05 Viruses and Diseases Part 1 Duncan Flashcards Preview

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Flashcards in 05 Viruses and Diseases Part 1 Duncan Deck (48):
1

What are the DNA viruses?

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

2

What viruses cause the common cold?

Rhinovirus. Coronavirus

3

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

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

4

What is Orthomyxovirus?

Influenza virus

5

What are the surface proteins associated with influenza virus?

Hemagglutinin: attachment to cells. Neuraminidase: cell detachment

6

What is Antigenic drift?

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

7

What is Antigenic shift?

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

8

What is the pathogenesis of the Influenza Virus?

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

9

What are the clinical manifestations from Influenza Virus?

Fever. HA. Muscle aches. Chills. Coughing

10

What does the Respiratory Syncytial Virus cause?

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

11

What are the characteristics of Respiratory Syncytial Virus?

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

12

What is the epidemiology of Respiratory Syncytial Virus?

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

13

What is the pathogenesis of Respiratory Syncytial Virus?

Bronchiolar and alveolar inflammation. Bronchiolar and alveolar necrosis

14

What are the clinical manifestations of Respiratory Syncytial Virus?

Fever. Runny nose. Cough. Wheezing, sometimes

15

What is the prevention and treatment for Respiratory Syncytial Virus?

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

16

What are the general characteristics of Adenovirus?

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

17

What is the pathogenesis of Adenovirus?

Epithelial cell inflammation. Epithelial cell necrosis

18

What are the clinical manifestations of Adenovirus?

Respiratory distress (cold-like symptoms, to pneumonia)

19

What is the prevention and treatment for Adenovirus?

No specific therapy. Vaccines, but of questionable value

20

What are the general characteristics of Parainfluenza Virus?

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

21

What is Type 1 Parainfluenza Virus?

Crop (young), pharyngitis

22

What is Type 2 Parainfluenza Virus?

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

23

What are the general characteristics of Rhinovirus?

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

24

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

ICAM-1

25

What is the prevention and treatment for Rhinovirus?

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

26

What are the general characteristics of Coronavirus?

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

27

What are the general characteristics of Varicella-Zoster Virus?

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)

28

What is the epidemiology of Varicella-Zoster Virus?

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)

29

What are the clinical manifestations of Varicella-Zoster Virus?

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

30

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

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)

31

What are the general characteristics of the Measles Virus?

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

32

What is the epidemiology of Measles Virus?

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

33

What are the clinical manifestations of Measles Virus?

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

34

What are the long term consequences of the Measles Virus?

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

35

What is the prevention and treatment for Measles Virus?

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

36

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

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

37

What is the epidemiology of Rubella Virus?

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

38

What is the pathogenesis of Rubella Virus?

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

39

What is the prevention and treatment of Rubella Virus?

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

40

What are the general characteristics of the Mumps Virus?

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

41

What is the epidemiology of Mumps Virus?

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

42

What is the pathogenesis of Mumps Virus?

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

43

What is the prevention and treatment of Mumps Virus?

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

44

What are the general characteristics of Parvovirus B19?

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

45

What is the epidemiology of Parvovirus B19?

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

46

What is the Pathogenesis of Parvovirus B19?

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

47

What are the potential complications of Parvovirus B19?

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

48

What is the prevention and treatment of Parvovirus B19?

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