Epidemiology and Healthcare Burden Attributable to Laboratory-Confirmed RSV Cases Among Children Under Five Years Old in Saudi Arabia

INTRODUCTION

• RSV, a major pediatric healthcare burden globally and in Saudi Arabia, accounts for >60% of acute respiratory infections in young children and >80% in infants <1 year of age worldwide, with 15%-50% of LRTI infections in infants attributed to RSV.^1,2
• While regional RSV data remains scarce, MENA region has reported a higher RSV prevalence (24.4% vs. 22% globally) with cases predominantly occurring in winter and disproportionately affecting infants under one year of age.³
• This underscores the urgent need for updated epidemiological data to inform effective prevention strategies in Saudi Arabia.

OBJECTIVE

This study aims to assess the clinical and healthcare burden attributable to laboratory-confirmed RSV cases among children <5 years old in Saudi Arabia, with particular focus on infants aged 0–11 months.

METHODS

Study Design And Setting

• This descriptive, observational study conducted across 5 MNGHA facilities in Saudi Arabia: Riyadh (576 beds), Jeddah (170 beds), Al-Ahsa (67 beds), Al-Madinah (65 beds), and Dammam (34 beds), along with 71 affiliated PCCs.

Study population

• Children ≤5 years with documented RSV testing (January 2018–December 2023) were included in the study.

Data source and endpoints

• Data was collected from the MNGHA BESTCare^® database
• The primary endpoint was RSV-associated hospitalization rate; secondary endpoints include    ICU admission rates, length of stay, case-fatality rate, age-specific prevalence, and risk factors for hospitalization.
• The analysis stratified across pre-pandemic (2018–2019), pandemic (2020–2021), and post-pandemic (2022–2023) periods.

Statistical analysis

Descriptive statistics other statistical tests: chi-square test, Fisher's exact test, t-test or analysis of variance

RESULTS

• Out of 44,632 children with ARI symptoms, 34,957 (78.3%) children were tested and 7,371 (21.09%) tested were RSV-positive (median age 10 months; IQR 3.5–23.5). (Table 1)
• Infants <12 months accounted 55% of cases (36.6% in those <6 months).
• RSV-positive children had significantly higher hospitalization proportion than RSV-negative children (63.2% vs 26.2%, p<0.001). (Figure 1)

Table 1: Demographics and baseline characteristics

*Percentages are rounded off to their nearest values. IQR: Interquartile Range; n: Number; RSV: Respiratory Syncytial Virus

Figure 1: Seasonal Variation in confirmed cases Comparison with hospital admissions, 2018-2023 in children <5 years

RSV-associated hospitalization

• Hospitalization proportions remained consistently high across all age groups, with infants demonstrating particularly elevated rates: 63.5% in those <1 month, 62.9% in 1-3 months, and 59.2% in 3-6 months age groups. (Table 2)
• In pre-pandemic years, with clear winter seasonality, hospital admission rates were relatively stable (23%–28%) but spiked in the first two years following the pandemic.
• The highest proportion of admissions was observed in 2022, followed by 2021 (off-season resurgence after 2020 suppression) and 2023. (Figure 1)

Clinical burden and risk factors

• Infants (<1 month) had the highest ICU admission rate at 6.7% (mean LOS: 8.0-17.7 days), which progressively decreased with age to 0.7% in the 18-24 months group. (Table 2)
• RSV-related 30-day case-fatality was 0.3%.
• Age <2 months (OR 2.83; 95% CI 2.20–3.64) and underlying comorbidities (OR 5.02; 95% CI 3.36–7.50) independently predicted hospitalization. Notably, most hospitalized children were previously healthy.

Table 2: RSV-positive hospital admissions (N, %) categorized by age group

^*Percentages are rounded off to their nearest values. ICU: Intensive Care Unit; LOS: Length of Stay; n: Number; N: Total number; RSV: Respiratory Syncytial Virus; SD: Standard Deviation

Clinical burden and risk factors

• In Saudi Arabia, RSV typically peak during the winter months, particularly from November to February.
• Factors associated with a higher individual risk of hospitalization include comorbidities and infant age.
• However, majority of the RSV-associated hospitalizations occurred in infants < 1 year and previously healthy
• This underlines the importance of universal RSV prevention strategies targeting all infants in Saudi Arabia and considering the seasonal patterns of virus transmission.