MICRO Ch. 20

Which of the following statements concerning Rocky Mountain spotted fever is correct? A. The causative bacterium is transmitted by Ixodes ticks. B. Disease symptoms include fever, headache, and rash. C. An infection rarely has complications beyond mild discomfort. D. Infections are seen in highest numbers in the Rocky Mountains.

Disease symptoms include fever, headache, and rash.

Which of the following statements regarding the structure of blood vessels is incorrect? A. In contrast to veins, arteries have higher blood pressure, more tissue layers, and are thinner vessels. B. Connective tissue and muscle fibers are found in the layers of tissue surrounding both arteries and veins. C. Capillaries have only a single layer of endothelium, rendering them fragile and leaky during an infection with a hemorrhagic fever virus. D. Blood vessels are often found in parallel with lymphatic vessels.

In contrast to veins, arteries have higher blood pressure, more tissue layers, and are thinner vessels.

The cardiovascular and lymphatic systems have no normal biota.

TRUE

True/ False: Plague is a quarantinable disease.

TRUE

True/False: Aedes mosquitoes are the vectors involved in Chikungunya and dengue fever.

TRUE

True/False: In severe cases of Rocky Mountain spotted fever, the enlarged lesions of the rash can become necrotic and predispose the patient to gangrene of toes and fingertips.

TRUE

True/False: Under normal healthy circumstances, the lymphatic system filters any microorganisms present.

TRUE

Which of the following is not true of tularemia? A. Its symptoms include fever, swollen lymph nodes, ulcerative lesions, conjunctivitis, and pneumonia. B. It is a zoonosis. C. It is sometimes called rabbit fever. D. The causative agent is a gram-positive bacterium. E. It is transmitted by arthropod vectors.

The causative agent is a gram-positive bacterium.

Which of the following statements regarding Q fever is incorrect? A. The disease is mild, and most cases go undetected. B. Symptoms include fever, muscle aches, rash, and occasionally pneumonia. C. The causative agent, Coxiella burnetii, produces resistant endospore-like structures. D. Humans can be infected from the airborne spread of particles from infected animals. E. The causative agent, Coxiella burnetii, is transmitted by lice.

The causative agent, Coxiella burnetii, is transmitted by lice.

Which of the following statements is incorrect regarding patients with AIDS? A. AIDS patients get repeated, life-threatening, opportunistic infections. B. The highest number of AIDS cases worldwide is in the United States. C. AIDS patients have an immunodeficiency. D. AIDS patients have a CD4 T-cell titer below 200 cells/mm3 of blood. E. AIDS patients can get unusual cancers and neurological disorders.

The highest number of AIDS cases worldwide is in the United States.

Pasteurization of milk helps to prevent ______. A. endocarditis B. mononucleosis C. brucellosis D. tularemia E. plague

brucellosis

The most important defense of the cardiovascular system against infection is ______. A. lymphocytes in the blood B. lymph nodes C. the blood-brain barrier D. fever

lymphocytes in the blood

The reservoir for the Lassa fever virus is the ______. A. fruit bat B. Aedes mosquito C. deer tick D. Anopheles mosquito E. multimammate rat

multimammate rat

Acute endocarditis is most commonly contracted through ______. A. parenteral entry B. droplets C. ingestion D. fomites E. casual contact

parenteral entry

The fibrous sac that encloses the heart is the ______. A. myocardium B. epicardium C. endocardium D. pericardium E. ectocardium

pericardium

Control of rodent populations is important for preventing ______. A. malaria B. Q fever C. brucellosis D. plague

plague

Cat scratch disease can be prevented by ______, A. vaccination B. avoiding unpasteurized milk C. avoiding environments with ticks D. animal control E. promptly cleaning any scratch wound

promptly cleaning any scratch wound

The causative organism of malaria is a ______. A. prion B. fungus C. virus D. protozoan E. bacterium

protozoan

The cyclic bouts of fever and chills in malaria are caused by ______. A. neurological involvement B. red blood cell lysis C. the timing of the viral life cycle D. white blood cell lysis

red blood cell lysis

An HIV-positive patient should be treated with a wide array of drugs because A. the sooner s/he is treated with antivirals, the more likely it is that the virus will be eliminated from their blood. B. s/he is susceptible to a variety of opportunistic infections and AIDS-defining illnesses. C. most HIV-positive patients are also intravenous drug users and require chemotherapy for their addiction. D. multiple antibiotics and antivirals should kill HIV and any resistant strains that might arise.

s/he is susceptible to a variety of opportunistic infections and AIDS-defining illnesses.

