Micro J210 RNA Virus

• -Poliovirus
• -Rhinovirus
• -Coxsackievirus and echoviruses
• -Influenza
• -Respiratory syncytial virus
• -MMR
• -Rhabdovirus
• -Arbovirus
• -Rotavirus
• -Norovirus
• -HIV

• -Poliomyelitis
• -ss RNA, naked virus
• -three serotypes, human is the only host
• -Route: fecal- oral
• Alimentary canal to replication in GI tract to lymph to blood to CNS/muscles

-It is highly transmissible

• -Fever, malaise, sore throat, followed by muscle pain, stiffness, and paralysis 1-2 days later in 1% of cases
• -Clinical disease is paralysis
• -Spinal cord gets infected may lead to paralysis of legs and arms
• -Partial recovery is seen
• -If in lung, may require iron lung

-No treatment except for physical therapy to recover function

• 1. Salk vaccine: injected USA
• -Killed vaccine, all 3 serotypes
• -It protects from disease but does not prevent the spread
• -Need 3 shots 2-18 mo plus booster at 4-6 yrs
• 2. Sabin vaccine: oral vaccine, weaker
• -Live, attenuated vaccine, protects against all 3 serotypes
• -Protects from both disease and spread of disease
• -Usually life long immunity
• -There is one disadvantage: 1 serotype may revert to wild type virulent polio in 1 i in 1 million

• -Condition that affects polio survivors around 10-40 yrs after recovery
• -PPS is characterized by a further weakening of muscles that were previously affect by the polio infection
• -Some patients experience only minor symptoms, while others develop spinal muscular atrophy

• -Fatigue
• -Slowly progressive muscle weakness and possibly muscular atrophy
• -Difficulty swallowing and breathing
• -Joint pain and increasing skeletal deformities
• -Gradual decline in the ability to carry out activities of daily living

• -Used to treatment breathing problems in those with polio or pps.
• -60 people still use the iron lung

• -ss RNA containing naked viruses that cause common cold
• -#1 causes of common cold
• -About 140 serotypes that cause 30-50%of upper respiratory tract infections
• -Usually 3/5 cases per person per year
• -Transmitted by personal contact (just about anyway)
• -incubation time 2-3 days

-Cough, inflammation of nasal cavity, sore throat, headache, and no fever usually.

-Just like any other common cold virus, there are no treatments that can kill a rhinovirus. Therefore, it involves relieving symptoms as the body fights the virus

• -There is no vaccine because of the mildness of the disease large number of serotypes involved. You need 140 colds to get immunity
• -Reduce chance by: Washing hands regularly, keep hands away from nose, mouth, and eyes, limiting exposure to infected people, practicing healthy habits, using disinfectants

-Family on non-enveloped small RNA viruses that live in the human digestive tract and the 2nd most common viral infectious agents in humans and transmitted by fecal-oral route

-Coxsackieviruses, polioviruses, echoviruses, and hepatitis A virus

• -Enteroviruses
• -31 serotypes
• -High infectious, target is children
• -Among the leading causes of acute febrile illness in infants and children
• -Most common cause of aseptic meningitis

• -enterovirus
• -two types: A (23 serotypes) and B (6 serotypes)
• -Both effect the heart
• -Named after a town in NY

• -Generally tend to infect the skin and mucous membranes
• 1. Herpangina: an acute febrile illness associated with small vesicular or ulcerative lesions on the posterior orophayngeal structures
• 2. Acute hemorrhagic conjunctivitis (AHC) conjunctival congestion, onset of edema
• 3. Hand-foot-and mouth (HFM): vesicular lesions in the mouth and can involve the HFM, buttocks and/or genitalia

• -Generally infects the heart, pleura
• 1. Pleurodynia: fever, intense abd and chest pains with headache. Chest pain is worsened by breathing or coughing like pleurisy. Illness lasts 4-7 days and is self limiting.

• -Aseptic meningitis
• -Myocarditis, pericarditis (inflammation of heart): Most older children and adults usually recover, it can be fatal in neonates
• -the development of IDDM has recently been associated with enteroviral infection, group B.

