Denise Nicole Thomas RNBSNAuburn University

Nurse Practitioner Student

Influenza: Is Pregnancy an Infection Risk?

Goals of Presentation•Identify the impact pregnancy has on influenza infection risk/complications

•List prevention and control strategies for influenza in pregnant population

What is Influenza?

•Influenza is a very significant acute upper respiratory tract infection caused by influenza viruses. Influenza can occur year round but usually occurs in winter and spring.

Pathology of Influenza

•Virus attaches to and penetrates respiratory epithelial cells in trachea and bronchi

•Virus replicates and destroys host cell

• Symptoms occur but viremia absent

•Virus shed in respiratory secretions for 5-10 days, runs course in 2 weeks.

Signs and Symptoms of Influenza

•IMMEDIATE onset of muscle aches, fatigue and high fever. Also includes cough, sore throat, headache, chills, nonproductive cough, conjunctivitis, runny nose.

•In children, diarrhea and seizures

Definition of Close Contact•Close contacts are defined as persons within approximately 6 feet (2 meters) or within the room or care area of a confirmed or probable H7N9 case patient for a prolonged period of time, or with direct contact with infectious secretions (such as being directly in the path of a sneeze) while the patient was likely to be infectious (beginning 1 day prior to onset of signs and/or symptoms and continuing until resolution of illness).

CDC – 2013-2014

Influenza Transmission – Close Contact

•Coughing, sneezing into air•Inhaling infected air•Kissing or sharing handkerchiefs/tissues•Sharing eating utensils/sharing food•Touching contaminated smooth surfaces (door knobs, handles, telephones)

High Risk Groups

•Groups at high risk for complications secondary to influenza are those with:

Chronic lung disease, diabetes mellitus, chronic renal failure, cardiac disease, immunosuppressed, those in residential homes and long term care facilities

Morbidity/Mortality•2006 through 2013 – Annual influenza related hospitalizations = 226,000•2006 through 2013 – Annual influenza associated deaths = 24,000/year•2006-2013 – Annual influenza associated deaths = 36,000/year (8,000 due to influenza associated pneumonia)

Pandemic versus Epidemic Influenza

Pandemic Influenza•Pandemic occurs when:•new influenza type-A virus emerges (antigenic shift)

- no immunity in population - virus spreads efficiently between humans - results in worldwide outbreaks of disease

Recent Pandemics•1889- Pandemic•1918- 1919 Spanish pandemic (influenza

virus type H1)•1957- subtype H2N2 •1968- 1969 Hong Kong H2N2•1977- Russian subtype H1N1•2009- H1N1•2013- H3N2

Epidemic Influenza•Type A or B influenza virus appearing in groups or clusters •Virus is not new virus•Vaccine usually available•Post exposure prophylaxis available

Influenza Virus Vaccines

•Inactivated influenza virus vaccine- Prepared annually- No live virus in vaccine

- Injectable - 2 doses for children with zero prior influenza vaccination

Live attenuated virus vaccine (LAV)

•Live weakened flu vaccine•Intranasal administration•Limited to healthy individuals•Not administered to children under 2 years old.•Two doses for children with zero prior influenza vaccination•Vaccine for 2 years and younger Thimerosol- free

Influenza and Pregnancy

•19 flu seasons- 4,300 women of child bearing age- Pregnant women 5 times more likely than post-partum patients to require hospitalization- (Harvard Health, 2010)

•1970’s- 3 flu seasons rates of medical visits for acute respiratory disease more than twice as high in pregnant vs. non-pregnant. (CDC, 2012)

Routine Vaccines for Pregnant Patients

•Hepatitis A & B• Influenza (inactivated)•Tetanus/Diphtheria or T dap (2nd or 3rd trimester)•Meningococcal•Rabies

ACIP Guidelines- February 2013

Why does pregnancy appear to increase risk of influenza

complications?

•Mechanical & hormonal changes associated with pregnancy•Decreased lung capacity •Changes in the cardiovascular system

•Altered immune response due to pregnancy---shift away from cell mediated immunity

•Hospitalization for women 37-42 weeks gestation= 5 fold compared to women one to six months post partum

•Greatest risk in 3rd trimester!!!

Use of Antiviral

•Start anti-viral treatment immediately if influenza suspected.•Antivirals MOST effective when given within 48 hours of symptoms•BUT, start ASAP even if beyond 48 hours.

Prophylaxis during Pregnancy

•No evidence of adverse effects of antiviral use (Tamiflu) in pregnant female.

•Better to treat than risk increased illness in pregnant female.

CDC 2013

Influenza and the Neonate•Flu vaccine risk to infants quite low•Some studies show vaccine protects mother and infant (NEJM- 2013)•Virus does not appear to pass through placenta•Neonatal problems associated with maternal inflammatory process & fever (Int J Dev Neuroscience- 2013)

2013 H1N1 Influenza Lessons Learned

•Number of new cases declined with vaccine, prevention strategies and post- exposure management.•99% of serotype Influenza type A were H1N1•H1N1 vaccine supply started below expected level but increased mid-season

Lessons Learned cont’d.•Ongoing surveillance did not reveal unusual adverse effects associated with vaccine

•Child deaths from H1N1 in otherwise healthy children associated with co-infection with bacteria, usually Staphylococcus or Pneumococcal pneumonia.

2012-2013 Seasonal Vaccine Recommendation Changes

•Recommends 6 month and older (previously 19-49 years old.)•Vaccine dose (under 8 year old) related to

# vaccine doses received in 2011.• 2012-2013 vaccine includes 2 A viruses

and one B virus. (H1N1 included).

(CDC, 2013)

Conclusions

• Influenza is a seasonal viral infection that affect males and females, young & old, pregnant and non pregnant.

• Influenza vaccine should be taken by all eligible consumers

• Implement prevention/control policies including hand hygiene, including pets

• Avoid close contact with infected

• Administer antivirals following exposure

Preventing Influenza•Hand hygiene•Vaccine •Post-exposure prophylaxis for all exposed including pregnant•Home quarantine in epidemics•ER/MD office segregation sick/pregnant

Questions?

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