When bacteria flourish and grow in the blood stream, the condition is termed ______. A. sepsis B. fungemia C. viremia D. bactocarditis

sepsis

Symptoms of infectious mononucleosis include A. fever, severe diarrhea, pneumonitis, hepatitis, and retinitis. B. sore throat, fever, cervical lymphadenopathy, and splenomegaly. C. fever and pocks on skin. D. vesicular lesions in oral mucosa.

sore throat, fever, cervical lymphadenopathy, and splenomegaly

Rabbits and rodents are the chief reservoirs of the causative agent of ______. A. tularemia B. plague C. Lyme disease D. brucellosis E. mononucleosis

tularemia

Bubonic plague is transmitted by ______. A. mosquitoes B. fomites C. rats D. sexual contact E. fleas

fleas

After a Drug Enforcement Agency raid on a location that housed intravenous drug users, several were brought to the hospital with rapid breathing, fever, and an altered mental state. Which of the following statements is correct? A. Stained blood smears should be performed promptly to look for abnormalities in the blood cells. B. A broad-spectrum antibiotic is needed promptly, as they are likely to be in septic shock from intravenous introduction of microbes into the blood. C. Unsanitary conditions in the house probably resulted in infestations with insects, so it's prudent to examine them for insect bites that may provide a clue. D. Many drug users are HIV-positive, so the patients should all be monitored for levels of CD4 T-cells before any other action is taken.

A broad-spectrum antibiotic is needed promptly, as they are likely to be in septic shock from intravenous introduction of microbes into the blood.

For the following list of anti-HIV drugs and their mechanism of action, identify the mismatch. A. Protease inhibitor; blocks the active site of the protease required for assembling new viral particles. B. Integrase inhibitor; blocks the active site of the enzyme required to splice HIV DNA into the human genome C. Reverse transcriptase inhibitor; blocks the active site of the enzyme required to convert viral RNA to DNA D. AZT (azidothymidine); as an analog of thymidine, it is incorporated into viral RNA in place of thymidine

AZT (azidothymidine); as an analog of thymidine, it is incorporated into viral RNA in place of thymidine

Anthrax is A. a zoonosis. B. transmitted by contact, inhalation, or ingestion. C. a disease that, in humans, can cause a rapidly fatal toxemia and septicemia. D. only seen sporadically in the United States. E. All of the choices are correct.

All of the choices are correct.

Brucellosis is A. treated with a 3-6 week course of antibiotics. B. seen in patients as a fluctuating fever, with headache, muscle pain, and weakness. C. diagnosed with serological testing of the patient's blood. D. an occupational illness of people who work with animals. E. All of the choices are correct.

All of the choices are correct.

Lyme disease involves A. early symptoms of fever, headache, and stiff neck. B. crippling polyarthritis, cardiovascular issues, and neurological problems. C. people exposed to wooded or forested areas. D. treatment with antimicrobials. E. All of the choices are correct.

All of the choices are correct.

Malaria may be prevented by A. using bed nets sprayed with insecticide. B. eliminating standing water. C. taking prophylactic drugs. D. using genetically engineered mosquitoes. E. All of the choices are correct.

All of the choices are correct.

Plague exhibits a A. septic form historically called the Black Death. B. bubonic form in which swollen lesions termed buboes develop. C. pneumonic form that manifests as a respiratory disease. D. All of the choices are correct.

All of the choices are correct.

Which of the following are features that make Bacillus anthracis a potential bioterrorism weapon? A. It is naturally occurring worldwide in soil, and intentional release may not be suspected. B. It forms endospores that can be stored in powder form indefinitely. C. Pulmonary anthrax is rapidly fatal. D. Vaccination is not widespread in the United States. E. All of these choices are correct.

All of these choices are correct.

Which of the following statements regarding the Epstein-Barr virus is incorrect? A. The virus has a 30-50 day incubation period. B. The virus is transmitted by direct oral contact and saliva. C. An infection typically requires hospitalization for about a week. D. An infection results in sudden leukocytosis. E. Transmission has been documented through contaminated blood transfusions and organ transplants.

