is predominantly transmitted through the oral-fecal route, typically through ingestion of contaminated food or water.

Answer 55

b. HHV6 Human Herpesvirus 6 (HHV-6) is the primary cause of exanthema subitum (also known as roseola infantum), a common childhood disease characterized by a high fever followed by a rash.

Answer 56

b. primary cell culture is the best cell culture systems available since they support the widest range of viruses

Answer 57

A. Genome and Capsid The nucleocapsid is the combination of the viral genome (DNA or RNA) and the capsid, which is the protein coat that encases the genome.

Answer 58

A. Many viral infections are subclinical and do not produce clinical disease Many viral infections do not result in clinical disease and can be subclinical, meaning they do not show symptoms. This is a fundamental aspect of viral pathogenesis.

Answer 59

A. None of the choices is correct HSV-1 and HSV-2 (Herpes Simplex Virus types 1 and 2) are primarily transmitted between humans and do not have animal vectors in their transmission cycle.

Answer 60

B. Absence or slight increase in IgM

Answer 61

a. all of the choices are correct

Answer 62

A. Lymphoid tissue

Answer 63

D. Their genome RNA can be translated directly as mRNA

Answer 64

C. All of the choices are correct

Answer 65

d. Viral hepatitis A

Answer 66

C. Anti-HBs

Answer 67

C. All of the choices are correct

Answer 68

C. B Virus B Virus, also known as Herpesvirus simiae or Cercopithecine herpesvirus 1, is transmitted to humans primarily through bites and scratches from macaques, a type of Old World monkey.

Answer 69

D. Influenza virus

Answer 70

A. 300 nm - 1 um Ultramicroscopic size (20nm-450nm) diameter

Answer 71

B. Both choices are correct

Answer 72

A. Viral hepatitis C

Answer 73

E. None of the choices are correct

Answer 74

B. corrected by Pat. D. kasi nakalagay.

Answer 75

c. Alpha Interferon

Answer 76

c. infect female of chinese origin Nasopharyngeal carcinoma (NPC) is not specific to females of Chinese origin; it has a higher incidence in certain geographic regions, including Southeast Asia and North Africa, and affects both males and females. While there is a notable prevalence among individuals of Chinese (particularly Southern Chinese) origin, the statement as phrased suggests a specificity that is not accurate. NPC is associated with Epstein-Barr Virus (EBV) infection across various demographics, not just Chinese females.

Answer 77

C. Roughly spherical

Answer 78

C. Both choices are correct

Answer 79

D. Both Hep B & C

Answer 80

A. Human herpes virus 8

Answer 81

D. Rhinoviruses

Answer 82

D. Herpesvirus

Answer 83

B. Viral Hepatitis C

Answer 84

D. All of the choices are correct

Answer 85

D. Neurons Herpes Simplex Virus 1 (HSV-1) primarily targets neurons, where it can establish latency, particularly in sensory ganglia such as the trigeminal ganglia.

Answer 86

A. Both hepatitis C and D

Answer 87

A. Via scratches and breaks in the skin Human papillomavirus (HPV) infections most commonly occur through direct contact, often via minor scratches or breaks in the skin, allowing the virus to infect the epithelial tissues.

Answer 88

D. Lysozyme Virions, which are complete virus particles, do not contain lysozyme, an enzyme that breaks down the cell walls of bacteria. Viruses rely on host cell machinery for replication and do not use lysozyme in their life cycle.

Answer 89

D. Are active both inside and outside of host cells Viruses are not active outside of host cells. They are obligate intracellular parasites, meaning they can only replicate and perform their life cycle functions within a host cell.

Answer 90

B. Lymphoid Tissue Kaposi's Sarcoma-associated herpesvirus (KSHV), also known as Human Herpesvirus 8 (HHV-8), primarily targets lymphoid tissue and is associated with several types of cancers, including Kaposi's Sarcoma, which affects the skin and other organs.

