Chapter 19 - Epidemiology

Epidemiologists are usually more interested in the ____ of a particular disease, as it compares to the population as a whole, rather than the sheer number of cases

rate

The natural habitat of a pathogen is called the _____

reservoir of infection

Clostridium tetani, the causative agent of tetanus, a disease that infects humans, is found widespread in soils. Therefore, the reservoir for this organism is ____

soils

Infectious disease _____ is one of the most important aspects of disease prevention; it involves both recognizing and reporting disease cases to public health authorities

surveillance

People with ____ illnesses are an obvious source of infectious agents

symptomatic

An epidemic of typhoid fever in a Swiss ski resort occurred only in ____, because the locals rarely drank water, preferring wine instead

tourists

A ____ is any living organism, most commonly an arthropod, that can carry a disease-causing microbe externally or internally

vector

If an HIV-infected pregnant woman transfers HIV to her fetus, this is an example of ______ transmission

vertical transmission

Successful pathogens have multiple ____ factors that enable them to adhere to a host or penetrate host cells, avoid recognition or destruction by the immune system, and the damage of the host

virulence

______ are more susceptible to urinary tract infection because their urethra is relatively short and microbes can ascent the urethra into the bladder

women

Animals such as skunks, raccoons, and bats are reservoirs of the rabies virus. Therefore, rabies is considered a(n) ______ disease

zoonoses

Animals such as skunks, raccoons, and bats are reservoirs the rabies virus. Therefore, rabies is considered a(n) _______ disease.

zoonoses

In a case-control study, which characteristics should the controls share with the cases?

- Age - Gender - Socioeconomic status

Mechanisms to prevent airborne transmission of pathogens include _____

- Air circulation through high-efficiency particulate (HEPA) filters - Ventilation systems that constantly change air - Reduction of air pressure in hospital microbiology laboratories

Match the type of pathogen transmission involving respiratory droplets with the description

- Airborne transmission (a type of indirect transmission) - Small droplets from which fluid evaporates to create droplet nuclei - Droplet transmission (a type of direct transmission) - Large droplets that generally fall to the ground within 1 meter (approximately 3 feet of) release

Which of the following have directly resulted in emergence of certain food-borne illnesses

- Importation of food - Widespread distribution of food - Mass production of food

Transmission of pathogens via direct contact _____

- May be reduced by routine hand washing - Often involved organisms with a low infectious dose - Can be as simple as a handshake or as intimate as sexual intercourse

Factors in the physical environment that can influence the epidemiology of disease by determining which organisms can exist and reproduce include ______

- Temperature - Oxygen level - Water and nutrient supply

Patients with infectious disease are often hospitalized and may inadvertently spread the disease to others. This spread can be minimized via ______

- Use of disinfectants - Scrupulous cleaning

Diseases that can be transmitted from one host to another, such as influenza, are _____ diseases

- contagious - communicable diseases

A healthcare-associated infection (HAI) is one acquired in a ________

- doctor's office - hospital - long-term care facility - urgent care facility

Droplet transmission of infectious agents can be minimized by ______

- having people cover their mouth when they sneeze or cough, preferably not with their bare hands - placing desks or bed more than 1.5 meters apart in densely populated building

In order to minimize the risk of nosocomial infections from visitors, hospitals may ______

- limit the number of visitors - ban live plants or animals in some patients rooms

Humans have been enormously successful in eliminating or reducing the occurrence of certain diseases through efforts in _______

- vaccination - antibiotic treatment - reservoir and vector control - improved sanitation

_____ studies are designed to determine which of the potential risk factors identified by the descriptive studies are relevant in the spread of the disease

Analytical

The ____ collects data on diseases of public health importance in the United States and summarizes their status in the Morbidity and Morality Weekly Report (MMWR)

CDC

Match each scenario with the related emerging disease

Cholera - Refugee camps that have substandard living quarters West Nile encephalitis - Climate changes that favor the reproduction and survival of some arthropods, which can serve as vectors

The fungal pathogen _____ appeared in Washington state in 2007, causing lung infections and meningitis in healthy people. Cases must now be reported in Washington and Oregon and are closely watched by health authorities in other states

Cryptococcus gattii

Match each term with its definition

Endemic - Constant present in a given population Sporadic - Cases occur only from time to time Epidemic - An unusually large number of cases Outbreak - A group of cases occurring during a brief time interval Pandemic - An unusually large number of cases occurring on several continents

Match each term with the correct example scenario

Endemic - The fungal disease histoplasmosis, which is constantly present in the Mississippi and Ohio River drainage area Epidemic - Cholera, when it was reintroduced into Haiti in 2010 Outbreak - A cluster of botulism cases arising from a group picnic Pandemic - A new type of influenza that is infecting large numbers of people on several continents

A woman is still recovering from shigellosis diarrhea has a bowl movement but doesn't wash her hands afterward. She then shakes hands with another woman, who later touches her mouth with her fingers and develops shigellosis. This is an example of _______

Fecal-oral transmission & direct contact

Some descendants of North European ancestry are genetically less susceptible to _____ because they lack a specific receptor on their white blood cells

HIV

When people talk, sneeze, laugh, cough, and sing, they discharge microbes in small liquid droplets that evaporate, leaving behind airborne particles called droplet _______

Nuclei

Because of its resistance to chemicals and ability to grow in nutrient-deprived environments, many nosocomial infections have been traced to soaps, disinfectants, and other aqueous solutions that were contaminated with ______

Pseudomonas aeruginosa

The opportunistic pathogen ____ causes many nosocomial infections, thrives in hospital sinks, respirators, and toilets, and grows readily in nutrient-poor environments

Pseudomonas aeruginosa

Match each organism with the correct description

Staphylococus aureus - Often colonizes the nose without causing damage Neisseria gonorrhoeae - Causes an asymptomatic infection that can be damaging and should be treated

Humans can serve as reservoirs for most communicable diseases. Which situation is easier to control?

