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This course will expire or be updated on or before November 1, 2015.
ABOUT THIS COURSE
You must score 70% or better on the test and complete the course evaluation to earn a certificate of completion for this CE activity.
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Wild Iris Medical Education, Inc. is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's Commission on Accreditation.
Wild Iris Medical Education, Inc. (CBRN Provider #12300) is approved as a provider of continuing education for RNs and LVNs by the California Board of Registered Nursing.
Wild Iris Medical Education, Inc. provides educational activities that are free from bias. The information provided in this course is to be used for educational purposes only. It is not intended as a substitute for professional health care. See our disclosures for more information.
Copyright © 2014 Wild Iris Medical Education, Inc. All Rights Reserved.
COURSE OBJECTIVE: The purpose of this course is to prepare healthcare providers to educate patients and the general public, using evidence-based, up-to-date information about the symptoms, treatment, and prevention of seasonal influenza.
Upon completion of this course, you will be able to:
Influenza is an ancient and deadly disease, first described by Hippocrates more than 2,400 years ago. Since then, the disease has sickened and killed millions of people in local epidemics and global pandemics. The most lethal pandemic of record began in 1918, just after World War I, when 40 to 100 million people died from what was called the Spanish flu.
In 1931, Richard Schope discovered the cause of influenza (the Orthomyxoviridae family of viruses) in pigs; and in 1944, Thomas Francis Jr. developed the first significant steps toward preventing the disease with an inactivated-virus vaccine. His work was made practical by Frank MacFarlane Burnet, who showed that the virus lost virulence when it was cultured in fertilized hens’ eggs. This allowed researchers at the University of Michigan to develop the first influenza vaccine. Since then, vaccination has limited its spread but has not prevented pandemics of the disease (Potter, 2001).
In 1957, the Asian flu swept around the world, killing 1 to 1.5 million people, and in 1968, a pandemic called Hong Kong flu killed nearly a million more. Then, in 2009, a pandemic called swine flu, caused by virus found in pigs, swept around the world. As a consequence, a vaccine against the three causative viruses was developed. However, because viruses change constantly, each year WHO publishes vaccine recommendations to prevent what is now called seasonal influenza (CDC, 2014a; WHO, 2014).
All influenza viruses belong to the Orthomyxoviridae family of RNA virus, including types A, B, C, Isa virus, thogotovirus, and others. Each type contains two surface glycoprotein antigens, called subtypes hemagglutinin (HA) and neuraminidase (NA). The HA antigen enables the virus to enter cells, while the NA antigen facilitates cell-to-cell transmission. These subtypes are further differentiated by their numbered surface antigens, serotypes 1 to 10.
Type A viruses are the most virulent of influenza types, producing the most severe symptoms. They infect humans, other mammals, and birds and are the cause of all known pandemics, including:
Type B viruses have only one serotype and infect humans and seals.
Type C viruses have one serotype, infect humans and pigs, and are relatively uncommon.
Isa virus infects fish and causes infectious anemia in salmon.
Thogotovirus is found in ticks, mosquitoes, and mammals; human epidemics from them are unknown.
Additional types of influenza viruses are being discovered, but to date, type A and B are known to pose the greatest threat to human health.
A number of human cases of “swine flu” (H3N2v) have been reported in the United States beginning in August 2011. This virus normally occurs in pigs but does not usually infect people. Evidence from the 2011 and 2012 flu seasons suggests the strain produces mild symptoms and is judged to pose a relatively low risk of pandemic. Although the virus can be spread from human to human, it is primarily a zoonotic transmission (from animal to human). Most cases were contracted at fairs after exposure to pigs, and the CDC therefore recommends that children who are at high risk should avoid fairs where they may be exposed to pigs.
Early steps to make a vaccine against H3N2 have been taken, but there is no plan to mass-produce the vaccine at this time. (Seasonal flu vaccine is not designed to protect against H3N2v.) Public health authorities are watching this situation closely. They advise those who are in contact with pigs to take normal precautions such as washing hands frequently with soap and running water before and after exposure to animals and avoiding drinking, eating, or putting things in one’s mouth while in animal areas.
Source: CDC, 2014b.
