RSV Enters the Airway — How Infection Begins
RSV attaches to ciliated respiratory epithelial cells and starts spreading.
- 4–6 days: Incubation period (placeholder timing figure)
- Fall–winter: Peak season (placeholder seasonal note)
- Epithelium: Primary target (placeholder cell type)
- Droplet/contact: Transmission (placeholder route)
Viral attachment and early replication
RSV fusion protein binds host receptors and triggers cell entry.
Local spread within the respiratory tract
Infection spreads from upper to lower airway over several days.
Age strongly shapes where and how severely RSV spreads next.
Bronchiolitis in Infants — Small Airways, Big Consequences
Infant airways are narrow, so mucus and swelling block airflow easily.
- 2–6 months: Peak age (placeholder age range)
- Small: Airway diameter (placeholder anatomic note)
- Wheezing: Key sign (placeholder clinical sign)
- Self-limited: Common outcome (placeholder outcome note)
Mucus plugging and airway narrowing
Inflammatory debris and mucus obstruct already-narrow infant airways.
Work of breathing increases
Infants show retractions and rapid breathing as obstruction worsens.
Severe plugging can trap air and impair oxygen exchange quickly.
RSV Pneumonia in Older Adults — Alveolar Consolidation
In elderly patients RSV can descend deep into alveoli causing pneumonia.
- 65+ years: Higher risk age (placeholder age threshold)
- Consolidation: Key finding (placeholder imaging note)
- COPD/CHF: Comorbidity link (placeholder comorbidity note)
- Elevated: Case fatality (placeholder mortality note)
Alveolar fluid accumulation
Fluid and inflammatory cells fill alveolar spaces reducing gas exchange.
Reduced reserve in older lungs
Aging lungs and comorbidities limit compensation for lost function.
Underlying heart or lung disease compounds RSV pneumonia severity.
Risk Factors That Amplify RSV Severity
Prematurity, COPD, and heart disease each raise hospitalization odds.
- High risk: Prematurity (placeholder infant factor)
- High risk: COPD (placeholder elderly factor)
- High risk: Heart disease (placeholder elderly factor)
- High risk: Immunosuppression (placeholder shared factor)
Infant-specific risk contributors
Prematurity and congenital heart disease worsen infant RSV outcomes.
Elderly-specific risk contributors
COPD, heart failure, and frailty worsen elderly RSV outcomes.
Risk factor burden scales hospitalization risk in the simulator directly.
Determining Overall Hospitalization Risk
Age group and risk burden combine into a final hospitalization estimate.
- <40%: Low risk band (placeholder threshold)
- 40–70%: Enhanced band (placeholder threshold)
- >70%: ICU band (placeholder threshold)
- 2 sliders: Model inputs (placeholder input count)
Combining age and risk burden
The simulator blends age group and risk score into one gauge.
Monitoring level recommendation
Higher combined risk triggers escalated monitoring recommendations automatically.
This mirrors how clinicians weigh age and comorbidities together.