Answer 91

D. All of the choices are correct

Answer 92

B. anti-HBc

Answer 93

b. BCG vaccine

Answer 94

d. only certain cells are susceptible to viral infections

Answer 95

E. viral m RNA, viral t RNA, and viral ribosomes are used in viral replication.

Answer 96

C. B lymphocytes

Answer 97

b. a cytokine storm

Answer 98

B. Viral genome detection

Answer 99

e from DNA to RNA to protein

Answer 100

C. Viral hepatitis B

Answer 101

E. Virus do not possess the necessary components for self-replication

Answer 102

b kaposi sarcoma

Answer 103

A. Some viruses with broad host ranges can multiply in many types of cells

Answer 104

C. Light microscopy

Answer 105

C. Herpesviruses

Answer 106

A. viral hepatitis

Answer 107

A. Polymerase chain reaction

Answer 108

a. Papillomavirus Papillomavirus, specifically Human Papillomavirus (HPV), can enter the body through small abrasions in the skin, leading to infections that may result in warts or, in some cases, cancers.

Answer 109

d. virus nucleocapsids are either icosahedral or helical Viruses exhibit a variety of geometric structures in their nucleocapsids, with the most common shapes being icosahedral and helical. This diversity allows for a wide range of virus sizes and properties, accommodating their different modes of infection and replication.

Answer 110

A. all of the choices are correct This statement is incorrect as presented because all the options listed (B, C, D, E) represent nucleic acid types that can be found in viruses. Viruses can have circular single-stranded RNA, linear double-stranded DNA, circular double-stranded DNA, and linear single-stranded RNA.

Answer 111

D. adsorption The first step in the infection of a host bacterial cell by a bacteriophage (phage) is adsorption, where the phage attaches to specific receptors on the surface of the bacterial cell.

Answer 112

d. virus nucleocapsids are either icosahedral or helical Viruses exhibit a variety of geometric structures in their nucleocapsids, with the most common shapes being icosahedral and helical.

Answer 113

C. Chemistry of the DNA and RNA The most important factor for virus classification is the chemistry of the nucleic acid (DNA or RNA), including its structure (single-stranded or double-stranded), and whether it is linear, circular, or segmented.

Answer 114

c. Administration of human IgM prepared from plasma pools obtained from healthy persons with high titers of CMV The administration of human IgM for CMV control is not a standard practice. Control measures typically include screening of transplant donors and recipients for CMV antibodies, development of vaccines, and isolation of infected newborns, but not the administration of human IgM in the manner described.

Answer 115

B. Naked viruses Naked viruses, which lack an envelope, are generally more resistant to environmental stresses such as acid and bile in the enteric tract. This resilience facilitates their spread, especially via the fecal-oral route.

Answer 116

B. Delta agent

Answer 117

B. VIral hepatitis B

Answer 118

A. Both hepatitis A and B

Answer 119

D. Varicella-Zoster virus Varicella-Zoster virus, which causes chickenpox and shingles, has not been strongly associated with human cancer, unlike the other viruses listed, which have associations with various forms of cancer.

Answer 120

A. Viral Hepatitis D Viral Hepatitis D (HDV), especially when co-infecting with Hepatitis B Virus (HBV), is known to have a higher mortality rate compared to infections with HBV, HCV (Hepatitis C Virus), or HAV (Hepatitis A Virus) alone. HDV infection can lead to more severe liver disease, including fulminant hepatitis and a higher risk of developing cirrhosis and liver cancer.

Answer 121

A. Induces apoptosis via caspases

Answer 122

B. Acyclovir

Answer 123

c. virus replication happens in intracellular level

Answer 124

D. Lysogeny

Answer 125

D. Solid phase immune electron microscopy (SPIEM)

Answer 126

B. Uncoating is necessary

Answer 127

B. Lymphoid tissue

Answer 128

A.Presence and type of envelope

Answer 129

A. Viral hepatitis A

Answer 130

A. Viral hepatitis A

Answer 131

A. The disease is multisystemic Prion diseases are primarily neurodegenerative and are confined to the nervous system rather than being multisystemic.

Answer 132

a. Transmitted by arthropods Rubella is not transmitted by arthropods; it is spread through respiratory droplets.

Answer 133

d. subacute sclerosing panencephalitis Subacute sclerosing panencephalitis (SSPE) is a rare and chronic form of progressive brain inflammation caused by a persistent infection with a mutated form of the measles virus.