When viruses laden with antigens infect a human or an animal, the body recognizes them as foreign substances and reacts in what is called an immune response. This response creates antibodies against the foreign substance. After recovery from the infection, the human or animal is usually immune to getting the same viral disease for years (perhaps a lifetime). Influenza vaccines help develop immunity by imitating an infection and causing the immune response that protects against the virus in the future (CDC, 2013).
Due to their immature immune response systems, children 6 months to 8 years old who are receiving an influenza vaccine for the first time require an additional dose. An optimal immune response will be initiated by administering a second dose a minimum of four weeks after the first dose. Because the strains contained in the 2014–15 seasonal influenza vaccines are identical to those contained in the 2013–14 vaccines, only one dose is required for any child aged 6 months through 8 years who previously received one or more doses during the 2013–14 flu season (CDC, 2014c).
Late in life, the immune systems become less responsive. In answer to this, a high-dose trivalent influenza vaccine has been developed for those 65 and over; it has been shown to induce significantly higher antibody responses and provide better protection against influenza illness. Progress is being made in the development of a high-dose vaccine for use in those under age 65 (DiazGranados et al., 2014).
Influenza viruses change constantly. They do this in two ways: antigenic drift and antigenic shift.
Antigenic drift is caused by an accumulation of the many small mutations that are continually occurring in both influenza A and B viruses. These mutations occur within both HA and NA genes. When this happens, antibodies may only partially recognize the resultant viruses or may not recognize them at all. Thus, when an antigen drift occurs, the current vaccine may not provide protection against disease. This is the reason why influenza vaccines must be updated annually.
Antigenic shift is an abrupt, major change in the influenza viruses, resulting in new HA and/or NA proteins. As a result, a new vaccine must be made to combat the altered virus. For this reason, people must be vaccinated anew to be protected from the altered virus of seasonal influenza (CDC, 2014d).
|ANTIGENIC DRIFT||ANTIGENIC SHIFT|
The most common way influenza viruses spread from person to person is by droplet infection. Infected people exhale, cough, or sneeze, and virus-containing droplets fly through the air into the nose and throat of others or onto some intermediate surface such as a doorknob. When other people touch a contaminated surface, viruses may stick to their fingers. When they touch the mucus membranes of their body, they inoculate themselves with the virus.
To prevent the spread of disease, individuals are instructed to:
There is limited evidence, but no proof, that face masks offer some protection against influenza. However, it is recommended that for those who must come into close contact with a sick person (within 6 feet), a mask may provide protection. Those with the flu may wear a mask when near other people and if they must leave home. In areas where influenza is widespread, uninfected individuals may wish to wear a face mask in crowded settings (DeNoon, 2014).
According to the CDC, sick adults are able to infect others beginning 1 day before symptoms appear and up to 5 to 7 days after they become ill. Sick children may be able to infect others beginning 1 day before symptoms appear and for more than 7 days after they become ill.
Symptoms develop 1 to 4 days after the virus enters the body. That means people may be able to pass on the flu virus to others even before they know they are sick. Any individual who is infected with viruses can infect others whether they show symptoms or not (CDC, 2014f).
John Smith, a 57-year-old man with a history of asthma, had been experiencing flu-like symptoms for three days. He was running a fever and, despite using his inhaler more frequently, finding himself increasingly short of breath. At the urging of his wife, he went to the emergency department (ED) to be checked.
The ED intake staff noticed that Mr. Smith was frequently coughing, so they responded per facility policy by offering him a facemask to wear while he sat in the waiting room. A few minutes later he was brought into triage, where the nurse confirmed that his symptoms were consistent with a contagious phase of influenza. During triage, the nurse allowed Mr. Smith to remove his facemask for his comfort but donned a facemask herself to minimize the risk that she might transmit the virus to her family or other patients who had not yet been vaccinated. During further diagnostic testing, the ED team continued the practice established by the triage nurse of wearing facemasks when they were within three feet of the patient while allowing him the comfort of not wearing a facemask.
Mr. Smith was admitted to the hospital with a diagnosis of left lower lobe pneumonia. On the advice of the infection prevention nurse, he was presumed to be infectious and was asked to wear a facemask when out of his room or being transported, while healthcare workers and visitors donned facemasks when they expected to come within three feet of him.
