Infectious Diseases Flashcards
Why are infectious disease is particularly tragic?
They are largely preventable and treatable.
Infectious agent is a disease causing organisms
Pathogen
Diseases transmitted by human contact
Contagious, or communicable
Diseases that cannot be transmitted directly from person to person
Noncommunicable
The study of the transmission, occurrence, distribution, and control of disease.
Epidemiology
Number of new cases of a disease in a population
Incidence
The number of existing cases of a disease
Prevalence
When a disease always occurs at low levels in the population, it is said to be
Endemic
It’s a disease occurs in unusually large numbers over a specific area, it is a
Epidemic
When an epidemic has spread to include several large areas worldwide, it is said to be
Pandemic
When a disease suddenly occurs in unexpected numbers in a limited area and then subsides
Outbreak
Certain diseases that are under constant surveillance in the United States
Notifiable diseases
The source of an infectious agent
Reservoir
Examples of reservoirs
Humans, animals, insects, soil, and water
Infectious disease is that can be transmitted directly from an infected human to a susceptible human
Horizontal transmission
Diseases transmitted to newborns from infected mothers
Vertical transmission
What’s the most frequent and easiest portal of entry for pathogens?
Respiratory tract
Punctures, injections, bites, and surgery can allow microorganisms to be deposited directly into the tissues below the skin
Parenteral route
Inanimate object that is contaminated by direct contact with the reservoir
Fomites
Short for proteinaceous infectious particle, is an infectious agent composed only of protein
Prion
Disease caused by a prion
Creutzfeldt-Jakob disease (CJD)
Infectious particles made of core of genetic material wrapped in a protein coat (capsid)
Viruses
The viruses insert themselves in cells and do not reproduce. At this time, no signs and symptoms may be present until a trigger activates the virus.
Latent infection
Microscopic, single celled organisms
Bacteria
What are the different shapes of bacteria?
Spherical (cocci), rod shaped (bacilli), spiral shaped (spirilla), corkscrew shaped (spirochetes), comma shaped (vibrios)
Thick cell walls turn blue-purple and thin-walled cells become red; thus, bacteria can be identified using this technique.
Gram stain
Many bacteria secrete on their surface of a substance, also called sugarcoat
Glycocalyx
Often protect bacteria from the phagocytosis by host cells
Capsule
Aid in attachment of bacteria to surfaces
Slime layer
A particularly potent Thompson that causes life-threatening shock, produced by bacteria
Endotoxin
Process in which bacteria grow rapidly and reproduce by splitting in half
Binary fission
Single celled eukaryotic microorganisms
Protozoa
Single celled or multicelled organisms with cell walls contain special polysaccharide called chitin.
Fungi
Another name for fungal infections
Mycoses
Parasitic worms
Helminths
Hospital acquired infections
Nosocomial infection
Treatment for infectious diseases
Bacterial infections can be treated with a variety of antibiotics
Treatment for viruses
Some antiviral drugs act as nucleic acid analogs
Treatment for fungal infections
Antifungal drugs target fungal walls and membranes but can affect human cells as well
Treatment for protozoan infections
Treated with drugs that interfere with protein synthesis and metabolism
Known diseases that have reappeared after a significant decline in incidence
Reemerging infectious diseases
A highly contagious disease caused by the rubeola virus. Is spread by respiratory droplets or airborne transmission.
Measles
Signs and symptoms of measles
Fever, cough, runny nose, and fatigue, followed by a rash that usually begins on the head and spreads over the body. Grayish spots, called Koplik spots, develop inside the mouth. Diagnosis is based on history of exposure and physical examination.
Is there a cure for measles?
There is no cure, but usually runs it’s course in 7 to 10 days, and can be prevented with the MMR vaccine
Caused by the rubella virus. Is highly contagious and spread by respiratory droplets, by airborne transmission, and can be transmitted from pregnant women to their fetus.
Rubella (German measles or three day measles)
What happens when a pregnant woman gets rubella?
It may cause congenital rubella syndrome, with potentially devastating consequences for the developing fetus.
