INFLUENZA The Flu What Nurses Should Know

1
INFLUENZA (The Flu)What Nurses Should Know

• Felissa R. Lashley, RN, PhD, FAAN, FACMG
• Professor, College of Nursing, and
• Interim Director, Nursing Center for Bioterrorism
  and Infectious Disease Preparedness, College of
  Nursing
• Rutgers, The State University of New Jersey
• This module is designed to highlight important
  information about influenza. The influenza virus,
  in addition to being the cause of influenza, an
  important infectious disease, is also considered
  to be a potential agent for bioterrorism and is
  considered as a possible Category C bioterrorism
  agent by the Centers for Disease Control and
  Prevention (CDC). This module was supported in
  part by USDHHS, HRSA Grant No. T01HP01407.

2
Some General Points

• The influenza virus is considered to have the
  potential for use as an agent for bioterrorism,
  most probably by altering it to a mutated form
  with greater virulence, infectivity, more
  efficient human-to-human transmission, and
  antiviral resistance.
• CDC considers it to be a Category C agent under
  others.

3
Some General Points cont.

• This module is arranged as follows etiology,
  epidemiology, transmission, incubation period,
  overall clinical illness picture, clinical
  manifestations, clinical differentiation between
  the common cold and flu, complications,
  diagnosis, treatment, management including
  infection control measures and patient/staff
  education, and prophylaxis and vaccination.
• Avian influenza is considered at the end of the
  content before the case studies.
• Case studies, test questions and information
  sources appear at the end of the module.

4
Objectives

• At the conclusion of this module, the
• participant should be able to
• Identify the viruses that can cause influenza
• Describe signs and symptoms commonly associated
  with influenza
• Identify the major complications of influenza
• Describe symptoms that can help differentiate
  between upper respiratory infection and influenza

5
Objectives cont.

• Identify antiviral agents in current use for
  prevention of influenza
• Identify antiviral agents in current use for
  treatment of influenza
• Name the groups for whom flu vaccination is
  recommended
• Describe what is meant by avian influenza

6
Etiology

• Influenza viruses types A, B, C infect humans
• Influenza types A B can cause widespread
  outbreaks
• Influenza type A tends to be the most severe
• Influenza A virus types have most potential for
  use as bioterrorism weapon
• Influenza viruses are RNA viruses classified in
  Orthomyxoviridae family
• Can mutate and cross species barrier such as fowl
  to humans

7
Etiology cont.

• Influenza subtypes are referred to by their
  hemagglutinin (H) and neuraminidase subtypes (N)
  which are surface glycoproteins of the virus
• Examples Avian influenza virus subtypes A H5N1
  and H9N2 which appeared recently in Hong Kong and
  other areas
• Influenza viruses have the ability to develop
  antigenic variants through viral mutation.
  Persons develop antibodies to specific variants
  which may not confer protection against another.
  This helps explain why there are seasonal
  epidemics and provides the basis for
  understanding the rationale for what strains of
  the virus will be used each year in vaccine
  production.

8
Epidemiology

• Worldwide distribution
• Outbreaks usually occur suddenly
• Flu spreads through communities resulting in an
  epidemic. Cases tend to peak after about 3 weeks
  and begin to subside after another 3-4 weeks

9
Epidemiology cont.-2

• Have been several great influenza pandemics
• 1918-19 Spanish flu
• Caused 20-40 million deaths worldwide
• A large proportion of these deaths was in healthy
  adults 15 to 35 years of age
• 1957 Asian flu
• 1968 Hong Kong flu
• 1977 H1N1 influenza A virus subtype, Russian flu

10
Epidemiology cont.-3

• Peak season is November through March
• Each year about 10 to 20 of Americans develop
  influenza
• In the US, approximately 100,000 people are
  hospitalized with influenza each year, and about
  36,000 die

11
Transmission

• Major transmission route is through airborne
  large respiratory droplets with particles larger
  than 5 microns (µ) in diameter that are expelled
  from the respiratory tract of an infected person
  when they cough or sneeze
• Direct contact with fomites (inanimate objects)
  contaminated with infected droplets or secretions
  and then touching ones nose or mouth
• Transmission from infected birds, poultry or pigs
  (less common)

12
Incubation Period

• 1 to 4 days with average of 2 days
• Adults are infectious from day before symptoms
  begin through about 5 days after onset children
  can be infectious for 10 or more days after onset
  and those who are immunosuppressed can shed virus
  for weeks or even months.

