MIC 1: Microbiology and Parasitology Module 8.2 — Infections (Key Concepts)

A comprehensive set of practice flashcards covering infectious diseases by body system, major pathogens, transmission, and clinical features from the notes.

What is dermatitis?

Inflammation of the skin.

What is folliculitis?

Inflammation of a hair follicle.

What is a sty (stye)?

Inflammation of a sebaceous gland opening into an eyelash follicle.

What is a furuncle?

A localized pus-producing skin infection arising from folliculitis (a boil).

What is a carbuncle?

A deeper pus-producing skin infection formed from merging multiple furuncles.

What is a macule?

A flat skin lesion that is not raised or sunken.

What is a papule?

A firm, raised skin lesion.

What is a vesicle?

A small, fluid-filled sac or blister.

What is a pustule?

A skin lesion filled with pus.

What causes otitis media (middle ear infection) most commonly?

Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.

What causes otitis externa (swimmer’s ear) often?

Pseudomonas aeruginosa; other causes include E. coli, Proteus vulgaris, Staphylococcus aureus.

What are the infectious diseases of the eye listed?

Conjunctivitis, keratitis, and keratoconjunctivitis.

What is conjunctivitis?

Infection or inflammation of the conjunctiva.

What is keratitis?

Infection or inflammation of the cornea.

What is keratoconjunctivitis?

Infection/inflammation affecting both cornea and conjunctiva.

What are the infectious diseases of the respiratory system mentioned?

Bronchitis, bronchopneumonia, epiglottitis, laryngitis, pharyngitis, sinusitis.

What causes epiglottitis and what risk does it pose to children?

Inflammation of the epiglottis; can cause serious respiratory obstruction, Hib is a common cause.

What causes bronchitis primarily?

Respiratory viruses.

What is bronchopneumonia?

A combination of bronchitis and pneumonia.

What causes pharyngitis and its common etiologies?

Inflammation of the pharynx; most cases are viral, bacterial cause can be Streptococcus pyogenes.

What are the common causes of sinusitis?

Streptococcus pneumoniae and Haemophilus influenzae; less common: S. pyogenes, Moraxella catarrhalis, Staphylococcus.

What is pneumonia?

Inflammation of one or both lungs with exudate in alveolar sacs.

Which dental condition begins with enamel destruction by acids from microbes?

Dental caries; most common cause is Streptococcus mutans.

What causes gingivitis?

Inflammation of the gums (gingiva).

What is periodontitis?

Inflammation of the periodontium, including gums and bone supporting teeth.

What is colitis?

Inflammation of the colon.

What is diarrhea?

Abnormally frequent, loose or watery stools.

What is dysentery?

Watery diarrhea with abdominal pain, fever, dehydration; stools may have blood or mucus.

What is enteritis?

Inflammation of the intestines, usually small intestine.

What is gastritis?

Inflammation of the stomach lining.

What is gastroenteritis?

Inflammation of the stomach and intestine.

What is hepatitis?

Inflammation of the liver; often viral but can be toxin-induced.

What is cystitis?

Inflammation of the urinary bladder; most common UTI.

What are common causes of cystitis?

Escherichia coli is most common; others include Klebsiella, Proteus, Enterococcus, Staphylococcus saprophyticus, Candida albicans.

What is pyelonephritis?

Inflammation of the renal parenchyma (kidney tissue); commonly caused by E. coli.

What is nephritis?

General term for inflammation of the kidneys.

What is ureteritis?

Inflammation of one or both ureters.

What is urethritis?

Inflammation of the urethra; often sexually transmitted.

What is prostatitis?

Inflammation of the prostate gland; can be bacterial, viral, fungal, or protozoal.

What are endocarditis, myocarditis, and pericarditis?

Inflammation of the endocardium (heart valves), myocardium (heart muscle), and pericardium (heart sac), respectively.

What is lymphadenitis?

Inflammation and swelling of lymph nodes.

What is lymphadenopathy?

General term for diseased lymph nodes.

What is lymphangitis?

Inflammation of lymphatic vessels.

What are encephalitis, encephalomyelitis, meningitis, and meningoencephalitis?

Inflammation of brain, brain and spinal cord, meninges, or both brain and meninges respectively.

What is myelitis?

Inflammation of the spinal cord.

What is acne and its key pathogen?

Common teen skin condition; pores clogged with sebum and Propionibacterium acnes.

What are the two forms of leprosy and their pathogens?

Lepromatous leprosy and tuberculoid leprosy; caused by Mycobacterium leprae.

What causes bacterial conjunctivitis (pinkeye) and its common agents?

Redness and discharge; common agents include Haemophilus influenzae subsp. aegyptius and Streptococcus pneumoniae.

What is diphtheria and its pathogen?

Upper respiratory disease caused by toxin-producing Corynebacterium diphtheriae.

What is streptococcal pharyngitis (strep throat) and its pathogen?

Acute bacterial throat infection; caused by Streptococcus pyogenes (Group A Strep).

What is tuberculosis and its transmission?

Lower respiratory infection by Mycobacterium tuberculosis; airborne transmission.

What organism causes whooping cough and what are its stages?

Bordetella pertussis; prodromal, paroxysmal (severe coughing with whoop), and convalescent stages.

What is Helicobacter pylori-associated disease?

Causes chronic gastritis and duodenal ulcers; transmitted likely by ingestion; stored on stomach mucosa.