Symptoms and signs of rubella
Develop a rash that appears is either pink or light red spots, which may merge to form evenly colored patches. Symptoms found in teens and adults may include headache; loss of appetite; mild conjunctivitis, a stuffy or runny nose with pain and swelling
How do you treat rubella?
Treatment is supportive and may include pain relievers and fever reducers.
But how do I prevent rubella?
With the MMR vaccine, stupid!
A highly contagious BACTERIAL infection caused by Bordetella pertussis. Is spread by direct contact with respiratory droplets.
Whooping cough
What are the signs and symptoms of whooping cough?
Runny nose, sneezing, mild cough, and low-grade fever. After a few weeks, the cough develops into coughing spells that end with a working sound when the patient breeds in. It is diagnosed by surveillance and bacterial cultures of nose and throat.
How do you treat whooping cough?
With use of antibiotics (because it’s a bacterial infection)
How do I prevent whooping cough?
With the DTaP vaccine
A highly contagious bacterial disease caused by Corynebacterium diphtheriae, and is primarily spread by respiratory droplets.
Diphtheria
What are the signs and symptoms of Diphtheria?
Low-grade fever and a sore throat. Bacteria produce a toxin that can cause a thick coating in the nose, throat, or airway that may hinder breathing and swallowing. This toxin may damage the heart, kidneys, and nervous system. 50% of patients who do not get treatment die.
How do you treat diphtheria?
Because it’s a bacterial infection, use of antibiotics and antitoxins will treat this.
How do you treat Diphtheria?
With the DTaP vaccine
Need bacterial infection caused by Clostridium tetani. This bacteria is found in contaminated soil and animal excrement and enters the body via wounds.
Tetanus
How can I tell if someone has tetanus?
Bacteria produce a toxin that affects the nervous system, causing stiff neck, lock jaw, muscle spasms, and difficulty swallowing. Diagnosis is based on history of exposure, and signs with symptoms.
How do you treat tetanus?
With antibiotics and injection of tetanus immunoglobulin.
How do I treat tetanus?
With the DTaP vaccine.
A highly contagious VIRAL infection caused by the varicella zoster virus. Is spread by direct contact, droplet transmission, and airborne transmission.
Chickenpox
What are the signs and symptoms of chickenpox?
Symptoms begin with a runny or stuffy nose, sneezing, fever, and a cough. A few days later and itchy rash appears on the chest and face. At first looks like pinkish dots that quickly develop with a blister on top. Person is contagious from up to 48 hours before initial ration occurs.
How do I treat chickenpox?
Treatment is supportive and include treatments to control scratching, pain relievers, and fever reducers.
Is there a vaccine for the varicella zoster virus?
Yes
What bacterium causes disease including meningitis and pneumonia?
Haemophilus influenzae type b (Hib)
How does Hib spread?
By respiratory droplets. This causes fever, chills, lack of appetite, extreme sleepiness, severe headache, and stiff neck or back. Severe cases may cause mental confusion, convulsions, shock, and coma.
How do you treat someone with Hib?
With antibiotics, and a vaccine is available
Caused by the poliovirus
Poliomyelitis. Is transmitted by direct person-to-person contact or by indirect contact with infectious saliva or feces or with contaminated sewage or water.
What are the symptoms and signs of polio?
It is asymptomatic in 95% of cases. However, patients may have sore throat, fever, nausea, vomiting, and constipation. Some patients may develop acute flaccid paralysis. limbs appear loose and floppy.
Can you treat someone with polio?
Treatment is supportive and maybe including release. A vaccine is available for polio.
A bacterium that causes diseases including meningitis and upper and lower respiratory disease.
Streptococcus pneumoniae
Signs and symptoms of streptococcus pneumoniae?
Chills, fever, headache, your pain, cough, chest pain, disorientation, shortness of breath, occasional stiff neck.
Can you treat someone with streptococcus pneumoniae?
Yes, with antibiotics, although antibiotic resistance is a problem. There is a vaccine available for this bacterium.
Review questions on page 52
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