Micro 261 Chapter 34

Controlling most rickettsial diseases involves managing food safety procedures. human behavior. the vector. immunization strategies.

the vector

Animal diseases transmissible to humans are known as ferals. zoonoses. radicals. vectors.

zoonoses

The primary disease reservoir for plague is Select one: a. humans b. mosquitoes c. rats d. fleas

c. rats

Clostridium species that can be associated with gas gangrene include __________. A) Clostridium botulinum B) Clostridium tetani C) Clostridium novyi D) none of the listed species

C) Clostridium novyi (Gas gangrene occurs when there is tissue destruction and the proteins are fermented. This causes the production of carbon dioxide, hydrogen gas, and a number of smelly organic compounds.)

Borrelia burgdorferi is an interesting spirochete that is unusual when compared to other bacteria. Which of the following is the reason that it is so unusual? A) it has a linear chromosome B) it has ribosomes C) it has flagella D) it has a cell wall

A) it has a linear chromosome

The causative agent of Lyme disease is ________, which is carried primarily by the ________. A) Yersinia pestis / Xenopsylla cheopis (rat flea) B) Rickettsia prowazekii / Culex species (mosquito) C) Borrelia burgdorferi / Ixodes sp. (deer tick) D) a flavivirus / Ixodes sp. (deer tick)

C) Borrelia burgdorferi / Ixodes sp. (deer tick)

Which of the following statements about hantaviruses is true? A) They are related to Ebola and other hemorrhagic viruses. B) They are transmitted to humans by contaminated rodent droppings. C) They are single-stranded, segmented, negative-sense RNA viruses. D) All of the listed statements are true.

D) All of the listed statements are true.

There are three forms of human anthrax. Which of the following choices contains a form of human anthrax correctly matched with its description? A) cutaneous: least severe form B) intestinal: always fatal C) respiratory: most common form D) cutaneous: easily treatable

D) cutaneous: easily treatable ( Bacillus anthracis is the causative agent of human anthrax. It is a gram-positive endospore former that is commonly found in soil. )

The common methods to control the spread of West Nile virus include __________. a. using insect repellents b. providing water in yards for birds to drink c. wearing loose-fitting clothes when outside d. a vaccine for humans

a. using insect repellents

Animal-transmitted diseases are generally spread to accidental hosts by Select one: a. direct contact. b. aerosols. c. bites. d. all of the above.

d. all of the above

Control of certain diseases is nearly impossible because Select one: a. we cannot control vector animals. b. we cannot control reservoir animals. c. we cannot eradicate organisms from the soil. d. of all the above.

d. all of the above

Animal-transmitted diseases are generally spread to accidental hosts by a. aerosols. b. bites. c. direct contact. d. direct contact, aerosols, and bites.

d. direct contact, aerosols, and bites.

If Lyme disease is not treated early, it can infect the central nervous system. True False

true

The study of hantaviruses requires biosafety level (BSL) 4 precautions. True False

true

Animal diseases transmissible to humans are known as Select one: a. ferals. b. radicals. c. zoonoses. d. vectors.

c. zoonoses

An animal disease transmitted to humans by direct contact, inhalation of aerosols, or bites is called __________. a zoophyte epizootic a zoonosis enzootic

zoonosis

Which of the choices shows the correct progression of bubonic plague? 1. Human is bitten by infected flea. 2. Rodent is infected with Yersinia pestis. 3. Yersinia travels to lymph nodes. 4. Flea is infected with Yersinia pestis. 5. Septicemia occurs. 6. Yersina pestis reproduces in intestine of infected organism. 7. Human is bitten by infected rodent. 2, 4, 6, 7, 3, 5 4, 2, 6, 7, 3, 5 2, 4, 6, 1, 3, 5 4, 2, 6, 1, 3, 5

2, 4, 6, 1, 3, 5: 2. Rodent is infected with Yersinia pestis. 4. Flea is infected with Yersinia pestis. 6. Yersina pestis reproduces in intestine of infected organism. 1. Human is bitten by infected flea. 3. Yersinia travels to lymph nodes 5. Septicemia occurs.

Of the arthropod-borne diseases, there is a vaccine to prevent __________. a. West Nile fever b. Lyme disease c. yellow fever d. dengue fever

c. yellow fever

Which of the following explains why treatment of symptomatic tetanus requires an antitoxin and an antibiotic? A. The tetanus toxin binds irreversibly, causing damage to axons. The only way to heal the axons is with an antitoxin. B. It is always better to use multiple treatments to elicit a stronger response. C. Because C. tetani bacteria excrete tetanus toxin, it is important to neutralize the toxin while also killing the bacteria that are producing more. D. Because the toxin is within the cell wall of the bacteria, it can only be eliminated by killing the bacteria.

C. Because C. tetani bacteria excrete tetanus toxin, it is important to neutralize the toxin while also killing the bacteria that are producing more.

Clostridium tetani is an obligate anaerobe that can cause tetanus. When it enters the human body, it can produce tetanus toxin. Considering that C. tetani is an obligate anaerobe, which of the following explains how it can survive and cause disease in the human body? A. C. tetani can't access atmospheric oxygen, so it can grow as long as it stays on the surface of the skin rather than in well-oxygenated deeper tissues. B. It doesn't survive; it simply releases toxin as it dies. C. Especially in deep wounds, C. tetani can sometimes survive in areas with damaged tissue and poor to no blood flow. D. C. tetani can only survive when other bacteria are available to consume oxygen and to keep oxygen levels low.

