Infectious Disease Flashcards
What is a host?
A human or animal that a pathogen lives in or on. You = Airbnb for germs!
What is a pathogen?
A microorganism that causes disease (bacteria, viruses, fungi, parasites). The villains of microbiology!
What is colonization?
A pathogen living in a host WITHOUT causing symptoms (yet).
What is an infection?
The pathogen invades, multiplies, and causes disease.
What is virulence?
How strong or dangerous a pathogen is! (Is it a tiny gremlin or a full-blown supervillain? 🤔)
What is a reservoir?
Where the pathogen hangs out when it’s not infecting someone.
Example: A person (Typhoid Mary) or an object (dirty water, doorknobs!).
What is a vector?
A living thing that carries pathogens to a new host (like a mosquito, tick, or flea). Think of it like Uber for germs! 🚖
What is epidemiology?
The study of how diseases spread & affect populations. Like detective work for germs!
What is incidence vs. prevalence?
✔️ Incidence = New cases (like new COVID cases this month).
✔️ Prevalence = All current cases (like total active cases worldwide).
What do endemic, epidemic, and pandemic mean?
🟢 Endemic → Normal, steady level of disease (Example: Common cold! 🤧).
🟡 Epidemic → Sudden increase in cases in one area (Example: Ebola outbreak!).
🔴 Pandemic → Global outbreak (Example: COVID-19!).
What is normal microbial flora?
Good bacteria that live in or on your body and help keep you healthy!
How do normal flora help?
They produce nutrients & block harmful pathogens.
Example: Gut bacteria help digest food!
Why do doctors worry about normal flora getting into sterile sites?
If they enter areas like the blood or brain, they can cause serious infections!
What is immunocompetence?
Your body’s ability to fight infection! 💪 Strong immune system = less likely to get sick!
What is immunosuppression?
A weak immune system = higher risk of infections.
What is an opportunistic infection?
A disease that attacks when your immune system is weak.
Example: HIV patients getting pneumonia.
What are the 4 major types of infectious microbes?
1️⃣ Bacteria (unicellular, prokaryotic, named by shape & staining).
2️⃣ Viruses (DNA or RNA inside a protein coat, need a host to multiply).
3️⃣ Fungi (mold-like organisms → Example: Ringworm, Candida).
4️⃣ Parasites (protozoa, worms, insects → Example: Malaria, tapeworms).
What’s a fomite?
A contaminated object that spreads infection.
Example: Doorknobs, phones, dirty needles!
What’s the difference between innate & adaptive immunity?
✔️ Innate immunity = First line of defense, general protection (skin, stomach acid, WBCs).
✔️ Adaptive immunity = Specific, slower but smarter! (T cells, B cells, memory cells).
What are antibodies (Igs)?
Proteins made by B cells that attack specific pathogens.
What are the 5 ways pathogens enter the body?
1️⃣ Skin (Cuts, bites, burns, surgical wounds).
2️⃣ Respiratory tract (Airborne viruses, bacteria).
3️⃣ GI tract (Contaminated food & water → Fecal-oral route).
4️⃣ Genitourinary tract (STDs, UTIs).
5️⃣ Blood-to-blood transmission (Needles, transfusions, childbirth).
What’s an example of a congenital infection?
A baby getting rubella from its mother before birth.
What bacteria causes MRSA?
Methicillin-resistant Staphylococcus aureus (S. aureus) → Antibiotic-resistant! 😨
What is Streptococcus pyogenes (GABHS)?
A bacteria that causes strep throat & rheumatic fever.
What causes pneumonia?
Streptococcus pneumoniae → The #1 cause of community-acquired pneumonia!
What bacteria causes meningitis?
Neisseria meningitidis → Spreads by droplets & can be deadly!
What bacteria cause food poisoning?
• Salmonella → From raw eggs, poultry.
• Shigella → Causes bloody diarrhea!
• E. coli O157:H7 → Found in undercooked meat, can cause kidney failure (HUS).
• Cholera (Vibrio cholerae) → Causes “rice water” diarrhea.
What viruses are covered by the MMR vaccine?
Measles, Mumps, Rubella!
What virus causes chickenpox & shingles?
Varicella-Zoster virus (VZV).
What virus causes cold sores & genital herpes?
Herpes Simplex Virus (HSV).
HSV-1 = Cold sores
HSV-2 = Genital herpes
What is Candida albicans?
A fungus that causes yeast infections & thrush.
What is malaria?
A disease caused by Plasmodium protozoa, spread by mosquitoes.