13
Overall Clinical Illness Picture

• Influenza infection can run a spectrum from
  asymptomatic or mild illness through fulminant
  primary viral pneumonia
• For most uncomplicated cases, influenza resolves
  spontaneously in a few days but cough and malaise
  often last 2 weeks or more
• Major clinical pictures
• Rhinotracheobronchitis
• Primary viral pneumonia
• Respiratory viral infection followed by secondary
  bacterial pneumonia
• There is no stomach flu - these manifestations
  are from other disorders

14
Major influences on clinical illness development
and complications of influenza

• Age - elderly (over 65 years of age) and young
  children particularly younger than 5 years of age
  and especially those 6 to 23 months are
  particularly vulnerable
• Presence of other chronic underlying illnesses
  such as chronic cardiac or pulmonary disease
• Compromised immune status such as from
  immunosuppressive drugs, or conditions such as
  malnutrition or pregnancy
• Lack of access to health care
• Crowded living conditions that facilitate
  transfer of respiratory pathogens that can
  include congregate and institutional settings
  especially if precautions such as respiratory
  hygiene dn cough ettiquette are not observed
• Health care workers may be at higher risk for
  transmission

15
Clinical Manifestations

• Abrupt onset of constitutional and respiratory
  symptoms
• Fever, duration typically 1 to 5 days, with an
  average of 3 days and peak within 12 hours after
  symptoms. Typical temperatures are 38 to 40 deg.
  C.
• Myalgia
• Headache
• Chills
• Cough, usually unproductive
• Sore throat

• Malaise
• Rhinitis
• May have eye tearing, burning, photophobia or eye
  pain
• Children may have otitis media and nausea and
  vomiting as well as febrile convulsions in
  addition to other symptoms
• Elderly persons may present with minimal
  respiratory symptoms but show lassitude, high
  fever and confusion
• Respiratory symptoms may increase as fever
  decreases

16
Clinical Differentiation Between the Common Cold
and the Flu (see Table 1 at end of module)

• The following symptoms are more commonly seen in
  influenza rather than the common cold
• High fever lasting 3 to 4 days
• Headache
• Myalgia
• Fatigue and weakness
• Extreme exhaustion
• Severe chest discomfort and cough

• The following symptoms are more commonly seen in
  the common cold rather than influenza
• Stuffy nose is common
• Sneezing is common
• Cough is generally mild to moderate
• Symptoms such as fever, headache, aches and pains
  and exhaustion are rare in those with colds.

17
Complications may be respiratory or
non-respiratory or both

• Major respiratory complications include
• Primary viral pneumonia
• Occurs most frequently in elderly or persons with
  cardiopulmonary disease
• Can occur in healthy immunocompetent persons or
  pregnant women
• Usually develops rapidly, within 1 day or onset
  of illness
• Symptoms include rapidly progressing fever,
  tachypnea, tachycardia, cyanosis and hypotension
• Signs include bilateral crepitant rales on chest
  examination, chest x-rays showing
  nonconsolidating pulmonary infiltrates, but
  sometimes areas of consolidation, blood gas
  studies show hypoxemia, blood counts may show
  leukocytosis with a left shift
• Mortality is high, and extensive fibrosis and
  interstitial inflammation may develop