C. Especially in deep wounds, C. tetani can sometimes survive in areas with damaged tissue and poor to no blood flow.

Bacillus anthracis is an endospore-forming bacterium. Which of the following is most likely? A. B. anthracis spores can be killed by boiling water. B. B. anthracis spores require a moist environment in order to stay dormant for an extended time. C. B. anthracis uses spores to reproduce, so spores develop into new offspring. D. B. anthracis spores can remain dormant for hundreds of years without needing nutrients.

D. B. anthracis spores can remain dormant for hundreds of years without needing nutrients.

Tetanus is highly contagious through person-to-person contact. True False

False

In bubonic plague, buboes are swellings formed in the lymph nodes and filled with Yersinia pestis. Clostridium tetani. Xenopsylla cheopis. Rickettsia prowazekii.

Yersinia pestis.

Which insect functions in the host-to-host transmission of typhus? Select one: a. body louse b. dog tick c. rat flea d. deer tick

a. body louse

Tetanus develops from a puncture wound because a. endospores germinate in anoxic conditions. b. the organism gains access to the circulatory system and then invades the nervous system. c. the organism needs access to the circulatory system and deep connective tissues. d. the organism digests deep connective tissues.

a. endospores germinate in anoxic conditions.

Tetanus develops from a puncture wound because Select one: a. endospores germinate in anoxic conditions. b. the organism gains access to the circulatory system and then invades the nervous system. c. the endotoxin is released at the site of the infection and can travel to the nervous system. d. of all of the above.

a. endospores germinate in anoxic conditions.

If you were exposed to a sick animal that was found to have negri bodies in its nervous system in a postmortem examination, how would you be treated to prevent disease? a. passive and active immunization against rabies b. antiviral medication c. observation to detect tick or lice bites d. antibiotics to treat Lyme disease

a. passive and active immunization against rabies

If a human is bitten by an animal that has rabies, then it is recommended that the human receive immune globin (human rabies antibodies) and a rabies vaccination (with inactive virus) as well. Which of the following is the best (and most specific) explanation for why both are recommended in this case? a. Because rabies is such a serious illness, using antibodies and a vaccine provides the strongest possible immediate protection. Both antibodies and the vaccine provide a rapid immediate response to prevent illness from developing. b. The rabies antibodies provide a rapid response but short-lived response while the vaccination provides slower but longer-lasting protection. c. The rabies vaccination is relatively new and ineffective, so it is important to give the immune globin as well to make certain that the viruses cannot cause disease.

b. The rabies antibodies provide a rapid response but short-lived response while the vaccination provides slower but longer-lasting protection.

Lyme disease and syphilis are similar in that they __________. a. are both contracted by person-to-person contact b. are both chronic infections that involve the nervous system c. are both caused by spirochetes and are chronic infections that involve the nervous systems d. are both caused by spirochetes

c. are both caused by spirochetes and are chronic infections that involve the nervous systems

The most serious types of fungal infections are Select one: a. mycotoxic infections. b. subcutaneous infections. c. systemic mycoses. d. superficial mycoses.

c. systemic mycoses.

West Nile Virus is an arbovirus that can be transmitted by birds because they develop viremia when infected. In contrast, infected humans cannot spread the disease because they do not develop viremia. Why is viremia associated with the ability to transmit the disease? a. The virus is only found within red blood cells if there is no viremia, so it cannot be spread by mosquitoes that do not consume those cells. b.Direct contact with blood is required for infection. If there are no viral particles in the blood, then infection can't occur using this mechanism. c.If there are no (or only very few) viral particles in the blood, then they are not picked up by vectors feeding on the blood in sufficient amounts to cause infection. d. Because white blood cells are found in the blood, any virus in the blood would be attacked by the immune system. With no viral particles available for the immune system to attack, the virus cannot be spread.

c.If there are no (or only very few) viral particles in the blood, then they are not picked up by vectors feeding on the blood in sufficient amounts to cause infection.

Malaria Select one: a. is the most common cause of death due to infectious disease worldwide. b. may be prevented and treated with chloroquine and closely related drugs. c. is controlled primarily by controlling the mosquito vector. d. is all of the above.

d. all of the above

A person is most likely to contract diseases such as Rocky Mountain spotted fever and ehrlichiosis if he or she Select one: a. enjoys visiting metropolitan cities. b. enjoys snowskiing. c. enjoys traveling in European countries. d. enjoys camping and hiking in the backcountry.

d. enjoys camping and hiking in the backcountry.

Negri bodies are found Select one: a. circulating in the blood of humans (and other mammals) suffering from HPS. b. in the respiratory tract of animals carrying Lyme disease. c. in the intestines of humans suffering from malaria. d. in postmortem samples of rabid animals.

d. in postmortem samples of rabid animals.

Control of certain diseases is nearly impossible, because we cannot a. eradicate organisms from the soil. b. control reservoir animals. c. control vector animals. d.all of the above

d.all of the above

Hantaviruses are most commonly transmitted by ________ of virus-contaminated rodent ________. ingestion / saliva inhalation / saliva ingestion / excreta inhalation / excreta

inhalation / excreta

The primary disease reservoir for plague is fleas. humans. mosquitoes. rats.

rats