Answer 134

A. EB virus Epstein-Barr virus (EBV) is associated with Burkitt's lymphoma, especially in endemic areas.

Answer 135

A. Picornavirus Poliovirus is a member of the Picornaviridae family.

Answer 136

C. Eating the brain of dead relatives Kuru was transmitted among the Fore people of Papua New Guinea through ritualistic cannibalism, specifically the consumption of the brains of dead relatives.

Answer 137

A. Bunyavirus Hantaviruses, which are part of the Bunyaviridae family, are transmitted to humans through aerosolized virus from rodent urine, droppings, or saliva.

Answer 138

A. detection of virus antigens Immunofluorescence and immunoperoxidase techniques are used for the detection of virus antigens in samples.

Answer 139

D. Flavivirus Japanese encephalitis virus is a member of the Flavivirus genus.

Answer 140

B. Human Papillomavirus Human Papillomavirus (HPV) is strongly associated with the development of genital squamous cell carcinoma.

Answer 141

A. Picornavirus Picornaviruses are naked, ether-resistant, and have icosahedral symmetry.

Answer 142

A. Infection does not kill cells Retroviruses can indeed kill cells, particularly when they are cytocidal. While some retroviruses are associated with tumor formation and can integrate into the host genome (potentially activating or transducing cellular oncogenes), not all retroviruses are non-cytocidal. The statement "Infection does not kill cells" does not fully represent the diversity of retroviral infections, as some can lead to cell death, contradicting the provided context.

Answer 143

A. These are conventional infectious agents Prions are unconventional infectious agents, known for causing degenerative CNS diseases and transmissible spongiform encephalopathies.

Answer 144

A. Picornavirus Picornaviruses are naked RNA viruses.

Answer 145

B. Togavirus The causative agent of German measles (Rubella) belongs to the Togaviridae family.

Answer 146

D. Reovirus Reoviruses are naked, icosahedral RNA viruses.

Answer 147

A. Progressive multifocal leukoencephalopathy Progressive multifocal leukoencephalopathy (PML) is associated with the JC Polyomavirus.

Answer 148

A. Creutzfeldt-Jakob disease Creutzfeldt-Jakob disease (CJD) is characterized by rapid neurodegeneration, leading to severe dementia, ataxia, and myoclonus, usually resulting in death within a year.

Answer 149

A. Hepadnaviridae The Hepadnaviridae family, particularly the Hepatitis B virus, is associated with hepatocellular carcinoma.

Answer 150

A. Arenaviridae Lassa fever is caused by the Lassa virus, which belongs to the Arenaviridae family.

Answer 151

B. Rhabdovirus Rationale: The clinical presentation of difficulty swallowing (dysphagia), agitation, and a history of being bitten by a dog suggests rabies. The causative agent of rabies is the Rabies virus, which belongs to the Rhabdoviridae family, thus making Rhabdovirus the correct answer.

Answer 152

D. Months to decades Rationale: Prion diseases, also known as transmissible spongiform encephalopathies (TSEs), have a prolonged incubation period that can range from months to decades before symptoms appear. This long latency period is characteristic of prion diseases.

Answer 153

A. EB virus Rationale: Nasopharyngeal carcinoma is strongly associated with the Epstein-Barr virus (EBV), which is a member of the herpesvirus family. EBV infection is a major risk factor for developing this type of cancer.

Answer 154

D. ether sensitive Rationale: The Rubella virus (Togaviridae) , which causes rubella (German measles), is an enveloped virus that is sensitive to ether. This property is due to the lipid envelope that surrounds the virus, which can be disrupted by ether.

Answer 155

D. Flavivirus Rationale: The clinical presentation suggests a severe febrile illness with hematologic abnormalities, which could be indicative of dengue fever, caused by the Dengue virus. The Dengue virus belongs to the Flaviviridae family, making Flavivirus the correct answer.

Answer 156

C. Household bleach Rationale: Prions are extremely resistant to conventional methods of inactivation. However, certain protocols including the use of household bleach (sodium hypochlorite) at a specific concentration have been shown to be effective in deactivating prions.

Answer 157

A. togavirus Rationale: Togaviruses are enveloped viruses that are sensitive to ether due to their lipid envelope. This property distinguishes them from other icosahedral RNA viruses in this list.

