05 Viruses and Diseases Part 1 Duncan

Question 1

What are the DNA viruses?

Answer 1

Poxvirus (smallpox). Herpes Virus. Adenovirus. Hepatitis B Virus. Papilomavirus

Question 2

What viruses cause the common cold?

Answer 2

Rhinovirus. Coronavirus

Question 3

What are some general characteristics of respiratory infections caused by viruses?

Answer 3

Frequently occur because of bacterial superinfection. Typically, short incubation period. Spread by infectious droplets (fomites)

Question 4

What is Orthomyxovirus?

Answer 4

Influenza virus

Question 5

What are the surface proteins associated with influenza virus?

Answer 5

Hemagglutinin: attachment to cells. Neuraminidase: cell detachment

Question 6

What is Antigenic drift?

Answer 6

Small changes in cell surface proteins caused by one or a few point mutations

Question 7

What is Antigenic shift?

Answer 7

Large changes in cell surface proteins caused by recombination between different flu types (e.g. H2N1 –> H3N1 in flu virus)

Question 8

What is the pathogenesis of the Influenza Virus?

Answer 8

Infection of respiratory epithelial cells. Cell function impaired. Immune response compromised. Interferon response. CTL response

Question 9

What are the clinical manifestations from Influenza Virus?

Answer 9

Fever. HA. Muscle aches. Chills. Coughing

Question 10

What does the Respiratory Syncytial Virus cause?

Answer 10

Single most important cause of viral respiratory disease in infants under 1 year old - almost everyone has been infected by age 2, but usually with no adverse consequences

Question 11

What are the characteristics of Respiratory Syncytial Virus?

Answer 11

Paramyxovirus. Single-Stranded, non-segmented, negative strand RNA. Surface proteins: G protein, F protein

Question 12

What is the epidemiology of Respiratory Syncytial Virus?

Answer 12

Annually, in fall and winter. Affects a significant proportion of kids. Lasts 5-7 days. Spread by older siblings

Question 13

What is the pathogenesis of Respiratory Syncytial Virus?

Answer 13

Bronchiolar and alveolar inflammation. Bronchiolar and alveolar necrosis

Question 14

What are the clinical manifestations of Respiratory Syncytial Virus?

Answer 14

Fever. Runny nose. Cough. Wheezing, sometimes

Question 15

What is the prevention and treatment for Respiratory Syncytial Virus?

Answer 15

Supervision. Hygiene. Prophylactic passive immunity - for babies with elevated risk of RSV with severe consequences. Synagis (palivizumab): humanized mouse monoclonal antibody: treatment for premature infants (< 36 weeks) with underdeveloped immunse systems. Treatment of children with congenital heart disease or chronic lung disease as well. Ribavirin (or IgG + Ribavirin) can be used in immunocompromised infants

Question 16

What are the general characteristics of Adenovirus?

Answer 16

Over 49 different infectious types. DOUBLE-STRANDED DNA virus. Infects infants predominantly. Can become latent in tonsil or adenoids. In many instances there is no obvious infection

Question 17

What is the pathogenesis of Adenovirus?

Answer 17

Epithelial cell inflammation. Epithelial cell necrosis

Question 18

What are the clinical manifestations of Adenovirus?

Answer 18

Respiratory distress (cold-like symptoms, to pneumonia)

Question 19

What is the prevention and treatment for Adenovirus?

Answer 19

No specific therapy. Vaccines, but of questionable value

Question 20

What are the general characteristics of Parainfluenza Virus?

Answer 20

Paramyxovirus. Single-Stranded, non-segmented, negative strand RNA. Four subtypes. Hemagglutinin surface protein targets human cell receptor. Neuraminidase

Question 21

What is Type 1 Parainfluenza Virus?

Answer 21

Crop (young), pharyngitis

Question 22

What is Type 2 Parainfluenza Virus?

Answer 22

Severe lower respiratory disease. Significant cause of severe respiratory disease in the young

Question 23

What are the general characteristics of Rhinovirus?

Answer 23

Over 100 different infectious types. Picornavirus (same family as poliovirus). Single-stranded, positive sense RNA virus

Question 24

What do Rhinovirus cells need to attach to in order to infect bronchial cells?

Answer 24

ICAM-1

Question 25

What is the prevention and treatment for Rhinovirus?

Answer 25

"No" specific therapy. Pemciclovir - binds to surface, prevents virus-cell interaction

Question 26

What are the general characteristics of Coronavirus?

Answer 26

Minor cause of the common cold - 5-10% of cases. Single-Stranded, positive sense RNA virus. Receptor - ICAM (same as rhinovirus). Mild upper respiratory distress. No specific therapy available. SARS-causing Coronavirus: high [mortality/infection] ratio

Question 27

What are the general characteristics of Varicella-Zoster Virus?

