Respiratory Syncytial Virus Infection (RSV) - Causes, Symptoms and Treatments

A subgroup of the myxoviruses resembling paramyxovirus causes respiratory syncytial virus (RSV) infection. RSV is the leading cause of lower respiratory tract infectious in infants and young children; it's the major cause of pneumonia, tracheobronchitis, and bronchiolitis in this age-group and a suspected cause of the fatal respiratory diseases of infancy. It has been linked to apnea in cases of acute infection in infants. Antihody titers seem to indicate that few children under age 4 escape contracting some form of RSV infection, even if it's mild. In fact, RSV infection is the only viral disease that has its maximum impact during the first few months of life. (Incidence of RSV bronchiolitis peaks at age 2 months.)

This virus creates annual epidemics that occur during the late winter and early spring in temperate climates, and during the rainy season in the tropics.

Causes of Respiratory Syncytial Virus Infection:

The organism is transmitted from person to person by respiratory secretions and has an incubation period of 4 to 5 days.

Reinfection is common, producing milder symptoms than the primary infection. School-age children, adolescents, and young adults with mild reinfections are probably the source of infection for infants and young children.

Signs and symptoms of Respiratory Syncytial Virus Infection:

Clinical features of RSV infection vary in severity, ranging from mild coldlike symptoms to bronchiolitis or bronchopneumonia and, in a few patients, severe, life-threatening lower respiratory tract infections. Generally, symptoms include coughing, wheezing, malaise, pharyngitis, dyspnea, and inflamed mucous membranes in the uose and throat.

Otitis media is a cornmon complication of RSV in infants. RSV has also been identified in patients with a variety of central nervous system disorders, such as meningitis and myelitis.

Diagnosis of Respiratory Syncytial Virus Infection:

Diagnosis is usually based on clinical findings and epidemiologic information.

Cultures of nasal and pharyngeal secretions may show RSV; however, the virus is very labile, so cultures aren't always reliable. Serum antibody titers may be elevated, but before age 6 months, maternal antibodies may impair test results. Two serologic techniques that aid in diagnosis are the indirect immunofluorescence and the enzyme-linked immunosorbent assay (ELISA) methods. These tests are sensitive and will give results in less than one hour. Chest X-rays help detect pneumonia.

Other conditions to consider are pneumonia, croup, asthma, influenza, and the common cold.

Treatment of Respiratory Syncytial Virus Infection:

Among the goals oftreatment are support of respiratory function, maintenance of fluid balance, and relief of symptoms. Mild and even moderated cases do not require specific therapy. Treating the symptoms with nebulized beta-agonists (albuterol) or racemic epinephrine have been shown to be effective. Short courses of oral steroids may also help decrease inflammation of the bronchioles.

Special considerations of Respiratory Syncytial Virus Infection:

1. Monitor respiratory status. Observe the rate and pattern; watch for nasal Haring or retraction, cyanosis, pallor, and dyspnea; and auscultate for wheezing, rhonchi, or other signs of respiratory distress. Monitor arterial blood gas values.

2. Maintain a patent airway, and be especially watchful when the patient has periods of acute dyspnea. Perform percussion and provide drainage and suction when necessary. Provide a high-humidity atmosphere. Semi-Fowler's position may help prevent aspiration of secretions.

3. The head of the bed or crib may be elevated to help prevent aspiration of secretions.

4. Monitor intake and output carefnlly. Observe for signs of dehydration such as decreased skin turgor. Encourage the patient to drink plenty of high-calorie Huids. Administer I.V. fluids as needed.

5. Promote bed rest, allowing for as much uninterrupted rest as possible.

6. Hold and cuddle infants; talk to and play with toddlers. Offer diversional activities suitable to the child's condition and age. Foster parental visits and cuddling. Restrain a child only as necessary.

7. Impose contact isolation. Enforce strict hand washing, because RSV may transmitted from fomites.

8. Staff members with respiratory illnesses shouldn't care for infants.