Answer 158

A. Bunyavirus Rationale: Hemorrhagic fever with renal syndrome (HFRS) is associated with exposure to rodent droppings and is caused by certain viruses within the Bunyaviridae family, making Bunyavirus the correct answer.

Answer 159

B. Parvovirus Rationale: Parvovirus is a DNA virus, distinguishing it from the other options, which are all RNA viruses. This makes Parvovirus the correct answer for the virus that is not an RNA virus.

Answer 160

C. Paramyxovirus Rationale: Paramyxoviruses are enveloped, ether-sensitive viruses with helical symmetry. This group includes viruses that cause diseases such as measles, mumps, and respiratory syncytial virus (RSV), making Paramyxovirus the correct answer.

Answer 161

D. Household bleach Rationale: Household bleach (sodium hypochlorite) is known to be effective in decontaminating surfaces and medical supplies from prions, which are highly resistant to most forms of disinfection. Guanidine thiocyanate, formaldehyde, and urea are not as effective in inactivating prions.

Answer 162

b. Human Papillomavirus (HPV) Rationale: Human Papillomavirus, especially HPV types 16 and 18, is strongly associated with oropharyngeal carcinoma, particularly cancers of the tonsils and base of the tongue.

Answer 163

a. Arenaviridae Rationale: Arenaviridae virions incorporate host cell ribosomes during maturation, which gives the viral particles a characteristic "sandy" appearance under electron microscopy.

Answer 164

C. Prions Rationale: Prions are the etiologic agents associated with neurodegenerative diseases such as Kuru and Creutzfeldt-Jakob disease. These are proteinaceous infectious particles that cause disease by inducing abnormal folding of normal cellular prion proteins.

Answer 165

A. Congenital heart disease Rationale: Congenital heart disease, such as patent ductus arteriosus and pulmonary artery stenosis, is a common manifestation of Congenital Rubella Syndrome, along with cataracts and deafness.

Answer 166

B. Orthomyxovirus Rationale: Orthomyxoviruses, which include the influenza viruses, have a helical capsid and are ether-sensitive due to their lipid envelope. This property is used in virology to distinguish enveloped from non-enveloped viruses.

Answer 167

D. Detects for Antigen-Antibody reactions

Answer 168

A. Immunoassays Rationale: Immunoassays, such as enzyme-linked immunosorbent assay (ELISA), are commonly used to detect the surface antigen (HBsAg) of Hepatitis B virus, indicating an active infection.

Answer 169

D. Coronavirus Rationale: Coronaviruses have a complex or "unknown" capsid symmetry due to their unique structure, characterized by the club-like spikes that emanate from their surface, giving them a crown-like appearance under electron microscopy.

Answer 170

A. Picornavirus Rationale: Picornaviruses, which include poliovirus, coxsackievirus, and rhinovirus, are non-enveloped viruses and thus are resistant to ether. Ether typically disrupts the lipid envelopes of viruses, so non-enveloped viruses are unaffected.

Answer 171

C. Rubella virus Rationale: Rubella virus, the sole member of the genus Rubivirus within the family Togaviridae, causes rubella (also known as German measles), characterized by a generalized maculopapular rash and occipital lymphadenopathy.

Answer 172

A. Viruses are always complete carcinogen Rationale: This statement is not true as a tenet for viral carcinogenesis. Viruses are seldom complete carcinogens; they may act as part of a multistep carcinogenesis process, where they initiate the cancerous process but other factors, such as genetic predisposition and environmental factors, also play a crucial role.

Answer 173

C. Detection of virus nucleic acids Rationale: Polymerase Chain Reaction (PCR) is a molecular technique used to amplify and detect specific DNA or RNA sequences, making it a powerful tool for identifying the presence of virus nucleic acids in samples.

Answer 174

D. HTL virus Rationale: Adult T-cell leukemia/lymphoma (ATL) is associated with Human T-lymphotropic virus type 1 (HTLV-1), often referred to as HTL virus in this context.

Answer 175

A. Flaviviridae Rationale: The Hepatitis C virus, a member of the Flaviviridae family, is associated with hepatocellular carcinoma. Hepatitis B virus, although not a member of the Flaviviridae family, is also associated with hepatocellular carcinoma but belongs to the Hepadnaviridae family.