• -Treat the symptoms
• -No drugs for treatments or vaccines
• -Provide supportive care and bed rest

• -Flu
• -Helical, ss RNA, 8 RNA segments, enveloped (but hardy virus, can be spread)
• -Serotype A: pandemics
• -Serotype B: Local epidemics
• -Serotype C: rarely causes diseases in man

• -URT by coughing and sneezing
• -Virus survives better in cold, dry air
• -Hence, so many cases in the winter time
• -Incubation period 1-2 days
• -More in winter

-fever, cough, headache, muscular aches and sore throat, and retro-orbital pain (looking up hurts more)

• - envelope contains 2 proteins (H and N)
• H (Hemagglutinin) Attaches to ciliated epithelial cells and kills them
• N (Neuraminidase) Destroys the mucous layer in the throat
• -Decreases PMN activity
• -Secondary bacterial infections common: strep pneumoniae and staph aureus

-Elderly patients with decreased cardio-pulmonary function are especially susceptible to flu and post-flu pneumonia. It can be fatal (40,000 deaths per year in the US)

-Antibod is important for future protection against infection and is specific for defined epitopes on HA and NA proteins. Therefore on you get the flu, you should have life-long immunity, but this does not always happen

-the flu virus changes its H and N antigens

-Minor antigenic change only

• -Minor change (drift): Point
• -Major change (Shift): panademic, antigenic changes to ensure the presence of immunologically naive, susceptible people
• -A can infect humans and animals

• -Minor change
• -Mutation in HA
• -Occurs in influenza A and B viruses: resulting the local epidemic of flu

• -Major changes
• -Reassortment of genomic fragments in A flu only with those in animals which results in major antigenic change in viral HA and NA resulting in pandemics of flu
• -Complete change

Example: H3N2 to H5N1: Pigs were infected with a duck virus and another set of pigs with a human virus. At some point a pig underwent mixed infection with both viruses. The result virus created by reassortment of the viral gene segments that could be transmitted to and infect humans

• -Severe illness
• -Animal Reservoir
• -Spread in human: pandemic
• -Shift and drift change

• -Less severe than A
• -No animal reservoir
• -Epidemic
• -Drift change

• -Not very severe
• -No animal reservoir
• -sporadic in humans
• -Drift change

• 1918: HswN1: probable swine flu strain
• 1947: H1N1
• 1957: H2N2: asian flu strain
• 1968: H3N2, hong kong flu strain
• 1977: H1N1
• H5N1, bird flu, recently in china

• -Amantadine: inhibits uncoating of the virus
• -two new drugs approved in 1999 by the FDA: Relenza: nasally inhaled neuraminidase inhibitor (used for little kids) and tamiflu oral neuraminidase inhibitor

• -killed vaccine is available about 70% effective. Immunity short lived about 1 year, but you should still use it
• -LAIV live, attenuated vaccine called FluMist: nasal spray for 2 mo-49yr old healthy individuals, approved in 2003. Used for children and high risk older individuals
• -Bird flu vaccine approved in 2007, 45% vaccine
• -Swine flue vaccines was FDA approved on sept 15, 2009

• -Complications of the flu vaccine
• -Self-limiting paralysis that occurs within 8 weeks after vaccination in 10 in million people
• -Destroys the protective covering of the myelin sheath, disabling the nerves from transmitting signals to the muscles
• -5-10% have weakness which may last and about 5% die

• -Complication of the flu vaccine
• -Associated with aspirin consumption by children with viral diseases
• -Rare but deadly illness that can affect the liver and brain
• -Vomiting, lethargy, and delirium and if untreated coma and death in 40% of patients
• -Brain damage to survivors

• -Giant cell forming virus, ss RNA, enveloped virus
• -Three serotypes
• -Leading cause of bronchiolitis and pneumonia among infants and children under 1. Most children recover in 8-15 days
• -Kills 14,000/yr

