2. The name Reoviridae is derived from respiratory enteric
orphan viruses.
The term orphan virus means that it is
not associated with any known disease.
Even though viruses in the Reoviridae family have
more recently been identified with various
diseases, the original name is still used.
A family of viruses that can affect the gastrointestinal
system and respiratory tract.
3.
4. REOVIRIDAE of VERTEBRATES
ORTHOREOVIRUSES
ORBIVIRUSES
WorldwideOral/fecalMammalian reoviruses
types 1, 2, 3
Humans, cattle,
sheep, swine
Gastroenteritis,
respiratory disease
Wide range of
symptoms from
inapparent to lethal
Asia, Americas
ROTAVIRUSES
Groups D, E, F Mammals, birds Oral/fecal
Table 3.13
Fusogenic
Non-fusogenic
GENUS/
MEMBERS
USUAL
HOST(S)
TRANSMISSION
or VECTOR
DISEASE WORLD
DISTRIBUTION
VIRUS NAME
ABBREV.
MRV
Nelson Bay virus Flying foxes (bats) AustraliaNBV
Avian reoviruses
5 serotypes
Birds Oral/fecal WorldwideARV
Equines Culicoides Cardiopulmonary
disease
AfricaAfrican horse sickness
10 serotypes
AHSV
Sheep, cattleBluetongue
24 serotypes
Culicoides Africa, Australia,Rhinitis, stomatitisBTV
Changuinola Phlebotamines Fever PanamaHumansCGLV
COLTIVIRUSES
Colorado tick fever Humans Ticks Fever, encephalitis North AmericaCTFV
Group A Humans, animals Infant diarrhea WorldwideOral/fecalRV-A
Group B Humans, animals Epidemic adult
diarrhea
Primarily ChinaOral/fecalRV-B
Group C Humans, animals Clinical significance
unknown
Oral/fecalRV-C
Reptilian reoviruses Snakes? ?
Baboon reovirus Monkeys Oral/fecalBRV ?
Kemerovo serogroup:
Ticks
Fever,
encephalitis
E. Europe,
United States
Wad Medani
Great Island
Chenuda Seabirds
Domestic animals
Kemerovo Humans?
GIV
CNUV
WMV
Fish
AQUAREOVIRUSES
five serogroups ? ? ?
SEADORNA VIRUSES
Eyach EYA Humans Ticks EuropeFever, encephalitis
Banna BAV
Kadipiro KDV
Humans Mosquitos
(Culex sp.)
Fever, encephalitis Southeast Asia.
Indonesia, China
5. Rotavirus is a virus that infects the intestinal tract of almost
all young children by age 5. Children can get rotavirus more
than once, but the first infection is usually the worst. This
infection causes stomach upset and diarrhea.
Causes severe gastroenteritis.
The most common cause of severe diarrhea among infants
and children.
Causes death of about 500,000 children worldwide every
year.
6. 1973: the virus was identified by Ruth Bishop and collagues.
1974: Named by Thomas Henry Flewett.
1980: Rotavirus serotypes were first described.
1981: Rotavirus from humans was first grown in cell
cultures derived from monkey kidneys, by adding trypsin
to the culture medium.
8. Linear Double-stranded RNA genome housed within an
icosahedral capsid.
Non-enveloped.
The outer capsid has T=13 icosahedral symmetry.
The inner capsid has T=2 icosahedral symmetry.
Consists of 10 to 12 segments.
The 5th terminus of the segments have a methylated
nucleotide cap.
9.
10. Replication begins by attachment to host receptors and endocytosis
into host cell vesicles. Particles are then partially uncoated in
endolysosomes, and penetrate into the cytoplasm. Replication of the
Reoviruses occurs by early transcription of each segment of the
dsRNA genome by viral polymerase inside the sub-viral particle
resulting in full-length plus-strand transcripts from the [-] strand
template. These +sense RNA molecules are then translated into the
various viral proteins. Some of the [+] RNAs are then encapsulated in
a sub-viral particle, and are transcribed to give [-] RNA
molecules. The [-] RNAs remain base-paired with the [+] RNAs,
giving rise to the dsRNA viral segments of the genome. The capsid is
then assembled on the sub-viral particle to form the mature virion.
11.
12. Rotavirus spreads easily
Often spreads where many children are together.
Spreads through contact with stool from an infected child.
Children who get the rotavirus germs on their hands can
get the infection when they put their hands in their
mouths. They can also get infected with rotavirus by
chewing on a toy that has the germs on it.
Incubation period is typically around two days.
13. Fever
Vomiting
Watery diarrhea
Abdominal pain
Dehydration (dry mouth, crying without tears, little or no
urination)
Sometimes bloody diarrhea
14. There's no specific treatment for a rotavirus infection.
Antibiotics won't help a rotavirus infection.
Usually, the infection resolves within three to eight days.
Preventing dehydration is the biggest concern.
15. Two rotavirus vaccines, RotaTeq and Rotarix.
both are given orally and do not require an injection,
these vaccines are most effective if the first dose is
given before age 15 weeks.
RotaTeq (RV5): is given on a schedule of three doses at ages
2 months, 4 months, and 6 months.
Rotarix (RV1) is given on a schedule of two doses at ages 2
months and 4 months.
