Influenza

Question 1

Influenza

• Symptoms
• Onset
• Complications

Answer 1

Contagious respiratory illness caused by a virus.

Symptoms- very suddenly, fever, chills, cough, sore throat, runny nose, muscle/body aches, headaches, fatigue, vomiting, diarrhea
Spread by droplet, sneezing/coughing, may contract from a fomite

Most contagious first 3-4 days, may spread 1 day prior to symptoms and 7 days after symptoms.

Onset approximately 2 days after exposure, can be 1-4 days.

Complications- pneumonia, otitis, sinus infections, worsening of chronic medical conditions

Question 2

Influenza Testing

Answer 2

Not always needed, may make a clinical diagnosis

Rapid influenza molecular assays recommended for outpatients

RT-PCR for inpatients . Higher sensitivity, may differentiate the type

Rapid influenza diagnostic test are available with lower sensitivity (many false negatives)

Testing is most accurate in the first 3-4 days

Question 3

Influenza Treatments

Answer 3

Aims to shorten the duration of fever/illness symptoms and may reduce the risk of some complications.
Benefit is greatest in the first 48 hours of symptom onset.

Antiviral treatment is recommended for hospitalized patients, severe, complicated, or progressive illness, patients with a high risk of complications.

Antiviral treatment can be considered in otherwise healthy patients if treatment can be started in the first 48 hours.

Question 4

At Risk Individuals for Influenza

Answer 4

Children <2
Adults >65
Chronic pulmonary, cardiovascular, renal hepatic, hematological, metabolic & neurological disorders
Immunocompromised
Age <19 on chronic aspirin therapy
American indians/alaskan natives
Pregnant or within 2 weeks postpartum
BMI >40
Residents of nursing homes & chronic care facilities.

Question 5

Influenza Drug Treatments

Answer 5

Tamiflu (oseltamivir) adults 75mg BID x 5 days (needs renal dosing)

• Prophylaxis- adults 75mg once daily x7 days
• May cause nausea, vomiting, headache, skin reactions, neuropsychiatric events

Inhaled Zanamivir- adults two inhalations twice daily x5 days

• Prophylaxis- adults two inhalations once daily x7 days
• May cause bronchospasm, dizziness, skin reactions, neuropsychiatric events

Prophylaxis is 70-90% effective at prevention of influenza in exposed patients. Routine use not recommended, must be given within 48 hours of exposure.

Question 6

Influenza Vaccinations

Answer 6

Recommended for everyone age >6 months without contraindications
Offered by the end of October but continue throughout season.
Children 6 months to 8 years receive two doses >4 weeks apart
Healthy, non-pregnant persons 2-49 may receive nasal vaccine
Egg allergies may receive regular vaccine, but egg free is available.
Regular & high dose vaccines available.
Can be given with other vaccines.