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An In vitro Model to Study Immune Responses of Human Peripheral Blood Mononuclear Cells to Human Respiratory Syncytial Virus Infection
Published on: December 10, 2013
Respiratory syncytial virus infection--risk factors for hospital admission: a case-control study
H E Nielsen1, V Siersma, S Andersen
1Department of Paediatrics, Gentofte University Hospital, Hellerup, Denmark. Hanie@gentoftehosp.kbhamt.dk
Insights
Several factors increase the risk of hospitalization for respiratory syncytial virus (RSV) in infants. However, these risk factors have small effects, and no single factor explains most severe RSV hospitalizations.
Area of Science:
- Pediatrics
- Infectious Diseases
- Epidemiology
Background:
- Respiratory syncytial virus (RSV) commonly infects infants, typically causing mild illness.
- However, 1-2% of infants experience severe RSV infection requiring hospitalization.
- Identifying risk factors for severe RSV disease is crucial for prevention and management.
Purpose of the Study:
- To investigate risk factors associated with hospital admission due to RSV infection in children under two years old in Denmark.
- To analyze demographic, medical, and immunological factors contributing to severe RSV outcomes.
Main Methods:
- A retrospective case-control study involving 1252 infants hospitalized with RSV infection.
- Matched controls were used for comparison.
- Multivariate analysis examined risk factors including innate immunity markers (MBL concentration, maternal antibodies) in infants under 3 months.
Main Results:
- Identified independent risk factors for hospitalization: infant's age, sex, birth month, gestational age, birthweight, having an older sibling, and maternal smoking during pregnancy.
- Maternal RSV antibody levels showed a marginal effect.
- Neonatal mannose-binding lectin (MBL) concentration and household crowding were not significant risk factors.
Conclusions:
- While multiple risk factors contribute to RSV hospitalizations, their individual effects are small.
- No single factor adequately explains the severe RSV cases requiring hospitalization.
- The majority of both cases and controls exhibited at least one risk factor, highlighting the multifactorial nature of severe RSV disease.
Unlabelled:
Most infants are infected with respiratory syncytial virus (RSV) during the first 2 y of life. The majority have only a mild upper respiratory tract infection, but 1-2% develop a more severe illness and are admitted to hospital.
Aim:
To carry out a study of risk factors for hospital admission because of RSV infection in Denmark in children aged less than 2 y of age.
Methods:
The study population included all 1252 children admitted to hospital with verified RSV infection in two Danish counties during the 5-y period 1990-1994. The investigation comprised a retrospective case-control study with five matched controls per case. In a multivariate analysis the risk factors included medical and demographic variables, and in infants <3 mo of age at hospitalization, two aspects of innate immunity: mannose-binding lectin (MBL) concentration and maternal RSV serum antibody titre, measured on eluates from stored dried blood from the infants' 4th day of life. The effect of each risk factor is expressed as an odds ratio, corresponding to the relative risk of being a case rather than a control if the risk factor is present.
Results:
The following independent risk factors were identified: age, sex, month of birth, gestational age, birthweight, presence of a sibling, up to 5 y older than the case, and maternal smoking during pregnancy. There was a marginal effect of maternal RSV antibody levels, but no effect of neonatal serum MBL concentration or of crowding in the household.
Conclusions:
Ninety percent of cases and 80% of controls had one or more risk factors. Even though several factors were found to increase the risk for hospitalization for RSV disease, all the effects were small and no single specific factor could be identified to explain the hospitalization of the minority of children with RSV infection.
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