Chapter 14 Homework

Which one of the following does NOT contribute to the incidence of healthcare-associated infections? antibiotic resistance gram-negative cell walls lapse in aseptic techniques lack of handwashing lack of disinfecting surfaces

gram-negative cell walls

Which of the following is considered a major category of transmission of disease? Vehicle transmission Contact transmission Vector transmission Contact, vehicle, and vector transmission

Contact, vehicle, and vector transmission

In the last segment of the animation, when does the first epidemic occur? September of year three January of year three April of year four January of year four March of year two

January of year three

If a disease occurs at a fairly stable rate, it is said to be pandemic. sporadic. endemic. epidemic.

endemic.

Which of the following definitions is INCORRECT? pandemic: a disease that affects a large number of people in the world in a short time incidence: number of new cases of a disease epidemic: a disease that is constantly present across the world endemic: a disease that is constantly present in a population sporadic: a disease that affects a population occasionally

epidemic: a disease that is constantly present across the world

Which of the following is NOT a communicable disease? tuberculosis malaria tetanus AIDS typhoid fever

tetanus

What is the role of epidemiology? To learn what diseases can be caused by respiratory pathogens. To learn how to treat and prevent various diseases. To learn which organisms cause disease. To learn which medicines are effective at killing pathogens.

To learn how to treat and prevent various diseases.

In the last segment of the animation, how many regions of the world experience the pandemic during April of year four? Four Two Six Five

Five

What features of West Nile virus make it an emerging disease of special concern? West Nile virus has a positive, single-stranded RNA genome that is 11,000 to 12,000 nucleotides long. West Nile virus is an arthropod-borne virus transmitted by mosquitoes. 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. West Nile virus is maintained in nature through biological transmission between susceptible hosts by blood-feeding arthropods.

West Nile virus is an arthropod-borne virus transmitted by mosquitoes. 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. West Nile virus is maintained in nature through biological transmission between susceptible hosts by blood-feeding arthropods.

A healthcare-associated infection (traditionally known as a nosocomial infection) is always present, but is inapparent at the time of hospitalization. always caused by pathogenic bacteria. only a result of surgery. acquired during the course of hospitalization. always caused by medical personnel.

acquired during the course of hospitalization.

The yeast Candida albicans does NOT normally cause disease because of symbiotic bacteria. antagonistic bacteria. parasitic bacteria. commensal bacteria. other fungi.

antagonistic bacteria.

Symptoms of disease differ from signs of disease in that symptoms always occur as part of a syndrome. are specific for a particular disease. are changes felt by the patient. are changes observed by the physician.

are changes felt by the patient.

During a six-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined as fever ≥ 39°C lasting >2 days with three or more symptoms (i.e., chills, sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratory-confirmed case was defined as a positive result for antibodies against Coxiella burnetii. Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positive for C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years. sheep. wind. Coxiella burnetii. pneumonia.soil.

Coxiella burnetii.

Which of the following is the best mode of controlling the spread of West Nile infections? Kill all mosquitoes to prevent the transmission of West Nile virus. Kill all birds to prevent the amplification and transmission of West Nile virus. Limit exposure to mosquitoes to prevent the transmission of West Nile virus. Limit exposure to birds to prevent the transmission of West Nile virus.

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

Which of the following statements concerning pathology, infection, and disease is true? The majority of microorganisms are pathogenic. Microorganisms that make up the normal microbiota of an individual never cause disease. The term infection is synonymous with the term disease. Pathology refers to the study of structural and functional changes that occur in the body as a result of a disease.

Pathology refers to the study of structural and functional changes that occur in the body as a result of a disease.

How can health care workers reduce the occurrence of nosocomial infections? Administer all medications orally instead of through injections Limit the number of visitors who can see the patient Reduce the number of times they visit a patient Practice more stringent aseptic techniques

Practice more stringent aseptic techniques

In the sixth segment of the animation, why is the disease epidemic in North America? The disease has spread to North America from Europe. The disease occurs at a higher rate than what would normally be expected in this region. The disease occurs at a lower rate than what would normally be expected in this region. Only a few cases are occurring in this region.

The disease occurs at a higher rate than what would normally be expected in this region.

Koch's postulates established criteria for proving that a specific organism causes a specific disease. Which of the following is NOT one of the criteria given by Koch's postulates? The pathogen isolated from a pure culture must cause the disease in a healthy lab animal. The pathogen must be isolated from the diseased host and grown in pure culture. The pathogen must be isolated from inoculated animals and must be different from the original organism. The same pathogen must be present in every case of the disease.

The pathogen must be isolated from inoculated animals and must be different from the original organism.

