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45 Cards in this Set
- Front
- Back
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Nervous and cardiovascular systems |
- harder for pathogens to breech but easier to grow once they're there - "inside" = to microbiota - less competition & sometimes less immunity |
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Meninges |
- nervous system - 3 continuous membranes - cover, protect CNS |
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cerebrospinal fluid (CSF) |
- nervous system - fluid circulating in space between two of the meninges --> little immunity = easy to multiply |
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Blood brain barrier |
- nervous system - capillaries selective in substances able to pass blood --> brain (non-lipid soluble drugs can't) |
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Meningitis |
- nervous system disease - symptoms: initially fever, headache, stiff neck - then nausea, vomiting, can lead to convulsions/coma |
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Meningitis |
- nervous system disease - mortality rate: varies by pathogen, but is generally high for an infectious disease today - can be bacterial, viral, fungal, or protozoan - viral likely more common than bacterial but often milder - mostly enteroviruses |
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Bacterial Meningitis |
- most commonly caused by Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae - virulence factor: all have capsules for protection against phagocytosis |
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H. influenzae type B (Hib) |
- bacterial meningitis - aerobic, gram-negative - almost eliminated in US thanks to vaccine, but most cases worldwide - mortality about 6%; also throat microflora, pneumonia |
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N. meningitidis (meningococcal) meningitis |
- aerobic, gram-negative - transmit via droplet aerosols, direct secretion contact - potent endotoxin: can cause death within hours |
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Meningococcal meningitis |
- symptoms: throat infection -> bacteremia -> meningitis - outbreaks in crowded areas: dorms, military barrocks - treatment: quick death after fever onset, but antibiotic has reduced mortality |
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S. pneumoniae meningitis |
- Gram + diplococci - pneumococcal meningitis - leading cause - vaccine available - Problem: antibiotic resistant strains appearing |
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Meningitis |
- life threatening & fast development - treatment often initiated before diagnosis is complete - need cerebrospinal fluid sample |
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Tetanus |
- Clostridium tetani - Gram +, endospore forming obligate anaerobe - often found in soil contaminated by animal feces - extremely potent exotoxin; neurotoxin tetanospasmin |
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Tetanus |
- spastic paralysis of muscles, starts with lock jaw then affects other muscles - toxin enters CNS or PNS through the blood - rare thanks to DTaP vaccine, but need boosters |
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Botulism |
- Clostridium botulinum - Gram +, endospore-forming obligate anaerobe - Foodborne intoxication: ingesting cells/endospores usually causes no harm but ingesting the exotoxin does - infants: less microbiota, so can get infectious |
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Botulism |
- neurotoxin blocks release of acetylcholine from nerve synapses; so can't transmit nerve/impulse leads to... - Flaccid paralysis for 1-10 days - can result in cardiac/respiratory may precede |
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Botulism |
- 3 types (A, B, E) vary in severity - rare due to current food industry practices - treatment is heavily supportive - extended respirator distance, neurological impairment may persist for months - Antibiotics useless due to performed toxin but antitoxin can help if early |
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Rabies |
- rabies virus - untreated, almost always results in fatal encephalitis - incubation up to 6 years - often transmitted by saliva of infected animal during bite - once symptoms develop, no real effective treatments |
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Rabies |
- Treatment = post-exposure passive immunization followed by active vaccine - incubation period usually long enough to allow immunity to develop from active immunization - natural infection usually low dose = no immune response |
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Septicemia |
- bacterial cardiovascular/lymphatic disease - acute illness associated with microbes or their toxins in the blood |
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Sepsis |
- bacterial cardiovascular/lymphatic disease - systematic inflammatory response syndrome (SIRS) when infection leads to inflammatory compounds to blood. |
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Severe sepsis |
- sepsis - shock - drop in blood pressure - at least one organ starts to malfunction |
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Septic shock |
- sepsis - low blood pressure no longer controlled by addition of fluids |
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lymphangitis |
- inflamed lymph vessels - visible as red streaks under skin infection site -> arms or legs - often accompanies septicemia & sepsis |
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Gram-negative sepsis |
- sepsis - caused by endotoxin - most common cause of septic shock |
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Gram-positive sepsis |
- now most common sepsis cause - S. aureus, S. pyogenes - Enterococcus faecalis & E. faecium: leading nosocomial infections - drug resistance |
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Anthrax |
- Bacillus anthracis - endospore forming Gram + soil dwelling aerobe - very rare in humans but seen in grazing animals like cattle & sheep - infection initiated by endospores = taken up by macrophages & germinate - antibiotics are effective |
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Edema toxin |
- B. antracis virulence factor - exotoxin - causes localized swelling, interferes with macrophage phagocytosis
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Lethal toxin |
- B, anthracis virulence factor - Exotoxin - targets & kills macrophages |
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Protective antigen |
- B. anthracis virulence factor - binds two primary toxins to target cells & permits their entry |
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Unique capsule |
- B. anthracis virulence factor - compromised of amino acids, not polysaccharides - no immune inhibition until there are tens of millions of cells per ml of blood - amount of toxin secreted by many bacteria leads to death |
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Cutaneous |
- type of anthrax - skin - usually don;t enter bloodstream - with antibiotics, mortality greater than 1% |
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Gastrointestinal |
- type of anthrax - rare - nausea, abdominal pain, blood diarrhea, ulcerative lesions along tract - greater than 50% mortality |
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Inhalation |
- type of anthrax - most dangerous - inhaled into lungs = high probability of entering blood - close to 100% mortality |
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Plague |
- Yersenia pestis - Gram -, rod shaped enteric bacterium - can survive in phagocytic cells - transmitted by rat fleas, inhalation - rarer now, few cases per year |
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Bubonic plague |
- Yersenia pestis - enters bloodstream, lymph via flea bite - overwhelming infection as increase in cell number - leads to fever, swollen lymph nodes in groin, armpit |
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septicemic plague |
- Yersenia pestis - when enters blood and proliferates - leads to septic shock - more serious form |
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Pneumonic plague |
- Yersenia pestis - after septicemic, eventually enters lungs - rarely can be controlled if not recognized within 12-15 hours of onset fever - spread by airborne droplets |
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Lyme disease |
- Borrelia burgdorferi - spirochete transmitted by tick bite - need 2-3 days of tick attachment for transfer, infection - "bull's eye" rash - flu-like symptoms in couple of weeks - antibiotics very effective at early stage |
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Lyme disease |
- untreated chronic -> arthritis in 40-60% of patients - heart damage - chronic neurological symptoms - diagnosis likelihood of incidence + serological tests - treatable w/ antibiotics, earlier is better |
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Burkitt's lymphoma |
- Epstein Barr (EB) viral disease - fast growing tumor of the jaw; most common childhood cancer in Africa - mechanism/cause not well understood - malaria impairs EB IR --> lymphoma |
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Infectious mononucleosis |
- EB viral disease - sore throat, fever, swollen nodes, general weakness - transmitted by saliva - 20% adults carry - self-limiting, immunity is permanent |
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Malaria |
- Protozoan cardiovascular disease - Plasmodium transmitted by mosquito - chills & fever, often vomiting & severe headache - alternate symptoms or no symptoms ~2-3 days |
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Chaga's disease |
- Protozoan cardiovascular disease - Trypanosoma cruzi - transmitted by wild animals & kissing bug - acute stage fever/swollen glands, can go chronic up to 20 years later |
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Toxoplasmosis |
- Toxoplasma gondii - ingest cystis from undercooked meat or while cleaning cat liter - mild to no symptoms in healthy -> dormant cysts - impaired IR: reactivate -> eye / neurological damage |
