Case 43: Rotavirus

Question 1

what’s another name for rotavirus?

Answer 1

infantile gastroenteritis

Question 2

are rotaviruses RNA or DNA viruses?

Answer 2

nonenveloped RNA viruses

Question 3

what family are rotaviruses?

Answer 3

Reoviridae

Question 4

what is the structure of the capsid?

Answer 4

2 concentric shells

Question 5

what is the shape of the virion particle?

Answer 5

double-shelled particles shaped like wheels with short spokes on an outer rim

virions have an icosahedral structure and lack an envelope

Question 6

how many types of rotavirus are there?

Answer 6

3 major subgroups : A, B, C

9 serotypes

Question 7

what type of genome do rotaviruses have?

Answer 7

they have a segmented genome with 11 segments of a double-stranded RNA genome

however, gene reassortment has played no role in genetic diversity of rotaviruses,
and the virus strains have remained stable

Question 8

do rotaviruses grow well in cell cultures?

Answer 8

eh not really, enteric viral agents don’t normally

Question 9

what is used to diagnose rotavirus?

Answer 9

rotavirus and other enteric viral agents grow poorly in cell culture

so instead, assays that detect viral antigen in stool
specimens have become the most widely used method of diagnosis

rotavirus antigen can be detected in the stool using enzyme immunoassay

Question 10

what type of virus is responsible for the majority of the cases of gastroenteritis?

Answer 10

enteric viruses

Question 11

what are the leading viral pathogens?

Answer 11

rotaviruses and noroviruses

followed by enteric
adenoviruses, astroviruses, and coronaviruses

Question 12

what is the major clinical effect of rotaviruses?

Answer 12

rotaviruses are the single most
important cause of severe dehydrating diarrhea in infants and children younger
than 3 years of age worldwide

they are also responsible for up to 10% of all diarrheal episodes among children younger than 5 years in the US

Question 13

during what season are rotaviruses most prominent?

Answer 13

rotavirus
infection has a seasonal distribution in the United States, with transmission occurring
during the winter months

Question 14

how are rotaviruses transmitted?

Answer 14

fecal-oral route

rotaviruses are shed in high concentrations in the stools of
infected children and are transmitted by the fecal-oral route, both through close
person-to-person contact and through fomites

Question 15

what are fomites?

Answer 15

objects or materials which are likely to carry infection, such as clothes, utensils, and furniture

Question 16

how can rotaviruses negaitvely effect elderly?

Answer 16

elderly individuals who are
immunocompromised or who have undergone hematopoietic or solid organ
transplantation experience severe, prolonged, and sometimes fatal rotavirus diarrhea

Question 17

what is the pathogenesis of the rotavirus?

Answer 17

after fecal-oral acquisition, the virus infects the mature villus tip cells of the small intestine

viral invasion of the epithelial cells of the small intestine results in
destruction of the mature absorptive cells

damaged cells on villi are replaced by
immature crypt cells that cannot absorb carbohydrates or other nutrients
efficiently, resulting in osmotic diarrhea

the severity of rotaviral diarrhea is
proportional to the extent of mucosal damage in the small intestine

Question 18

how do you treat rotavirus?

Answer 18

there is no specific antiviral agent for this disease

symptomatic care is directed at
supportive measures, with particular attention to the prevention of dehydration through
the use of intravenous hydration or oral rehydration therapy

Question 19

how do you prevent rotavirus?

Answer 19

an oral live attenuated rhesus-based rotavirus vaccine-tetravalent was licensed in the
United States in 1998 for vaccination of infants – it was withdrawn a year later because
of reports of intussusception, a form of intestinal obstruction, as an uncommon but
serious side effect

adherence to hand washing and barrier methods are important for
preventing disease spread in day care and in the hospital setting

in view of the fecaloral
route of transmission, wastewater treatment and sanitation are important control
measures in the community

Question 20

what are some of the hallmark features of rotavirus?

Answer 20

1. little kids
2. winter months
3. vomiting, watery diarrhea, fever
4. acute, sudden onset presentation
5. dry mucous membranes