Answer 176

C. Rubella virus Rationale: The symptoms described are characteristic of rubella, caused by the Rubella virus, which leads to a maculopapular rash and post-occipital lymphadenopathy.

Answer 177

C. Cancer producing viruses Rationale: Lentiviruses, a subgroup of retroviruses, are known for causing slowly progressive, chronic diseases and infecting cells of the immune system. They are not typically associated with cancer production; this characteristic is more closely associated with other virus families like Papillomaviridae and Herpesviridae.

Answer 178

C. Human herpesvirus 8 Rationale: Kaposi's sarcoma is associated with Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus (KSHV).

Answer 179

A. Neurodegeneration and spongiform changes Rationale: Diseases caused by prions in the nervous system, such as Creutzfeldt-Jakob disease and kuru, are characterized by neurodegeneration and spongiform changes in the brain, leading to a sponge-like appearance due to the formation of vacuoles.

Answer 180

B. Retroviridae Rationale: The Retroviridae family includes the Human Immunodeficiency Virus (HIV), which causes AIDS, and the Human T-lymphotropic virus (HTLV), associated with adult T-cell leukemia/lymphoma, both of which can lead to AIDS-related malignancies.

Answer 181

C. adenovirus

Answer 182

D. majority of children have antibodies against calciviruses by age of six Rationale: This statement is not true; it is more accurate for viruses like rotavirus due to widespread exposure and vaccination in some cases. Caliciviruses, particularly noroviruses, can infect individuals of all ages, and immunity is not always long-lasting or fully protective.

Answer 183

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Answer 184

B. Norwalk agent and Calicivirus Rationale: Norwalk virus (a member of the Norovirus genus) and other caliciviruses are known for causing epidemic viral gastroenteritis in both adults and children.

Answer 185

A. The diagnosis is usually made by isolating the virus in cell culture Rationale: Hepatitis A Virus (HAV) diagnosis is typically made through the detection of specific IgM antibodies in the blood, not by isolating the virus in cell culture, which is difficult and not routinely done for clinical diagnosis.

Answer 186

B. Polioviruses Rationale: While most picornaviruses are resistant to the acidic environment of the stomach, allowing them to infect the gastrointestinal tract and spread via the fecal-oral route, the clarification provided indicates that poliovirus can be inactivated by stomach acid after prolonged incubation. This makes poliovirus the exception among the options given, as it has a relative sensitivity to gastric acidity compared to the other picornaviruses listed, which are generally resistant to such conditions.

Answer 187

b. respiratory syncytial virus Rationale: Respiratory Syncytial Virus (RSV) is a common cause of pneumonia in infants and young children, characterized by fever, persistent cough, and infiltrates seen on chest radiographs.

Answer 188

C. Enterovirus Rationale: Enteroviruses are the most common cause of aseptic meningitis of viral etiology, causing a significant number of cases worldwide.

Answer 189

A. TRUE Rationale: Major pandemics, especially of influenza, are associated with antigenic shifts, which involve significant changes in the viral hemagglutinin (H) or neuraminidase (N) proteins, or both. This can lead to the emergence of a virus to which the population has little to no immunity, resulting in widespread disease.

Answer 190

B. Paralytic poliomyelitis Rationale: Paralytic poliomyelitis is characterized by flaccid paralysis resulting from lower motor neuron damage. This severe form of polio can lead to permanent paralysis in some limbs.

Answer 191

A. Influenza A Rationale: Only Influenza A viruses are known to undergo both antigenic drift and antigenic shift. Antigenic shift can lead to pandemics by generating a significantly different virus to which the population has little or no immunity.

Answer 192

C. mononucleosis Rationale: Mononucleosis is typically associated with the Epstein-Barr virus (a herpesvirus), not picornaviruses. Picornaviruses can cause hepatitis (A), meningitis, and myocarditis among other syndromes.

Answer 193

C. Group B Coxsackievirus Rationale: Group B Coxsackieviruses are known to cause epidemic pleurodynia (Bornholm disease) and myocarditis, among other conditions.

