- Article
- Source: Campus Sanofi
- Jan 2, 2025
RSV Transmission & Incubation Period
Author: Sanofi
Editorial Team
The transmissibility of RSV
Symptomatic individuals with RSV are generally more infectious than those who are asymptomatic, particularly if they have high viral load shedding.4 Nonetheless, asymptomatic RSV transmission still occurs.5
Although viral load contributes to the level of infectiousness in symptomatic individuals, there is not yet enough evidence on this relationship in asymptomatic individuals.4
The RSV transmission period is also seasonal, with infections peaking at different times throughout the year.6,7
Modes of RSV transmission
RSV has multiple routes of transmission, sometimes divided into 3 categories: contact (direct and indirect), large respiratory droplets, and fine respiratory droplets.5,8
RSV transmission by direct contact
Direct, physical transmission of RSV occurs when individuals come into close contact with respiratory secretions from an infected person. This can happen through actions such as kissing a child when you are infected with RSV.5,9
RSV transmission via large respiratory droplets
RSV transmission primarily occurs through large droplet inoculation into the eyes, nose, or mouth, which requires close contact with an RSV-infected individual.8,10
Large droplet transmission refers to particles larger than 5 mm, which tend to settle quickly. Inhaling these larger droplets increases the likelihood of them being trapped in the upper airways.5
RSV surface transmission
RSV can also be transmitted through indirect (fomite) transmission such as when respiratory droplets containing RSV contaminate various surfaces. The RSV lifespan on surfaces vary depending on the surface type.5,10
On nonporous hard surfaces such as crib rails, RSV can remain viable for 6 to 12 hours. Conversely, on porous surfaces like paper, cardboard, and fabrics, the virus can survive for about 2 hours.8,10,11
Additionally, RSV can remain active for up to 2 hours on gloves, while its viability on skin is significantly shorter, lasting only around 15 to 60 minutes.11
RSV transmission by direct contact
Direct, physical transmission of RSV occurs when individuals come into close contact with respiratory secretions from an infected person. This can happen through actions such as kissing a child when you are infected with RSV.5,9
RSV transmission via large respiratory droplets
RSV transmission primarily occurs through large droplet inoculation into the eyes, nose, or mouth, which requires close contact with an RSV-infected individual.8,10
Large droplet transmission refers to particles larger than 5 mm, which tend to settle quickly. Inhaling these larger droplets increases the likelihood of them being trapped in the upper airways.5
RSV surface transmission
RSV can also be transmitted through indirect (fomite) transmission such as when respiratory droplets containing RSV contaminate various surfaces. The RSV lifespan on surfaces vary depending on the surface type.5,10
On nonporous hard surfaces such as crib rails, RSV can remain viable for 6 to 12 hours. Conversely, on porous surfaces like paper, cardboard, and fabrics, the virus can survive for about 2 hours.8,10,11
Additionally, RSV can remain active for up to 2 hours on gloves, while its viability on skin is significantly shorter, lasting only around 15 to 60 minutes.11
The RSV incubation period
Determining the incubation period of an RSV infection—the time between infection and symptom onset—is useful in infectious disease surveillance and control.12
The incubation period, also referred to as the eclipse phase of viral replication, is characterized by a lack of symptoms in individuals who remain contagious for 3 to 5 days before symptoms manifest.2
How long is the incubation period for RSV in infants?