The infection prevention nurse explained to Mr. Smith and his family that, although there is no definitive evidence that facemasks decrease the spread of the influenza virus, it is still recommended to use facemasks as a prudent measure to decrease the spread of the virus.
Anyone can be infected with the flu virus, but the disease is more severe and the consequences more critical for some people than others. The most vulnerable are children under 5 years of age, especially those younger than 2 years of age; adults 65 years of age and older; pregnant women; and American Indians and Alaskan Natives (CDC, 2014g).
In addition, influenza can make chronic health problems worse. For example, individuals with asthma may suffer asthma attacks, and people with chronic congestive heart failure may experience an accumulation of fluid in the lungs, abdominal organs, and peripheral tissue. Generally speaking, people with the following medical conditions are more vulnerable to serious influenza-related complications:
Influenza is a highly contagious infection of the respiratory tract. It can cause mild to severe illness and may lead to death. The incubation period is brief and the onset sudden, causing chills, fever, aching muscles, and general malaise. Symptoms include:
The indicators of influenza are referred to as “flu-like symptoms.” In the early stages of an infection, it may be difficult to distinguish between a common cold and influenza. However, the symptoms of flu are more severe and last longer than the common cold. A comparison of the usual symptoms of influenza and the common cold are listed below.
|Source: Nazario, 2013.|
|Fever||Characteristic, high (100 °F–102 °F), lasts three to four days||Rare in adults and older children; may rise to 102 °F in infants and young children|
|Headache||Sudden onset, may be severe||Rare|
|Muscle aches||Usual, often severe||Mild|
|Fatigue||Often extreme, may last 2 to 3 weeks||Quite mild|
|Weakness||Often extreme, may last 2 to 3 weeks; children may show low activity level||Mild and, if present, of brief duration|
|Rhinitis and runny nose||Common||Common|
|Sore throat||May occur||Common|
|Nausea, vomiting, diarrhea||May occur in adults; more common in children||Never in adults|
|Cough||Hacking; may be severe and last for weeks after infection||Mild to moderate hacking cough|
Diagnosis of influenza is based on presenting symptoms and viral tests. However, most individuals with flu symptoms do not require special testing because test results usually do not change their treatment. Individuals who have an acute febrile respiratory illness, sepsis-like syndrome, or are members of vulnerable groups listed above (such as infants, the elderly, and those with compromised immune systems) should be tested. This is because they require more intense treatment such as antiviral medications. Priority for diagnostic testing includes persons who 1) are at high risk for severe disease and 2) require hospitalization.
There are three types of tests that detect influenza viruses: rapid influenza diagnostic tests (RIDT), viral cultures (VC), and real-time RT-PCR. All require a mucus specimen collected from the back of the throat or nose by a healthcare provider (see “How to Obtain a Nasopharyngeal Specimen” below).
Rapid influenza diagnostic tests (RIDT) yield results in 15 minutes or less and display the results as “positive” or “negative.” However, these results are not foolproof and may give a false negative when the patient is actually infected or a false positive when the patient is not infected with influenza viruses. This test can help differentiate influenza from other viral and bacterial infections with similar symptoms. It is best used within 48 hours of symptom onset.
Viral culture (VC) of a mucus specimen is the “gold standard” for identifying which viruses and which strains of virus are present. However, traditional viral cultures can take up to 10 days for results. A faster culture method (shell vial culture) may detect the presence of a respiratory virus in 24 to 48 hours.
Reverse transcription-polymerase chain reaction (RT-PCR) is a molecular assay that can identify the presence of influenza viral RNA in respiratory secretions. It is increasingly being used in clinical settings and is most appropriate for hospitalized patients if a positive test would result in a change in clinical management. The test is used to detect newly emerging disease, such as new strains of flu (AACC, 2014).
HOW TO OBTAIN A NASOPHARYNGEAL SPECIMEN
Proper technique for obtaining a nasopharyngeal specimen. (Source: CDC, 2011.)
Source: Baden et al., 2009.
People young and old who are infected with the virulent viruses of flu are desperately ill. They sneeze and often have hacking coughs and runny noses. Their head and muscles ache, and they feel extreme fatigue. Nausea, vomiting, and diarrhea are common. Sick children and adults may crawl into a fetal position, shiver with chills and fever, and feel too sick to talk or even cry.
