Chapter 27: Diseases Caused by Prions or Viruses
What are the two forms of the polio vaccine?
1) Inactivated poliovirus, series of injection (The only form used today) 2) Oral vaccine, created a risk of actually getting polio
What percentage of bleach is needed to kill a non-enveloped virus?
10% bleach solution
What is Fatal Familial Insomnia?
A genetic disorder within families that results from a mutation of the normal prion protein in the brain. The specific portion of the brain affected in this disease is the thalamus, which is the sleep control center for the body. The presence of the wax-like buildup of amyloid tissues in the brain is a common aspect of this Begins with mild insomnia, they begin to deteriorate Fatal
Severe acute respiratory syndrome (SARS)
A respiratory illness that was first reported in 2003 in Asia, North America, and Europe. It is caused by a novel coronavirus called SARS-CoV. In general, SARS begins with a fever greater than 100.4°F (38.0°C) Headache, overall feeling of body aces, mild respiratory symptoms including, a dry cough Spread from person to person contact through droplet spray
COVID-19
A severe acute respiratory illness caused by a novel coronavirus called SARS-CoV-2, first identified in China in December of 2019. SARS-CoV-2 is an enveloped RNA virus primarily spread through aerosols and respiratory droplets, and can be spread by asymptomatic as well as from symptomatic individuals Impacts elderly, obese people, people with diabetes, high blood pressure more Now younger people are becoming affected 80% of people who are hospitalized are unvaccinated
Monkeypox
A viral disease with a clinical presentation in humans similar to that seen in the past in smallpox patients. The virus responsible for this is related to the virus that causes smallpox; both are orthopoxviruses. Before the eradication of smallpox, vaccination was widely practiced and protected against both diseases. Children born after 1980 have not been vaccinated against smallpox and are likely to be more susceptible to this than older members of the population. The death rate from this is highest in young children, reaching about 10 percent. Sporadic Causes raised, blister-like lesions Mostly found in central and West Africa In the U.S., you can get it from prairie dogs
Chickenpox
An acute inflammatory disease Caused by: Varicella-zoster an infectious disease spread by respiratory tract transmission. Primary symptom is the development of lesions on the skin. Like all herpesviruses, the varicella-zoster virus can remain latent in the body. After recovery from this, the varicella-zoster virus remains indefinitely in the dorsal root ganglia of the spinal cord Used to be a common childhood disease Later develops into Shingles Creates vesicles filled with pus, which would crust over, found on the face, back, neck Can be fatal if it leads to encephalitis Adults have a higher mortality rate
Rabies
An acute, neurotropic, infectious disease caused by a rhabdovirus known as the rabies virus. Can be spread to humans via the bite of infected animals or through aerosols of the virus entering the body. The rhabdovirus colonizes in skeletal muscle and connective tissue for a period of between a few days and several months. The virus then travels along a peripheral nerve to the spinal cord and brain where it causes encephalitis. Incubation period depends on how far away from the brain you've been bitten Can be fatal with no treatment Basically an easy injection for treatment Also called hydrophobia because the patient will have spasms and foaming at the mouth at the thought or sight of water.
Flu
An acute, viral, inflammatory disease of the respiratory system Caused by the influenza virus Chills, fever, general body ache, sore throat
Viral encephalitis
An inflammation of the brain, is caused by an arthropod-borne virus (arbovirus) that has a variety of strains causing endemic outbreaks of encephalitis worldwide. Mosquitoes carry the virus from infected animals to humans. Fatal about 25 percent of the time Characterized by chills, headache, fever, confusion, and coma
Hepatitis
An inflammatory disorder of the liver. It is most commonly spread by five separate viruses with the three most common viruses being: hepatitis viruses A, B, and C.