What causes cholera and how is it transmitted?

Vibrio cholerae; causes profuse watery stools; transmitted fecal–oral and via contaminated water/food.

What causes typhoid fever and its transmission?

Salmonella typhi; systemic illness; transmitted fecal–oral via contaminated food/water.

What pathogens cause gonorrhea and how is it transmitted?

Neisseria gonorrhoeae; contact with infected mucous membranes during sexual activity.

What are the stages of syphilis and the responsible pathogen?

Treponema pallidum; primary (chancre), secondary rash and symptoms, latent, and tertiary with organ damage.

What is tetanus and its causative organism?

Lockjaw; Clostridium tetani produces tetanospasmin neurotoxin; spores in soil enter wounds.

What is leptospirosis and its pathogen?

Zoonotic bacterial infection by Leptospira interrogans; can range from mild to severe multi-organ disease.

What are varicella (chickenpox) and herpes zoster (shingles)?

Varicella-zoster virus (VZV); chickenpox is primary infection, shingles is reactivation.

What viruses cause rubella, measles, and smallpox?

Rubella virus (German measles), Rubeola virus (measles), Variola virus (smallpox).

What precautions are used for influenza and why?

Droplet precautions; typical precautions for 5 days after symptom onset.

What is avian influenza and its notable subtypes?

Influenza in birds; subtypes include H5, H7, H9; H5N1 is highly virulent.

What is SARS and its transmission?

Severe Acute Respiratory Syndrome; SARS-CoV; spread via respiratory droplets and contact with contaminated surfaces.

What is viral gastroenteritis and its common agents?

Diarrheal illness caused by enteric viruses like rotavirus, norovirus, adenoviruses, astroviruses, caliciviruses.

What is viral hepatitis and its major types?

Liver inflammation caused by various hepatotropic viruses: HAV, HBV, HCV, HDV, HEV, HGV.

What is HIV/AIDS and its transmission routes?

Infection with human immunodeficiency virus; transmitted via sexual contact, blood, mother-to-child, or contaminated needles.

What is infectious mononucleosis and its cause?

Kissing disease; caused by Epstein-Barr virus (EBV); may involve fever, sore throat, swollen lymph nodes.

What is mumps and its causative virus?

Infection of salivary glands; mumps virus (Rubulavirus); precautions: droplet until 9 days after gland swelling begins.

What are viral hemorrhagic diseases and examples?

Serious viral infections causing bleeding; examples include dengue, yellow fever, Crimean-Congo hemorrhagic fever, Lassa, Ebola, Marburg.

What is poliomyelitis and its pathogen?

Polio; caused by polioviruses (Picornaviridae); spreads fecal–oral and via throat secretions.

What is rabies and its transmission?

Rabid encephalomyelitis; transmitted via bite with saliva containing virus; also possible airborne exposure in bats.

How are protozoa categorized by movement?

Sarcodina (amoebas), Mastigophora (flagellates), Ciliophora (ciliates), Sporozoa (non-motile as adults).

What disease is caused by Leishmania and what are its forms?

Leishmaniasis; forms: cutaneous, mucocutaneous, visceral (Kala-azar); transmitted by sandflies.

What is toxoplasmosis and its risk in pregnancy?

Systemic infection by Toxoplasma gondii; risk of fetal death or severe congenital defects if contracted in pregnancy.

What is trichomoniasis and its causative parasite?

Sexually transmitted protozoan infection by Trichomonas vaginalis; causes vaginitis in women and urethritis in men.

What is amebiasis and its pathogen?

Infection by Entamoeba histolytica; can cause dysentery and liver abscess; has cyst and trophozoite stages.

What is balantidiasis and its typical reservoir?

Balantidium coli infection; diarrhea or dysentery; pigs are common reservoir.

What is giardiasis and its causative parasite?

Giardia lamblia (Giardia intestinalis); causes diarrhea, steatorrhea; cysts and trophozoites shed in stools.

What causes malaria and what are the Plasmodium species?

Infection by Plasmodium parasites; species include vivax, falciparum, malariae, ovale; transmitted by female Anopheles mosquitoes.

What are the fever cycle characteristics of P. vivax/ovale and P. malariae and falciparum?

Vivax/ovale: tertian (48-hour) cycles; malariae: quartan (72-hour); falciparum: irregular cycle.

What is the life cycle route for malaria?

Cycle involves Anopheles mosquito bite (sporozoites) → liver cells → red blood cells.

What are the main fungal infection categories?

Superficial, cutaneous, subcutaneous, and systemic mycoses.

What are dermatophytes and tinea names?

Molds causing ringworm infections; examples: tinea pedis (foot), unguium (nails), capitis (scalp).

What is Candida albicans and how is it usually classified?

Opportunistic yeast; part of normal flora; can cause thrush and yeast infections.

What is thrush and its causative agent?

Oral candidiasis; white patches on tongue and mucosa; caused by Candida albicans.

What is Pneumocystis jiroveci pneumonia (PCP) and who is at risk?

Fungal-like organism causing pneumonia in immunocompromised individuals, especially AIDS patients.

What is yeast vaginitis and its common cause?

Candida albicans causing vaginal yeast infection with itching and discharge.

What are diagnostic forms for malaria?

Malaria smear (blood smear) and immunodiagnostic/molecular methods; detects intraerythrocytic Plasmodium.