• 1. Coryza: common cold-sneezing, watery eyes
• 2. Croup: inflammation/ narrowing of larynx and trachea (laryngotracheitis). Mucous lining becomes inflamed. Coarse cough
• -although croup is mild, causes severe breathing problems that may need ER treatment.
• 3. Bronchitis and bronchiolitis 50% of infants
• 4. Pneumonia in about 25% of children

• -Virazole brand of ribavirin (aerosol) is effective in lessening the severity of the diseas
• -Immunity is type-specific but not for life
• -Re-infections are common but milder
• -Try putting child in hot bath
• -Hospital staff plays an important role in the transmission
• -Attenuated vaccines are currently being tested

• -ss RNA, enveloped virus
• -Only one serotype
• -Man is the only host
• -Goes to the URT then blood then to the salivary glands
• -Effects one side
• -Incubation time 2-3 weeks

• -Fever, headache, sore throat, loss of energy
• -swelling of salivary glands, chewing painful
• -benign disease, infants rarely affected because of the protective effect of maternal antibodies: Deafness, pancreatitis, diabetes, aseptic meningitis, encephalitis, orchitis (can lead to sterility)

• -live, attenuated vaccine (MMR), 99% effective
• -Safest, only 31 states require proof before school
• -Not everyone immunized so cases increases
• -Immunity life-long, can only get once

• -Rubeola
• -ss RNA enveloped virus
• -One serotype
• -Man only host
• -Transmitted by coughing
• -URT then into the blood and into the skin
• -Incubation time 7-10 days, 7 day measles

• -Fever, headahce, cough, runny nose, photophobia, conjunctivitis and rash
• -Rash on face then goes down the body and the extremities
• -A day or so before rash is visible, small red sports appear on the inside of the cheek. These are called Koplik's spots

-Koplik's spots

• -Measles is one of the most communicable diseases in humans and in unimmunized populations almost every child will get measles early in life (6 mo-2 yrs)
• -Usually there is no scarring, complete recovery is normal, some complications

• -10% get secondary bacterial infections such as pneumonia
• -Encephalitis occurs in 1 of every 1000 cases, 20-40% die, 25% brain damage-can be serious problem
• -A rare sequela of measles infection (non-vaccine) is subacute sclerosing panencephalitis (SSPE) 100% DEATH

• -A live, attenuated vaccine is available
• -life long immunity
• -Should not be given to infants before their 1st bday
• -Pregnant women should not be vaccinated

• -ss RNA, enveloped virus
• -one serotype
• -man only host
• -URT to the blood to the skin, rash
• -3 day measles or german measles
• -Incubation is 7-14 days
• -Rash lasts 3 days, mild fever
• -Self limiting infection, arthritis seen in young women

• -Infection of the fetus from infected pregnant mother because rubella virus can cross the placental barrier
• -Infection in 1st trimester: 30% of fetuses will be stillborn, aborted or deformed at birth
• -Infection in 2nd trimester: 15% deaths, survivors will have cataracts, glaucoma, heart defects, deafness, encephalitis, and underdeveloped organs or tissues

• -No treatment
• -In infection occurs during the first trimester, therapeutic abortion is recommended

• -Attenuated vaccine
• -Immunity life long
• -Pregnant women should never by vaccinated because vaccine can cross the placenta and lead to abnormalities. Women should wait 4 weeks after vaccine to get pregnant
• -Periodic outbreaks at hospital, so all hospital personnel who come in contact with pregnant women must be vaccinated

• -Rhabdovirus
• -ss RNA enveloped virus, bullet shaped
• -One serotype
• -Man accidental host
• -Virus affects warm blooded animal
• -Transmitted by bite of infected animal
• -Bite goes to muscles and CT to PNS then CNS (cell damage in the brain).
• -Affects more wild animals
• -Incubation period 2-16 weeks, but can last up to 2-3 yrs

• -Fever, headache, nausea, sneezing and watery eyes
• -Excitable, develop photophobia, difficulty in swallowing, drooling, fear of water
• -Seizures, delirium, lapse into coma and death
• -50% of those bitten by a rabid animal, get encephalitis of those who are symptomatic, 100% die

