Influenza FAQ (adapted from CDC)

Influenza is a member of the Orthomyxovirus family and is responsible for causing a contagious respiratory illness, and is commonly known as the “Flu.”
The two main types of the virus are Type A and Type B and are responsible for the seasonal flu epidemics that occur every year.
Two surface proteins (hemagglutinin and neuraminidase) are responsible for the antigenic response elicited by the immune system. Still they may also slightly change every year through a mechanism known as antigenic drift, which is why we require a new flu vaccination every year.
Although symptoms may not present soon after once one becomes infected, healthy adults can potentially infect others with Influenza 1 day before symptoms present (although unrecognized low-grade fever may be present) and 5-7 days after the illness presents.
Influenza patients are most contagious during the first 3-4 days of having the illness.

Influenza is highly contagious, and Type A viruses are well-known pathogens causing pandemics.
Influenza causes a respiratory illness with symptoms ranging from mild to severe, depending on multiple factors.
Older individuals, young children, or have other medical conditions that suppress their immune system’s ability from fighting infections are at risk of severe complications if infected with this virus. People unvaccinated against the newest strain of Influenza are also at increased risk of contracting the illness.

Following and maintaining droplet precautions for known Influenza cases are the most effective means of preventing transmission.
Vaccination against Influenza is the single-most effective measure anyone can take to preventing Influenza.

Receiving the Influenza vaccine as early as it is available helps to protect yourself from contracting the flu and prevents the potential spread of the virus.
Maintaining appropriate hand hygiene also offers protection in contracting the virus.
Due to the highly contagious nature of the Influenza virus, it is strongly advisable for infected individuals to wear a mask when going in public areas to prevent the spread of the virus to others. Healthcare workers taking care of patients with known Influenza infection should always personal protective equipment (PPE), which includes respirator masks such as test-fitted N95 masks when interacting with patients.

Influenza infection is diagnosed clinically and with a rapid influenza test.
- Like many other tests available to clinicians, the test may contain false positives and false negatives. Therefore carefully considering the clinical presentation of potential influenza infection is highly significant, resulting in a more careful assessment of “pre-test likelihood.”
Symptoms can include a combination of fever, chills, cough, muscle aches/pains, diarrhea, nausea, or vomiting.
Other bacterial or viral pathogens that cause similar symptoms may also cause a “flu-like illness” and should be taken into consideration when working up a diagnosis.

Strong evidence exists for maximizing the anti-viral and clinical benefit when influenza treatment is initiated within 48 hours of flu illness onset. Urgent medical attention may be needed when post-infection complications arise. Influenza infection is otherwise treated supportively until symptoms resolve.
Some providers may prescribe the medication Oseltamavir in early known cases of Influenza.
- It is important to recognize that this medication is not an antibiotic, and it works by preventing viral replication. Therefore some providers may opt to use this only in cases where a diagnosis has been made within 48 hours.

Severe respiratory complications may arise in the form of bacterial pneumonia superinfection, respiratory distress, or even respiratory failure.

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