Which of the following statements about the development of infectious diseases is correct? The period of decline is the time when the infected individual's health rapidly deteriorates. During the incubation period, the infected individual exhibits obvious signs of sickness. The period of convalescence is the time during which the person regains health and fully recovers (back to the pre-disease state). The prodromal period is characterized by very severe symptoms.

The period of convalescence is the time during which the person regains health and fully recovers (back to the pre-disease state).

The science that deals with when diseases occur and how they are transmitted is called public health. communicable disease. morbidity and mortality. epidemiology. ecology.

epidemiology.

A commensal bacterium is beneficial to its host.may also be an opportunistic pathogen. isn't capable of causing disease in its host. always causes disease in its host. does not receive any benefit from its host.

may also be an opportunistic pathogen.

The major significance of Robert Koch's work is that microorganisms are present in a diseased animal. diseases can be transmitted from one animal to another. microorganisms are the result of disease. microorganisms cause disease.microorganisms can be cultured.

microorganisms cause disease

Expected prevalence of a disease is the anticipated geographical spread of a disease based on past observances. the number of new cases of a disease over a period of time. the total number of cases of a disease over a period of time. the expected occurrence of a disease based on past observations.

the expected occurrence of a disease based on past observations.

In which of the following diseases can gender be considered a viable predisposing factor? urinary tract infections anthrax pneumonia salmonellosis tetanus

urinary tract infections

As a health care worker, you are keenly aware of how important it is to avoid harming patients. You worry about inadvertently transmitting an infectious disease to an already compromised individual. According to the CDC, what is the most important thing you can do to avoid this? wear a lab coat wear shoe covers shave my head wash my hands before and after interacting with any patient

wash my hands before and after interacting with any patient

Epidemiology is defined as the study of how a disease is transmitted. when a disease occurs. where a disease occurs. where and when a disease occurs, and how it is transmitted.

where and when a disease occurs, and how it is transmitted.

A rabbit was found to have floppy ear disease, which causes long-ear infections. Its etiology (cause) is unknown. Unknown Microorganism X from the infected rabbit's right ear is successfully isolated and cultured on laboratory growth media. The ear of a healthy laboratory mouse is then inoculated with isolated microorganism, and after a period of time, no disease is observed. Which of the following statements accurately describe(s) the conclusion(s) that can be drawn from this experiment?

-A laboratory mouse might not be an appropriate, susceptible host; an experiment with a laboratory rabbit may be needed. -Microorganism X might not be linked to floppy ear disease, because the inoculated mouse remained healthy.

Understanding Koch's Postulates This activity asks you to identify Koch's postulates for determining the etiology of infectious diseases. Which statements accurately describe Koch's postulates?

-The same pathogen must be present in every case of the disease. -The pathogen must be isolated from the diseased host and grown in pure culture. -The pathogen from the pure culture must cause the disease when it is inoculated into a healthy, susceptible laboratory animal. -The pathogen must be isolated from the inoculated animal and must be shown to be the original organism.

Which of the following would be considered a vector? Water droplets that come from a sneeze from an infected individual Saliva that is transmitted between individuals during kissing Water containing bacteria from fecal matter A fly carrying disease from fecal matter to food

A fly carrying disease from fecal matter to food

Which of the following can contribute to postoperative infections? using syringes more than once normal microbiota on the operating room staff errors in aseptic technique antibiotic resistance All of the answers are correct

All of the answers are correct

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? An arbovirus is an arthropod-borne virus. An arbovirus is a virus isolated in Ann Arbor, Michigan. An arbovirus is maintained in nature through biological transmission. An arbovirus is a virus that originated from plants.

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

Which of the following would be considered a fomite? An infected toy Contaminated water A fly A tick

An infected toy

How might a patient who is not being treated with an antibiotic still be exposed to an antibiotic? Antibiotics can be used in aerosols, thereby entering the environment. Visitors currently being treated with antibiotics can pass them on to the patient. Health care workers being treated with antibiotics may pass the antibiotic on to the patient.

Antibiotics can be used in aerosols, thereby entering the environment.

Which of the following statements is TRUE? At least one member must not benefit in a symbiotic relationship. Members of a symbiotic relationship cannot live without each other. A parasite is not in symbiosis with its host. Symbiosis refers to different organisms living together and benefiting from each other. At least one member must benefit in a symbiotic relationship.

At least one member must benefit in a symbiotic relationship

What type of nosocomial infection is likely to arise from intravenous catheterizations? Cutaneous Surgical Lower respiratory Urinary tract Bacteremia

Bacteremia

Limitations to Koch's Postulates This activity asks you to sort statements that describe the benefits and limitations of using Koch's postulates to determine the etiology of infectious diseases. For each of the following statements, determine whether it describes a benefit or a limitation of Koch's postulates.