• -If a person is bitten, the animal is quarantined for 1-2 weeks to watch for symptoms of rabies. If symptoms develop its brain tissue is examined for the presence of negri bodies in the cytoplasm of nervous tissue.
• Negri bodies are seen in the purkinje cell of the human cerebellum
• -Immunofluorescence is used to look at the brain tissue of animal and human

• -After exposure known post-exposure prophylaxis or PEP is successful in preventing the disease if administered promptly, within six days after infection and consists over 28 days
• 1. Wound care: soap and virus killing cleanser
• 2. One time injection of human rabies immune globulin (HRIG) one day-short term protection against rabies
• 3. active immunization with a vaccine HDCV human diploid cell vaccine-killed vaccine in tissue culture. Given on days 1, 3, 7, 14 and 28

• -Vaccinate vets, park rangers, zoo animal handlers, boosters every 2 years
• -Vaccinate domestic animals and eliminate stray animals from the community
• -Wild-life rabies control is difficult
• -Vaccine laced wild animal cookies to fight rabies outbreak.

• -Arthropod-summer disease
• -ss RNA enveloped viruses
• -Man is accidental host, dead end
• -About 400 types of viruses known
• -Yellow fever eliminated except in some african countries

• 1. West Nile Virus (WNV)-mosquito bites. Crows, robins are mina hosts
• 2. California encephalitis virus (CEV): reservoir in small mammals
• 3. St. Louis encephalitis virus (SLEV): reservoir in birds-someimes causes death in the elderly
• 4. Easter equine encephalitis virus (EEEV): Reservoir in birds, but from horses imported from east coast-65% die, mental sequelae common

• -Arthropod (insect) borne viruses
• -arthropod bites animal then animal bites the human
• -Spread by mosquito bites
• -The virus grows in the salivary glands of the mosquitoes

• -The most effective method of control is through reduction or elimination of mosquitoes-Kerosene sprays in the summer
• -No vaccine has yet proved effective

• -ds RNA containing (11 segments), naked virus
• -Causes significant GI disease, diarrhea, infecting every child around the globe by age of 5.
• -In US and worldwide, leading cause of acute gastroenteritis. 50% infants infected
• -Incubation is 2 days

• -Fever, vomiting, and diarrhea
• -Recovery is normal, except in malnourished children-results in death because of dehydration and electrolyte imbalance
• -HIgh infant mortality in third world countries-formula milk

• -2006 vaccine: Rotateq (Merck): live attenuated pentavalent oral vaccine.
• -Has 5 different viruses in it

• -2nd leading cause of death in developing countries
• -Most common cause of child diarrhea
• -600,000 children die
• -Heavily affects undeveloped countries
• -30-40 deaths from dehydration each year

• -ss RNA containing naked capsid virus
• -Causes approx. 90% epidemic non-bacterial outbreaks of gastroenteritis around the world
• -50% of all found borne outbreaks of gastroenteritis in the US
• -fecal oral route (Ships, hotels, restaurants)
• -Incubation 1-2 days
• -no vaccine
• -hand washing remains an effective method to reduce the spread

• -HIV
• -Flu
• -Respiratory syncytial virus (RSV)
• -Mumps
• -Measles
• -Rubella
• -Rhabdovirus
• -Arbovirus
• These are all spread in closer contact- example droplets

• -Poliovirus
• -Rhinovirus
• -Coxsackievirus and echoviruses
• -Rotavirus
• -Norovirus
• All spread by fecal oral route

• -1985, first description of HIV infection, mononucleosis like, was published
• -ss RNA containing, enveloped virus
• -Two serotypes:
• 1. HIV 1 (Europe, Central Africa, and the Americans
• 2. HIV 2 (West Africa) and India

• -Sexual intercourse, exposure to contaminated blood, or perinatal transmission (mother to baby)
• -Targets include: dendritic cells, APC, macrophages, CD4+ T cells
• -Transmitted via genital, anal, and oral sex

