Chapter 21 Microbiology Flashcards

Flashcards covering key concepts related to systemic infections, including definitions and associated terms.

Systemic Infection

An infection that starts in one area of the body but eventually affects many other parts. Travels via lymph or blood.

Lymphatic system

Collects fluids and white cells that leave circulation

Pulmonary Circulation

Closed circuit between the heart and the lungs

Systemic circulation

Closed circuit between the heart and the rest of the body

Which chambers of the heart receive blood?

Right and left atria

What chambers of the heart pump blood out?

Right and left ventricles

Arteries

Move blood away from heart. (Oxygenated in system circuit, oxygen poor in pulmonary)

Veins

Bring blood to the heart (oxygen depleted in systemic circuit, oxygen rich in pulmonary)

3 layers of the heart chamber

Endocardium (inner), Myocardium, Pericardium (outer)

Endocarditis, Pericarditis, Myocarditis

Affects heart

Lymphadenopathy

Swelling of the lymph nodes

Lymphadenitis

Inflammation of the lymph nodes

Lymphangitis

Inflammation of the lymph vessels

What do lymph nodes do?

Trap for pathogens carried from infection sites. They swell, and skin over it may be red.

Infectious Mononucleosis (Kissing disease)

Caused by Epstein Barr Virus (member of herpes family). Shed in saliva. Proliferation of B and T cells. Decreased activity is recommended for the spleen and liver to be safe. Long term latent infection.

EBV (epstein barr) associated cancers

Hodgkin’s disease, nasopharyngeal carcinoma, BURKITTS LYMPHOMA (cancer of B lymphocytes, tumors form in upper and lower jaw). EBV integrates and moves cellular proliferation gene next to another highly expressed gene.

Cytomegalovirus Infections (HHV-5)

Commonly transmitted through bodily fluids, can cause serious complications in immunocompromised individuals and newborns. Healthy individuals asymptomatic or have nonspecific symptoms. Replicated in epithelial cells of salivary glands, infects circulating lymphocytes and monocytes. 50-80% OF U.S. ADULTS INFECTED.

Symptomatic CMV in immunocompromised (cytomegalovirus)

Spread to almost every organ. Fever, pneumonia, hepatitis, encephalitis, neuropathy, etc.

Cytomegalic Inclusion Disease (cytomegalovirus infection)

CMV can cross the placenta. Vertical transmission near 75%. Symptoms: low birth weight, microcephaly, seizures, petechial rash, hepatosplenomegaly. Complications later in life: blindness, intellectual disabilities. GIANT cells!

Dengue/dengue hemorrhagic fever (systemic disease)

Endemic in the tropical areas. Intense muscle and joint pain. From mosquitoes.

Chikungunya virus (systemic disease)

Debilitating joint pain. Indian Ocean, Europe, recently the United States.

Ebola virus

Rapid onset of fever, muscle pains, and bleeding from multiple orifices. 50-60% mortality. Contact with bodily fluids. 2014 West Africa outbreak significant.

Bacteremia

Bacteria in the bloodstream

Septicemia

Bacteria enters bloodstream and replicate to high numbers

Systemic Inflammatory Response (SIRS)

A systemic inflammatory response to infection, trauma, or stress, characterized by fever, increased heart rate, and increased respiratory rate.

Sepsis

Infection of the bloodstream; commonly called blood poisoning (triggers SIRS)

Septic Shock

Catastrophic drop in blood pressure due to severe sepsis. Superantigens or PAMPS (cytokine storm)

Plague

A severe bacterial infection caused by Yersinia pestis that can affect multiple organ systems, leading to high fever, lymphadenopathy, and potential septic shock. Endemic in 17 western states of U.S

Bubonic Plague

Moves from site of infection to lymph nodes - buboes.

Septicemic Plague

Enters bloodstream from lymph nodes. Shock induced from endotoxin.

Pneumonic Plague

Enters lungs. Easily passed from person to person. Can cause respiratory failure and pneumonia. Virulence factors: BIOFILM.

Lyme Disease

Caused by Borrelia burgdorferi (spirochete). Transmitted by lxodes species of hard tick. Organism is regurgitated by the tick because it travels to the salivary glands, then travels rapidly through host via bloodstream.

Symptoms of Lyme disease

Symptoms progress in stages. Stage 1 = erythema migrans (bull's-eye rash), fever, muscle and joint pain, headache. Stage 2 = arthritis and cardiac issues develop. Bell’s palsy. Stage 3 = months-years.

Treatment of Lyme disease

Doxycycline (at all stages)

Typhoid Fever

Caused by Salmonella enterica serovar Typhi. Transmission is fecal-oral route. Bacteria continuously shed during infection. Intracellular pathogen: invades macrophages in the GI tract and gains access to bloodstream. Infects variety of organ systems. GALLBLADDER INFECTION = chronic carrier. “Typhoid Mary”. Vaccine available.

Rickettsioses

Systemic infection caused by intracellular pathogens. Obligate intracellular pathogens will infect endothelial cells of blood vessels. (Rocky Mountain spotted fever and typhus.)

Rocky Mountain Spotted Fever

Caused by Rickettsia rickettsii. Transmitted by ticks. Rash begins on wrist and ankles, spreads to the center of the body.

Epidemic typhus

Caused by Rickettsia prowazekii, transmitted by lice. Characterized by confusion, headaches, chills, fever, muscle aches, and photophobia (sensitivity to light). Rash begins on trunk.

Infectious Endocarditis.

Pericarditis, myocarditis, and endocarditis. Infectious endocarditis is an infection of the inner lining of the heart chambers and valves, often caused by bacteria. Symptoms may include fever, heart murmur, and petechiae.

Subacute (endocarditis)

Develops slowly. Viridans streptococci from oral microbiota. Ex: Streptococcus mutans. Fever that lasts weeks, cough, joint pain, shortness of breath, diarrhea, abdominal/flank pain.

Acute (endocarditis)

Develops rapidly. Virulent species ex: Staphylococcus aureus. Fever, valvular regurgitation, abscess formation.

Chagas Disease

Caused by Trypanosoma cruzi (protozoan). Zoonosis endemic to Americas. Nearly 10,000 deaths/year. Transmission by Reduviid Bug. Wild and domestic animals. Symptoms: Romana sign (painless edema of the tissue around eye), Acute (fever and lymphadenopathy), Chronic (attacks various organs including heart, GI tract, and nervous system).

Toxoplasmosis

Caused by Toxoplasma gondii (protozoa). AIDS patients particularly susceptible. Congenital disease: transmission from infected mother to fetus, leading to severe neurological and ocular complications. Chorioretinitis, Hydrocephalus, Intracranial calcification. Can change behavior in infected hosts, leading to increased risk-taking behavior. RATS UNAFRAID OF CATS. “Cat people”.