An infection typically requires hospitalization for about a week

Despite the aggressive defense of the cardiovascular system by the immune system, some microbes can invade and establish an infection in the blood. From the following list of microbes and their virulence factors, identify the mismatch. A. Bacillus anthracis produces antioxidants to combat lysosomes. B. Coxiella burnetii produces an endospore-like structure. C. Trypanosoma cruzi cloaks itself in host proteins to avoid immune recognition. D. Borrelia burgdorferi changes its surface antigens to avoid immune recognition.

Bacillus anthracis produces antioxidants to combat lysosomes.

The gram-negative bacillus associated with abscesses from cat bites or scratches is ______. A. Brucella suis B. Salmonella typhimurium C. Bartonella henselae D. Francisella tularensis E. Yersinia pestis

Bartonella henselae

The causative agent of Lyme disease is ______. A. Leptospira interrogans B. Ixodes pacificus C. Borrelia burgdorferi D. Borrelia hermsii E. Ixodes scapularis

Borrelia burgdorferi

A common cardiovascular/lymphatic system disease in AIDS patients is ______. A. brucellosis B. Burkitt's lymphoma C. cytomegalovirus D. ehrlichiosis E. acute endocarditis

Burkitt's lymphoma

Which of the following statements regarding the development of AIDS following infection with HIV is incorrect? A. Antibodies to HIV antigens formed in response to HIV infection appear within a few weeks of infection and remain high through latency and AIDS. B. CD4 T cells are present in low numbers in an uninfected individual, but become elevated upon HIV infection, and ultimately fall to very low numbers (<200 cells/ml) as the infection progresses to AIDS. C. Viral antigens can be detected at high levels in the blood within days following infection, then their numbers fall dramatically during a latent period and rise again when AIDS symptoms occur. D. An HIV-positive individual in the latency phase can be distinguished from an uninfected individual by the presence of antibodies to HIV antigens in their blood.

CD4 T cells are present in low numbers in an uninfected individual, but become elevated upon HIV infection, and ultimately fall to very low numbers (<200 cells/ml) as the infection progresses to AIDS

Which of these diseases would most likely be identified by viewing a stained blood smear in a light microscope? A. Chagas disease B. Dengue fever C. HIV D. Ebola hemorrhagic fever

Chagas disease

Which of the following is a hemorrhagic fever? A. Cat-scratch fever B. Q fever C. Chikungunya D. Rocky Mountain spotted fever E. Trench fever

Chikungunya

Which type of hemorrhagic fever is also known as "breakbone fever" because of the severe pain in muscles and joints? A. Chikungunya B. Marburg C. Lassa fever D. Ebola E. Dengue fever

Dengue fever

Your 49-year-old mother has just been diagnosed with subacute endocarditis with the following symptoms: fever, a rash, and early congestive heart failure. You wonder how this infection occurred, particularly since she appeared to be healthy before this. Which of the following questions for her physician is most pertinent to understanding the cause of this infection? A. Is this infection related to menopause? B. Could she have contracted this from a mosquito bite, since she does so much gardening? C. Could she have AIDS? D. Does she have an abnormal heart valve or a murmur?

Does she have an abnormal heart valve or a murmur?

Epidemiologists classify diseases by their mortality rate (the percent of infected individuals who die from the disease) and by their communicability (how easy it is to transmit the disease). Which of the following diseases of the cardiovascular system is mismatched with a description of its properties? A. Ebola; high mortality rate and high communicability B. Malaria; low mortality rate and high communicability C. Plague; somewhat high mortality rate and low communicability D. AIDS; high mortality rate and low communicability

Ebola; high mortality rate and high communicability

Several infections of the cardiovascular system can be identified by inspecting a stained blood smear in the microscope. For the following infections, identify the microscope observation that does not fit the disease. A. Chagas disease; protozoan visible among blood cells B. Malaria; ring trophozoites visible inside red blood cells C. Epstein-Barr virus; virus visible inside red blood cells D. Babesiosis; protozoan visible inside red blood cells

Epstein-Barr virus; virus visible inside red blood cells

True/ False: Humans should be routinely vaccinated against Lyme disease.

FALSE

True/ False: Lyme disease is only seen in people living in Lyme, Connecticut.

FALSE

True/False: Rifampin is the drug of choice for malaria.

FALSE

Which of the following statements regarding Bacillus anthracis is incorrect? A. A capsule and exotoxins are virulence factors. B. Its reservoir includes grazing animals and soil. C. It is a gram-positive bacillus. D. It grows primarily under anaerobic conditions. E. It is capable of forming endospores.