• -RNA (2 codes) that makes DNA uses the host DNA (macrophages/lymph nodes) also in resting (memory T)
• -Incubation period of 200 to 20 years
• -Virus binds to cells that have CD4 antigen (1st receptor)
• -Virus requires 2nd receptor: CXCR4 (Fusin) for T cell tropic or CCR5 for M cell tropic
• -HIV is captured by dendritic cells and delivered to the lymph node where the virus is transmitted to CD4 T cels, lymph node site of virus production
• -Must have receptors to bind

-1% of caucasian population are naturally resistant to HIV infection because of mutation in CXCR4 gene

• 1. Binding and entry
• 2. Reverse transcription
• 3. Integration: Enzyme DNA to integrate into host cell
• 4. Transcription
• 5. Assembly
• 6. Release and protease (into the blood stream)

• -At time of initial infection with HIB, patients have a large # of susceptible CD4 t cells and no specific immune response
• -HIV destroy or disable t cells in an HIV infected individual by several mechanisms
• 1. Direct killing of CD4 cells by HIV gp120 Lysis
• 2. Syncytia formation b/w infected and unfected cells
• 3. Induction of apoptosis in infected cells: programmed cell death
• 4. Cytotoxic cell response to infected CD4 cells and kills them

• -Slow but progressive deterioration in the host immune system and most advanced stages is complicated by opportunistic infections, neurologic disorders, and some forms of cancer
• -Primary infection, HIV disseminates widely through the body. An immune response to HIV ensues with a detectable decrease in viral load. Clincial latency follows but CD4 t cells slowly continue to decrease until they fall to a critical level below which there is a risk of opportunistic infections
• -If person gets AIDs, it means death

• 1. 6 mo-1yr: antibodies in blood, fever, headache, fatigue, t cell count normal (800 mm3)
• 2. 3- yrs, usually no symptoms but swollen lymph glands, viral replication, 3-100 billion a day, immune system can handle
• 3. 1-2 yrs, CMIR is severely impaired, T cell count drops (< 400)
• 4/5. 1-2 yrs, T cell count <200, opportunistic infections
• 6. 1-2 yrs after stage 5, total loss of T cells, weight loss, dementia, unable to walk/talk, waste away

• -60 different opportunistic infections
• -Pneumocystis carinii (fungus): 70% of AIDs patients die of this
• -Mycobacterium tuberculosis
• -yeast, bacterial and viral infections
• -Reactivation of latent herpes viruses
• -Kaposi's sarcoma- HHV 8
• -Encephalitis
• -Thrush is a problem, yeast infection of gum. If get more than twice test for HIV

-Sub saharan africa

-Africa and asia

• - Black
• -Then white then hispanic

• -Women: heterosexual higher
• -Men: homosexual men are higher
• -Women high chance of STDs b/c of anatomy

• -16,000 (10/min)
• -more than 95% in developing countries
• -2000 are in children under 15 yrs of age
• -about 12,000 are persons aged 15 to 49 yrs of whom, almost 50% are women
• 50% are 15-24 years old

• 1. Azido-dideoxythymidine (AZT): first drug treatment inhibits viral genomic replication, side effects virus resistance, toxicity(kids legs swell)
• 2. Protease inhibitors (PI's) inhibit maturation of viral particles. Examples are: Saqunavir, ritonavir, indinavir, and viracept
• HAART (Highly active antiretroviral therapy): A combo of AZT and Pi's
• -Works by suppressing the virus and decreasing rate of opportunistic infections
• -May cause unpleasant side effects in some patients
• -can still transmit HIV to others

• -No vaccine
• -Avoid sex contact with those who have it
• -Use condoms
• -Avoid dirty needle sharing
• -screen blood and blood products for HIV before transfusion, avoid high risk blood donors
• -Abstinence best
• -Circumcision

• -Should assume that the blood and other body fluids are infectious
• -Routinely use barriers
• -Wash hands!
• -Carefully handle and dispose sharp instruments during and after us
• -Report accidental exposure right away
• -Watch for mouth to mouth oral secretions.