unit 5 Micro

CDC is an acronym for:

Center for Disease Control

When there is an outbreak of disease, epidemiologists follow a set of steps to prove that a particular organism is the cause of disease. These steps were developed by:

Robert Koch

Match the exotoxin with the appropriate target cell or action: peripheral neurons

botulinum

protein

exotoxin

ability to invade and spread

invasiveness

ability to cause disease

pathogenicity

Which of the following is never an example of a human carrier:

person during the prodromal phase of disease

a "sign" is

something a physician can observe or test for

The time period for the prodromal stage is:

1-2 days

An example of a re-emerging disease is:

TB due to Mycobacterium tuberculosis

Due to mutations, some pathogens which previously caused disease only in non-human animals are now causing disease in humans.

TRUE

A structure which helps bacterial pathogens attach to the surface of host cells is:

a glycocalyx fimbriae

Throughout life we come into contact with microbes. The initial contact is during birth. As we grow and age, some of those contacts:

become normal flora never colonize and are loss result in infection result in disease

Humans can serve as a source and reservoir for infectious agents. During acute disease, coughing or sneezing can transmit a pathogen to another human. Too, sometimes infectious agents are transmitted to other humans even though the infected person is not exhibiting any symptoms. A human who is infectious for others yet is not experiencing any symptoms is called a:

carrier

Match the exotoxin with the appropriate target cell and action: intestinal cells

cholera

Match the exotoxin with the appropriate target cell or action: causes loss of Cl- ions and failure to absorb Na+ ions; results in diarrhea with massive fluid loss

cholera

If the contact results in disease, the possible consequences include:

death the patient becomes a chronic carrier the patient is cured chronic illness

Worldwide, the infectious disease which accounts for the most illnesses due to an infectious agent is:

diarrhea

Tissue damage due to an infectious disease may be due to

direct damage caused by the infectious agent and its toxins a strong inflammatory response

If the contact results in infection, the possible consequences include

eliminate the pathogen without disease disease the patient becomes a chronic carrier

Match with the appropriate description: an infectious disease which has increased above normal for a particular geographic region

epidemic

In the US, the leading cause of death is:

heart disease

Sepsis has the following characteristics:

may lead to organ failure may lead to disseminated intravascular coagulation causes vasodilation

Another term for 'illness' is:

mortality

Match the type of pathogen with the appropriate description: endogenous

opportunistic

Match the type of pathogen with the appropriate description: normal flora

opportunistic

Match the type of pathogen with the appropriate description: only cause disease in people who are ill, immune compromised

opportunistic

Newly emerging diseases are due to:

organisms we've known exist but have never caused disease in the past newly discovered organisms

Match with the appropriate description: an infectious disease which has increased above normal globally

pandemic

Match the type of pathogen with the appropriate description: can cause disease in both ill and healthy humans

primary

Match the type of pathogen with the appropriate description: pathogens in the environment

primary

Although tuberculosis was a major cause of disease in the early 20th Century, during the mid-1900s, new treatments and better sanitation decreased the prevalence of TB. Then, in the 1970s, the number of homeless people increased dramatically and the TB bacillus acquired multi-drug resistance. This led to an increase in TB in the United States. This would be an example of:

re-emergence of an infectious disease changes in human behavior which aided re-emergence changes in the genetic make-up of a pathogen which aided re-emergence

Endotoxin which is systemic (widespread) can lead to:

sepsis

Match with the appropriate description: one or a few people experience the disease; location varies

sporadic

Sources of nosocomial infectious agents include:

staff patient's own normal flora physical structures

Match the exotoxin with the appropriate target cell or action: neurons in the spinal cord

tetanus

Match the exotoxin with the appropriate target cell or action: prevents release of inhibitory neurotransmitters; causes contraction paralysis

tetanus

Incidence refers to:

the number of patients in the population who became ill during a particular time period

Upon their return to the US, troops who served in the first Gulf War were banned from donating blood to the Red Cross. This was due to the possible contamination of their blood by a protozoan called Leischmania. Leischmaniasis is an infectious disease transmitted by sand fleas. The reservoir are rodents. The sand fleas acquire this protozoan from rodents and have been known to transmit it to humans. This is an example where:

the reservoir and the source of infection are different

ability to produce toxins

toxigenicity

Historically, one of the most common causes of nosocomial infections was failure of the staff to wash their hands in between patients. Today, it's still a concern.

true

Portals of entry for pathogens are sites typically colonized by normal flora.

true

Primary pathogens are always exogenous pathogens whereas exogenous pathogens are not always primary pathogens.

true

How does infectious disease rank as a cause of death in the US?

3rd

An example of a newly emerging infectious disease is

AIDS due to HIV diseases now caused by normal flora due to immune suppression

Reasons for the emergence of new infectious diseases include changes in human behavior and genetic changes in the infectious agents. The changes in the infectious agents may be due to mutations, or due to microbes which acquire resistance genes or virulence factors via conjugation, transduction or transformation.

TRUE

Today, much of epidemiology involves modeling. These models are mathematical equations which predict the advent as well as spread of infectious disease.