The typical RSV incubation period in babies ranges from 2 to 8 days, with a usual duration of 4 to 6 days depending on host factors, such as the age of the patient and whether it is their first infection with RSV.13
Following the RSV incubation period, clinical infection begins with symptoms of mucosal inflammation and irritation in the upper respiratory tract, such as congestion, rhinorrhea, and sneezing.3
People infected with RSV are usually contagious for 3 to 8 days and may become contagious a day or two before showing signs of illness. However, some infants and people with weakened immune systems can continue to spread the virus even after they stop showing symptoms, sometimes for as long as 4 weeks.14,15
RSV transmission precautions in infants
The week following exposure to an RSV case is critical for preventing transmission, due to viral shedding and an increased risk of household spread.1
Parents can take actions to help reduce the transmission of RSV and other respiratory viruses by practicing good hygiene habits, such as keeping their babies away from infected people and frequent hand washing or sanitizing.16
Thoroughly cleaning surfaces, toys, and other objects contaminated with RSV are also essential steps in reducing viral transmission.16
Transmission of RSV can still occur as long as viral shedding persists. The duration of viral shedding varies depending on factors like the severity of the infection and the individual's immune status. Infants may shed the virus for up to 14 days, while children with weakened immune systems may experience high levels of RSV shedding for periods ranging from a few days to several months.1,2,8
References
1. Otomaru H, Sornillo JBT, Kamigaki T, et al. Risk of transmission and viral shedding from the time of infection for respiratory syncytial virus in households. Am J Epidemiol. 2021;190(12):2536-2543. 2. Piedmonte G. RSV infections: state of the art. Cleve Clin J Med. 2015;82(11 suppl 1):S13-S18. 3. Manti S, Cuppari C, Lanzafame A, et al. Detection of respiratory syncytial virus (RSV) at birth in a newborn with respiratory distress. Pediatr Pulmonol. 2017;52(10):E81-E84. 4. Kombe IK, Munywoki PK, Baguelin M, Nokes DJ, Medley GF. Model-based estimates of transmission of respiratory syncytial virus within households. Epidemics. 2019;27:1-11. 5. Kutter JS, Spronken MI, Fraaij PL, Fouchier RA, Herfst S. Transmission routes of respiratory viruses among humans. Curr Opin Virol. 2018;28:142-151. 6. Yamin D, Jones FK, DeVincenzo JP, et al. Vaccination strategies against respiratory syncytial virus. Proc Natl Acad Sci USA. 2016;113(46):13239-13244. 7. Obando-Pacheco P, Justicia-Grande AJ, Rivero-Calle I, et al. Respiratory syncytial virus seasonality: a global overview. J Infect Dis. 2018;217(9):1356-1364. 8. Kaler J, Hussain A, Patel K, Hernandez T, Ray S. Respiratory syncytial virus: a comprehensive review of transmission, pathophysiology, and manifestation. Cureus. 2023;15(3):e36342. 9. About RSV. Centers for Disease Control and Prevention. Updated August 30, 2024. Accessed November 21, 2024. https://www.cdc.gov/rsv/about/index.html 10. Hall CB. Nosocomial respiratory syncytial virus infections: the “Cold War” has not ended. Clin Infect Dis. 2000;31(2):590-596. 11. Goins WP, Talbot HK, Talbot TR. Health care–acquired viral respiratory diseases. Infect Dis Clin North Am. 2011;25(1):227-244. 12. Linton NM, Kobayashi T, Yang Y, et al. Incubation period and other epidemiological characteristics of 2019 novel coronavirus infections with right truncation: a statistical analysis of publicly available case data. J Clin Med. 2020;9(2):538. 13. Jain H, Schweitzer JW, Justice NA. Respiratory Syncytial Virus Infection in Children. StatPearls Publishing; 2023. Accessed November 21, 2024. https://www.ncbi.nlm.nih.gov/books/NBK459215/ 14. National Foundation for Infectious Diseases (NFID). Respiratory syncytial virus (RSV). Updated September 2024. Accessed November 21, 2024. https://www.nfid.org/infectious-disease/rsv/ 15. How RSV spreads. Centers for Disease Control and Prevention. Updated August 30, 2024. Accessed November 21, 2024. https://www.cdc.gov/rsv/causes/index.html 16. RSV prevention and treatment. American Lung Association. Updated November 20, 2024. Accessed November 21, 2024. https://www.lung.org/lung-health-diseases/lung-disease-lookup/rsv/treatment
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