(11-30) Blood and Lymphatic Infections Flashcards
1. Relate the nature of circulatory and lymphatic systems to the occurrence of generalized infectious disease. 2. Describe the symptoms, causes, pathology, occurrence, prevention and treatment of Gram-negative septicemia. 3. Describe the history, symptoms, cause, pathology (including virulence factors), forms of the disease, modes of transmission, prevention and treatment of plague. 4. Describe the symptoms, cause, pathology, forms of the disease, modes of transmission, prevention and treatme
What is bacteremia, viremia, and fungemia?
Infections of the blood stream
What is septicemia?
“blood poisoning”
Explain what causes septic shock.
If Gram-negative bacteria enter the blood stream, immune system responds to LPS with system wide inflammation
How are urine output, respiration rate, pulse, and appendages affected by septic shock?
[Gram Negative Septicemia]
- Urine output drops
- Respiration rate becomes more rapid
- Pulse quickens
- Arms and legs become cool and dusky colored
What is the defining symptom of Plague (Black Death)?
Plague is characterized by large tender lymph nodes called buboes.
List 2 symptoms of plague (black death) that would be expected to occur in addition to buboes.
- High fever
2. Shock
Which characteristic is indicative of Pneumonic Plague, but is lacking in Bubonic Plague?
Cough with bloody sputum
[Only if lungs infected by Yersinia pestis]
Which microorganism causes Plague?
Yersinia pestis, a facultative intracellular bacterium.
How many types of plasmids does Yersinia pestis have?
3
Describe the smallest plasmid of Yersinia pestis.
Pla causes protective clots to dissolve via activation of plasminogen activator
Describe the middle plasmid of Yersinia pestis.
The middle plasmid codes Yops proteins and regulators of Yops proteins.
[Yops interferes with phagocytosis.]
Describe the last plasmid of Yersinia pestis (not Pla, not Yops-regulator).
F1 becomes anitphagocytic capsule.
What part of Y. pestis is used in the vaccine for Plague?
Its anitphagocytic capsule
Name an arthropod vector of Plague.
Oriental rat fleas (Xenopsylla cheopis)
How does Y. pestis get from the flea into a human?
Flea regurgitates infected material (that are obstructing its digestive tract) into the bite wound.
Which plasmid is essential for the spread of Plague from the bite site to other body areas within the host?
Pla
Within which cell type does Y. pestis replicate in the infected human, and which important anatomical feature does it create during that time?
- Macrophages
2. Produces F1 capsule
When does Y. pestis produce Yops proteins a long with other survival mechanisms?
After the infected macrophages die and spill the Y. pestis out.
What causes the characteristic swelling of a person infected with Bubonic Plague?
Inflammation
What is Septicemic Plague? How does it occur?
When a person has Bubonic Plague, the nodes may become neurotic and spill Yersinia pestis organisms into the bloodstream, causing a blood infection.
Describe the progression from Bubonic Plague to Pneumonic Plague.
- Flea infects human tissue with Y. pestis.
- Plague spills out of lymph nodes, into blood. [Septicemia]
- Plague travels, via bloodstream, to lungs.
How can Pneumonic Plague be transmitted?
Person-to-person
What are the mortality rates of untreated Bubonic and Pneumonic Plague, respectively?
- Bubonic: 50-80%
2. Pneumonic: ~100%
Can Plague spread person-to-person via household fleas?
Yes
What is the basic preventative measure taken against Plague directed at?
Rat control
Which 4 steps can be taken in an attempt to control rats (hence, Plague)?
- Proper garbage disposal
- Rat-proof buildings
- Guards on morning ropes
- Extermination programs
What type of vaccine is used against Plague, and how effective is it?
Killed vaccine gives partial short-term protection.
Which drug is given to exposed individuals in an attempt to control Plague epidemics?
Tetracycline
Which 3 drugs can be effective against Plague, if given early?
- Gentamicin
- Ciprofloxacin
- Doxycycline
How long is the incubation period for Infectious Mononucleosis?
Symptoms usually appear after long incubation (30 to 60 days) post infection.
List 5 symptoms of Infectious Mononucleosis.
- Fever
- Sore throat covered with pus
- Fatigue
- Enlarged lymph nodes
- Enlarged spleen
How long does it take for the symptoms of Infectious Mononucleosis to be resolved?
- fever and sore throat disappear within 2 weeks
2. lymph node enlargement within 3 weeks
Which agent causes Infectious Mononucleosis?
Epstein-Barr virus
How does an Infectious Mononucleosis infection begin, once the virus is passed to a human?
Infection begins in cells of throat and mouth and become latent in B cells
Where is the Epstein-Barr virus carried to after replication in epithelial cells of mouth, saliva producing glands, and throat?
The lymph nodes
Which 2 paths can the Epstein-Barr virus take once it infects B lymphocytes? What happens in each of those situations?
- Productive – kills cells
2. Nonproductive – virus is latent
What happens after the Epstein-Barr virus infects B-cells? How do T-cells respond to that action?
- Virus activates B cells to produce multiple clones, which produce random immunoglobulins, including heterophile antibodies.
- T-cells destroy the B-cells that are replicating the EB virus.
What happens to the Epstein-Barr infected B-cells that are not cloning?
They are effectively immortal because they do not get attacked by T cells.
Where is Infectious Mononucleosis distributed?
Worldwide
What are the long-term effects of Infectious Mononucleosis-infected individuals in crowded, economically disadvantaged areas vs. more affluent populations?
- disadvantaged areas: infects at early age without producing symptoms, therefore producing immunity
- affluent populations: missed exposure means that they lack immunity and can be infected at older ages
Where does Infectious Mononucleosis occur almost exclusively?
In adolescents and adults who lack antibody
How long can the Epstein-Barr virus be present in saliva?
for up to 18 months
What is an important mode of transmission for the Epstein-Barr virus?
Kissing
What is the animal reservoir for the Epstein-Barr virus?
There is no animal reservoir
How can the Epstein-Barr virus be prevented?
- Avoiding saliva of another person
2. No vaccine
How does Acyclovir work on the Epstein-Barr virus?
It inhibits productive infection, but has no activity on latent viruses.