Hantavirus
Belongs to the bunyavirus family, which contains five genera of viruses that are each made up of single-stranded RNA viruses. The only virus in the bunyavirus family that is rodent-borne, all the others are arthropod-borne Causes a respiratory disease known as hantavirus pulmonary syndrome (HPS) or just hantavirus disease. Although HPS is spread through contact with rodents—especially mice—many infected people do not report contact with rodents Severe shortness of breath, flu-like symptoms, diarrhea, irregular heartbeat Can be fatal
Ebola Hemorrhagic fever (EHF)
Caused by the Ebola virus High mortality rate (88 percent) that has appeared sporadically since it was initially discovered in Zaire, Africa, in 1976. The Ebola virus is an RNA virus that infects both human and nonhuman primates. The disease can then spread between people by way of nosocomial routes, needle-stick injury, or contact with infected bodily fluids. It is not known why some individuals recover from the disease and others do not Very rare
German Measles
Caused by the rubella virus A more mild form of measles than rubeola and often its symptoms are subclinical May get a mild rash and encephalitis Congenital rubella causes birth defects which typically kill the baby. If it doesn't, it will leave the baby with deformities, heart defects, deaf, and mental retardation Treated with MMR vaccine
Measles
Caused by the rubeola virus Extremely contagious and is spread from person to person via the respiratory route Humans are the only reservoir for the rubeola virus Similar to chickenpox and smallpox in its development A rash starts on the face, then trunk, then extremities After the development of a rash, they can get encephalitis which can become fatal. Treated with MMR
Smallpox
Caused by variola virus The virus enters the body through the respiratory system. Has been eradicated through vaccination programs. U.S. and Russia has a smallpox virus, this can be used for biological warfare Edward Jenner created a vaccine using cowpox. Vacca-cow
Hepatitis A virus
Causes Hepatitis A Single-stranded RNA and is non-enveloped Resistant to chlorine Can survive living on fomites Can get it from oysters and clams that live in water contaminated with fecal matter No animal reservoirs
Describe the influenza virus
Causes the flu Consists of eight weakly linked RNA segments enclosed in a layer of protein and an outer bilayer of lipids It can recombine it's eight segments, so it is able to spread through a variety of human and animal strains The vaccine doesn't cover every strain
CJD in deer and elk
Chronic wasting disease
Viscerotropic Diseases
(Visceral) Hepatitis A, B, and C Infectious mononucleosis Mumps Ebola Acquired immunodeficiency syndrome (AIDS)
When do people get infected with herpes simplex 1?
When they're infants
Acquired immunodeficiency syndrome (AIDS)
a contagious disease that compromises the immune system. Caused by the human immunodeficiency virus (HIV), which is transmitted in body fluids. HIV is a retrovirus that causes the depletion of CD4+ T cells within the immune system. No cure; however, a variety of chemotherapeutic agents are lengthening the lives of HIV- infected individuals. The average incubation period for this development is 10 years from the point of initial infection HIV won't necessarily develop into this Once your T cells get depleted to a certain level, then you're considered to have this Getting infusions can increase the risk of developing this Can get opportunistic infections pneumonia, Toxoplasma gondii, cytomegalovirus, histoplasma capulatum, tuberculosis Can be spread by needlesticks PPE, universal precautions
Amyloid
a large polymer of glucose often found in tuberculosis, leprosy, Hodgkin's disease, and cancers
What is a dermatropic disease?
a skin disease
Inclusion disease
a viral infection caused by the cytomegalovirus (CMV), a herpesvirus that causes cellular swelling resembling "owl's eyes." Chronic The virus is shed in body secretions such as saliva, urine, semen, vaginal secretions, and breast milk. It is estimated that 80 percent of the United States carries the cytomegalovirus. Harbored in the parotid salivary glands Can be transmitted to children Typically doesn't cause problems Causes problems during pregnancy and people with suppressed immune systems BIG problems in people with AIDS
What is a virus?
an intracellular, infectious parasite capable of living and replicating only in living cells. Can infect almost any living cell including bacteria, fungi, parasites, plants, animals, and human cells. Basically a piece of genetic material wrapped in protein, and they contain only one type of nucleic acid, either DNA or RNA. Some are also wrapped in a lipid membrane called an envelope. They replicate inside living cells by using the cell's own structures to reproduce more infected cells. Viruses are some of the smallest human pathogens.
Herpes
both a sexually transmitted disease and an infectious disease of the integument. The herpes simplex 1 virus The herpes simplex 2 virus
Hepatitis C
caused by the HCV, which is an enveloped RNA virus that is spread through direct contact with blood or other body fluids. Subclinical in 80 percent of the suspected cases, with an incubation period of between 2 and 22 weeks. Half of the cases progress to chronic hepatitis. The characteristics of this infection are similar to hepatitis B infection: jaundice, fatigue, dark urine, abdominal pain, loss of appetite, or nausea. Most cases of this are transmitted through the use of illegal injected drugs A lot of people are asymptomatic No vaccine
Shingles
Develops from the varicella-zoster virus that has remained latent. Develops under periods of stress or compromised immunity Causes extremely painful skin lesions Creates blisters that are similar to the ones as chicken pox except, they are typically unilateral, and the blisters will follow the path of the sensory nerve in the area. Can be found anywhere, including the eye Can be fatal (5-15%) Can be treated with cyclofere
When does herpes simplex 1 pop up?
During periods of stress
Mumps
Epidemic parotitis An infectious disease of the parotid salivary glands caused by the mumps virus, which is an enveloped RNA virus. The symptoms are swelling and pain in the parotid glands, fever, and painful swallowing. In males, four to seven days after the onset of symptoms, inflammation of the testicles can occur. Inflammation of the testicles is known as orchitis, a condition that can lead to sterility. A case of this can also lead to meningitis, inflammation of the ovaries (oophoritis), pancreatitis, and deafness. Enlarged neck Spread by droplets More of a concern in adults Prevented with the Measles, Mumps and Ruebella (MMR) vaccine
What does herpes simplex 1 cause? Is it curable?
