Fighting the Flu
How to get your staff and patients ready for the fall influenza
By Susan Dolan, RN, MS, CIC
1. To define influenza and recognize its symptoms.
2. To distinguish between influenza viruses and identify their traits.
3. To employ strategies for the influenza vaccine and prevent the spread of influenza.
"The flu" represents different things to different people. The term is often used incorrectly to describe a cold or a diarrheal illness, which are most likely due to other viruses such as rhinovirus or rotavirus. More accurately, flu is short for influenza, a much more serious illness known to affect 10 percent to 20 percent of the U.S. population each year. Annually, more than 110,000 people are hospitalized and 20,000 succumb to the virus and its associated complications.
Influenza is characterized by sudden onset of fever, chills, headache, sore throat, runny nose, non-productive cough, severe malaise, photophobia (light sensitivity) and muscle aches. Secondary complications can include pneumonia, encephalopathy, myositis, myocarditis, pericarditis, Reye's syndrome, transeverse myelitis and death.
There are A, B and C influenza viruses. The A and B strains are responsible for the epidemics we experience each winter and are separated into groups based on their antigenic characteristics. Influenza A viruses are further categorized on the basis of two surface antigens called hemagglutinin (H) and neuraminidase (N). As the A and B viruses replicate, they can undergo mutations from antigenic changes, which can result in a new variant of the virus. Components of the vaccine are often changed each year to account for this drift in virus makeup. The duration of protection from the vaccine is less than one year so it is necessary to get vaccinated each year with the new vaccine.
Influenza C is not responsible for epidemics but may cause mild respiratory symptoms or no symptoms at all. Humans are the only known reservoir for B and C strains, but A strains may infect humans and animals.
Influenza is spread from person to person by aerosolized or droplet transmission through coughing, sneezing and direct contact with the virus or contaminated objects. The time from influenza exposure to the onset of symptoms is one to three days and a person with influenza can be contagious from the day before they have symptoms until one week later. Young children and those who are immunocompromised can shed the virus longer.
The morbidity and mortality associated with influenza has prompted efforts to prevent the acquisition and spread of the disease. Vaccine campaigns are implemented in an effort to protect individuals most at-risk for complications of influenza. The Centers for Disease Control (CDC) Advisory Committee on Immunization Practices (ACIP) provides annual recommendations for the prevention and control of influenza. The ACIP uses viral isolate information submitted by worldwide influenza surveillance labs to ascertain which viruses are in circulation. The information is used to determine the composition of the flu vaccine for the following influenza season.
Each year the vaccine contains two A strains and one B strain. The vaccine for the 2002-2003 influenza season will include the following strains: A/Moscow/10/99 (H3N2)-like, A/New Caledonia/20/99 (H1N1)-like and B/Hong Kong/330/2001-like strains. The two A components are the same as those used in the 2001-2002 season vaccine, but the B component will be different. The change in the B component for the 2002-2003 vaccine was recommended because of the types of influenza B viruses circulating throughout the world.
The past two flu seasons, some manufacturers were delayed in distributing the vaccine due in large part to difficulties encountered with growing properties of one of the strains. It was frustrating when health clubs had vaccine to administer while hospitals did not have enough for high-risk patients.
Shipments of flu vaccine did come in, but were delayed and came in increments, forcing some to prioritize who could get the vaccine. In our hospital, representatives from high-risk departments determined how many vials would be needed and worked closely with pharmacy staff to identify how many vials of vaccine could be given to each department when part of the vaccine order arrived.
Many strategies are used in our hospital to maximize administration of the influenza vaccine.
- The vaccine is offered to staff and volunteers at no charge. Family members can get vaccinated in the clinic for a nominal fee.
- Employee Health Service (EHS) sends out written and electronic notices, strategically places posters and sets folding cards on cafeteria tables to alert staff to access times for vaccination.
- Bilingual posters are placed at entry areas throughout our institution to alert ill visitors that they should not visit our patients or our facility.
- Each year, the epidemiology department publishes an article on influenza in "Contagious Comments," a department publication distributed monthly to our staff and healthcare providers in the community. We complement Employee Health's vaccination efforts by using a roaming flu cart that enables us to take the vaccine to work areas, educate doubters and provide a convenient mechanism for staff to receive the vaccine. We park the cart at entrances and exits of key meeting locations, attend department staff meetings and vaccinate staff waiting in line for our free annual employee holiday meal.
- Nosocomial influenza cases by unit location are shared at the annual respiratory planning meeting. Some facilities track employee vaccination rates by department and hold contests with prizes for those boasting the highest vaccination rates.
Who should be vaccinated?
For the 2002-2003 influenza season, the ACIP encourages vaccinations for healthy children from 6 months old to 23 months old and their household members because of the increased risk for influenza-related hospitalizations in this young population. An official recommendation is expected in a year or so. Those in contact with children less than 6 months old should be vaccinated because the children are too young to receive the vaccine and are at the greatest risk of hospitalization for influenza-related illnesses.
