Chapter 10- Infectious Diseases Flashcards
Define
A. Mortality B. Morbidity C. Endemic D. Prevalance E. Incidence F. Epidemic G. Pandemic
A. Mortality is the deaths caused by a disease
B. Morbidity is a person that is in a state of a disease
C. Endemic is a disease that will always be present within a population(eg: TB)
D. Prevalance is the number of people with the disease at a specific time
E. Incidence is the number of new cases of a disease within a specific time
F. Epidemic is a localised concentration of a disease
G. Pandemic is the worldwide spread of a disease
What is infectious disease?
A disease caused by a pathogen(bacteria, virus, protoctist, fungi) that is transmissible via a vector or the environment
Measles; causative organism, name of pathogen, symptoms, treatment
Measles is caused by a virus, specifically the Morbilivirus
Measles is an airborne water droplets disease
Symptoms:
- High fever
- Rash
- Conjuctivitis
- Pneumonia(in severe cases)
Treatment:
- Drugs are only taken to treat the symptoms and associated fever(no specific treatment as it is caused by a virus)
Cholera; causative organism, name of pathogen, symptoms, treatment
Caused by bacteria, specifically Vibrio Cholerae
Cholera is a water borne and food borne disease
Symptoms:
- Severe diarrhea
- Vomitting
- Fatigue
Treatment:
- Oral rehydration therapy: to replace the water and salts lost through diarrhea and vomitting
- Antibiotics: inhibits the activities of the Vibrio Cholerae
How does the Vibrio Cholerae works?
Once the pathogen gets inside the body, it makes its way towards the digestive track
If the conditions of the stomach is acidic enough, the pathogen is destroyed, but about 1/3 makes it to the intestine
They develop flagellum to move through the intestinal wall. Once they reach the intestinal wall, production of flagellum is stopped and replaced with hair-like protein structures that assists the pathogen in attaching to the wall of intestine
Once attached, they invade the host cell and secretes cholera toxin that pumps out the chloride ions out of the cells. The solute potential is lowered, thus water leaves the cells by osmosis leaving the cells and body to be dehydrated
Tuberculosis; causative organism, name of pathogen, symptoms, treatment
TB is caused by bacteria, specifically the M. Tuberculosis/M . Bovis
TB is an airborne water droplets disease
Symptoms:
- Persistent cough
- Constant fatigue
- Loss of appetite
- Fever and night sweats
- Coughing up blood
Treatment:
- Drugs: Isoniazid, Pyrazinamide
- Vaccine: Bacillus Calmette-Guecerin(BCG) vaccination to infants
Malaria; causative organism, name of pathogen, symptoms, treatment
Caused by protoctist(eukaryote), specifically P. Falciparum/P. Vivax/P. Ovale/P. Malariae
P. Falciparum usually causes the most severe cases of malaria
Malaria is spread through an insect vector, the female Anopheles mosquito
Symptoms:
- Headache
- Profise sweating and chills
- Muscle pain and fatigue
- Nausea and vomitting
Treatment:
- Anti malarial drug: quinine and chloroquine
- Prophylactic(preventative) drug: stop infection from occuring if a person is bitten by an infected mosquito
What is MDR-TB and XDR-TB?
MDR-TB: multi drug resistant tuberculosis
XDR-TB: extensively drug resistant tuberculosis
Explain how malaria is transmitted and the pathogen’s life cycle
A mosquito takes in a blood meal from an infected person, taking up the pathogen’s gametes together
The male and female’s gametes fuse together inside the mosquito’s gut, forming an infective stage and moves to the mosquito’s salivary glands
The mosquito bites another person(uninfected) transmitting the pathogen as it passes down anticoagulant in its saliva during blood meal
The pathogen goes to the liver within minutes and starts reproducing rapidly(some may lie dormant in the liver and become activated years after initial infection)
The pathogen then gets into the blood stream, enters red blood cells and further reptoduction occurs inside it. The pathogen multiplies causing the red blood cell to burst.
This repeating cycle depleted the body of oxygen and red blood cells causing anemia and fever
Two types of bacterial DNA
- Bacterial DNA: contains genes that are responsible for cell functioning and activities
- Plasmid: contains genes that are not related to life functions, ie antibiotic resistance
How does bacterial resistance spread?
- Vertical transmission: involves normal mitosis/cell replication
- Horizontal transmission: involves conjuction between a bacteria with a mutation and one without(no mitosis) through sharing the plasmid via pilus(organelle)
What determines whether a mutation is good or bad?
Selective advantage
A mutation that makes a bacteria resistant to any type of drug may not be a good mutation during the time the drug was not yet discovered
Thus, a mutation is good or bad depends on the environment
HIV/AIDS; causative organism, name of pathogen, symptoms, treatment
Caused by a retrovirus, specifically the Human Immunodeficiency Virus(HIV)
Transmissible by blood and body fluids
Symptoms:
- They might not show for up to 8 years
- An infected person will have a weakened immune system
Treatment:
- ART(anti retroviral therapy): infected person takes up a regime of strict anti retroviral drug
- ART doesn’t cure HIV, but it helps the patients live a longer and healthier life and it reduces the risk of HIV transmission
How does HIV medicines work?
The medicine prevents HIV from multiplying/making copies of itself, reducing the number of HIV in the body
This provides the immune system time to recover
What is opportunistic infection and opportunistic disease?
Opportunistic infection is an infection caused by a pathogen(bacteria, virus, fungi, protoctist) that takes place due to a weakened immune system caused by another disease/pathogen
Opportunistic disease is a disease that occur more frequently and are more severe in individuals with weakened immune systems, including people with HIV