18
Complications cont.-2

• Secondary bacterial pneumonia
• Occurs most frequently in elderly or persons with
  pulmonary disease
• Typical course of influenza illness seems to be
  improving but fever with shaking chills returns,
  pleuritic-type chest pain, productive cough with
  bloody or purulent sputum
• Signs include local areas of lung consolidation
  on chest X-ray, sputum culture and Gram stain may
  reveal predominance of bacterial pathogen, most
  commonly Streptococcus pneumoniae, Staphylococcus
  aureus, Haemophilus influenzae, or Moraxella
  catarrhalis
• Mortality can approach 7

19
Complications cont.-3

• Combined bacterial-viral pneumonia
• Coinfection can yield varying symptoms which may
  be like primary viral pneumonia at first
• Coinfection with S. aureus may carry a
  particularly high mortality rate
• Exacerbation of chronic pulmonary disease such as
  asthma or in persons with cystic fibrosis

20
Complications cont.-4

• Major non-respiratory complications include
• Cardiac complications particularly
  electrocardiographic abnormalities and
  myocarditis
• Central nervous system complications such as
  seizures, especially in children, and acute
  encephalitis
• Reyes syndrome, a neurologic and metabolic
  disorder occuring mainly in children and
  adolescents from 2 to 16 years of age. It appears
  more closely associated with influenza B than
  influenza A and has a mortality rate of 10 to
  40. Not prescribing aspirin for patients,
  especially children and adolescents with viral
  infections has decreased the incidence of Reyes
  syndrome.
• Myositis may occur primarily in children and
  particularly after influenza B along with
  myoglobinuria and rhabdomyolysis leading to acute
  renal failure.

21
Diagnosis

• Important to make diagnosis as quickly as
  possible
• Facilitated by community surveillance knowledge
  about influenza outbreak patterns in the
  community
• May be made on basis of clinical signs and
  symptoms along with knowledge about influenza
  patterns in the community. Thus in the setting of
  a confirmed influenza outbreak in a given
  community, persons who are not residents of
  institutions and who have muscle aches, fever and
  two respiratory symptoms probably have influenza
  according to Shorman Moorman, (2003).

22
Diagnosis cont.

• Laboratory diagnostic methods include
• Viral culture (need expert technicians and time
  but excellent specificity and sensitivity),
  reverse transcriptase polymerase chain reaction
  (labor-intensive, costly but quick with excellent
  specificity and sensitivity), serology, rapid
  antigen testing, and immunofluroescence assays.

23
Treatment (this is not comprehensive and is not
meant as recommendations)

• Certain antiviral agents may be used
• Newer antiviral agents include zanamivir and
  oseltamivir (Tamiflu). Both are effective against
  influenza A and influenza B. These also need to
  be administered within the first 48 hours of
  symptoms. Both are category C agents in pregnancy
  and there is a risk for adverse effects in those
  with underlying respiratory disease. It is
  administered via oral inhalation. Oseltamivir may
  result in nausea and vomiting side effects so
  needs to be taken with food. It is administered
  orally. Transient neuropsychiatric events have
  been described in adolescents and some adults
  taking oseltamivir. These two agents were the
  only ones licensed for flu prevention and
  treatment in 2008.

24
Management including Infection Control Measures

• Management includes
• Symptomatic treatment such as encouraging fluids
  and rest the treatment of symptoms with
  over-the-counter medications but not aspirin in
  children or adolescents
• Comfort measures
• Specific management approaches depend upon
  symptoms, complications and characteristics and
  condition of the individual patient

25
Management including Infection Control Measures
cont.-2

• Infection Control Measures
• Appropriate prophylaxis and immunization is an
  important part and is discussed below
• Respiratory hygiene and cough etiquette programs
  are now a part of standard precautions
• Initiate at first point of contact with even a
  potentially infected person
• Includes education which may be visual and\or
  verbal at an appropriate educational level with
  cultural considerations of patients and the
  people who accompany them
• Should include informing personnel if they have
  any symptoms of respiratory infection, having
  tissues provided to patients and visitors, throw
  tissues away after use in proper container,
  instructing them to cover their mouth and nose
  when coughing or sneezing, providing alcohol
  based hand rubbing dispensers and supplies for
  handwashing and educating patients and staff in
  their use, encourage handwashing after coughing
  or sneezing, offering masks to persons who are
  coughing, encouraging coughing persons to sit at
  least 3 feet away from others, instruct patients
  and providers not to touch eyes, nose or mouth
  and have health care personnel observe Droplet
  Precautions in addition to Standard Precautions.
  Health care workers should use standard
  precautions with all patients.