An influenza vaccine is recommended for:
- Healthcare personnel in hospital, outpatient, community and home care settings.
- Children and teens (6 months old to 18 years old) receiving long-term aspirin therapy and who may be at risk of developing Reye's syndrome after influenza infection.
- Children (6 months and older) and adults with chronic disorders of the cardiovascular or pulmonary systems including asthma.
- Children (6 months and older) and adults requiring regular medical follow-up or hospitalization due to metabolic diseases like diabetes mellitus, renal dysfunction, hemoglobulinopathies or immunosuppression, including persons with HIV.
- Household members of a person in these high-risk groups.
- Women who will be in the second or third trimester of pregnancy during the influenza season.
- Persons 50 years or older.
- Residents and employees of nursing homes and other chronic care facilities housing persons of age with chronic medical problems.
What are the contraindications to receiving the influenza vaccination?
- Hives or severe anaphylactic reaction to chicken or eggs.
- Acute febrile illness (wait until symptoms have abated).
- Infants less than 6 months old.
- Individuals with a hypersensitivity to thimerosol (preservative).
- Most patients do not develop reactions even when patch or intradermal test for thimerosol indicates hypersensitivity; when reported, hypersensitivity to thimerosol has usually consisted of local, delayed-type hypersensitivity reactions.
- The American Academy of Pediatrics made recommendations to decrease the exposure to thimerosol in young children (particularly less that 6 months old) because of potential excess mercury exposure. The influenza vaccine, which uses thimerosol as a preservative, is not recommended for children less than 6 months old, so the concern does not apply to the recommended use of the influenza vaccine.
- A limited number of influenza vaccine doses with reduced thimerosol content (less than 1 mcg thimerosol/0.5 ml dose) will be available for the 2002-2003 season.
When should vaccinations programs be initiated?
For the 2002-2003 season, the ACIP recommends prioritizing vaccination efforts in October to target healthcare providers and persons at high risk of complications from influenza. Children 6 months old to 9 years old receiving the influenza vaccine for the first time should receive their initial dose in October and require a booster dose one month after the initial dose. Others should not begin vaccination until November. This was the strategy recommended by the ACIP the previous two flu seasons due to the delay in vaccine distribution.
What are the side effects of the vaccine?
Influenza vaccine contains only non-infectious (inactivated) virus; therefore it cannot cause influenza. The most frequent side effect of vaccination reported by less than one third of recipients is soreness at the vaccination site that up to two days. Fever, malaise, myalgia and other systemic symptoms occur infrequently and most often affect persons who have not had prior exposure to the influenza virus antigens in the vaccine. These reactions begin six to 12 hours after the vaccination and may persist for one to two days. Symptomatic relief may be obtained by using non-aspirin-containing analgesics. Aspirin should not be used for children due to the association of Reye's syndrome with influenza.
Immediate (presumably allergic) reactions such as hives, angioedema, allergic asthma and systemic anaphylaxis occur rarely and probably result from hypersensitivity to a vaccine component, a majority of which are most likely related to residual egg protein in the vaccine.
Can influenza vaccine be administered with other vaccines?
Influenza and pneumococcal vaccines may be administered at the same time using different sites without increasing side effects. However, influenza vaccine must be administered each year whereas pneumococcal vaccine is not. Children may receive influenza vaccine at the same time they receive other routine vaccinations including pertussis vaccine.
Should patients be tested for influenza?
Various methods for lab detection of influenza exist. The more rapid diagnostic tests can be useful in identifying influenza to initiate some of the newer treatment regimens. Isolation of the virus in culture is helpful when designated labs provide these isolates to laboratories that perform strain identification. This is helpful in knowing whether or not the vaccine is effective against the strains of influenza currently circulating. The identification of influenza can offer an early picture of local flu patterns. In general, testing should not be performed unless the information will alter the plan of care for the patient.
What about influenza medications for treatment and prophylaxis?
While vaccination remains the primary method of preventing and controlling influenza, influenza medications should be part of the plan for preventing influenza. Medications are used to treat ill patients, personnel, for the prophylaxis of exposed patients, unvaccinated individuals and those vaccinated less than two weeks before exposure.
Antiviral medications like amantadine and rimantadine work by interfering with the replication cycle of Influenza A. They should be started as soon as possible after the onset of symptoms to be effective and can be continued for two to seven days depending on clinical improvement. Both medications are approved by the FDA for children and adults for prophylaxis against Influenza A infection. The guidelines for prophylaxis include high-risk persons who are vaccinated after the start of a community outbreak of Influenza A, healthcare providers not vaccinated prior to the start of the outbreak, immune deficient patients who may have inadequate response to vaccine and persons for whom the vaccine is contraindicated. Amantadine is the only currently approved antiviral for the treatment of children with influenza. These medications are not effective against influenza B infections.
