Toga

flavi

corona(helical)

Picorna

calici

astro

Cubical nucleocapsid

translation first step

cytoplasmic life cycle

 Non segmented single strand one RNA genome

Rubella 

alphavirus

Positive sense RNA virus

single serotype

infects humans only

Acute disease/self limiting disease in adults

rubella, 3 days measles, third disease

blotchy, non confluent rash-appear on the face and descend to body

rashes stay for 3 days

cervical lymphadenopathy

Teratogenic effect of rubella 

first trimester infections of the fetus cause severe damage

Congential heart disease (ductus arteriosis)

total or partial blindness: cataract, chorioretinitis, glaucoma

neurosensory deafness

Thrombocytopenic purpura

hepatospleenomegaly

meningoencephalitis

Mental retardation 

progressive rubella panencephalitis

Mosquito transmitted togavirus

mostly subclinical or inapparent infections

eastern equine encephalitis(eee)

western equine encephalitis (wee)

venezuelan equine encephalitis (vee)

chikungunya: arthropathy

causes viremia

enecphalitis of horses, birds and humans

Encephalitis 

rash fevers

hemorrhagic fevers

virus introduced in bloodstream

viremia produced

fever, chills, aching, rapid onset

Insects (mosquito, sandfly, ticks)

toga, flavi, rhabdo, reo and bunya

all are RNA viruses

cytoplasmic life cycle

summer, fall, water stagnation, insect activity 

abandoned tires, rainfall, mosquito eggs

multiply in insects, heavy load in saliva

persistent infection in insects, no disease

viremia in insects and vertebrate host

overwintering in eggs

jungle cycle, urban cycle

Mosquito-borne flavivirus

birds as reservoir 

east coast, Midwest, endemic in the usa

Mosquito borne flavivirus

many Asian countries

Pigs, birds as reservoirs 

killed virus vaccine 

Mosquito Borne flavivirus

single serotype

live attenuated vaccine (17D)

endemic in South America, Africa

thousands died in the USA in the past

hepatitis, hemorrhage into stomach (black vomitus)

four different serotypes/vaccine hard

mosquito borne flavivirus

acute infection

dengue H shock syndrome

immune complex involving two different serotypes

asain countries, south america(Nicaragua)

Flavivirus, not transmitted by insects

multiple serotypes

most common cause of transfusion-associated non-A, non-B hepatitis

by sexual activity, I/V drug use, blood products

both acute and chronic infection

major cause of hepatocellular carcinoma

alpha interferon treatment

The only enveloped helical (+) sense virus

respiratory and gi infections

an important cause of common cause

infects animals and humans

Type of coronavirus

severe acute respiratory syndrome

flu like symptoms, pneumonia 

feb 2003, Asia, 12 countries

10,000 infected, 900 died

2004 very few cases

Smallest group of RNA virus

genome:single transcription, translation unit

protein linked at 5' end

Cap independent translation

Enteroviruses

rhinoviruses

heparnaviruses

Polio 1,2,3

coxsackie a and b

echoviruses

Cubical, non enveloped viruses

polyprotein produced from genome 

resistant to acid pH of stomach 

oral-fecal route of transmission

most infections in children

replicate in oropharynx, gut mucosa viremia, spread to CNS 

1,2,3 serotypes, human only host 

hematogenous and neuronal spread to CNS

anterior horn of brain stem or spinal cord infected 

Pleurodynia (muscle pain in the chest, epidemic myalgia, Bornholm disease) Aseptic meningitis and mild paresis Neonatal myocarditis, pericarditis, Myocardiopathy,

Diabetes Mellitus

enteric human orphan virus

aseptic meningitis

picorna virus, +stranded RNA, cytoplasmic cycle

unstable to acid pH of stomach (enteroviruses are acid stable)

more than 100 serotypes known, vaccine development difficult

most frequent cause of common cold

school children are considered to transmit this virus most efficiently

respiratory route of enter, personal contact

picorna, +sense RNA

no envelope, stable to ether, acid, and heat

relatively stable to disinfectants

only one serogroup

infectious hepatitis or short incubation hepatitis

no chronic hepatitis or parentaral

oral-fecal route (rarely by parentaral)

raw seafood probably derived from feces contaminated water

epidemic gasterenteritis

non-enveloped plus RNA

waterborne, food borne, (oral-fecal route) and shellfish associated

+ RNA, no envelope

oral-fecal route of transmission

raw seafood associated gastroenteritis and hepatitis

non-enveloped + RNA virus

oral-fecal route of transmission

infantile diarrhea