Chapter 17: COMMUNICABLE AND INFECTIOUS DISEASE PREVENTION AND CONTROL Flashcards
Women who develop vaginal fungal infections (commonly referred to as yeast infections) usually have a history of having been prescribed antibiotics for bacterial infections. Which component of the epidemiological triangle (agent–host–environment) contributes most to the development of vaginal infections? a. Agent b. Environment c. Host d. Agent and host
B
Antibiotic therapy not only eliminates a specific pathological agent but may also alter the balance of normally occurring organisms in the body. As a result, one of these agents overruns another, and disease, such as a yeast infection, occurs.
A communicable disease outbreak has occurred in a town. At a town meeting with public health officials, a community health nurse (CHN) is asked to explain the phrase “virulent organism.” Which of the following definitions of virulence is correct?
a.
Virulence is the ability to bypass normal immunological response mechanisms.
b.
Virulence is the ability to invade major organ systems.
c.
Virulence is the ability to produce toxins and poisons that weaken the body.
d.
Virulence is the ability to produce severe physical reactions.
D
Virulence is the ability to produce a severe pathological reaction.
CHNs have been advised by the medical director to give injections of hepatitis A immunoglobulin to selected susceptible persons in the event of a hepatitis A epidemic. Which of the following outcomes will be the result? a. Active immunization b. Long-lasting immunity c. Natural immunity d. Passive immunization
D
Passive immunization refers to immunization through the transfer of a specific antibody from an immunized individual to a nonimmunized individual, such as the transfer of antibodies from mother to infant or the administration of an antibody-containing preparation (immune globulin or antiserum). Passive immunity from immune globulin is almost immediate but short-lived. It is often induced as a stop-gap measure until active immunity has time to develop after vaccination. Examples of commonly used immune globulins include those for hepatitis A, rabies, and tetanus.
Of the following statements about Salmonella made by class members in a class about disease prevention, which one indicates that additional teaching is needed?
a.
“Certain pets and farm animals may be Salmonella carriers.”
b.
“It is possible to transmit Salmonella through person-to-person contact.”
c.
“Salmonella may be spread through blood once the infected blood is exposed to air.”
d.
“Salmonella outbreaks are usually due to contaminated meat, poultry, and eggs.”
C
Meat, poultry, and eggs are the foods most often associated with salmonellosis outbreaks. Animals are common reservoirs for the various Salmonella serotypes. Although infected humans may also be carriers, animals are more likely to be chronic carriers. Reptiles, such as iguanas, have been implicated as Salmonella carriers, as well as turtles, poultry, cattle, swine, rodents, dogs, and cats. Person-to-person transmission is an important consideration in daycare and institutional settings. Anthrax (not Salmonella) forms spores when infected blood is exposed to air.
Of the following interventions for infectious diseases, which one best represents primary prevention?
a.
Giving a tetanus booster every 10 years.
b.
Giving a tetanus booster to a client after she steps on a nail.
c.
Giving tetanus immunoglobulin to a client after he steps on a nail.
d.
Giving antibiotics to a client who has tetanus and placing the client on seizure precautions.
A
Giving tetanus boosters before any exposure has occurred is a primary prevention measure. Giving boosters after exposure (i.e., the client may be infected but disease has not developed) is considered to be a secondary prevention measure (similar to the textbook examples of immunoglobulin and rabies immunizations given after exposure). Tetanus immunoglobulin would be given if the client that steps on a nail had not been previously immunized; however, this is done following exposure and would therefore be a secondary prevention. Giving antibiotics to a client who has already developed tetanus is not primary prevention.
Of the following infectious disease interventions, which one is most representative of secondary prevention?
a.
Clients with human immunodeficiency virus (HIV) infection are encouraged to use condoms to protect their sexual partners.
b.
Clients with HIV infection are given medications to improve immunological response.
c.
Health care workers are encouraged to receive annual vaccinations for influenza.
d.
Health care workers are required to have a tuberculosis (TB) skin test or chest X-ray.
D
TB screening for health care workers is an example of secondary prevention. TB skin tests and chest X-rays are methods of TB screening. Encouraging HIV-positive clients to use condoms is an example of primary prevention because the goal is directed toward the partner (to prevent exposure of the unaffected partner to the infected partner), and administering medications to improve their immunological response is an example of tertiary prevention. Health care workers receiving annual vaccinations for influenza is an example of primary prevention.
A student asks the school nurse how acquired immune deficiency syndrome (AIDS) is diagnosed. Which of the following answers is correct?
a.
AIDS is diagnosed through the negative results of a screening test called an enzyme-linked immunosorbent assay (ELISA).
b.
Antibodies to HIV, which form in about 6 weeks to 3 months following infection with HIV, are detected in the blood.
c.
