infectious diseases Flashcards
pathogen
any microorganism or agent that is capable of producing disease
virulence
related to the frequency with which an agent causes disease or it’s degree of communicability.
normal flora
beneficial microorganisms that the body harbors. They often function to compete with and prevent infection from unfamiliar agents.
colonization
microorganisms that are often pathogenic are present in the tissues of the host but have not caused symptomatic disease because of normal flora.
surveillance
the tracking of infections and the ensuring of compliance with federal and local requirements as outlined by the Centers for Disease Control (CDC).
immunity
resistance to infection. Can be active or passive.
passive immunity
of short duration (days or months) and either natural by transplacental transfer or artificial by injection of antibodies.
active immunity
lasts for years and is nayural from infection or artificial stimulation of the body’s immune system like with vaccination.
toxin production
Continued multiplication of a pathogen is sometimes accompanied by toxin production.
Toxins are protein molecules released by the bacteria to affect host cells at a distant site.
exotoxins
produced and released by certain bacteria into the surrounding environment as in tetanus, botulism and E. Coli
endotoxins
produced and released only by cell lysis.
endotoxins
produced and released only by cell lysis.
transmission of infectious organisms
Need reservoir ( source of organisms ), susceptibility of host with a portal of entry, and a mode of transmission.
Microorganisms can be transmitted by:
a. Contact transmission ( direct or indirect )
b. Droplet transmission
c. Airborne transmission
direct contact transmission
With direct contact the source and the host have physical contact. Microorganisms are transferred directly from skin to skin or from mucous membrane to mucous membrane. Often is called person-to-person contact.
indirect contact transmission
Indirect contact involves the transfer of microorganisms from a source to the host by passive transfer from contaminated articles.
droplet transmission
Indirect contact can also involve contact with infected secretions or droplets. These are produced when a person sneezes or talks and can only travel short distances. CDC recommends that staff stay at least 3 feet from a patient with a droplet infection.
Influenza is an example of a droplet infection.
Droplets do not stay suspended in air.
airborne transmission
Occurs when small airborne particles containing pathogens leave the infected source and enter a susceptible host.
These pathogens can remain suspended in the air for a prolonged time. The particles containing the pathogens are usually contained in droplets or dust. An example would be tuberculosis.
methods of infection control
Hand washing for at least 15 seconds with friction.
Personal protective equipment or barriers ( PPE ).
Adequate staffing
Disinfection/sterilization
Patient placement and transport:
a. Private rooms
b. Cohorting is practice of grouping patients who
are colonized or infected with the same
pathogen.
standard precautions
reflect that all body secretions and excretions and moist membranes and tissues, excluding perspiration are potentially infectious.
contact precautions
are used for infections that are transmitted directly or indirectly like MRSA, VRE, and C. Diff. Private room preferred. Use gloves and gowns when in contact with patient. Should also have dedicated equipment for the infected person.
droplet precautions
like those who have influenza, mumps, pertussis, and meningitis. Private room preferred . Mask required when working within 3 feet of patient.
droplet precautions
like those who have influenza, mumps, pertussis, and meningitis. Private room preferred . Mask required when working within 3 feet of patient.
airborne precautions
for infections like tuberculosis, varicella, and measles. Private room required with monitored negative airflow ( with appropriate number of air exchanges and air discharge to outside or through HEPA filter). Must were N-95 HEPA filter mask.
MRSA
a. Staph aureas is a common bacteria on the
skin, perineum, and in the nose. About 25%
to 30% of the population carries staph in
their nose or on their skin. They do not
have any signs of illness. This called
colonization.
b. Sometimes staph bacteria causes infections
especially pimples, boils and other skin problems. If
the bacteria enters deep wounds, surgical incisions, the
lungs, or blood stream, serious infections can result.
hospital acquired MRSA
Within past 40 years, more and more staph aureas infections have not been responding to methicillin and other penicillin based drugs.
MRSA is a type of staph that that is resistant to antibiotics called beta-lactams which include methicillin, oxacillin, penicillin and amoxicillin.
Is a fast growing infection in health care today.
130,000 cases occur in hospitals per year. Has lead to 5000 deaths.
