Influenza

Excerpt

Influenza is a communicable viral disease that affects the upper and lower respiratory tract. A wide spectrum of influenza viruses causes it. Some of these viruses can infect humans, and some are specific to different species. These viruses are transmissible through respiratory droplets expelled from the mouth and respiratory system during coughing, talking, and sneezing. The influenza viruses can be transmitted by touching inanimate objects soiled with the virus and touching the nose or eye. Influenza can be transmitted before the patient is symptomatic and until 5 to 7 days after infection. After infection, it takes a few days for most of the healthy patients to recover fully, but complications that include pneumonia and death are common in certain high-risk groups. These groups include young children, the elderly, immunocompromised, and pregnant females. Symptoms of influenza include a runny nose, high fever, cough, and sore throat. Influenza spreads rapidly and efficiently in seasonal epidemics. Flu epidemics occur every autumn and winter in temperate regions and affect a significant portion of adults and children, but seasons differently impact age groups and severity.

Over the past few decades, more lethal strains of the influenza virus have evolved. Besides infecting humans, these viruses also infect animals. Clinicians should be aware that all rapid tests for detecting influenza have limited sensitivity, and false-negative results are common. The gold standard for diagnosis is the polymerase chain reaction test or viral culture of throat secretions, but these tests take a few days to yield results. The key strategy in reducing the morbidity of the infection is vaccination.