Fever, blisters, and cold sores. No, It will remain in the brain forever
Herpes simplex 2
Genital herpes 12% of the population in the U.S. between the ages of 15 and 50 are infected with this Highly transmittable because most people don't have symptoms Causes blisters on the genitals that crust over The first outbreak can be pretty severe Reoccurring outbreaks
Hepatitis A
Infectious hepatitis Spread via the fecal-oral route by the ingestion of contaminated food and water Caused by the Hepatitis A Virus (HAV) The virus resides in the epithelial lining of the human intestinal tract. After sufficient growth in the intestine, the virus replicates in the blood, and the kidneys, liver, and spleen become infected. Can get it from oysters and clams that live in water contaminated with fecal matter Self-limiting, once you know you have it, you're not contagious anymore Subclinical
Pneumotropic Diseases
Influenza Common cold Hantavirus Pulmonary Syndrome SARS COVID-19
West Nile Virus
It's a flavivirus Can infect humans, birds, mosquitoes, horses, and some other mammals. Usually causes mild disease in people Characterized by flulike symptoms lasting only a few days with no long-term health effects. The spread of disease is being limited through mosquito control Found in Africa Related to St. Louis encephalitis Causes meningitis, meningeal encephalitis, which is inflammation of the brain and the surrounding membrane
What is a prion?
It's a small, proteinaceous, infectious particle that is resistant to most procedures that modify nucleic acids Non-living Obligate intracellular Resistant to formaldehyde Usually not destroyed by any enzymes
Infectious mononucleosis
Kissing disease and college disease, is an infectious inflammatory disease Caused by the Epstein-Barr virus (EBV) also known as human herpes virus 4. It affects young adults between the ages of 15 and 25. Outside the United States, the disease is asymptomatic for most children in less developed nations because they are exposed to EBV at an early age. The disease is generally self-limiting and few fatalities occur. When the disease is fatal, the cause of death is usually a ruptured spleen during vigorous activity. Easily spread through droplet spray, kissing, sharing drinks Chronic fatigue for weeks Usually not fatal
CJD in cows
Mad cow disease
What does MMR stand for?
Measles, mumps, rubella
Common cold
More than 200 different viruses are known to cause the symptoms of this disease Rhinoviruses and coronaviruses are 2 of the most common causes More common in children because they aren't as sanitary and are in close contact with other kids Lasts ~14 days Runny nose, sore throat, cough, congestion Several medications are on the market to decrease the timeline of the cold. Zinc lozenges- The zinc binds to the site where the Rhinovirus or coronavirus would normally bind To keep it from spreading, wash hands
Is herpes curable?
No, but it's treatable
Poliomyelitis
Polio A neurotropic, viral infection caused by the poliovirus. Although the disease conjured images of paralyzed victims in the mid-1900s, less than 1 percent of those infected develop paralysis. Only about 10 percent of those infected with the virus even develop symptoms of sore throat, headache, fever, and nausea. Humans are the only known host for the poliovirus, and infected populations shed the virus in their feces. The virus is usually transmitted through contaminated water supplies Used to be treated with the iron lungs Begins in the throat and small intestine, in the CNS, where people become paralyzed Two forms of vaccines
Neurotropic (CNS) Diseases
Rabies Polio Viral encephalitis West Nile
CJD in sheep
Scrapie
Are enveloped sensitive or resistant to disinfectants? Why?
Sensitive because you can dissolve the fat layer. Non-enveloped viruses are more difficult to control
Hepatitis B
Serum hepatitis Spread through contaminated body fluids such as blood In the U.S., the most important routes of transmission of this are through sexual contact and perinatal. Perinatal transmission from mother to infant during childbirth can be very efficient Healthcare providers are at an increased risk Isolated in numerous bodily fluids (i.e., blood, saliva, breast milk, semen, vaginal secretion) HBV Can be severe, chronic, and fatal Common among IV drug users, and tattoo studios The vaccine has to be offered to employees for free
Dermatropic diseases
Smallpox Monkeypox Measles German measles Chickenpox Shingles Herpes
What are diseases caused by prions called? Why?
Spongiform encephalopathies, because that leave holes in the brain tissue that resemble a sponge
How do you get different strains of flu?
The eight segments of the influenza virus recombine
What is the common denominator of all prion disorders?
The presence of amyloid deposits in the tissues
Describe Creutzfeldt-Jakob Disease (CJD).
These people suffer severe dementia Prions are harbored in the brain and CNS Fatal Progressive disease that causes spongiform degeneration of the brain. There is a long incubation period measuring between months, years, and decades associated with the disease No treatment
How can Prion-diseases develop?
They can be inherited or develop sporadically and be transmitted through blood to blood contact
How do you treat someone with CJD?
Use universal precautions Avoid contact with the brain tissue and the spleen