Exam 4- Chapter 23 Flashcards
Gram-Negative Sepsis
- Also called endotoxin shock
- Endotoxins (lipopolysaccharides [LPS]) cause a severe drop in blood pressure
- Antibiotics can worsen the condition by killing bacteria
- Treatment involves neutralizing the LPS components and inflammatory-causing cytokines
Gram-Positive Sepsis
- Potent exotoxins that cause toxic shock syndrome
- Hospital-acquired infections (Enterococcus faeciumand Enterococcus faecalis, Inhabit the colon, Colonize wounds and the urinary tract, Resistant to many antibiotics)
- Group B streptococci (GBS) (Streptococcus agalactiae, Neonatal sepsis)
Puerperal Sepsis
- Also called puerperal feverand childbirth fever
- Caused by Streptococcus pyogenes
- Transmitted to the mother during childbirth
- Infects the uterus and progresses to an infection of the abdominal cavity (peritonitis
Subacute bacterial endocarditis
- Impairs the function of the heart valves
- Alpha-hemolytic streptococci from an oral or tonsil infection
Rheumatic Fever
- Autoimmune complication of S. pyogenes infections
- Inflammation of the heart valves (Immune reaction against streptococcal M protein)
- Subcutaneous nodules at the joints
- Sydenham’s chorea (Purposeless, involuntary movements)
Anthrax
- Caused by Bacillus anthracis (Gram-positive, endospore-forming aerobic rod)
- Found in soil
- Primarily affects grazing animals
- Spores introduced into the body are taken up by macrophages and germinate (Bacteria enter the bloodstream and release toxins)
- Treated with ciprofloxacin or doxycycline
- Vaccination of livestock
Protective antigen (anthrax)
binds the toxins to target cells, permitting their entry
Edema toxin (anthrax)
causes local swelling and interferes with phagocytosis
Lethal toxin (anthrax)
targets and kills macrophages
Cutaneous anthrax
- Endospores enter through a minor cut
- 20% mortality rate without treatment
Gastrointestinal anthrax
- Ingestion of undercooked, contaminated food
- 50% mortality rate
Inhalational (pulmonary) anthrax
- Inhalation of endospores
- Bacteria enter the bloodstream; progresses into septic shock
- Near 100% mortality rate
Lyme Disease (Lyme Borreliosis)
-Caused by Borrelia burgdorferi
-Most common tickborne disease in the United States
Field mice are the most common reservoir (Nymphal stage of the Ixodestick feeds on mice and infects humans)
-Ticks feed on deer, but are not infected
-Ticks must attach two to three days to transfer bacteria
Lymes diagnosis and treatment
- Diagnosis via ELISA, indirect fluorescent-antibody (FA) test, or Western blot
- Treated with antibiotics
- More difficult to treat in later stages
Lymes stages
First phase -Bull's-eye rash; flulike symptoms Second phase -Irregular heartbeat; encephalitis; facial paralysis; memory loss Third phase -Arthritis due to an immune response
Burkitt’s Lymphoma
- Tumor the of jaw; most common childhood cancer in Africa
- Due to Epstein-Barr virus (human herpesvirus 4)
- Malaria suppresses the immune system response to the virus
Infectious Mononucleosis
- Caused by Epstein-Barr virus
- Childhood infections are often asymptomatic
- Transmitted via saliva; incubation of 4 to 7 weeks
- Fever, sore throat, swollen lymph nodes, enlarged spleen
- Replicates in resting memory B cells (Form unusual lobed nuclei; Produce heterophile antibodies; Weak and multispecific)
Multiple sclerosis
- Autoimmune attack on the nervous system
- associated with Epstein-Barr virus
Hodgkin’s lymphoma
- associated with Epstein-Barr virus
- Tumors of the spleen, lymph nodes, and liver
Nasopharyngeal cancer
-associated with Epstein-Barr virus
Cytomegalovirus (CMV)
- human herpesvirus 5
- Remains latent in white blood cells
- Infected cells swell
- Form “owl’s eyes” inclusions
- May be asymptomatic or mild in adults
Cytomegalic inclusion disease (CID)
- Transmitted across the placenta; causes mental retardation or hearing loss in newborns
- Transmitted sexually, via blood, saliva, or by transplanted tissue
Ebola hemorrhagic fever
- Caused by the Ebolavirus (a filovirus similar to the Marburg virus)
- Reservoir is the cave-dwelling fruit bat near the Ebola River in Africa
- Spread by contact with infected body fluids
- Damages blood vessel walls and interferes with coagulation
- Blood leaks into surrounding tissue
- Mortality rate of 90%
Toxoplasmosis
- Caused by Toxoplasma gondii (Undergoes its sexual phase in cat intestines; Oocysts shed in cat feces)
- Contact with cat feces or undercooked meat introduces oocysts to the intestines (Oocysts form trophozoites that invade cells; may become a chronic infection)
- Primary danger is congenital infection (Stillbirth; Neurological damage)
Plasmodium vivax (Malaria)
-mildest and most prevalent form; dormant in the liver
Plasmodium falciparum (Malaria)
most deadly; severe anemia; blocks capillaries; affects the kidneys, liver, and brain
Malaria
- Transmitted by Anopheles mosquitoes
- Mosquito bite transmits sporozoite into the bloodstream (Enters the liver cells (which undergo schizogony), resulting in the release of merozoites into the bloodstream)
- Merozoites infect RBCs and again undergo schizogony (Ruptures the infected RBCs, releasing toxic compounds; Causes paroxysms of chills and fever)
- Some merozoites develop into gametocytes and are taken up by a mosquito, repeating the cycle
Malaria diagnosis and treatment
- Difficult to develop a vaccine (Plasmodiumrapidly mutates and evades an immune response)
- Difficult to diagnose without sophisticated equipment
- Prophylaxis (Chloroquine; Malarone for chloroquine-resistant areas)
- Treatment (Artemisinin)
- Prevention (Bed nets)
