What is RSV (Respiratory Syncytial Virus)?

RSV is a common virus that affects the respiratory tract. In most people, it causes mild symptoms similar to a “common cold,” but in infants, the elderly, and individuals with weakened immune systems, it can lead to lower respiratory tract infections and hospitalization. The World Health Organization reports that RSV is one of the leading causes of bronchiolitis and pneumonia in children and creates a significant disease burden in the elderly.

RSV can present with upper respiratory symptoms similar to influenza (the flu) and COVID-19; therefore, it is difficult to distinguish based on symptoms alone. When necessary, tests such as rapid antigen or PCR are used for a definitive distinction. Compared to COVID-19, its infectivity and the time elapsed until symptoms appear may differ; because symptoms overlap, testing is crucial for clinical diagnosis.

What are the symptoms?

Runny nose, nasal congestion, sore throat, cough, mild fever, and head and body aches are common. Some individuals may develop wheezing, rapid breathing, chest tightness, and lower respiratory tract findings. In severe cases, bronchiolitis or pneumonia may occur.

How is it diagnosed?

Diagnosis of RSV usually begins with a physical examination by a doctor and the patient’s complaints; however, a definitive diagnosis is made through laboratory tests. These tests are standard, especially in cases requiring hospitalization, as in your situation. The steps of the diagnostic process include:

1. Physical Examination and History

The doctor first listens to the lungs with a stethoscope, looking for “wheezing” or a whistling sound, which is the most typical sign of RSV. They also measure the oxygen level (saturation) in the blood. In mild cases, symptomatic treatment is usually given under the label of “viral upper respiratory tract infection” without testing.

2. Swab Tests (Definitive Diagnosis)

The method that clarifies whether RSV is present is testing with samples taken from the nose or throat.

• PCR Test (Molecular Test): This is the gold standard and most reliable method. A swab is taken from the nasopharynx using a long stick through the nostrils. It detects the genetic material of the virus and can catch even small amounts.
• Rapid Antigen Test: Provides results in about 15-30 minutes. It is frequently used in children but is not as sensitive as PCR; sometimes it may give a “negative” result even if the virus is present.

3. Blood Tests

Blood tests do not directly say “RSV is present,” but they help understand the severity and type of infection in the body (these are the ones performed in your lab results).

• Complete Blood Count (CBC): An increase in white blood cells (WBC) or specific cells like Monocytes indicates that the body is fighting a virus.
• CRP and Procalcitonin: These values help distinguish whether the infection is bacterial or viral. (Since your Procalcitonin was low, it was understood not to be bacterial).

4. Imaging (Chest X-ray)

This is not performed on every patient. However, a chest X-ray or tomography is taken to check for lung involvement (ground-glass appearance or infiltration) if the patient has:

• Shortness of breath,
• Low oxygen levels,
• Or suspicion of pneumonia.

Is it dangerous?

Most adults recover spontaneously in 1–2 weeks; however, the risk of severe progression, hospitalization, and death increases in cases such as ages 60–75+, chronic heart-lung disease, kidney disease, diabetes, immune deficiency, or organ transplantation. Besides pneumonia/bronchiolitis, RSV can worsen existing heart and lung conditions.

How is it treated?

For RSV, home care with rest, fluids, appropriate analgesics for pain/fever, and if necessary, steam/saline solution is often sufficient. In the hospital, oxygen, intravenous fluids, and respiratory support may be applied. The benefit of specific antiviral treatment is limited; drugs like ribavirin are considered by specialist teams only in selected severe and especially immunosuppressed patients. The routine use of corticosteroids and bronchodilators is generally not recommended.

Is there a vaccine? Can it be prevented?

Phase studies have shown that RSV vaccines approved by the FDA reduce the likelihood of hospitalization and the progression of the disease to a lower respiratory tract infection by at least 80%. RSV vaccines are not yet available in our country.