Benefit: -laboratory findings provide experimental evident that support the germ theory of disease -healthy, susceptible animals can be used as model organisms for testing many types of infections, thus avoiding the unethical inoculation of healthy human hosts -The steps are designed to systematically link a pathogen to specific infectious disease Limitation: -Different pathogens can produce the same signs and symptoms, making it difficult to determine which microorganism is causing a disease -Some pathogens cause several different diseases, which make it difficult to link on pathogen to one disease using Koch's postulates -Some infectious agents have specific growth requirements that prevent them from being artificially cultured in the laboratory

Experimental Approaches for Understanding Disease This activity asks you to view Foundation Figure 14.3 and determine the purpose of key components of this experiment. The key components include the diseased or dead animal, the healthy laboratory animal, the microscope, and the growth media. Robert Koch performed experiments to determine the specific microorganisms associated with specific diseases.

Diseased or dead animal- original source of the infectious microbial agent Healthy laboratory animal- organism injected with a potential infectious agent Microscope- tool used to view and identify individual microorganisms Growth media- nutrient-rich environment for isolating and culturing microorganisms

Which of the following is an example of the symbiotic relationship known as mutualism? Corynebacterium on the surface of the eye saprophytic Mycobacterium of the ear E. coli within the large intestine a tapeworm in the gastrointestinal tract of a human

E. coli within the large intestine

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 meninges. It is a concern to health care professionals because of how quickly the infection will spread to the rest of the body. Encephalitis is an inflammation of the peripheral nervous system. It is a concern to health care professionals because of how quickly the infection will spread to the rest of the body. 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. Encephalitis is an inflammation of the spinal cord. It is a concern to health care professionals because the infection will spread to the brain.

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.

Etiology and Infectious Disease This activity asks you to match each key term related to etiology and infectious disease with its description. Based on the information contained in the introduction, match each of the following concepts with its best description.

Etiology- the study of the cause of a disease Infectious disease- disease directly caused by microorganisms and not by other means, for example, genetic or degenerative diseases Germ theory of disease- this theory states that microorganisms cause infected diseases Koch's postulates- experimental requirements for identifying the agent of an infectious disease

Which is an example of vehicle disease transmission? Touching a telephone with cold viruses on its surface The bite of a mosquito containing malaria The transmission of MRSA from skin to skin contact The presence of Listeria on undercooked chicken served for dinner

The presence of Listeria on undercooked chicken served for dinner

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 large animals. It would be difficult to isolate West Nile virus from mosquitoes because they are small. The students tried to isolate and identify West Nile virus from birds because they had access to dead birds that were known to be infected with West Nile virus. 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. The students tried to isolate and identify West Nile virus from birds because it is faster to isolate the virus from a bird than to isolate it from a mosquito.

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.

Why are invasive procedures likely to increase the risk of nosocomial infections? Invasive procedures must use antibiotics. These procedures are carried out by health care workers, who carry resistant microbes. Invasive procedures require long term hospital stays, thereby increasing the number of visitors seen by the patient. These procedures allow microbes from the skin to enter the bloodstream of the patient.

These procedures allow microbes from the skin to enter the bloodstream of the patient.

Which of the following best describes why West Nile Virus is considered to be an emerging infectious disease? West Nile virus causes an infection and death in birds such as crows and blue jays. West Nile virus causes a latent viral infection that can emerge later in life. West Nile virus was first isolated in Uganda in 1937 and has caused significant outbreaks every year since then. West Nile virus outbreaks have increased in number and affected areas since 1937.

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

13) Transient microbiota differ from normal microbiota in that transient microbiota cause diseases. are found in a certain location on the host. are always acquired by direct contact. are present for a relatively short time. never cause disease.

are present for a relatively short time.

Which of the following is NOT an example of microbial antagonism? acid production by bacteria bacteriocin production bacteria occupying host receptors bacteria causing disease bacteria producing vitamin K

bacteria causing disease

In which of the following patterns of disease does the patient experience no signs or symptoms? prodromal decline convalescence incubation both incubation and convalescence

both incubation and convalescence

When aerosols containing pathogens spread disease from a distance of less than one meter, it is considered vector transmission. airborne transmission. waterborne transmission. contact transmission.

contact transmission.

Which of the following definitions is INCORRECT? acute: a short-lasting primary infection inapparent: infection characteristic of a carrier state secondary infection: a long-lasting illness chronic: a disease that develops slowly and lasts for months primary infection: an initial illness

secondary infection: a long-lasting illness

The rise in herd immunity amongst a population can be directly attributed to improved handwashing. increased use of antibiotics. vaccinations. antibiotic-resistant microorganisms. None of the answers is correct.

vaccinations.