It grows primarily under anaerobic conditions.

Which of the following statements is incorrect regarding subacute endocarditis? A. It is caused by autoantibodies that inappropriately target heart and valve tissue. B. It occurs exclusively in patients that have prior heart damage. C. Bacteria colonize previously damaged heart tissue resulting in biofilm growth. D. It can be caused by oral bacteria that are introduced to the blood by dental procedures.

It is caused by autoantibodies that inappropriately target heart and valve tissue.

Which of the following is not true of bubonic plague? A. An infection can progress to septicemia. B. It is transmitted by the fecal-oral route. C. A patient exhibits fever, headache, nausea, and weakness. D. A patient often has enlarged inguinal lymph nodes. E. It is caused by Yersinia pestis.

It is transmitted by the fecal-oral route.

Which of the following is incorrect regarding Yersinia pestis? A. It produces an enterotoxin. B. It exhibits bipolar staining and appears to resemble a safety pin. C. It is a gram-negative rod. D. It has a capsule as a virulence factor. E. It produces coagulase as a virulence factor.

It produces an enterotoxin.

Following unprotected sex with a guy you met at a party, you are now worried about what you might have been exposed to during this episode. Ten days later, you talk to your doctor about getting an HIV test. What is the doctor's response? A. HIV infection can be latent and asymptomatic for years, so testing should be postponed until you exhibit symptoms of AIDS. B. The antibiotic that you have been taking for a urinary tract infection will also destroy HIV, so you don't have to worry about an infection. C. It's too soon to detect the antibody produced by your immune system in response to HIV exposure, so a test will come back negative. Wait a few more weeks to be tested. D. The incidence of HIV infection in the United States is at an all-time low level, so transmission was not at all likely, especially after only a single possible exposure.

It's too soon to detect the antibody produced by your immune system in response to HIV exposure, so a test will come back negative. Wait a few more weeks to be tested.

A frequent cancer that is seen in AIDS patients is ______. A. Hodgkin's lymphoma B. myeloma C. Kaposi's sarcoma D. melanoma E. leukemia

Kaposi's sarcoma

Which type of hemorrhagic fever has been shown to respond to ribavirin? A. Lassa fever B. Marburg C. Ebola D. Rocky Mountain spotted fever

Lassa fever

Select the statement that is correct regarding Chagas disease. A. An effective vaccine is available for prevention in endemic areas. B. It is transmitted by respiratory droplets. C. It is caused by a fungal pathogen. D. Late-stage disease is characterized by autoimmune reactions in the host.

Late-stage disease is characterized by autoimmune reactions in the host.

Erythema migrans, a bull's-eye rash, at the site of a tick bite is associated with ______. A. Q fever B. Rocky Mountain spotted fever C. Lyme disease D. plague E. ehrlichiosis

Lyme disease

The white-footed mouse, deer, and deer ticks are important to maintaining the zoonotic transmission cycle associated with ______. A. babesiosis B. Q fever C. plague D. Lyme disease E. Rocky Mountain spotted fever

Lyme disease

At the blood donation facility, you are completing an information form. The form asks about your health history and includes a question about whether you have ever had malaria or visited a country where malaria is endemic. Why is this information relevant? A. If you are infected with malaria, you are probably also infected with HIV, and that would disqualify your donation. B. Recipients differ in their susceptibility to malaria; if you have had malaria, the staff will earmark your blood to specific kinds of recipients. C. This is just one of many pathogens that blood is screened for. The information given by the donor saves the staff time in testing the blood. D. Malarial parasites can persist in the liver, and, as a result, could be contaminating your blood and transferred to a recipient.

Malarial parasites can persist in the liver, and, as a result, could be contaminating your blood and transferred to a recipient

Which of the following statements is incorrect regarding malaria? A. Trophozoites develop in red blood cells. B. Gametocytes enter the mosquito as she draws a blood meal from a human. C. Merozoites enter and multiply in liver cells. D. The mosquito inoculates human blood with sporozoites.

Merozoites enter and multiply in liver cells.

Which of the following infectious agents and means of disposal are mismatched? A. Drums made with animal hides should be treated with sterilizing gas to eliminate endospores. B. Coagulation factors purified from blood must be heat-treated to destroy HIV. C. Carcasses of animals that died of anthrax must be incinerated to avoid endospores entering the soil. D. Mosquito bed nets must be washed in bleach weekly to eliminate any residual Plasmodium.