Such seriously ill people need rest, comfort, sleep, and extra fluids. They may benefit from analgesics and antipyretic medications such as ibuprofen (Advil) and acetaminophen (Tylenol). In spite of the misery for the first few days, most children and adults gradually recover in one to two weeks without complications or antiviral medications.
Because aspirin has been linked with Reye’s syndrome, children and adolescents under 18 years of age who are recovering from chickenpox or flu-like symptoms should not receive salicylates such as acetylsalicylic acid (aspirin) (Mayo Clinic, 2014). Aspirin should also be avoided due to its anticoagulant effects.
Antiviral medications can shorten the duration of fever and illness, reduce the risk of complications from influenza, and shorten duration of hospitalization. The CDC (2014h) recommends these drugs be given as early as possible to individuals who exhibit more critical symptoms and suffer from chronic conditions or influenza-related complications such as:
Antiviral drugs are recommended to treat children with severe, complicated, or progressive illness, or who are hospitalized with confirmed or suspected influenza, as well as children at higher risk of flu-related complications with influenza infection of any severity. Children at high risk for complications are those younger than 5 years and children of any age with chronic health conditions such as asthma, diabetes, heart disease, or lung disease (CDC, 2014i).
Drugs recommended by the CDC to fight type A and B influenza are:
Both antiviral drugs work best when started within two days of the onset of symptoms (without waiting for laboratory confirmation of the disease) and continued for at least five days. Hospitalized patients may benefit from treatment even if the drug is started more than 48 hours after symptoms begin and treatment is continued for a minimum of five days (CDC, 2014j).
The process of transmission of an infectious agent such as the influenza virus can be best explained by the epidemiologic model called the chain of infection. An infectious disease results from specific interactions between the organism, host, and environment. Transmission occurs when the infectious organism leaves the reservoir or host through a portal of exit, travels by some mode of transmission, and enters through a portal of entry to infect another susceptible host (CDC, 2012).
Chain of infection. (Source: Wild Iris Medical Education.)
By breaking any link of the chain of infection, healthcare professionals can prevent the occurrence of new infection. Infection prevention measures are designed to break the links and thereby prevent new infections. The chain of infection is the foundation of infection prevention.
|Link||Influenza Implications||Healthcare Provider Actions|
|Organism||Present in environment during flu season||Be aware of current strains and case reporting requirements|
|Reservoir||Potentially everyone, some higher risk||Promote vaccinations|
|Portal of Exit||Airborne particles||Teach/reinforce sneeze/cough etiquette and correct use/disposal of tissues|
|Transmission||Organism can remain active on environmental surfaces||Teach disinfection techniques|
|Portal of Entry||Nose/mouth||Teach/reinforce handwashing, not touching eyes/face, wearing masks|
|Vulnerable Hosts||Everyone; some people at greater risk||Promote vaccinations among high-risk groups|
FLU PREVENTION MEASURES
Because influenza produces such serious symptoms, the CDC issues prevention recommendations to the public.
Source: CDC, 2014a.
Routine cleaning and disinfection strategies can also help prevent the spread of influenza. Management of laundry, utensils, and medical waste should be performed in accordance with established procedures.
Everyone 6 months of age and older should get vaccinated against the flu except for a few select individuals (see below). Vaccination is especially important for vulnerable individuals with chronic medical conditions, healthcare workers, and others who live with or care for high-risk people. Those who care for children younger than 6 months should be vaccinated (CDC, 2014a).
Those who should not be vaccinated before talking to their doctor include:
CDC guidelines should be carefully reviewed on a case-by-case basis with a physician before administering a vaccine to a person with a history of egg allergy (CDC, 2014k). In the past, people with egg allergies were unable to receive the vaccine. Current guidelines include:
Since 1981 the CDC has recommended healthcare workers receive influenza vaccination, and the coverage among healthcare workers during the 2013–14 season was 75.2%. Coverage was highest (97.8%) among healthcare personnel working in settings in which flu vaccination was a requirement for employment (CDC, 2014).
The Affordable Care Act includes mandates for flu vaccinations of healthcare workers. Failure to meet certain percentages of a healthcare facility’s employees vaccinated for influenza will jeopardize federal reimbursement of Medicare and Medicaid funds beginning in 2015. The goal is to have 90% compliance for healthcare workers by 2020 (DHHS, 2011).