Is spread by direct skin-to-skin contact with another person. It has also spread through contact with items that have been touched by a person with staph. Fluid from staph infections like boils is very infectious.
MRSA is susceptible to a limited number of antibiotics like vancomycin.
Patients who develop HA-MRSA pneumonia, abscesses or bacteremia can quickly progress to sepsis and death.
MRSA infections can reoccur after being cured.
patients at risk for hospital acquired MRSA
Older adults
Immunosuppressed patients
Those with a long history of antibiotic therapy.
Those patients with invasive lines or tubes especially ICU patients.
nursing care for hospital acquired MRSA
Assess patients for risk of MRSA and look for possible symptoms. Some hospitals have MRSA surveillance programs in which all patients are screened for MRSA by nasal swab cultures.
Patients that are identified as having HA-MRSA infections or to be colonized will be placed on contact precautions. They will be placed in a private room or in a room with another patient who has MRSA.
Hospital workers will use gloves and gowns and possibly masks when caring for these patients.
Visitors will be asked to wash their hands thoroughly before and after contact with the patient. Alcohol hand sanitizers may be used by visitors.
community acquired MRSA
Used to describe MRSA infections in people who have not been hospitalized or had a medical procedure such as dialysis, surgery, catheters etc. in the past year.
People who get CA-MRSA have no risk factors or previous history of colonization.
Clusters of CA-MRSA skin infections have been reported among athletes, military recruits, children, Pacific islanders, Alaskan Natives, Native American and with men who have sex with men and prisoners.
factors associated with MRSA skin infections
a. Close skin-to-skin contact
b. Openings in the skin such as cuts or abrasions, contaminated items and surfaces, crowded living conditions, and poor hygiene.
Is treated with Minocycline (minocin), Apo-Minocycline and Doxycycline.
Teaching to prevent the spreading of MRSA;
a. Keep wounds that are draining or have pus
covered with clean, dry bandages.
b. Clean your hands. You and your family should clean hands when in close contact
or if changing the bandage.
c. Do not share personal items such as towels,
wash cloths, razors, or clothing.
d. Avoid contact sports and other skin-to-skin contact
until wound is healed.
e. Tell any health care provider who treats you that you had a
MRSA infection.
VRE
Enterococcus bacteria live in the intestinal tract and are important for digestion.
If they move to another area as in surgery, they can cause infection. Use to be treated with vancomycin.
In recent years, over ¼ of these infections have become resistant to vancomycin.
risk factors for VRE
Prolonged hospital stays and severe illness
Abdominal surgery, enteral nutrition
Immunosupression
Those who have VRE infections need to be on contact precautions
VRE can live on almost any surface for days or weeks and can cause infection.
other multi drug resistant organsims
Multi-drug resistant tuberculosis and gonorrhea
Vancomycin-Intermediate Staph aureas (VISA)
and Vancomycin resistant Staph aureas (VRSA) have recently appeared.
Shared Characteristics of VISA & VRSA
Prior MRSA infection
Prior and prolonged vancomycin therapy
Renal disease needing dialysis
Drugs that are effective in treating VISA &VRSA:
a. Linezolid (Zyvox)
b. Quinupristin-dalfopristin (Synercid)
Recent resistance has been reported to Zyvox.
influenza (flu)
Is highly contagious viral respiratory disease characterized by coryza, fever, cough,and systemic symptoms like headache and malaise.
Usually occurs in epidemics or pandemics (global), although sporadic cases do occur.
Localized outbreaks usually occur every 1 to 3 years. Pandemics usually occur every 10 to 15 years until the last 2 decades.
In healthy adults tends to be mild and self-limiting. In older adults and in those with chronic cardiac and pulmonary disease the flu can be very serious causing life threatening complications such as pneumonia.
pathophysiology of the flu
Flu is transmitted by airborne droplets and by direct contact.
There are three major strains:
a. Influenza A – is responsible for most outbreaks and is the most severe. This is due to its ability to alter its surface antigens, bypassing previously developed defenses to the virus. New strains of flu are named by strain, geographic area and year.
b. Influenza B – outbreaks are usually less extensive and less severe than influenza A.
c. Influenza C- is mild and may go unnoticed.