Mosquito bed nets must be washed in bleach weekly to eliminate any residual Plasmodium.

Which of the following statements regarding HIV is incorrect? A. The virus attaches to host cells with CD4 receptors. B. PCR is the primary technique for detecting HIV in blood. C. The viral DNA integrates into the host DNA. D. The virus becomes latent in host cells. E. The virus can enter into nervous tissues and cause abnormalities.

PCR is the primary technique for detecting HIV in blood

Which drug interferes with the action of an HIV enzyme needed for final assembly and maturation of the virus? A. Fusion inhibitor B. Reverse transcriptase inhibitor C. Integrase inhibitor D. Protease inhibitor

Protease inhibitor

Which of the following is not associated with sepsis? A. Drop in blood pressure B. Respiratory acidosis C. Endotoxic shock D. Parenteral or endogenous transfer E. Fever and shaking chills

Respiratory acidosis

Which of the following is mismatched? A. Bartonella henselae - cat-scratch disease B. Rickettsia typhi - Rocky Mountain spotted fever C. Bartonella quintana - trench fever D. Coxiella burnetii - Q fever E. Yersinia pestis - plague

Rickettsia typhi - Rocky Mountain spotted fever

The most common causative agent of acute endocarditis is ______. A. Neisseria gonorrhoeae B. Staphylococcus aureus C. Epstein-Barr virus D. Streptococcus pyogenes E. Streptococcus pneumoniae

Staphylococcus aureus

Your patient was admitted for a gunshot wound about a week ago. As a precautionary activity, the doctor placed her on antibiotics for a few days while recuperating. Blood specimens are drawn on the patient a several times daily and sent to the microbiology lab for analysis of bacteria. Nothing has grown in culture. On her 4th day in the hospital, she has had no fever and no other signs of infection, but one set of blood specimens has been reported positive for a bacterium. The culture was identified by the lab as Staphylococcus epidermidis, a common organism on the skin. Predict the likely situation leading to this. A. Staphylococcus epidermidis is a skin contaminant that ended up in the blood specimen as a consequence of poor aseptic technique during the venipuncture. B. Staphylococcus epidermidis is a very slow growing bacterium and was probably in the blood right after the gunshot wound, but failed to grow until now. C. The patient is immunodepressed and very susceptible to bacterial infection. D. Staphylococcus epidermidis has converted to a pathogen because of the antibiotics prescribed for the patient.

Staphylococcus epidermidis is a skin contaminant that ended up in the blood specimen as a consequence of poor aseptic technique during the venipuncture.

Which of the following statements regarding sepsis is incorrect? A. The presence of microbes in the blood results in increased viscosity, and a rise in blood pressure is a hallmark of sepsis. B. Both gram-negative and gram-positive bacteria in the blood can induce sepsis. C. The Gram-negative cell envelope stimulates an inflammatory response that leads to endotoxic shock. D. A sample of blood plated on a variety of bacterial media is a good method to identify the causative organism in sepsis.

The presence of microbes in the blood results in increased viscosity, and a rise in blood pressure is a hallmark of sepsis.

Which of the following is not true of Ebola and Marburg? A. Blood clotting is disrupted in an infection with these viruses. B. They are filoviruses. C. There is currently no effective treatment for infected individuals. D. They transmitted by direct contact with body fluids from affected individuals. E. The viruses are transmitted by mosquitoes.

The viruses are transmitted by mosquitoes.

Ehrlichiosis, Rocky Mountain Spotted Fever, dengue fever, and tularemia are all infectious diseases of the cardiovascular system. What feature do they have in common? A. People with immune deficiencies are especially susceptible to these diseases. B. They are all transmitted by arthropod vectors. C. They are all endemic in the mountain states in the western U.S. D. The causative agent of each of these diseases is a bacterium.

They are all transmitted by arthropod vectors.

Which of the following statements regarding erhlichiosis is incorrect? A. It often coinfects with Borrelia burgdorferi. B. Treatment requires an extensive course of antibiotics, usually 3-6 weeks. C. The disease vector is transmitted by Ixodes ticks. D. Symptoms include fever, headache, and muscle pains. E. The disease is diagnosed by PCR or indirect fluorescent antibody tests.

Treatment requires an extensive course of antibiotics, usually 3-6 weeks.