Answer 27

Herpevirus. Large, double-stranded, DNA virus. Causes chicken pox in kids, shingles in adults. Following childhood infection, virus becomes latent in neurons (latency can persist into old age - Shingles)

Question 28

What is the epidemiology of Varicella-Zoster Virus?

Answer 28

Most prevalent in late winter to spring. 95% untreated children will get chicken pox. Highly infectious (contagious from 1-2 days pre-rash until all form scabs. Incubation period preceding overt rash: 10-20 days)

Question 29

What are the clinical manifestations of Varicella-Zoster Virus?

Answer 29

Itchy rash (a few lesions, to hundreds). Blisters, which dry, and scab over, lasting 4-5 days. Fever. Malaise

Question 30

What is the prevention and treatment of Varicella-Zoster Virus?

Answer 30

Vaccine: a highly effective one is available (Varivax): vaccination is recommended for all kids between 12-18 months. Chemotherapeutics (primarily for immunocompromised): Acyclovir or Immunge globulin (from Ab-producing individuals)

Question 31

What are the general characteristics of the Measles Virus?

Answer 31

Paramyxovirus. Single-stranded, negative sense, RNA virus. Surface proteins: Hemagglutinin, F protein. Causes rash in kids

Question 32

What is the epidemiology of Measles Virus?

Answer 32

Affects primarily children. Highly infectious (contagious from 1-2 days pre-rash until all form scabs. Incubation period preceding overt rash: 10-14 days). Top 10 viral killer of youths worldwide

Question 33

What are the clinical manifestations of Measles Virus?

Answer 33

Initially: Fever, cough, conjunctivitis, sore throat, HAs. Later (2-4 days): Macular, morbilliform rash, Koplik's spots in mouth. Immunosuppression

Question 34

What are the long term consequences of the Measles Virus?

Answer 34

Encephalitis. Neurologic damage. CNS infection leading to (2-10 years later) subacute sclerosing panencephalitis (very rare)

Question 35

What is the prevention and treatment for Measles Virus?

Answer 35

Vaccine (highly effective: MMR) for all kids 12-18 months. Chemotherapeutics: Immune globulin, from Ab-producing individuals (primarily for immunocompromised)

Question 36

What are the general characteristics of Rubella Virus (German Measles)?

Answer 36

Togavirus. Single-stranded, positive sense, RNA virus. Causes German, or 3 day, measles

Question 37

What is the epidemiology of Rubella Virus?

Answer 37

Common in childhood. Only 30-60% infected kids develop detectable illness

Question 38

What is the pathogenesis of Rubella Virus?

Answer 38

First targets upper respiratory tract. Then spreads to distant sites. Disease is mild, non-specific. Maculopapular rash, lasts for ~48 hrs. Fetal infection occurs, with potentially severe consequences

Question 39

What is the prevention and treatment of Rubella Virus?

Answer 39

Vaccine (highly effective: MMR) all kids 12-18 months. No specific (chemo-) therapy

Question 40

What are the general characteristics of the Mumps Virus?

Answer 40

Paramyxovirus. Single-stranded, negative sense, RNA virus. Surface proteins: Hemagglutinin, Neuraminidase

Question 41

What is the epidemiology of Mumps Virus?

Answer 41

Most common age of infection: 5-15 years of age. 30-40% infected kids do not develop detectable illness

Question 42

What is the pathogenesis of Mumps Virus?

Answer 42

First targets upper respiratory tract. Then spreads to salivary glands; also kidneys. Can include rash. Potential complications (meningitis, encephalitis, nerve and spine infection). In adult males, orchitis can result

Question 43

What is the prevention and treatment of Mumps Virus?

Answer 43

Vaccine (highly effective: MMR) for all kids 12-18 months. No specific (chemo-) therapy

Question 44

What are the general characteristics of Parvovirus B19?

Answer 44

Parvovirus. Single-stranded DNA virus (+ and - strands). Cause of "fifth" disease. "Slapped cheek" rash

Question 45

What is the epidemiology of Parvovirus B19?

Answer 45

Common in young: 5-15 years old. Mild to undetectable illness

Question 46

What is the Pathogenesis of Parvovirus B19?

Answer 46

Initially targets hematopoietic lineage cells (receptor: erythrocyte P antigen). Slapped cheek skin rash. Lacy reticular rash on trunk

Question 47

What are the potential complications of Parvovirus B19?

Answer 47

Maternal: fetal transmission leading to fetal death. Infrequent: medical oversight to monitor

Question 48

What is the prevention and treatment of Parvovirus B19?

Answer 48

No vaccine available (rarely necessary). No chemotherapy regimens characterized