Acute Communicable
Disease Control

Contact Information
County of Los Angeles
Department of Public Health
Acute Communicable Disease Control
313 N. Figueroa Street, #212
Los Angeles, CA 90012
Phone: (213) 240-7941
Fax: (213) 482-4856

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Acute Communicable Disease Control

    Flu Main Page Flu Materials Healthcare Outreach Unit LAHAN

Revised 10/2/2023

About RSV

Respiratory syncytial (sin-SISH-uhl) virus, or RSV, is a common respiratory virus that usually causes mild, cold-like symptoms. Most people recover in a week or two, but RSV can be serious, especially for infants, older adults and those with weakened immune systems. RSV is the most common cause of bronchiolitis (inflammation of the small airways in the lung) and pneumonia (infection of the lungs) in children younger than 1 year of age in the United States. RSV circulation in the United States usually starts during fall and peaks in the winter. The timing and severity of RSV circulation can vary from year to year.


In most people, RSV causes a mild, cold-like illness that lasts for 1-2 weeks. Symptoms usually appear 4 to 6 days after getting infected. Symptoms of RSV infection usually include:

  • Runny Nose
  • Decrease in appetite
  • Coughing
  • Sneezing
  • Fever
  • Wheezing

Symptoms usually appear in stages and not all at once. In very young infants with RSV, the only symptoms may be:

  • Irritability
  • Decreased activity
  • Breathing difficulties*

*Call your healthcare provider right away if you or your child is having difficulty breathing, not drinking enough fluids, or your symptoms are getting worse. 

Home Care for RSV

Most RSV infections go away on their own in a week or two. There is no specific treatment for RSV infection, but you can take the following steps to relieve symptoms: 

  • Manage fever and pain with over-the-counter fever reducers and pain relievers, such as acetaminophen or ibuprofen. Never give aspirin to children.
  • Drink enough fluids to prevent dehydration (loss of body fluids).
  • Talk to your healthcare provider before giving your child nonprescription cold medicines. Some medicines contain ingredients that are not good for children.

People at Risk for Severe Disease

Occasionally, RSV infection can cause lower respiratory infections like bronchiolitis and pneumonia. RSV infection can also sometimes lead to exacerbations of chronic health conditions such as asthma, chronic obstructive pulmonary disease (COPD) or congestive heart failure. People most at risk of serious illness from RSV infection include: 

  • Premature infants
  • Young children with congenital (from birth) heart or chronic lung disease
  • Young children with weakened immune systems due to a medical condition or medical treatment
  • Children with neuromuscular disorders
  • Adults with weakened immune systems
  • Older adults, especially those with underlying heart or lung disease


People infected with RSV are usually contagious for 3 to 8 days and may become contagious a day or two before they start showing symptoms. Some infants, and people with weakened immune systems, can continue to spread the virus even after they stop showing symptoms, for as long as 4 weeks. RSV can spread when:

  • An infected person coughs or sneezes
  • Virus droplets from a cough or sneeze get in your eyes, nose, or mouth
  • A person has direct contact with the virus, like kissing the face of a child with RSV
  • A person touches a surface that has the virus on it and then touches their face before washing their hands. RSV can survive for many hours on hard surfaces such as tables and crib rails. It usually lives on soft surfaces such as tissues and hands for a shorter amount of time.


The following are steps that can be taken to prevent the spread of RSV:

  • Cover your coughs and sneezes with a tissue or cough or sneeze into your elbow not your hand
  • Wash your hands often with soap and water for at least 20 seconds
  • Avoid close contact, such as kissing and shaking hands with others
  • Stay home from work or school when sick, until symptoms improve
  • Avoid sharing cups and eating utensils with others
  • Clean frequently touched surfaces

Vaccines and vaccine-like products:

There are several safe and effective vaccines and immunization products currently recommended for infants, seniors, and pregnant women. These products can prevent severe RSV disease in infants and older adults. Although these products are highly effective at preventing severe disease, they are not fully protective against all RSV infections so people who are high risk should continue to take the above prevention precautions in addition to receiving these products.

Older Adults (60 years and older)

  • RSV vaccine helps protect adults aged 60 years and older from serious RSV disease. Please speak to your provider about getting the RSV vaccine now to protect yourself this fall and winter.


  • One dose of nirsevimab, a long acting monoclonal antibody, is recommended for infants younger than 8 months of age who were born shortly before or are entering their first RSV season (typically October 1 through March 31st) to protect them from RSV disease during the first 5 months of life. This includes infants in the following situations:
    • The mother did not receive RSV vaccine during pregnancy.
    • The motherís RSV vaccination status is unknown.
    • The infant was born within 14 days of maternal RSV vaccination.
    • lnfants should receive nirsevimab starting in October through the end of March.
    • Additionally, infants and children 8-19 months of age who are at increased risk for severe RSV disease and entering their second RSV season should receive also receive a dose of nirsevimab. This includes:
      • American Indian/Alaska Native children.
      • Children with chronic lung disease of prematurity who require medical support during the six months before the start of their second RSV season.
      • Children with severe immunocompromise.
      • Children with severe cystic fibrosis.

Pregnant Persons

  • Pregnant persons should be offered RSV vaccine between September and January during weeks 32 through 36 of pregnancy. This vaccine will protect infants from RSV infection during the first 6 months of life.
    • To prevent severe RSV disease in infants, either maternal RSV vaccination or Nirsevimab is recommended. Most infants will not need both.


Individual cases of RSV are not currently reportable to LACDPH. Data tracking RSV trends in Los Angeles County are available in the latest issue of Influenza Watch

Fact Sheets


News and Updates

  • LAC DPH Health Advisory: Immunize Infants and Older Adults to Protect them from Severe RSV (9-6-23)
  • CDC Health Advisory: Increased Respiratory Virus Activity, Especially Among Children, Early in the 2022-2023 Fall and Winter (11-4-22)

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Public Health has made reasonable efforts to provide accurate translation. However, no computerized translation is perfect and is not intended to replace traditional translation methods. If questions arise concerning the accuracy of the information, please refer to the English edition of the website, which is the official version.
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