While it is obvious that recommending and increasing influenza vaccination in healthcare workers is important, it is less obvious how best to achieve this goal. During 2013 there was an increase in the number of healthcare facilities mandating nurses and other healthcare workers to receive flu vaccinations as a condition of employment.
There is great controversy, however, over the issue of mandatory vaccination, with strong arguments for differing points of view regarding individual rights versus the right of patients to be protected from disease transmitted by a healthcare worker.
Influenza vaccines are updated annually to provide a combination of the most likely flu strains to be in circulation. There are several flu vaccine options for the 2014–15 season. Traditional flu vaccines made to protect against three different flu viruses (trivalent) are available. Additionally, flu vaccines made to protect against four different flu viruses (quadrivalent) are available.
Trivalent vaccine protects against two influenza A viruses (H1N1 and H3N2) and one influenza B virus. The trivalent flu vaccine available for the 2014–15 flu season is made from the same three viruses as the 2013–14 vaccine:
This year’s quadrivalent vaccine contains the above three strains plus a B/Brisbane/60/2008-like virus (CDC, 2013l).
The U.S. Food and Drug Administration has licensed the following seasonal flu vaccines for use in the United States in 2014–15 (CDC, 2014l):
The increasing number of vaccination dosing and route options is leading to improved targeting and specificity in delivering influenza immunization while also allowing more people to be vaccinated than ever before. However, the variety of options is beyond what providers can commit to memory, particularly considering the frequency with which the options are updated.
Nurses who expect to be providing influenza vaccines should familiarize themselves with the CDC references and obtain copies of the most current vaccine dosing and administration tables so, in consultation with medical providers, they are prepared to quickly ascertain the best vaccine options for their patients (see “Resources” at the end of this course).
On a Friday in early September, a female patient asked Maria Jones, RN, when she should receive her annual flu shot and if she could have the nasal spray so she didn’t need to have “a shot.” Maria was embarrassed because she was unprepared to answer the question. She told the patient she wasn’t sure but thought it was still a little early and reassured the patient that she would look into it and give her a call with further information.
Over the weekend, Maria went to the CDC website and read about seasonal influenza vaccinations. She found a table that showed dosing and route information as well as information regarding when vaccinations should be provided. She printed the table and presented it to her nurse and physician coworkers when she came to work Monday morning. Together, they practiced using the tables to determine the best option for a variety of their patients.
With a confirmation from the physician, Maria was then able to call her patient. She told the patient that the CDC recommends vaccines be given as soon as they are available and that the clinic expected to have their first doses available in early October. Maria informed her patient that, unfortunately, she was outside the age recommendations for the nasal spray and would need to get a shot.
PNEUMOCOCCAL VACCINE RECOMMENDATIONS FOR PERSONS AGE 65 AND OLDER
A serious complication of influenza is pneumococcal pneumonia caused by Streptococcus pneumonia. It is the leading cause of vaccine-preventable illness and death in the United States. Adults 65 years and older are at greater risk for contracting this disease. Also, because some strains of this bacterium have become resistant to drugs that were effective in the past, prevention through vaccination has become even more important.
The best prevention of pneumococcal pneumonia is by vaccination with both the influenza and pneumococcal vaccines. It is recommended that:
Source: AAFP, 2014.
Prevention of epidemics and pandemics depends on education of the public about the importance of vaccination and personal hygiene. The greater the number of vaccinated individuals, the fewer the cases of influenza. With increased prevention by individuals, such as covering a sneeze or cleansing the hands, the flu virus will be less likely to infect other people. For these reasons, healthcare providers have a special responsibility to encourage the general public to be vaccinated and to practice preventative measures.
Influenza continues to be a deadly disease, but due to the work of scientists and clinicians, people can be protected from infection by the ever-changing influenza viruses. With vaccination against the viruses and protective sanitary measures, infections can be reduced; and with antiviral medications, vulnerable individuals and those who are infected can be treated. Healthcare providers play an important role in delivering this message to those they serve.
NOTE: Complete URLs for references retrieved from online sources are provided in the PDF of this course (view/download PDF from the menu at the top of this page).