26
Management including Infection Control Measures
cont.-3

• Infection Control Measures cont.
• Standard Precautions are detailed in a separate
  module
• Droplet Precautions are detailed in a separate
  module

27
Management including Infection Control Measures
cont.-4

• Persons with respiratory infection symptoms
  should not visit patients
• Health care workers with respiratory infection
  symptoms should be excluded from work for the
  duration of the illness
• In health care settings, influenza testing should
  be done early in the outbreak to obtain the type
  and subtype of virus responsible
• Droplet Precautions with suspected or confirmed
  influenza should be implemented and authority to
  do so should be decided with nursing staff
  inclusion
• As detailed further under Droplet Precautions,
  suspected or confirmed influenza patients should
  be separated from asymptomatic patients

28
Management including Infection Control Measures
cont.-5

• Health care staff movement between units and
  buildings should be restricted
• In a setting or unit with influenza, patients
  without influenza should receive influenza
  antiviral prophylaxis unless contraindicated
• Influenza antiviral therapy should be
  administered to those who are acutely ill with
  influenza within 48 hours of onset of illness
  unless contraindicated
• Current inactivated influenza vaccine should be
  administered to unvaccinated patients and health
  care personnel if not contraindicated
• Influenza antirviral prophylaxis should be
  offered to unvaccinated personnel for who it is
  not contraindicated and who work in the affected
  unit or who are caring for high-risk patients

29
Management including Infection Control Measures
cont.-6

• Limit or eliminate elective medical and surgical
  admissions and restrict cardiovascular and
  pulmonary surgery to emergency cases only when
  influenza outbreaks especially those
  characterized by high attack rates and severe
  illness, occur in the community or acute care
  facility
• Recommendations for peri-and post-partum settings
  may be found at http//www.cdc.gov/flu/professiona
  ls/peripostpartumguid.htm

30
Prophylaxis and Vaccination

• Antiviral agents may be used for prophylaxis,
• often in combination with the flu vaccine in an
• outbreak situation
• Drugs used most often in the U.S. for prevention
  of flu are zanamivir and oseltamivir and are used
  particularly for those at high risk for
  complications from the flu or to prevent a person
  in close proximity from passing the flu to a high
  risk person

31
Prophylaxis and Vaccination cont.-2

• Influenza vaccine
• Current vaccines are inactivated influenza vacine
  administered by injection (Fluzone) and live
  attenuated, intranasal vaccine (FluMist)
• In late July, 2008, the Advisory Committee in
  Immunization Practices (ACIP) issued their
  updated recommendations on prevention and control
  of influenza. The entire document is in
  Morbidity and Mortality Weekly Reports,
  Recommendations and Reports, 57 (early release) ,
  1-60, July 17, 2008

32
Prophylaxis and Vaccination cont.-3

• Recommendations for 2008-2009 Influenza season
  are given below
• It is recommended that all children aged 5-18
  years old receive vaccination .
• Children younger that 6 months should not be
  vaccinated.
• Children and adolescents at higher risk for
  influenza complication are those
• aged 6 months 4 years
• who have chronic pulmonary (including asthma),
  cardiovascular (except hypertension), renal,
  hepatic, hematological or metabolic disorders
  (including diabetes mellitus)
• who are immunosuppressed (including
  immuno-suppresion caused my dedications or by
  human immunodeficiency virus)
• who have any condition (e.g., cognitive
  dysfuction, spinal cord injuries, seizure
  disorders, or other neuromuscular disorders) that
  can compromise respiratory function or the
  handling of respiratory secretions or that can
  increase the risk for aspiration
• who are receiving long-term aspirin therapy who
  therefore might be at risk for experiencing Reye
  syndrome after influenza virus infection
• who are residents of chronic-care facilities
  and,
• who will be pregnant during the influenza season.
• Source CDC, MMWR 57, 2008 pg 2

