Respiratory syncytial virus infection (RSV) presents as cold symptoms in children and adults. RSV most frequently causes bronchiolitis and pneumonia in young children, especially in the 2-3 month age group. RSV is responsible for 75% of the bronchiolitis cases in young children.
CASES/YEAR
5,000,000 (US); 100,000,000 (Global)
OTHER NAMES
RSV; Parainfluenza virus infections (Related Infection); Human metapneumovirus infections (Related Infection);
INCUBATION
2-8 days; [PPID, p. 2095]
INITIAL SYMPTOMS
Cold symptoms in children and adults; Infants may have severe disease with bronchiolitis; also can cause pneumonia, croup, bronchitis, and otitis media. [CCDM]
PRECAUTIONS
In infants, young children, and immunocompromised adults: Contact for duration of illness; Wear mask according to Standard Precautions; In immunocompromised patients, extend the duration of Contact Precautions due to prolonged shedding. Reliability of antigen testing to determine when to remove patients with prolonged hospitalizations from Contact Precautions uncertain. [CDC 2007 Guideline for Isolation Precautions]
COMMENTS
FINDINGS:
RSV most frequently causes bronchiolitis and pneumonia in young children, especially in the 2-3 month age group. RSV also causes the common cold in adults (occasional) and pneumonia in the elderly and immunosuppressed (infrequent). RSV is responsible for 20-25% of hospitalizations for pneumonia and 75% of the bronchiolitis cases in young children. Common symptoms in children are low grade fever, rhinorrhea, cough, and wheezing. Among infants with RSV infection, 20-40% develop lower tract disease (pneumonia, bronchiolitis, and tracheobronchitis). [Harrisons, 18th Ed, p. 705] Common findings in adults are cough, fever, rhinitis, sore throat, and wheezing. Otitis media is common in young children with RSV, and pleural effusions are rare.. [PPID, p. 2096-2100] Seizures and encephalopathy are rare complications. [Guerrant, p. 384]
EPIDEMIOLOGY:
Transmission occurs after contact with secretions and self-inoculation into nasal or eye mucosa. How the virus evades neutralizing antibodies is not known. [ID, p. 2032-3] RSV can cause severe disease and death in immunocompromised patients. Particularly at risk are patients with congenital immunodeficiencies, transplantation, and AIDS. [PPID, p. 2096-2100] 60% mortality in patients undergoing cytotoxic chemotherapy after bone marrow transplant or leukemia if they develop RSV pneumonia; [Cecil, p. 2153]
RELATED INFECTIONS:
Parainfluenza virus is related to RSV and is the most common cause of croup in young children. It occasionally causes common cold, pharyngitis, and tracheobronchitis in adults and infrequently causes lower respiratory tract disease in immunosuppressed patients. [Harrisons, 18th Ed, p. 704] Human metapneumovirus is a similar but separate virus that causes illness similar to RSV. [Merck Manual, p. 2763]
DIAGNOSTIC
"Rapid antigen tests with high sensitivities for RSV are available for use in children;" [Merck Manual, p. 2763] In infants: viral culture 60-70% sens; Ag detection 80-90% sens; RT-PCR is most sens.& preferred; for older children & adults; [ABX Guide]
SIGNS & SYMPTOMS
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>fatigue, weakness
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>fever
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E pharyngitis
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E rhinitis
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N headache
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N seizure
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R cough
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R dyspnea
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R wheezing
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X lung infiltrates
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X pleural effusions
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*ARDS
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*myocarditis
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*pneumonia
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*pneumonitis
ENTRY
Inhalation, Skin or Mucous Membranes (Includes Conjunctiva)
RISK FACTORS
- AIDS patients
- Cancer patients
- Care for patients (droplet/airborne)
- Live together in close quarters
TREATMENT
Preventive measures in high-risk infants may include IM palivizumab (monoclonal antibody against RSV) given monthly during the RSV season. [CCDM, p. 124] Ribavirin is no longer recommended "except for infections in severely immunocompromised patients." [Merck Manual, p. 2764]
REFERENCES FOR CASES/YEAR
1. (US) Causes 100,000 hospitalizations in the US every year; About 1-3% of infections result in hospitalizations. [Cecil, p. 2152] Calculate: 2% X = 100,000; X = 100,000/0.02; X = 5 million cases per year in the US and 20 x 5 million = 100 million (worldwide);
2. (Global) 20 X US cases/yr;