An Analysis of Point-of-Care Testing & Treatment for Influenza, Influenza-Like Illness, and Group A Streptococcus

The 2017-18 influenza (flu) season ranks as the deadliest in more than four decades. An estimated 80,000 Americans died of flu and its complications last winter, according to the U.S. Centers for Disease Control and Prevention (CDC). An additional 900,000 or more Americans were hospitalized because of flu. Flu is particularly deadly for pregnant women, children, older adults, and people with chronic conditions.

Each week in Florida, influenza and influenza-like illness (ILI) kill 23 people aged 65 and older, admit two pregnant women to the Intensive Care Unit, and send more than 1,000 children to the Emergency Department. In children under age five, ILI is responsible for more than 55,000 Emergency Department visits annually and more than $20,000/day ($7 million each year) in lost productivity. In adults aged 65 and older, ILI is responsible for more than 12,500 Emergency Department visits annually.

Streptococcus is a type of bacteria that can cause strep throat (group A) or infections of the blood (type B). The CDC estimates approximately 11,000 to 13,000 cases of invasive group A streptococcus disease occur each year in the United States. Each year between 1,100 and 1,600 people die due to invasive group A streptococcus disease. The CDC does not track non-invasive group A streptococcus infections.

Influenza and streptococcus are diagnosed by a physician, who will conduct a physical exam, looking for signs and symptoms, and possibly ordering a test that detects the presence of viruses. The most commonly used test is called a rapid influenza diagnostics test (RIDT), which looks for substances (antigens) on a swab sample from the back of the nose or throat. 

These tests can provide results in about 15 minutes; however, the results may vary greatly and may not always be accurate. Tests can be categorized as “waived” from regulatory oversight if they meet certain requirements established by the Clinical Laboratory Improvement Amendments of 1988 (CLIA) law. CLIA offers waivers if a laboratory test can be performed at “minimal level of complexity and low risk of erroneous results.” 

Treatment for influenza and influenza-like illness ranges from bed rest and plenty of fluids to prescribed antiviral medications, such as oseltamivir (Tamiflu) or zanamivir (Relenza). If taken soon after noticing symptoms, these drugs may shorten the illness by a day or so and help prevent serious complications.

Streptococcus cannot be diagnosed simply by a visual inspection. A physician may conduct a physical exam, looking for signs and symptoms of streptococcus, supported by one or more of the following tests:

• Rapid antigen test --- using a swab sample from the patient’s throat, a rapid antigen test can detect streptococcal bacteria in minutes by looking for substances (antigens) in the throat. If the test is negative but your physician still suspects strep, he or she might do a throat culture.
• Throat culture --- a sterile swab is rubbed over the back of the throat and tonsils to get a sample of the secretions. It’s not painful, but it may cause gagging. The sample is then cultured in a laboratory for the presence of bacteria, but results can take as long as two days.

If a patient is diagnosed with streptococcus, the physician will likely prescribe an oral antibiotic to reduce the duration, severity of symptoms, risk of complications, and likelihood that infection will spread to others. Over-the-counter pain relievers may also be used to relieve throat pain and reduce fever.