Micro Flashcard 10: Gi Virus And Childhood Virus

Front 1

Most common agent for acute gastroenteritis (viral or bacterial)

Back 1

Viral gastroenteritis most common

Front 2

General features of viral gastroenteritis symptoms (incubation and onset time):

Back 2

short 1-2 incubation period, 1-10 days in duration, watery stool, self limiting in healty persons.

Front 3

Six common viral causes of gastroenteritis?

Back 3

Rotavirus (seg dsRNA), Adenovirus (linear dsRNA), Norovirus, Sapovirus, Astrovirus, Aichi virus; 4/6 are ss+RNA

Front 4

Four important epidemiological factors to consider in gastroenteritis cases?

Back 4

Age, season, duration of symptoms and severity of symptoms.

Front 5

Peak age and peak time of year for gastroenteritis:

Back 5

Peak age 6-24 monthes, peak time winter

Front 6

General and exceptional time lines of virues causing gastroenteritis:

Back 6

Most 1-2 day incubation, 5-7 day diarrhea; Adenovirus has long incubation and long diarrhea time; Norovirus has short vomit, short diarrhea but LONG shedding time (1-3 weeks)

Front 7

GI virus transmission (route, outbreak source, locations)

Back 7

GI virus ( similar to Hep A) transmit easily fecal-orally (only 10 particles needed); outbreak can be caused by handler or food source (esp Shell fish); NOSOCOMIAL important.

Front 8

Pathogenesis of viral gastroenteritis:

Back 8

Virus replict in intestinal villi; Virus causes shortening of villi, exfoliation, deepening crypts and more mononuclear cells, columnar to cuboidal change. Patchy changes. Loss of fluid and electrolytes occur.

Front 9

Rotavirus Classification and structure:

Back 9

Rotavirus is a reoviridae family virus; it has 11 segmented dsRNA genome, each piece codes for structural or nonstructural protein (reassortment); looks like wheels, 3 capsid layers

Front 10

Rotavirus subtyping and antigenic properties, human disease importance:

Back 10

Rotavirus have 3 capsid layers; VP6 on the second layer is most abundant and determines Group and Subgroup; VP4 and VP7 on surface determine serogroup. For human disease: Group A, G1-4, 9; P1A/B are most important.

Front 11

Rotavirus epidemiology (cause for what, peak age group, peak time, peak sites transmission):

Back 11

Rotavirus is the single most important factor causing dehydrating diarrhea in <2yrs. Main cause for watery diarrhea in kids. Peak in 4-24 month olds; peak in winter (SW to NE in US); often in hospitals and daycares; transmission easy due to stable on hand for at least 4hrs.

Front 12

Rotalvirus clinical symptoms (viremia)?

Back 12

Rotavirus: explosive and frequent diarrhea and vomit; fever; isotonic dehydration; possible viremia and other extraintestinal infection.

Front 13

Rotavirus immunity (locations and importance)?

Back 13

Both serum and intestinal antibodies exist; but intestinal response more important.

Front 14

Rotavirus vaccines?

Back 14

Rotavirus has 1 failed vaccine and 2 successful multivalent vaccine for infants.

Front 15

Calicivirus features and two important GI members:

Back 15

Calicivirus are ss+RNA, nonenveloped virus; sapvirus (3% of kids with hospitalized diarrhea), norovirus are both members.

Front 16

Norovirus features and disease responsible (subtyping & immunity)?

Back 16

Norovirus is a calicivirus that is the primary cause of nonbacterial diarrheas in adults and 2nd most in kids; divided into genogroups and subdivided into genotype; this causes transient immunity.

Front 17

Norovirus clinical features compared to other viral GI ills (adult v kids?)?

Back 17

Norovirus have shorter vomiting and diarrhea time, but longer shed time (3wks); kids vomit more, adult have diarrhea more.

Front 18

Norovirus examplse of routes of transmission:

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food (shellfish), water, ice, aerosolized vomitus, direct contact with infected person.

Front 19

Why are norovirus infection so common (7):

Back 19

Hard to inactivate virus, large human resevior, immunity transient, long shedding time,highly contagious, multiple routes of transmission, strain diversity

Front 20

Norovirus' dependence on host factor:

Back 20

H type 1 epitopes is needed as ABH histo-blood group on the gut epithelium for norovirus to infect.

Front 21

Enteric adenovirus features (structure, disease time course, patient population)

Back 21

Nonenveloped dsDNA virus, long incubtion time with long diarrhea time; cause of pediatric diarrhea.

Front 22

Astrovirus features (structure, disease, patient population)

Back 22

nonenveloped ss+RNA virus, 5-6 pointed star appearance, cause symptoms in kids similar to rotavirus, but less severe.

Front 23

Viral gastroenteritis treatment:

Back 23

Treatment is mainly supportive, replenish water and correct for electrolyte balance.

Front 25

Childhood infections

Front 26

Five childhood rash viral causes:

Back 26

Measles, Rubella, Varicella, Parvovirus B19 (fifth, slapped check), HHV-6 (roseola, 6th)

Front 27

Viral families for MMR:

Back 27

Measles and Mumps are both paramyxoviridae; Rubella is a Togaviridae.

Front 28

Examples of virus of the paramyxoviridae family (4):

Back 28

parainfluenza, Measles, Mumps, RSV

Front 29

Common features of MMR viruses:

Back 29

ss RNA viruses, one antigen on the lipid envelope, transmission by respiratory droplets, human only natural host

Front 30

Where do MMR viruses replicate and how do they spread to multiple tissues:

Back 30

MMR replicates in the nasopharynx and regional lymph nodes, but they spread throughout body via viremia.

Front 31

Peak age and time for MMR infections in pre-vaccine era?

Back 31

Peak age at 5-9, peak time during winter for MMR in prevaccine era.

Front 32

Measles other names, incubation, prodrome, rash

Back 32

Rubeola, 5 day measles, hard measles; incubation for 8-12 days, Prodromes: 3Cs (cough, Coryza, Conjunctivis), Koplik spots, fever; Rash follows prodomes, starts/clears head to feet, maculopapular that confluences.

Front 33

Measles contagious, transmission, risk factor, immunity;

Back 33

Measles most contagious from prodrome to 3-4 days of rash; transmit via aerosolized particulates, 90% attack rate; risk factors include: malnutrition, immunocompromised, young age; life time immunity, rash is cell mediated immunity hypersensitivity that is not seen in patients lacking cell mediated immunity.

Front 34

Measles complications and likely at risk?

Back 34

Measles complications include pneumonia, otitis media, Subacute Sclerosing Panencephalitis (SSPE); most at risk <5 or >20

Front 35

Modified measles, atypical measles and HIV measles:

Back 35

Modified measles from patient with previous maternal AB; atypical measles due to formalin vaccine sensitization; HIV measles see giant cell pneumonia.