TRUE

Re-emerging diseases are diseases which:

are due to organisms which caused disease in the past but due to treatments and better hygiene were eliminated as a cause disease, but are now beginning to cause disease again

Arthropods infect other animals by:

biting or defecating the infectious agent transmitting the agent from a body part to the animal transmitting the agent to water or food which is consumed by an animal

Match the exotoxin with the appropriate target cell or action: at the neuromuscular junction, prevents release of stimulatory neurotransmitters; causes flaccid paralysis

botulinum

Some people are a constant source of a pathogen and are infectious for others their entire life. This category of carrier is called

chronic

During the early winter months of November thru January, 110 people in Hutchinson had been sick with influenza. Of those 110, 10 came down with the disease during the month of November. If the total population is 40,000, the incidence for November is:

10 per 40,000

As a leading cause of death worldwide, infectious disease ranks:

2nd

Another term for 'death' is:

morbidity

Prevalence is defined as:

the percent of people with the infectious disease

Some exotoxins are coded by genes found on plasmids. This means that some exotoxin genes can be shared with other bacteria via conjugation.

true

Some species of bacteria may have a variety of exotoxins. And if they happen to be gram negative, they have endotoxin as well.

true

Some species of pathogens are adapted to enter at a specific portal

true

Some toxins are considered bioterrorist agents

true

Sometimes humans can pick up an infectious agent on their hands and then infect others. This occurs in the hospital when a nurse or doctor fails to wash his or her hands in between patients. This is referred to as a passive carrier.

true

Symptoms during the prodromal period are general and alert you that you're getting sick. Symptoms during the period of invasion are more specific and characteristic of the disease

true

The most common site for a nosocomial infection is the:

urinary tract

exotoxins

usually specific effect on the human body may be an enzyme some are heat stable

The time period for the acute disease is:

varies from disease to disease

The time period for the incubation stage is:

varies from disease to disease

which of the following causes edema?

vasodilation

Besides humans, animals can serve as sources of infectious agents. For example, there are many diseases transmitted by arthropods. Many of these are insects which pick up a pathogen from its reservoir and then transmit it to a host. Arthropods which transmit infectious agents are called:

vectors

If the avenue for infection is from mother to fetus. This transmission is called:

vertical

degree of pathogenicity

virulence

Some viruses produce spikes. If they use the spike to attach to host cells to initiate an infection, the spike would be considered a:

virulence factor

structures and toxins which enable the organism to cause disease

virulence factor

Another way that genes for exotoxins are shared is via transduction. For transduction to occur, what is responsible for transmitting the exotoxin gene from one bacterium to another?

viruses

Does citizenship involve being vigilant for outbreaks of infectious disease and notifying authorities?

yes

Vertebrate animals can serve as both a reservoir and the source of infection. When they transmit an infectious agent, the resulting disease is called a(n):

zoonose

Worldwide, the leading cause of death is:

heart disease

Some of the general functions of exotoxins include:

helping the bacterium spread through its host lysing host cells affecting host physiology

If the avenue of infection is from one adult to another adult, this transmission is an example of:

horizontal

Which of the following is not a reason why normal flora cause nosocomial infections:

in the hospital, normal flora may mutate so that they cause disease

Regarding human behavior, which of the following may contribute to emerging infectious diseases?

increased mobility of the human population widespread export of food centralized food processing changes in morality

The stages of disease include a prodromal period. This stage comes after:

incubation

Nosocomial infections refer to:

infections acquired at a hospital or clinic

Worldwide, the category of infectious disease which accounts for the most deaths due to an infectious agent is:

infections of the respiratory tract

The amount of pathogen which enters the body is also a factor which determines if a person will become infected. The minimal amount of inoculum which is needed to cause disease is called the:

infectious dose

You are familiar with coagulase from lab. This exotoxin helps a bacterium wall itself off from white blood cells once it's caused an infection. In contrast, which of the following breaks down structures so the bacterium can spread?

DNAse

An example of a new infectious disease due to an organism which in the past never caused disease is:

diseases now caused by normal flora due to immune suppression

Which of the following is due to activation of the clotting mechanism in the blood?

disseminated intravascular coagulation

Match with the appropriate description: an infectious disease which is always more prevalent in a particular geographic area compared to other parts of the country

endemic

HIV infected patients eventually lose their ability to mount a specific immune response. At this stage, these patients have AIDS. Most AIDS patients die from their own normal flora. Hence, the pathogen which kills most AIDS patients is considered a(n):

endogenous pathogen

binds to a molecule on the surface of a macrophage

endotoxin

component of the outer membrane of a gram negative bacterium

endotoxin

lipopolysaccharide

endotoxin

stimulates a monocyte to release inflammatory chemicals

endotoxin

One of the stages of a bacterial infection is when the host is damaged. For example, Hantavirus infections induce a strong inflammatory reaction that causes the capillaries of the lungs to become leaky. This, in turn, causes the lungs to fill with fluid and the patient literally drowns. This is an example of damage caused by the host's response to the infectious agent, and is not directly due to the pathogen. Another example of damage caused by the host's response is:

endotoxin which causes secretion of inflammatory chemicals; these inflammatory chemicals cause gram negative sepsis

secreted from the cell

exotoxin

Regarding infectious disease, an epidemiologist undertakes an investigation which looks at signs and symptoms experienced by patients, the time of onset and the characteristics of the patient group, and:

experimentally determines the infectious agent possible etiological agents

Epidemiology is the study of:

factors which lead to disease mechanisms involved in the development of disease ways to prevent disease both infectious and non-infectious diseases

The phrase 'source of infection' means the same as 'reservoir'. For example, the reservoir for hantavirus is the deer mouse and the source of contact is also the deer mouse.

false

There are a variety of endotoxins, and each endotoxin has a specific effect on the human body. In contrast, exotoxins all work the same way by causing a generalized inflammatory reaction.

false

Another source of infectious agents is non-biological. For example, if an infectious agent is on an inanimate object and the inanimate object serves as the route of infection for a human, the inanimate object is called a:

fomite