Reoviridae Flashcards
Reoviridae Envelope? \_\_\_\_\_\_ capsid, 80nM \_\_\_\_\_\_ stranded, RNA/DNA, \_\_-\_\_ segmented genome \_\_\_\_\_\_-borne and enteric pathogens
Reoviridae Envelope? NO DOUBLE capsid, 80nM DOUBLE stranded, RNA, 10-12 segmented genome ARTHROPOD-borne and enteric pathogens
African horse sickness, bluetongue viruses, epizootic hemorrhagic disease of deer and Ibaraki virus are all species of what genera?
Orbivirus
African Horse Sickness _-_ virus serotypes -highly lethal disease of \_\_\_\_\_ -Two forms: \_\_\_\_\_\_\_ (100% mortality) and \_\_\_\_\_\_\_ (50-70% mortality) -Pathogenesis 1) Infection by \_\_\_\_\_\_ bite 2) Replication in local \_\_\_\_\_\_ 3) \_\_\_\_\_\_ viremia 4) Infection of reticuloendothelial cells 5) \_\_\_\_\_\_ viremia 6) Replication in \_\_\_\_\_\_\_\_ cells 7) Vasculitis, damage to blood vessels 8) \_\_\_\_\_\_ edema, petechial hemorrhages in pericardium
African Horse Sickness 1-9 virus serotypes -highly lethal disease of EQUIDAE -Two forms: PULMONARY (100% mortality) and CARDIAC (50-70% mortality) -Pathogenesis 1) Infection by CULICOIDES bite 2) Replication in local LYMPH NODES 3) 1º viremia 4) Infection of reticuloendothelial cells 5) 2º viremia 6) Replication in ENDOTHELIAL cells 7) Vasculitis, damage to blood vessels 8) PULMONARY edema, petechial hemorrhages in pericardium
CLINICAL PRESENTATION NAME THE AGENT Sheep - fever, "wool break" -salivation, hyperemia of oral mucosa, oral ulcers, frothing of mouth -cyanosis of tongue -nasal discharge, serous to mucopurulent -edema of muzzle, ears, head, neck -coronitis, lameness, recumbency -high morbidity, low mortality
Bluetongue virus (Acute infection)
How is Bluetongue virus transmitted?
Culicoides spp.
Where is bluetongue virus maintained and for how long?
RBCs of infected cattle and sheep, infectious to culicoides for 21 days
Clinical presentation guess that agent Sheep -maternal viremia, fetal infection -congenital defects: hydrocephalus, hydrancephaly, porencephaly, mummification, arthrogryposis, -abortion -transient infertility in rams -reduced lamb crop
Bluetongue virus (reproductive effects)
Epizootic Hemorrhagic Disease of Deer Agent: \_\_\_\_\_-_ and _ serotypes in NA (10 serotypes worldwide), \_\_\_\_ serotypes found in western and SE US Dz: Host range: \_\_\_\_, \_\_\_\_\_, yaks, pronghorn Transmission:
Epizootic Hemorrhagic Disease of Deer
Agent: EHDV-1 and 2 serotypes in NA (10 serotypes worldwide), BTV serotypes found in western and SE US
Dz: ACUTE HEMORRHAGIC FEVER
Host range: WTD, MULE DEER, yaks, pronghorn
Transmission: CULICOIDES SPP.
What are the 5 genera of Reoviridae?
Orbivirus Rotavirus Orthoreovirus Coltivirus Aquareovirus
Name that genera and family! Double-shelled, icosahedron (80nM) dsRNA, 10-12 segmented genome stable in environment stable at low pH resistant to lipid solvents
Rotaviruses!
Reoviridae!!
Rotavirus classification Group A: B: C: D: E: F:
Rotavirus classification Group A: humans, cattle, other species B: humans, lambs, kids C: swine, D: fowl E: swine F: fowl
What diseases are associated with Rotaviruses?
-rotavirus diarrhea, rotaviral enteritis, “milk scours”, malabsorptive diarrheas, dehydration, acid-base imbalance
Clinical presentation, GUESS THAT VIRUS!
1) neonatal cattle, sheep, pig, horse, rabbit, rodent or human, 2 days to 8 wks of age
2) Anorexia, depression, vomiting
3) watery diarrhea
4) recovery in 3 to 4 days
5) death due to severe dehydration secondary to fluid loss
Rotavirus
Pathogenesis of Rotaviruses
1) infection and cytolysis of mature _______ at tips of _____
2) exposure of basement membrane
3) migration of immature _____ from crypts to cover BM
4) blunting and fusion of adjacent villi leads to _____ absorptive surface
5) immature ____ do not have full digestive and absorptive fx
6) transient ______ of nutrients
7) decreases ______-isomaltase expression on apical brush border
8) undigested nutrients provide increased osmotic pressure on luminal surface of epithelium
9) ____ secreted from rotavirus infected cells fx like bacterial enterotoxins and stimulates efflux of ____ from cells
Pathogenesis of Rotaviruses
1) infection and cytolysis of mature ENTEROCYTES at tips of VILLI
2) exposure of basement membrane
3) migration of immature ENTEROCYTES from crypts to cover BM
4) blunting and fusion of adjacent villi leads to DECREASED absorptive surface
5) immature ENTEROCYTES do not have full digestive and absorptive fx
6) transient MALABSORPTION of nutrients
7) decreases SUCRASE-isomaltase expression on apical brush border
8) undigested nutrients provide increased osmotic pressure on luminal surface of epithelium
9) NSP4 secreted from rotavirus infected cells fx like bacterial enterotoxins and stimulates efflux of WATER from cells
What 4 factors influence rotavirus dz?
Proteases (cleave VP4)
Milk (osmotic pressure)
Age (receptors)
Immunity (IgA)
Colorado Tick Fever Family? Genera? Zoonotic? -Fever, myalgia, headache, meningoencephalitis, hemorrhagic fever -\_\_\_\_\_-borne D. andersoni -transmitted trans\_\_\_\_\_\_\_\_ -virus overwinters in \_\_\_\_ and \_\_\_\_\_ -prolonged viremia in rodents
Colorado Tick Fever Family? REOVIRIDAE Genera? COLTIVIRUS Zoonotic? YES -Fever, myalgia, headache, meningoencephalitis, hemorrhagic fever -TICK-borne D. andersoni -transmitted transSTADIALLY -virus overwinters in NYMPHS and ADULTS -prolonged viremia in rodents