Answer 194

A. infect villi of large intestine Rationale: Rotavirus primarily infects the villi of the small intestine, not the large intestine. This infection leads to diarrhea due to malabsorption and destruction of enterocytes, which are replaced by crypt cells with different transport features.

Answer 195

B. rotavirus Rationale: Rotavirus is a double-stranded RNA virus that is segmented, belonging to the Reoviridae family. It is a leading cause of severe diarrhea among infants and young children globally.

Answer 196

A. Parainfluenza virus Rationale: Parainfluenza virus, particularly types 1 and 2, can cause croup (laryngotracheobronchitis), which is a very serious condition characterized by a distinctive barking cough, stridor, and difficulty breathing.

Answer 197

B. Enterovirus Rationale: Acute hemorrhagic conjunctivitis is most commonly caused by Enterovirus 70 and Coxsackievirus A24. These viruses lead to sudden onset of eye pain, redness, and hemorrhage.

Answer 198

A. Hillary Koprowski Rationale: Hillary Koprowski developed the first successful oral polio vaccine using a live attenuated virus. However, it was Albert Sabin's oral vaccine that became more widely used and known for controlling polio.

Answer 199

A. enveloped symmetrical RNA virus Rationale: Hepatitis A virus (HAV) is a non-enveloped, symmetrical RNA virus. It is indeed part of the Picornaviridae family and shares many characteristics with picornaviruses, but being enveloped is not one of them.

Answer 200

A. F. glycoprotein Rationale: The F (fusion) glycoprotein is responsible for the fusion of the viral envelope with the cell membrane, leading to syncytial formation, where multiple cells fuse to form a single cell with multiple nuclei. This is characteristic of certain viruses like respiratory syncytial virus (RSV).

Answer 201

A. Genetic reassortment amongst 8 genes Rationale: Influenza A virus has a segmented RNA genome consisting of 8 segments, which allows for genetic reassortment when two different strains of the virus infect the same cell. This reassortment is a major mechanism behind the antigenic shift, leading to new influenza virus subtypes.

Answer 202

E. exocytosis is thought to mediate infection Rationale: Coronavirus infection and replication involve entry into the cell, replication in the cytoplasm, and release of new virions by budding into the ER and Golgi apparatus, followed by exocytosis. However, exocytosis is not thought to mediate infection; rather, it's a part of the virus release process from infected cells.

Answer 203

D. Astrovirus causes gastroenteritis only in adults Rationale: Astroviruses can cause gastroenteritis in both children and adults, but they are more commonly associated with gastroenteritis in young children, not exclusively in adults.

Answer 204

B. GIT Rationale: Poliovirus primarily enters the body through the gastrointestinal tract (GIT), where it infects and replicates before spreading to other parts of the body, including the nervous system in cases of paralytic disease.

Answer 205

A. they are the most frequent causative agent of the common cold Rationale: Rhinoviruses are indeed the most frequent causative agents of the common cold, responsible for a significant percentage of all colds in both children and adults.

Answer 206

C. Parainfluenza Hemagglutinin (HA) and Neuraminidase (NA)

Answer 207

D. Fecal-oral mode of transmission Rationale: Both Rotavirus and Norwalk virus (a type of Norovirus) share the fecal-oral mode of transmission. They are transmitted by the ingestion of contaminated food or water and person-to-person contact.

Answer 208

C. Hepatitis E virus Rationale: Hepatitis E virus belongs to the family Hepeviridae, not Caliciviridae. None of the hepatitis viruses listed belong to the Caliciviridae family, which includes noroviruses and sapoviruses, known for causing gastroenteritis.

Answer 209

E. All of the choices are correct Rationale: Mumps virus is a paramyxovirus with the following characteristics: humans are its only natural host, it typically confers lifelong immunity after a single infection, it is a single-stranded RNA virus with negative sense, and its HN spikes possess both hemagglutinin (HA) and neuraminidase (NA) activity.

Answer 210

E. Low expression in lung alveolar epithelial cells and intestinal enterocytes Rationale: SARS-CoV (Severe Acute Respiratory Syndrome Coronavirus) is known for its high expression in lung alveolar epithelial cells, which is a major site of infection and replication, contributing to the severe respiratory symptoms observed in infected individuals. This statement is incorrect in the context of SARS pathology.

