Micro ch 19

The single most important measure to prevent the spread of disease is

hand washing.

Which of the following is not a vector?

Fomite

Important sources of contamination in crowded locations are

droplets of saliva or mucus

Nosocomial infections are those acquired at a hospital.

True

A fly that walks on feces and picks up E. coli O157:H7 then lands on food and transfers the microorganisms, is considered a

mechanical vector.

Gonorrhea is a disease that may be

asymptomatic

The guidelines designed for prevention of nosocomial disease during care of all patients is called

Standard Precautions

If the number of people who become ill during an epidemic rises and falls rapidly, this is called a(n)

common source epidemic

Cross-sectional surveys are very useful in establishing cause of a disease.

False

SARS-CoV-2, the virus that causes COVID-19, appears to have originated as a virus that infects bats. The factor that contributed to the emergence of this diseases is

microbial evolution.

Explain the most likely reason why smallpox was successfully eradicated but rabies probably never will be.

Smallpox was only found in humans; rabies is found in numerous animal reservoirs. We cannot reasonably eliminate rabies in all of the animal reservoirs that exist.

The number of people in a defined population who die during a given period is called the

Mortality rate

WHO has targeted for elimination of

polio, dracunculiasis, AND measles

Schistosomiasis has increased in areas where

dams have been built.

Which of the statements about transmission of pathogens is TRUE?

Droplet transmission is a particularly important source of contamination in densely populated buildings such as schools.

A gradual rise in numbers during an epidemic indicates a common source epidemic.

False

Which of the following contributes to nosocomial disease?

-Other patients

-Patient's own normal microbiota

-Hospital environment

-Susceptible population

All of the choices are correct

Which of the following is NOT a political/societal reason for a decrease in rates of childhood immunizations?

A lack of a proper "cold chain" for stable transport of vaccines into tropical areas.

Please select the FALSE statement.

Herd immunity can never be overcome by a pathogen.

Why is it important to include a placebo in a scientific study to assess the effectiveness of a drug?

A placebo-treated group will determine if the changes observed in the drug-treated illness group are due to a psychological effect rather than a physiologic/pharmacologic one.

Explain how the incubation period can influence the spread of an infectious agent.

Depending on the microbe and the illness, an asymptomatic carrier in the incubation period might be shedding infectious microbes to his/her surroundings. In such a case, a longer incubation period would lead to a greater spread of the disease as the carrier comes into contact with more individuals while he/she is generally appearing to be healthy.

An epidemic that spreads worldwide is called a(n)

pandemic

Generally, the smaller the infective dose, the lower the chance of disease.

False

The first identified case in an outbreak is called the

Index case

Which of the following best defines an endemic disease?

It is a disease that is always present at some level in a population

The World Health Organization (WHO) is part of the

United Nations

When an infectious disease cannot spread in a population because it lacks a significant number of susceptible hosts, the phenomenon is referred to as

herd immunity.

The threat of bioterrorism

is due largely to the ease of spread and severity of diseases AND may include rarely seen infectious agents

The number of cases of a specific disease per one hundred people exposed is called the

attack rate

Please select the INCORRECT match between a hospital-acquired infection and the source of the causative agent.

Urinary tract infections - intravenous catheters

Which is not a common cause of healthcare-associated infections?

Yeasts such as Saccharomyces cerevisiae

So far, the only disease that has been globally eradicated is

smallpox

The member of the hospital staff who surveys the types and numbers of nosocomial infections is called the

infection control practitioner.

In order to prevent spread of microorganisms from the microbiology laboratory, the room air should be

under negative pressure AND filtered

All of the following is/are reservoirs of infection in a hospital setting EXCEPT

sterile surgical equipment.

Which of the following statements regarding epidemiology is FALSE?

Herd immunity occurs when a population does not engage in a given behavior that could increase their risk of disease.

If the number of people who become ill during an epidemic rises gradually, this is called a(n)

propagated epidemic.

Which of the following pathogens/diseases would be the easiest to eradicate?

A pathogen that only infects humans and causes obvious signs and symptoms.

Transmission-Based Precautions

are guidelines to use with patients infected with a highly transmissible or epidemiologically important pathogen

The natural habitat of a pathogen is referred to as its

reservoir

Diseases constantly present in a population are called

endemic

Women died after childbirth of

puerperal fever

A cluster of cases in a specific population occurring in a brief period of time is called a(n)

outbreak

A placebo is a mock drug.

true

The amount of infecting agent received by susceptible individuals is called the

infectious dose

The publication of the CDC that reports new cases of reportable infectious diseases is titled

Morbidity and Mortality Weekly Report (MMWR)

Diseases with long incubation periods are more likely to spread extensively.

True

The portal of entry typically has little effect on the course of a disease.

False

An infection acquired during hospitalization is referred to as a(n)_________ infection.

nosocomial

Identify three characteristics that make a disease a good candidate for eradication.

-One that causes obvious signs and symptoms.

-One that only infects humans.

-One for which a preventative vaccine is available.

Approximately what percentage of hospitalized patients may develop a nosocomial infection?

5%

A fly may serve as a mechanical vector.

True

Which of the following can lead to the reemergence of a disease?

Decline in vaccination rates for that disease.

Prevention of patient-to-personnel transmission of disease depends on limiting contact with

body fluids

The immunity of some black Africans to malaria is probably due to their

genetic background

Because of the natural evolution of microorganisms, it is necessary to use techniques that allow distinguishing them at the level of

strain

Which of the following contributes to nosocomial disease?

-Susceptible population

-Other patients

-Patient's own normal microbiota

-Hospital environment

All of the choices are correct

A picnic was attended by 1,000 people. Potato salad was served at the event. The next day, 140 people reported vomiting and diarrhea. What was the attack rate of this food-borne illness?

14%