Antibodies to HIV reach peak levels of 200/mL of blood.
d.
AIDS is diagnosed through positive ELISA results and clinical signs of AIDS.
D
The ELISA test is a laboratory procedure that detects HIV antibodies and is the test commonly used to screen blood for the presence of the HIV antibody. Clients must know that the antibody test is not diagnostic for AIDS but is indicative of HIV infection. Therefore, a positive ELISA test is confirmed using the Western blot test (a confirmatory test). If individuals test positive for HIV and also exhibit clinical signs of AIDS, they are infected and have the disease.
A CHN asks a class to describe the ways in which HIV can be transmitted. Which of the following responses by a student indicates a need for additional teaching?
a.
“HIV can be transmitted by droplet spread from sneezing or coughing.”
b.
“HIV can be transmitted by having unprotected sex with someone who is infected.”
c.
“HIV can be transmitted by sharing needles when shooting up drugs.”
d.
“HIV can be transmitted through transfusions of blood products that are contaminated with HIV.”
A
HIV transmission can occur via sexual contact, involving the exchange of body fluids, with an infected person; sharing or reusing needles, syringes, or other equipment used to prepare injectable drugs; perinatal transmission from an infected mother to her fetus during pregnancy or delivery or to an infant when breastfeeding; and transfusions or other exposure to HIV-contaminated blood or blood products, organs, or semen. It is not transmitted by insects, coughing, sneezing, office equipment, or sitting next to or eating with someone who has HIV infection.
For which of the following reasons should the school nurse recommend that an HIV-infected child not be allowed to attend school?
a.
The child develops allergies with sneezing.
b.
The school system requires students to receive routine immunizations.
c.
There is an outbreak of chicken pox at the school.
d.
There is strong objection from parents of well children.
C
School attendance may not be advisable for the child with HIV if other children are suffering from common childhood diseases, such as chicken pox or measles. The immunosuppressed child is at greater risk of contracting any of these infectious diseases and suffering serious complications. HIV is not spread by sneezing, and immunizations are not contraindicated in children with HIV. Objection from parents of well children presents a unique opportunity to the CHN to educate these parents about HIV transmission.
Which one of the following sexually transmitted infections (STIs) can be prevented through immunization? a. Chlamydia b. Gonorrhea c. Hepatitis B d. Herpes
C
According to current knowledge, hepatitis B infection can be prevented by immunization. In Canada, Twinrix® is a vaccine that protects against hepatitis A and B. Vaccines for Chlamydia, gonorrhea, and herpes are not yet available.
Which of the following presents a challenge with human papillomavirus (HPV) prevention?
a.
HPV can be transmitted through all body fluids.
b.
HPV warts may grow in areas that a barrier (e.g., a condom) does not cover.
c.
With HPV, thin-walled pustules may rupture to form honey-coloured crusts.
d.
With HPV, vesicles are hidden and ulcerate within 1 day.
B
The challenge of HPV prevention is that condoms do not necessarily prevent infection. Warts may grow in areas that barriers, such as condoms, do not cover, and skin-to-skin contact may occur.
Which one of the following would be a tertiary prevention measure implemented by the CHN to prevent TB?
a.
Administering a purified protein derivative (PPD) to the contacts of those infected with TB
b.
Initiating directly observed therapy (DOT) for TB-positive clients
c.
Providing education about the prevention of TB to members of the community
d.
Using skin tests to screen all health workers for TB
D
Tertiary prevention, for example, DOT, is carried out among persons already infected with the disease.
A client with TB wants to know why DOT is required as part of the treatment. Which of the following responses by the CHN would be the most appropriate one?
a.
“Clients with TB are often noncompliant; DOT will ensure that you take the drugs prescribed to you.”
b.
“This therapy is recommended by TB experts as the best way to ensure that you receive the treatment you need and that the infection doesn’t become resistant to treatment.”
c.
“This ensures that you get your medication even at the late stages of TB, when your memory may be affected by inadequate oxygenation to the brain.”
d.
“TB medications are very expensive, and this method ensures that government health care resources are not wasted by those who will not take the drugs regularly.”
B
While responding truthfully to questions, it is important for CHNs not to talk down to clients with health concerns and to consider their perspective and psychological health as well. One tertiary intervention is DOT programs for TB medication monitoring. The CHN observes and documents individual clients taking their TB drugs. When clients prematurely stop taking TB medications, there is a risk of the TB becoming resistant to the medications. This can affect an entire community of people who are susceptible to this airborne disease. Health professionals share in the responsibility of adhering to treatment, and DOT ensures that TB-infected clients have adequate medication. Thus, DOT programs are aimed at the population level to prevent antibiotic resistance in the community and to ensure effective treatment at the individual level. Many health units and health authorities have DOT home health programs to ensure adequate treatment.