33
Prophylaxis and Vaccination cont.-4

• For adults for the 2008-2009 flu season
  recommendations are for any adult and for and for
  all adults in the following groups because of
  higher risk
• Persons aged 50 years
• Women who will be pregnant during the influenza
  season
• Persons who have chronic pulmonary (including
  asthma), cardiovascular (except hypertension),
  renal, hepatic, hematological or metabolic
  disorders (including diabetes mellitus)
• Persons who have immunosuppressions (including
  immunosuppression caused by medications or by
  human immunodeficiency virus)
• Persons who have any condition (e.g., cognitive
  dysfunction, spinal cord injuries, seizure
  disorders, or other neuromuscular disorders) that
  can compromise respiratory function or the
  handlig of respiratory secretions or that can
  increase the risk for aspiration
• Residents of nursing homes and other chronic-care
  facilities
• Health-care personnel
• Household contracts and caregivers of children
  aged 50 years, with
  particular emphasis on vaccinating contracts of
  children aged
• Households contracts and caregivers of persons
  with medical conditions that put them athigh risk
  for severe complication from influenza.
• Source CDC, MMWR 57, 2008 pg 2

34
Nasal Spray Vaccine

• Live, attenuated vaccine administered by nasal
  spray
• Option for those healthy people ages 2 to 49
  years old
• Option for health care workers who take care of
  sick persons or care for babies under 6 months of
  age and who are healthy between 2 and 49 years of
  age
• Not to be used in pregnancy
• Not to be used by those who care for or live with
  someone with a compromised immune system or
  children less than 2 years of age

35
Table 1. Is It a Cold or the Flu?Source
National Institute of Allergy and Infectious
Diseases
36
Special Notes on Avian Influenza

• Avian influenza viruses refers to those that are
  carried by birds, usually wild birds that when
  infected, shed virus in saliva, nasal secretions
  and feces. Birds or fowl become infected when
  they come into contact with secretions or
  excretions from infected birds most often through
  fecal-oral transmission. Transmission also occurs
  through contact with surfaces or materials such
  as feed, water, cages or dirt that are
  contaminated with the virus. Contaminated cages,
  for example, can carry the virus from one place
  to another.
• Avian influenza viruses vary in their degree of
  pathogenicity

37
"Hong Kong" Flu

• First documented direct transmission of an avian
  influenza (influenza A) virus (H5N1) to humans
  occurred in 1997 in Hong Kong
• Severe respiratory disease occurred in 18 healthy
  young adults and children and 6 died
• The outbreak was controlled by slaughter of the
  poultry population. More than 1.2 million
  chickens and 0.3 million other poultry were
  killed and imports of chickens from Hong Kong and
  China were banned by other countries. Quarantine
  and depopulation or culling of birds are common
  ways of control for the outbreak

38
"Hong Kong" Flu-2

• Live poultry markets were source of the avian
  influenza virus strain H5N1 in this outbreak. In
  both influenza and SARS, the so-called
  wet-markets have been implicated as sources.
  This illustrates a cultural influence on
  emergence of infectious diseases since the
  preference of many Asian people for buying fresh
  foods at these markets have resulted in an
  increase in these types of markets. In New York
  City, these increased in number from 44 in 1994
  to 80 in 2002.

