Question 1

During which phase of an infectious disease are immunopathologies most likely to first appear?

Accepted Answer

During the invasive phase, the immune response is at its highest and immunopathologies such as inflammation, tissue damage, and autoimmune reactions are most likely to occur.

Question 2

The ability of a microbe to cause disease is known as

Accepted Answer

The term "pathogenicity" specifically refers to the ability of a microbe to cause disease. Emergence refers to the appearance of a new disease or the re-emergence of an existing disease that has significantly increased in prevalence or geographic range. Invasiveness is the ability of a microbe to spread and invade host tissues. Virulence refers to the severity or degree of pathogenicity of a microbe. While all of these terms are related to disease-causing abilities of microbes, only "pathogenicity" specifically refers to the ability to cause disease.

Question 3

Which of the following can weaken the host immune response?

Accepted Answer

Too little sleep can weaken the host immune response by reducing the production of cytokines, a protein that signals the immune system to fight off pathogens. Lack of sleep can also lead to an increase in stress hormones, which can further suppress the immune system. The other choices (B, C, and D) can actually strengthen the immune response.

Question 4

The main reason that climate change can affect infectious disease patterns is by

Accepted Answer

Climate change can shift the distribution and availability of habitats and resources for pathogens, vectors, and hosts. As a result, some regions may become more suitable for the growth and transmission of certain diseases, while others may become less hospitable. For example, rising temperatures and increasing rainfall may expand the geographic range of mosquitoes and ticks that carry diseases such as malaria, dengue fever, and Lyme disease. Similarly, changes in precipitation and temperature may affect the seasonal timing and intensity of outbreaks of diseases that depend on water and soil conditions, such as cholera and hantavirus pulmonary syndrome.

Question 5

An infectious disease that rapidly increases in incidence throughout the world is known as a ________.

Accepted Answer

The answer of An infectious disease that rapidly increases in...

Question 6

CASE HISTORY
In 1884,Yong Ding was a 38-year-old male in Canton,located in southern China.Life was hard,but Yong Ding,a cook,still managed to support his family.As he walked to his restaurant each day,he barely noticed the small bands of rats scurrying through the streets.Disease was rampant that year;victims of the Shuyi (rat epidemic)were stacked like firewood in the streets,five bodies high in places,waiting to be taken to burial.Yong knew that the disease started as a swollen gland in the armpit and often had a black appearance (now called a bubo).He checked himself daily for these swellings and,seeing none,always felt relief.Then,one morning,he found one.Within days,Yong Ding began coughing blood as the agent (a mystery at the time)spread through his bloodstream to his lungs.Once that happened,Yong Ding knew death was not far behind.More than 60,000 died this way in what was to be the start of the Third Pandemic of bubonic plague.Yong Ding's body was one of many lining the street that year.
We now know that the cook Yong Ding was living through the Third Epidemic of bubonic plague.We also know that the rats that scurried randomly through the streets were infested with fleas,which carried the causative agent of the bubonic plague: Yersinia pestis.In this complex infection cycle,which organism was the vector?

Accepted Answer

Fleas are the vector in the complex infection cycle of bubonic plague, as they carry the causative agent Yersinia pestis from infected rats to humans.

Question 7

The ability of a microbe to attach to a body surface is known as ________.

Accepted Answer

The answer of The ability of a microbe to attach...

Question 8

Francisella tularensis is a highly infectious bacterium that can be contracted via multiple routes including inhalation.It causes severe disease but is treatable.Into what risk level does F.tularensis fall?

Accepted Answer

Francisella tularensis is classified as a risk group III pathogen due to its high infectivity, potential for aerosol transmission, and the severity of disease (tularemia) it causes, although it is treatable with antibiotics. Risk group III includes pathogens that can cause severe human or animal disease but for which preventive or therapeutic interventions are often available.

Question 9

What is the difference between an emerging and a reemerging disease?

Accepted Answer

Emerging diseases are those that are newly discovered or have recently appeared in humans or have recently undergone a significant increase in incidence or geographic range. Reemerging diseases are those that were once well-known but have recently undergone a resurgence in incidence or geographic range. Vaccines may or may not exist for both emerging and reemerging diseases, and they may be caused by viruses or bacteria. The origin of the disease (whether it evolves within humans or is of zoonotic origin) is not the defining characteristic that separates emerging and reemerging diseases.

Question 10

Which of the following is NOT true of climate change?

Accepted Answer

Climate change can indeed affect human disease patterns by altering the range and behavior of disease-carrying insects, fostering the emergence of new diseases, and the reemergence of old ones.

Question 11

A disease that can spread to humans from nonhuman animals is known as a ________ disease.

Accepted Answer

The answer of A disease that can spread to humans...

Question 12

The typical signs and symptoms of a disease first appear during the ________ phase of an infectious disease.

Accepted Answer

The answer of The typical signs and symptoms of a...

Question 13

Which of the following is NOT a driver of emerging diseases?

Accepted Answer

Decreased human drug use is not a driver of emerging diseases. Rather, it is the opposite - the inappropriate use of drugs can contribute to the emergence of antibiotic-resistant infections. The other choices - climate change, microbial evolution, and changing land use patterns - are all recognized as drivers of emerging diseases.

Question 14

A fever is often a host response to a pathogen.As such,fever is an example of ________.

Accepted Answer

The answer of A fever is often a host response...

Question 15

Transplacental transmission is an example of

Accepted Answer

Transplacental transmission, where a pathogen is transmitted from mother to fetus across the placenta, is considered a form of direct transmission because it involves direct contact between the mother and the fetus.

Question 16

Infectious dose is measured by determining how many microbes are required to cause

Accepted Answer

Infectious dose is the amount of microbes required to cause disease symptoms in half of an experimental group of hosts. It is measured to determine the virulence of a pathogen and the potential risk of infection.

Question 17

Which of the following is most likely true of pathogens with a broad host range?

Accepted Answer

Pathogens with a broad host range are able to infect multiple species, indicating that they recognize receptors that are very similar among different hosts. This enables them to adapt to new hosts and infect them successfully.

Question 18

Known diseases that rapidly increase in incidence and/or geographic range are known as

Accepted Answer

The answer of Known diseases that rapidly increase in incidence...

Question 19

Which of the following host factors can prevent disease by limiting exposure?

Accepted Answer

Proper hygiene, such as frequent handwashing and avoiding close contact with individuals who are sick, can limit exposure to harmful pathogens and prevent disease. Too little sleep and moderate exercise may have other health benefits, but they do not directly prevent exposure to pathogens. Working in the healthcare field may actually increase exposure to pathogens.

Question 20

A particular virus has a high infectious dose 50% and extremely low mortality,causing only mild symptoms.Which of the following is true of this virus?

Accepted Answer

The answer of A particular virus has a high infectious...

Quiz 2: Basic Concepts of Infectious Disease