Chapters 28 and 30 Study Questions

Which of the following explains why treatment of symptomatic tetanus requires an antitoxin and an antibiotic?

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

Pathogens and hosts provide selection pressure to each other, resulting in varying degrees of co-evolution. Which of the following types of diseases would most likely be affected by co-evolution resulting in a lessening of virulence over time?

Person-to-person

An animal disease transmitted to humans by direct contact, inhalation of aerosols, or bites is called __________.

a zoonosis

There are three forms of human anthrax. Which of the following choices contains a form of human anthrax correctly matched with its description?

cutaneous: easily treatable

A disease that is constantly present in a population at low numbers is a(n) __________.

endemic

Appropriate action to control infectious disease where humans are the reservoir would include __________.

immunization

The typical progression of symptoms for an acute infection would be __________.

infection-incubation-acute period-decline period-convalescence

Deaths because of infectious disease are more common in developing countries, such as Africa, compared to the Americas because of __________.

limited immunization programs inadequate sanitation limited access to clean water

The incidence of disease in a population is termed the __________.

morbidity

During the early 20th century, pandemics typically took months to years to span the globe, while the 2009 H1N1 swine flu spread globally within weeks and had affected most countries within 6 months. This difference in the rate of spread is mainly due to__________.

the increased volume and speed of global transportation.

The common methods to control the spread of West Nile virus include __________.

using insect repellents

Rickettsia are obligate intracellular parasites that are transmitted by arthropods. Which of the following places would you be most likely to find the parasites in a living organism during the course of infection?

within macrophages

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, 1, 3, 5

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?

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

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?

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

The yellow fever virus replicates in lymph nodes and in other immune system cells. How does it arrive in lymph nodes?

The yellow fever virus is phagocytosed by white blood cells, and then travels through the lymph vessels. Lymph nodes contain white blood cells and filter lymph as it moves through the lymph vessels. White blood cells with yellow fever virus can become established there. Some viruses, like the yellow fever virus, can replicate inside of white blood cells like those in lymph nodes.

Which of the following statements about hantaviruses is true?

They are related to Ebola and other hemorrhagic viruses. They are single-stranded, segmented, negative-sense RNA viruses. They are transmitted to humans by contaminated rodent droppings.

Lyme disease and syphilis are similar in that they __________.

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

A person who tests positive for the human immunodeficiency virus but shows no symptoms of AIDS would be termed a __________.

carrier

All students that ate in the school dining hall on Monday developed stomach cramps and diarrhea. The student clinic was overwhelmed with patients. However, by Thursday the number of patients seen in the clinic was back to normal. This could have been caused by a __________.

common-source epidemic

H5N1 avian influenza is widely considered to be the most serious global pandemic threat today, and is the target of much worldwide surveillance. Currently, the virus is not readily passed person-to-person, but reports that the virus may have recently entered (or re-entered) the swine population are of concern because of__________.

possible reassortment of the influenza genome with swine and human strains.

Of the arthropod-borne diseases, there is a vaccine to prevent __________.

yellow fever