39
Additional Recent Avian Flu Outbreaks

• In 1999, avian influenza viruses, H9N2, were
  isolated in Hong Kong from children with mild
  influenza
• In 2003, the avian influenza virus strain, H5N1,
  again emerged in 2 family members in Hong Kong
  after traveling in China. One died.

40
Additional Recent Avian Flu Outbreaks-2

• In 2003, the avian influenza virus strain H7N7
  occurred in poultry farms in the Netherlands,
  spreading to Germany and Belgium. Infection,
  mainly conjunctivitis occurred in 83 humans with
  1 death. The outbreak was controlled by
  destroying over 30 million domestic poultry
• In 2003, the avian influenza virus, H9N2 was
  identified in a child in Hong Kong with influenza
  who recovered

41
Additional Recent Avian Flu Outbreaks-3

• In 2003, an outbreak of avian influenza virus,
  H5N1, occurred in South Korea, and in 2004
  emerged in Vietnam and Thailand. Human cases
  presented with severe respiratory infection and
  out of 23 known and confirmed cases, 18 died.
  Many countries banned the import of poultry
  products from the Asian countries affected. Other
  countries in which poultry were infected included
  Japan, Laos, China, Cambodia, and Indonesia.

42
Additional Recent Avian Flu Outbreaks-4

• In 2004, an outbreak of avian influenza, H7N7
  occurred in British Columbia, Canada. Infection
  has been reported in 5 humans whose major illness
  was conjunctivitis.
• In 2004-2005, east Asia again saw an outbreak of
  H5N1, particularly in Thailand, Cambodia, and
  Vietnam.
• By June 19, 2008, there were 385 reported human
  cases of avian flu and 243 reported deaths.
• Concern about pandemic flu has resulted in global
  efforts at prevention.

43
Documented human-to-human transmission of H5N1
has been noted but is limited. Of concern is that
the virus could mutate to allow sustained
person-to-person transmission.

• Transmission includes
• Direct exposure to infected birds/poultry
• Exposure to surfaces contaminated with infected
  bird/poultry excretions, mostly through
  fecal-oral transmission
• Rare human-to-human transmission

• Symptoms
• Fever, over 38 deg. C or 100.4 deg. F
• Shortness of breath
• Cough
• Diarrhea

44
Suspecting Avian Influenza (H5N1)

• Laboratory testing should be prompted for a
  hospitalized or ambulatory patient with
• temperature over 38 deg. C AND
• with any one or more of the above symptoms AND
• a history of contact with domestic poultry such
  as a visit to a poultry farm or bird market
• Laboratory testing should be prompted for
  hospitalized patients
• with radiologically confirmed acute respiratory
  distress syndrome, pneumonia or other severe
  respiratory illness for which an alternate
  diagnosis has not been established AND
• history of travel to an area with documented H5N1
  avian influenza within 10 days of the beginnings
  of symptoms.

45
Isolation Precautions

• For hospitalized patients who have or are
  suspected of having avian influenza A (H5N1),
  isolation precautions are same as for severe
  acute respiratory syndrome (SARS). These include
• Careful hand hygiene before and after all patient
  contact
• Use gloves and gown for all patient contact
• Wear eye protection when within 3 feet (and
  perhaps 6 feet) of the patient

46
Isolation Precautions-2

• Place patient in an airborne infection isolation
  room (AIIR).
• When entering the patient's room, use a fit
  tested respirator at least as protective as an
  N95 filtering-facepiece respirator approved by
  the National Institute for Occupational Health
  and Safety (NIOSH)
• Outpatients or hospitalized patients discharged
  in less than 14 days should be isolated in the
  home setting on the basis of principles for home
  isolation of SARS patients
• These precautions should be continued for 14 days
  after onset of symptoms until an alternative
  diagnosis is established or diagnostic test
  results indicate that the patient is not infected
  with inflenza A virus (CDC, 2004). Also see
  http//www.cdc.gov/flu/avian/index.htm, and
  http//www.cdc.gov/ncidod/dhgp/pdf/isolation2007.p
  df