Answer 211

C. Poliovirus Rationale: CD155 (also known as the poliovirus receptor) is a receptor for poliovirus, facilitating its entry into cells. It is not a receptor for alpha herpesviruses.

Answer 212

A. True Rationale: The live oral poliovirus vaccine (OPV) induces a strong immune response, including the production of IgM and IgG antibodies in the blood and secretory IgA antibodies in the intestine, providing both systemic and mucosal immunity.

Answer 213

B. False Removing the type 2 strain from OPV will eliminate vaccine-associated poliomyelitis in recipients caused by this serotype.

Answer 214

C. The testes, ovaries and pancreas can be involved Rationale: Mumps virus can cause inflammation of the testes (orchitis), ovaries (oophoritis), and pancreas (pancreatitis) in addition to its well-known effect on the salivary glands. There is a vaccine against mumps, and the diagnosis can be supported by laboratory tests including virus isolation and serologic tests.

Answer 215

A. True Rationale: Herpangina, caused by certain group B coxsackieviruses, is a self-limiting illness characterized by severe febrile pharyngitis, and it is most common in young children.

Answer 216

C. Hemmagglutinin Rationale: The type-specific antigen of influenza viruses is found in the hemagglutinin (HA) protein. HA is responsible for binding the virus to the cell that is being infected and varies among different strains of influenza viruses, contributing to their antigenic diversity.

Answer 217

E. All of the choices are correct Rationale: Enteroviruses are implicated in a wide range of diseases, including gastrointestinal disturbances, skin and mucous membrane lesions, conjunctivitis, and upper respiratory tract infections.

Answer 218

C. Adenoviruses Rationale: Adenoviruses are among the viruses with a double-stranded DNA genome. RSV, rhinoviruses, reoviruses, and enteroviruses all have RNA genomes, with reoviruses having a double-stranded RNA genome.

Answer 219

B. Enteroviruses 68-71 and Hepatitis A virus Rationale: While enteroviruses 68-71 and Hepatitis A virus can be found in the gut, they are not primarily associated with gastroenteritis. Enteroviruses 68-71 are more associated with respiratory illnesses and neurological disease, and Hepatitis A virus causes liver infection.

Answer 220

E. Multiply in enterocytes Rationale: Rotavirus multiplies in the enterocytes of the small intestine, leading to gastroenteritis. This aspect of its pathogenesis is well-documented, and the virus is known for its efficient person-to-person transmission and as a common cause of nosocomial (hospital-acquired) infections, especially in pediatric settings.

Answer 221

E. Rotavirus group A Rationale: Rotavirus group A is the most important cause of gastroenteritis in infants and young children worldwide, causing severe and potentially life-threatening infections.

Answer 222

E. Rotavirus group A Rationale: Rotavirus group A is the most important cause of gastroenteritis in infants and young children worldwide, causing severe and potentially life-threatening infections.

Answer 223

B. The influenza vaccine contains several serotypes of virus Rationale: The influenza vaccine is formulated each year to contain the strains most likely to circulate in the upcoming flu season, often including multiple serotypes to provide broad protection.

Answer 224

E. ICAM - 1 Rationale: Coxsackievirus A21 uses ICAM-1 (Intercellular Adhesion Molecule 1) as a receptor for entry into cells. ICAM-1 is a cell surface protein that is involved in the inflammatory response.

Answer 225

C. Norwalk Virus Rationale: Norwalk virus, a type of norovirus, is a common cause of acute gastroenteritis following the consumption of contaminated food or water, including raw oysters. It is known for causing sudden onset of vomiting and diarrhea.

Answer 226

B. False Rationale: The killed poliovirus vaccine (inactivated polio vaccine, IPV) induces humoral antibodies but does not induce local intestinal immunity as effectively as the oral polio vaccine (OPV). Therefore, the virus can still multiply in the gut of individuals vaccinated with OPV but not those vaccinated with IPV.

Answer 227

B. Vaccination Rationale: Vaccination is the primary method for controlling influenza, especially in "risk" groups such as the elderly, healthcare workers, and those with chronic health conditions.

Answer 228

D. I, IV, V I. Reovirus IV. Norwalk virus; Calicivirus V. Astrovirus; Rotavirus B