American Academy of Family Physicians. (2014). ACIP recommends routine PCV13 immunization for adults 65 and older. Retrieved from http://www.aafp.org
American Association for Clinical Chemistry (AACC). (2014). Influenza tests. Retrieved from http://labtestsonline.org
Baden LR, Drazen JM, Kritek PA, Curfman GD, Morrissey S, & Campion EW. (2009). H1N1 influenza a disease—information for professionals. New England Journal of Medicine, 360(25), 2666–7.
Centers for Disease Control and Prevention (CDC). (2014a). What you should know for the 2014–2015 influenza season. Retrieved from http://cdc.gov
Centers for Disease Control and Prevention (CDC). (2014b). Protect yourself against H3N2v. Retrieved from http://www.cdc.gov
Centers for Disease Control and Prevention (CDC). (2014c). Prevention and control of seasonal influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices (ACIP)—United States, 2014–15 influenza season. Retrieved from http://www.cdc.gov
Centers for Disease Control and Prevention (CDC). (2014d). How the flu virus can change: “drift” and “shift.” Retrieved from http://www.cdc.gov
Centers for Disease Control and Prevention (CDC). (2014e). CDC says “Take 3” actions to fight the flu. Retrieved from http://cdc.gov
Centers for Disease Control and Prevention (CDC). (2014f). How flu spreads. Retrieved from http://www.cdc.gov
Centers for Disease Control and Prevention (CDC). (2014g). People at high risk of developing flu-related complications. Retrieved from http://www.cdc.gov
Centers for Disease Control and Prevention (CDC. (2014h). Influenza antiviral medications: summary for clinicians. Retrieved from http://www.cdc.gov
Centers for Disease Control and Prevention (CDC). (2014i). Children and antiviral drugs. Retrieved from http://www.cdc.gov
Centers for Disease Control and Prevention (CDC). (2014j). Influenza antiviral medications: summary for clinicians. Retrieved from http://www.cdc.gov
Centers for Disease Control and Prevention (CDC). (2014k). Influenza vaccination: a summary for clinicians. Retrieved from http://www.cdc.gov
Centers for Disease Control and Prevention (CDC). (2014l). Prevention and control of seasonal influenza with vaccines: recommendations of the Advisory Committee on Immunization Practice (ACIP) – United States, 2014–2015 influenza season. Table 6. Retrieved from http://www.cdc.gov
Centers for Disease Control and Prevention (CDC). (2014m). Live attenuated influenza vaccine (LAIV). The nasal spray flu vaccine. Retrieved from http://www.cdc.gov
Centers for Disease Control and Prevention (CDC). (2013). Understanding how vaccines work.
Retrieved from http://www.cdc.gov
Centers for Disease Control and Prevention (CDC). (2011). Manual for the surveillance of vaccine-preventable diseases (5th ed.). Atlanta: Author. Retrieved from http://www.cdc.gov
DeNoon DJ. (2014). Cold, flu & cough health center: swine flu (H1N1) and face masks. Retrieved from http://www.webmd.com
Derlet RW. (2014). Influenza clinical presentation. Retrieved from http://emedicine.medscape.com
DiazGranados CA, Dunning AJ, Kimmel M, Kirby D, Treanor J, Collins A, Pollak R, et al. (2014). Efficacy of high-dose versus standard-dose influenza vaccine in older adults. N Eng J Med, 371, 635–45. Retrieved from http://nejm.org
Mayo Clinic. (2014). Reye’s syndrome. Retrieved from http://www.mayoclinic.org
Nazario B. (2013). Is it a cold or flu? How to tell the difference. Retrieved from http://symptoms.webmd.com
Potter CW. (2001). A history of influenza. Journal of Applied Microbiology, 91, 572–9. Retrieved from http://ddata.over-blog.com
U.S. Department of Health and Human Services (DHHS). Centers for Medicare & Medicaid Services. (2011). Acute care hospitals and long-term care hospital prospective payment system and FY 2012 rates; hospital FTE resident caps for graduate medical education payment; final rule. Retrieved from http://www.gpo.gov
World Health Organization (WHO). (2014). WHO recommendations for the post-pandemic period. Retrieved from http://www.who.int
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