In 1999, the FDA approved two new antivirals for the treatment of influenza in patients who have been symptomatic for no more that two days. These medications inhibit the enzyme neuraminidase and inhibit viral penetration of the mucus lining, thereby inhibiting the release of the virus out of cells that are already infected. Zanamivir and oseltamivir have been shown to decrease the duration of flu-related symptoms by one to one-and-a-half days. Oseltamivir, administered via an oral capsule, has been approved for prophylaxis in patients older than 13. Zanamivir, administered via oral inhalation, has been approved for the treatment of patents 7 years and older, while oseltamivir is approved for treatment of children older than 1 year.
The limitations of these medications are that they must be administered within 48 hours of the onset of symptoms, have not been shown to prevent disease transmission and have not been adequately studied in patients with serious health conditions or with renal or hepatic impairments. Additionally, oseltamivir has shown some benefit as a prophylactic agent when given once daily for six weeks, although the cost may be prohibitive.
These medications are not without contraindications and precautions. Zanamivir is not recommended for patients with underlying airway disease including asthma or chronic obstructive pulmonary disease (COPD) because of the lack of safety and efficacy data in these patents. Serious adverse events including bronchospasm and decline in lung function have been reported with zanamivir use, most commonly in patients with underlying airway disease. If zanamivir is used in patients with underlying airway disease, they should be instructed to have a fast-acting bronchodilator available.
What is the nasal spray vaccine all about?
The intranasal influenza vaccine is a live-attenuated, cold-adapted trivalent (three viruses) influenza vaccine administered intranasally. Cold-adapted means the virus has adapted to growing in colder temperatures. It can infect the cooler upper respiratory tract and stimulate immunity, but not cause disease in the warmer lungs.
A five-year trial showed this vaccine to be as effective as the currently available inactivated vaccine. The nasal vaccine was studied during the 1996-1997 flu season. In the study of 1,602 children, 1 percent of those receiving the nasal vaccine and 18 percent of the placebo group developed influenza. The nasal vaccine is 93 percent effective in preventing disease. There were 30 percent fewer episodes of otitis media in vaccine recipients compared to controls. FDA approval is still pending with hope that the vaccine may be available this coming season, although there will be cost considerations.
Susan Dolan, RN, MS, CIC, is hospital epidemiologist for The Children's Hospital, Denver, and Educator of the Year, Infection Control Today magazine.
|Test Questions: True or False||T||F|
|1. Influenza is a serious illness known to affect 10 percent to 20 percent of the U.S. population each year.|
|2. Secondary complications can include pneumonia, encephalopathy, myositis, myocarditis, pericarditis, Reye's syndrome, transeverse myelitis and death.|
|3. The C strain is responsible for the influenza epidemics we experience each winter.|
|4. The time from influenza exposure to the onset of symptoms is one to three weeks.|
|5. Each year the influenza vaccine contains two A strains and one B strain.|
|6. The Advisory Committee on Immunization Practices (ACIP) encourages vaccinations for healthy children from 6 months old to 23 months old because of the increased risk for influenza-related hospitalizations in this young population.|
|7. An influenza vaccine is not recommended for healthcare personnel in hospital, outpatient, community and home care settings.|
|8. An influenza vaccine is recommended for women who will be in the second or third trimester of pregnancy during the influenza season.|
|9. When reported, hypersensitivity to thimerosol usually consists of local, delayed-type hypersensitivity reactions.|
|10. Influenza vaccine contains only non-infectious (inactivated) virus; therefore it cannot cause influenza.|
|11. Fever, malaise, myalgia and other systemic symptoms begin immediately after the vaccination and may persist for one to two days.|
|12. Aspirin should not be used for children to relieve symptoms due to the association of Reye's syndrome with influenza.|
|13. Influenza and pneumococcal vaccines may be administered at the same time using different sites without increasing side effects.|
|14. The identification of influenza can offer an early picture of local flu patterns.|
|15. Antiviral medications like amantadine and rimantadine work by interfering with the replication cycle of Influenza A.|
|16. Antiviral medications should be started two to seven days after the onset of symptoms to be effective.|
|17. In 1999, the Federal Drug Administration (FDA) approved two new antivirals for the treatment of influenza in patients who have been symptomatic for no more that two days.|
|18. Zanamivir and oseltamivir have been shown to decrease the duration of flu-related symptoms by eight to 12 hours.|
|19. Zanamivir is not recommended for patients with underlying airway disease including asthma or chronic obstructive pulmonary disease (COPD).|
|20. Despite the administration of influenza vaccine and prophylactic medications, patients with influenza will continue to be admitted to hospitals and become potential sources for the spread of influenza.|