Incubation period is short, usually 18 to72 hours. The virus effects the respiratory epithelium. It rapidly replicates in infected cells and is released to infect neighboring cells.
Inflammationl eads to necrosis and shedding of serous and ciliated cells of the respiratory tract.
The respiratory epithelial necrosis increases the risk for secondary bacterial infections. Sinnusitis and otitis media are frequent complications from flu. Tracheobronchitis may occur and last for up to 3 weeks. There is also a risk for pneumonia especially in older adults.
Viral pneumonia is very serious and can result in death. Bacterial pneumonia usually presents as a relapse of the flu. Reyes syndrome is a rare complication of flu but extremely dangerous. It is more likely to occur in children.
symptoms of influenza
Virus produces one of three syndromes: uncomplicated nasopharyngeal inflammation, viral upper respiratory followed by bacterial or viral pneumonia.
Onset is rapid with profound malaise. May have abrupt onset of chills, fever, muscle aches and headache. Respiratory symptoms may include dry, non-productive cough, sore throat, substernal burning and coryza. Acute symptoms usually subside in 2-3 days but fever may last for a week. Cough can become severe and productive and persist for days or weeks.
collaborative care of influenza
Preventing influenza by immunization yearly. Vaccines are only 85% effective in preventing the infection.
Medical care focuses on identifying the infection and providing symptomatic relief.
Vaccines should be given in the fall, prior to the annual winter outbreak. Should not give to people who have allergy to egg protein.
meds for flu
Anti-viral drugs may reduce the duration and severity of flu symptoms. Some that may be used are:
a. Oseltamivir (Tamiflu) b. Zanamivir (Relenza) c. Ribavirin (Virazole) d. Amantadine
nursing care for flu
Maintain isolation
Monitor respiratory status.
Maintain adequate hydration
Facilitate effective sleep pattern and balance between rest and activity
C-Diff
C-Diff are bacteria that live in the intestinal tract of 5% of healthy adults and 50% of healthy infants.
Taking antibiotics may kill many of the bacteria living in the intestine but C-Diff can survive. It is called antibiotic-associated diarrhea. It can reproduce in large numbers and cause severe diarrhea and illness.
Virulent forms are now appearing in the U.S. and Canada.
Can be spread by having direct contact with people who have the infection and indirectly by contact with inanimate objects that have been contaminated.
C-Diff has toxins that can cause colon dysfunction and cell death from sepsis.
Patients who have 3 or more liquid stools for 2 or more days are suspected of having C-Diff associated disease ( CDAD ). Older patients are at special risk.
risk factors for c-diff
People who are taking one or more antibiotics or anyone who has finished a course of antibiotics. Hospitalized patients Older adults People receiving chemotherapy People with serious underlying illness
medical nursing care for C-Diff
Is confirmed by a stool culture.
Patient will be placed on contact precautions.
The current antibiotics may be stopped or changed. Usually the patient is given Flagyl or vancomycin for antibiotics.
Fluid replacement to prevent dehydration.
Staff will wear gloves and gowns when entering room.
Patient will be in a private room or in a room with a patient with the same condition .
Visitors should not sit on the patient’s bed and not use the patient’s bathroom. Visitors must wash their hands thoroughly with soap and water before and after contact with the patient.
discharge teaching for c-diff
Proper hand washing and disinfecting of contaminated surfaces.
People who are very ill should avoid contact with infected person and should not handle the person’s feces.
Clean and disinfect your room and personal items periodically with a commercial disinfectant or a fresh solution of 1 part bleach to 9 parts water.
If someone is caring for you, they should wear gloves when handling any feces.
Many people do experience a relapse, but most will respond to a second round of medicine.
how to decrease risk of antibiotic resistant organisms
do not take antibiotics to prevent illness
wash hands frequently
follow directions when taking antibiotics (don’t skip doses)
finish antibiotics
do not request antibiotics for flu or colds
do not take left over antibiotics
a) may not be appropriate for you
b) old antibiotics can lose effectiveness
c) not enough doses for full treatment