You just returned from a hiking/camping trip and are experiencing symptoms of an infection: high fever, swollen lymph nodes, and black-and-blue marks or hemorrhages under the skin. Your doctor asks if you have been in the four corners area of the U.S. (where the states of Arizona, Colorado, New Mexico, and Utah all meet). What does the doctor suspect? A. Since there are many mosquitoes in that area, you might have been infected with Plasmodium. B. Hemorrhagic fever is often associated with bats in that region of the U.S. C. Those four states have high rates of Chikungunya, which is what the doctor suspects that you have. D. You might have picked up the plague bacterium from fleas that normally feed on rodents in that area.

You might have picked up the plague bacterium from fleas that normally feed on rodents in that area

Retroviruses have all of the following characteristics except ______. A. an envelope B. integration into the host genome C. glycoprotein spikes D. reverse transcriptase E. a DNA genome

a DNA genome

Most cases of sepsis are caused by ______. A. prions B. fungi C. viruses D. bacteria E. protozoans

bacteria

The symptoms that occur in cyclic 48- to 72-hour episodes in a malaria patient are A. sore throat, low grade fever, and swollen lymph nodes. B. urinary frequency and pain, and vaginal discharge. C. chills, fever, and sweating. D. bloody, mucus-filled stools, fever, diarrhea, and weight loss. E. fever, swollen lymph nodes, and joint pain.

chills, fever, and sweating.

The preferred treatment for anthrax is ______. A. penicillin B. ciprofloxacin C. decided after consultation with the CDC D. quinine E. the Bio-Thrax vaccine

decided after consultation with the CDC

The heart wall has three layers. In order from the outer layer to the inner layer, they are ______. A. epicardium, myocardium, and endocardium B. endocardium, epicardium, and myocardium C. endocardium, myocardium, and epicardium D. myocardium, endocardium, and epicardium

epicardium, myocardium, and endocardium

The cardiovascular system is highly protected from microbial infection because A. it is the only body system that is liquid-based, i.e., with blood. B. it is the only body system that has no normal microbiota. C. it is so close to the skin that even minor injuries could lead to major infection. D. failure to do so will result in a systemic infection.

failure to do so will result in a systemic infection

The causative agent in a case of sepsis can be isolated by A. inoculating blood agar with a sample of the patient's blood. B. performing a Kirby-Bauer assay on a sample of the patient's blood. C. sending a blood sample to the CDC laboratories in Atlanta. D. centrifugation of the blood to separate cells and plasma.

inoculating blood agar with a sample of the patient's blood.

Yersinia pestis A. does not respond to antimicrobial drugs. B. was virulent historically but currently circulating strains are not virulent. C. is usually transmitted by a flea vector. D. has deer as an endemic reservoir.

is usually transmitted by a flea vector.

Anthrax is not routinely diagnosed in the U.S. because A. it is a rare infection. B. infections are usually asymptomatic. C. infection is generally only seen in late-stage AIDS patients. D. health care workers haven't been trained to detect it.

it is a rare infection.

Hemorrhagic and nonhemorrhagic fever diseases have a common feature of a high fever. These categories of diseases are distinguished by A. viral causes in hemorrhagic fevers and bacterial or protozoan causes in nonhemorrhagic fevers. B. the overall mortality rate, as hemorrhagic fevers have a much higher mortality rate. C. the integrity of the capillary endothelium and its ability to contain the blood. D. the pattern of the fever, whether it is constant or varies with time. E. the viral load in the blood, specifically the viral titer.

the integrity of the capillary endothelium and its ability to contain the blood

Endocarditis is often a consequence of bacteria attached to the heart valves. These microbes are not eliminated by circulating lymphocytes because A. lymphocytes cannot engulf microbes attached to tissue. B. Gram-positive microbes don't have an exotoxin surface molecule to trigger an immune response. C. these microbes become covered in platelets and fibrin which is not recognized as foreign by the immune system. D. lymphocytes do not circulate through the heart valves to detect the presence of microbes.

these microbes become covered in platelets and fibrin which is not recognized as foreign by the immune system

Lyme disease is transmitted by ______. A. droplets B. ticks C. lice D. fleas E. flies

ticks

Documented transmission of HIV involves ______. A. respiratory droplets B. unprotected sexual intercourse or contact with blood/blood products C. mosquitoes D. contaminated food

unprotected sexual intercourse or contact with blood/blood products

The presence of viruses in the blood is called ______. A. septicemia B. fungemia C. viremia D. hemovirus

viremia