body as host test #2 rna viruses

Small ssRNA virus
No envelope
Rhinovirus & Enterovirus

A type of Picornavirus
1-100 species
common cold (coryza)
only grow at 33 degrees Cel and lower (upper resp. tract--not in GI tract)

A type of Picornavirus
Coxsackie A,B, Echo and Polio can cause aseptic meningitis

Picornavirus
Enterovirus
Hand-foot-mouth disease (mostly in children)
Lesions in oral cavity and lips, hands and feet

Picornavirus
Acute hemmorrhagic conjunctivitis

A type of picornavirus
Paralysis and encephalitis

A type of picornavirus

A type of picornavirus
Only reservoir is humans
Sabin vaccine: attenuated/live oral vaccine
Salk vaccine: dead virus/IV injection
Polio myelitis: paralysis, can be fatal

DS linear RNA virus
No envelope
Segmented (see some reassortment)
Rotaviruses (A,B,C) & Coltivirus (ColoradoTickFever)

Types of Reovirus
#1 cause of diarrhea in children (sig. cause of fatality in children due to electrolyte imbalance)
Fecal oral route

Type of Reovirus
Colorado Tick Fever
High fever, rash, nausea, can be very serious
Remission and then returns within weeks

ss linear RNA Virus
Icosahedral
No envelope
Norwalk Virus and Hepatitis E

Calicivirus
Common cause of GI diarrhea, via water & food
Lasts 3 days, usually not fatal
'Cruise ship virus'
Some people are immune
I.d.ed by serologic IgM antibodies

A type of Calicivirus

ss linear RNA
Enveloped
Most (not Hep. C) transmitted by insect bites

A type of Flavivirus

A type of Flavivirus
Can hide out in animals
Mosquito vector
Jaundice & Hemorrhage (high fatality rate)
Only 1 Serotype
Only one vaccine but does not elicit life-long protection

A type of Flavivirus
* Bone Pain
High fever, rash, nausea, bone pain
Remission for a few days but then a 2nd round of acute infection...fever returns with a new maculopapular rash
Hemorrhagic fever
Can be fatal
Symptoms resolve in 2 weeks
Mosquito vector

A type of Flavivirus

A type of Flavivirus
Encephalitis
Mosquito Vector
Reservoirs--Birds & Horses

ss linear RNA
Envelope wraps around like a toga
Icosahedral
Have hemagglutinin protein spike
Alphavirus & Rubivirus

Type of Togavirus
Eastern equine encephalitis
Western equine encephalitis
Venezuela equine encephalitis
(50% fatal, no treatment)

Type of Togavirus
Rubella
Only one serotype, so vaccine is efective
Light, mild rash, often misdiagnosed as measles
Self-limiting but can spread in epidemics
MMR vaccine--live attenuated virus (not for the immunocomp.)
Pregnant women infected in 1st trimester--may cross placenta & cause Teratogenic infection (congenital abnormalities)
CNS--Infant mental retardation, deafness
Eyes--cataracts, glaucoma
Heart--Patent ductus arteriosius
Malformed fingers
Immunize women before childbearing age

ss circular RNA
Enveloped
Looks like grains of sand on envelope ('arena' means sand in Latin)

A type of Arenavirus
Can progress from fever & GI bleeding to shock

A type of Arenavirus
May cause fetal eye infection

A type of Arenavirus
High Fatality rate

A type of Arenavirus
High fatality rate

ssRNA linear
Bullet-shaped
Enveloped
Has Negri Bodies--inclusion bodies in the neurons
Lyssavirus (Rabies)

A type of Rhabovirus
Rabies
Transmission: Zoonotic via rabid animal bite (Bats, racoons, dogs. Animals are infections one week before they die)
Can also be acquired from other fluids or via inhalation (inhalation of air in bat cave)

1. Dumb form: Animal looses its fear of humans
2. Rabid form: Animal acts crazy

linear ssRNA
Enveloped
Oncovirus (HTLV I & II) & Lentivirus (HIV)

A type of Retrovirus
HTLV I (Human T cell Lymphotrophic Virus Type I)
Adult T-cell leukemia/Lymphoma
Malignant proliferation of mature T-cells
Impaired immunity

A type of Retrovirus
HIV

Non-DNA, Non-RNA, Protein particles
Cause chronic, latent, slowly progressive and consistently fatal infections of the CNS
Creutzfeldt-Jacob Disease, Kuru, Familial Prion Diseases

Influenza virus is the only virus that belongs to this group
Only causes resp. infection
Large enveloped RNA virus
8 RNA segments (reassortment)
Complex envelope with hemagglutinin and neuraminidase

Responsible for the attachment of viruses, it recognizes the receptors on the host cell

Responsible for the release of virus from infected cell--releases through budding

Usually associated with epidemic outbreaks

Usually endemic outbreaks but can cause epidemics

Endemic or local outbreaks; self limited infection

Hemogglutinin, Endocytotic

Minor changes in viral genome
Every 2-3 years
Causes local outbreaks of Flu A or B
Antibodies from previous infections somewhat protective

Major changes in viral genome: Reassortment of RNA segment
Every 10-20 years
Cause epidemic outbreaks and pandemics
Immunity not effective

aerosol inoculation, Respiratory Tract,

...Staph aureus (bact. pneumonia)

Possible secondary infection following the flu (mainly in children).

Possible secondary infection following the flu.
Cardiac involvement and sore muscles for months.

Possible secondary infection following the flu.
Transient Motor Paralysis
Encephalopathy
Encephalitis

Possible secondary infection following the flu.
Encephalopathy and causes fatty liver and other viscera (Mit. shut down)
Can be caused by aspirin usage in children with viral infections.

...Look for Immunofluorescence antibodies (IFA)

Rimantadine-to shorten course of infection
Amantadine-in serious infections or in compromised patients.
No aspirin for children.
Ribavirin/Oseltamivir/Zamamivir
Supportive therapy in most cases.

Live attenuated influenza vaccine.
Protects against many strains.
Do not give to pregnant women, cardiac or respiratory compromised patients.

Enveloped.
May have neurominidase or hemagglutinin.
May have small glycoprotein spikes.
NON-Segmented (different from orthomyxoviruses-no reassortment)
ssRNA linear

Attach and uncoat in cytoplasm.
Complete synthesis of protein coat and nucleic acid and assembly in cytoplasm.
Classic RNA budding exit.

Paramyxovirus.
Only one serotype.
Has Hemagglutinin but NOT neuraminidase.
Also has fusion spikes.

Measles

Lymphoid Hyperplasia
Subacute sclerosing panencephalitis (SSPE)

Kopli's Spots

4 serotypes.

Nasopharynx-lower resp. tract-Layrgotracheo bronchitis-croup-pneumonia.

Respiratory tract transmission.
Short-lived immunity. No vaccine.

Paramyxovirus.
1 serotype-vaccine effective.
Can infect any type of glandular tissue, the pancreas, and possibly the CNS.

Mumps.

Mumps. It is an ovary/testes inflammation. More worry with males because of high temp...kills sperm cells.
Risk of infertility.

Paramyxovirus.
Lacks N and H antigens.
Has Fusion spikes.

RSV--Infects virtually everyone by 5 years old. Reinfection possible.

...Ribavirin inhalation.

No vaccine.

Exclusively in the cytoplasm.

Subacute sclerosing panencephalitis (SSPE)-Occurs in about 7/1,000,000 cases
Replication in the CNS