Symptomatic infections

True or False: Because of the widespread use of antimicrobial drugs in hospitals, many organisms causing nosocomial infections have become resistant to these medications

True

True or false: News media alert the public to the presence of infectious disease

True

True or false: Pathogens that have environmental reservoirs are difficult or impossible to eliminate

True

True or false: Some pathogens are more likely to cause disease than others when transmitted to a new host

True

Match each bacterium with the appropriate method of controlling its transmission

Vibrio cholerae - Sewage Treatment Mycobacterium tuberculosis - Cover mouth when coughing Nesseria gonorrhoeae - Abstinence, monogamy, or safer sex practices.

Successful pathogens have multiple ____ factors that enable them to adhere to a host or penetrate host cells, avoid recognition or destruction by the immune system, and the damage the host

Virulence

Match each season with the diseases that typically have a higher rate then.

Winter - Respiratory diseases Summer - Vector-borne and food-borne diseases

The _____ compromises 193 member states and is devoted to achieving the highest possible level of health around the world.

World Health Organization (WHO)

The _____ rate is the proportion of susceptible individuals developing illness within a population exposed to an infectious agent

attack

The proportion of susceptible individuals developing illness in a population exposed to an infectious agent is the ______

attack rate

Healthcare workers who are asymptomatic _____ of pathogens may not recognize that they pose a risk to patients until they are implicated in an outbreak

carriers

The _____ -______ rate is the proportion of persons diagnosed with a specific disease who die from that disease

case - fatality

_____ studies take into account past events that may have led up to the onset of the disease

case-control

The proportion of persons diagnosed with a specific disease who die from that disease is the _______

case-fatality rate

The spread of an infectious disease follows a series of steps called the ____ of infection

chain

John Snow performed an epidemiological study in the 1800s to figure out the cause of a _____ outbreak

cholera

A(n) ___ study looks ahead to see if the risk factors identified by previous studies predict a tendency to develop the disease

cohort

An epidemic in which the patients were all exposed to a single source of infectious agent is called a ______-______ epidemic

common-source

In a _____ epidemic, there is a rapid rise in the numbers of people who become ill, suggesting that they were all exposed to a single source

common-source

If Treponema pallidum, the causative agent of the sexually transmitted disease syphilis, gained the ability to survive for long periods of time in the environment, then transmission from one host to another

could be indirect as well as direct

When pathogens from one food are transferred to another, this is referred to as ________- contamination

cross

A _____ - _____ study surveys a range of people to determine the characteristics of the population such as behaviors, exposures, and disease, without attempting to establish the cause of the disease

cross-sectional

In a _____ study epidemiologist collect data that characterize those that are ill and the time and place of a disease outbreak, so that a list of possible risk factors may be compiled

descriptive

The infectious _____ is the minimum number of a particular microbe required to cause disease

dose

Infectious diseases that are newly recognized or have recently increased in incidence are called ______ infectious diseases

emerging

If human skin can serve as a reservoir for Staphylococcus aureus, then this pathogen will be shed along with the skin cells, Shedding skin cells are therefore the portal of ____ for this pathogen.

exit

A(n) _____ study is generally used to evaluate the effectiveness of a treatment or an intervention in preventing disease

experimental

In a disease outbreak, the index case is the ______

first person who developed the disease

An inanimate object such as a doorknob that can transmit infectious agents is called

fomite

An inanimate object such as a doorknob that can transmit infectious agents is called a ______

fomite

Healthcare workers should wear personal protective equipment such as disposable ____ if they are at risk of touching blood, mucous membranes, broken skin, or body fluids

gloves

A disease is not likely to spread within a population if 90% or more of the individuals are immune to the disease agent. This type of immunity is called _____ immunity

herd

When a patient receives intravenous fluids, ____ may gain access to the bloodstream, potentially leading to bacteremia

his or her own microbiota

Transfer of a pathogen from you to your parent is an example of _____ transmission

horizontal

A morbidity rate refers to the relative amount of ______

illness in a population

The _____ of disease reflects the number of new cases in a specific time in a given population

incidence

malnutrition, overcrowding and fatigue ___ people's susceptibility to infectious disease

increase

Uses of urinary catheter ____ the risk of developing a urinary tract infection

increases

The time it takes before a pathogen begins to cause symptoms of disease is called the ______ period

incubation

Transfer of a pathogen from one host to another via an inanimate object is an example of _____ transmission

indirect

_____ contact involves transfer of pathogens via inanimate objects such as doorknobs, drinking glasses, or clothing, otherwise known as fomites

indirect

Many hospitals employ an ______ control practitioner (ICP) whose role is to perform active surveillance of the types and numbers of infections that arise in the hospital

infection

The ____ of disease acquisition identifies the general site of contact between the person and the infectious agent.

location

The incidence of illness in a population is reflected in the ______

morbidity rate

A young child does not have fully developed immune system and therefore is generally _____ vulnerable to disease

more

Groups who eat raw freshwater fish are ____ to acquire tapeworms than those who eat cooked fish

more likely

The ______ rate reflects the overall rate of death in a given population at risk

mortality

An epidemic that occurs when a disease contagious, with one person transmitting it to several others, who then transmit it to several more, and so on, is called a _____ epidemic

propagated

Match each scenario with the related emerging diseases

Dysentery - Refugee camps that have substandard living quarters Malaria - Climate changes that favor reproduction and survival of some arthropods, which can serve as vectors

A 1993 disease outbreak involving hamburger patties contaminated with ____ stopped by the prompt response of health authorities in Washington State.

E. coli O157:H7