Pre-Lec Ch.29

During his research on West Nile virus, Bill learned that this virus is placed within a functional grouping known as arboviruses. What is meant by the term arbovirus?

1. An arbovirus is an arthropod-borne virus. 2. An arbovirus is maintained in nature through biological transmission.

Lyme disease is caused by ____________ and is transmitted by __________.

B. burgdorferi; Ixodes

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.

Which of the following is the best mode of controlling the spread of West Nile infections?

Limit exposure to mosquitoes to prevent the transmission of West Nile virus.

Yellow fever was named because it can cause liver damage, resulting in a yellowish appearance. Which of the following explains why liver damage causes someone to have a yellowish appearance?

Bilirubin is a breakdown product of hemoglobin that has a yellowish color. When bilirubin is not being properly excreted as bile, it can build up in the blood.

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

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

d. a zoonosis

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?

it has a linear chromosome

A patient exhibiting arthritis secondary to Lyme disease is likely in which phase of the infection?

third

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

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

yellow fever

Which of the following statements about hantaviruses is true?

1. They are related to Ebola and other hemorrhagic viruses. 2. They are transmitted to humans by contaminated rodent droppings. 3. They are single-stranded, segmented, negative-sense RNA viruses. 4. All of the listed statements are true.

What features of West Nile virus make it an emerging disease of special concern?

1. West Nile virus is an arthropod-borne virus transmitted by mosquitoes. 2. West Nile virus has a high mortality rate in immunosuppressed humans and infects many species of birds in southern Europe, the Mediterranean basin, and North America. 3. West Nile virus is maintained in nature through biological transmission between susceptible hosts by blood-feeding arthropods.

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

The brain tissue of the birds indicated the possibility of encephalitis. What is encephalitis, and why should this type of infection cause concern among health care professionals?

Encephalitis is an inflammation of the brain tissue. It is a concern to health care professionals because an infection in the brain means the virus has breached protective measures.

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.

If mosquitoes are the mode of transmission for West Nile virus, why did the students in Bill's virology class focus on finding the virus in the dead birds rather than collecting mosquitoes to examine?

The students tried to isolate and identify West Nile virus from birds because they are an amplifying host for the virus, making it more likely that the virus can be isolated from these animals.

Based on the concept map, which of the following must happen during Lyme disease?

There is an adaptive immune response.

Which of the following best describes why West Nile Virus is considered to be an emerging infectious disease?

West Nile virus outbreaks have increased in number and affected areas since 1937.

The tetanus exotoxin, produced by Clostridium tetani, __________.

prevents inhibitory signals that allow for muscle relaxation