Vaccination status and severity of pertussis among hospitalized pediatric patients at a tertiary center in Riyadh: an exploratory study
摘要
Pertussis remains a clinically significant vaccine-preventable respiratory infection, with the greatest morbidity concentrated in young infants who are not yet eligible for, or have not yet completed, the primary pertussis-containing vaccine series. Despite established immunization programs, hospitalizations continue to occur, and locally generated evidence is needed to describe clinical severity, complications, and healthcare utilization among admitted children.
ObjectiveTo describe the clinical characteristics, in-hospital management, and outcomes of children hospitalized with PCR-confirmed pertussis at King Saud Medical City (KSMC), Riyadh, and to explore unadjusted associations between pertussis vaccination status and severity-related outcomes.
MethodsA retrospective exploratory chart review was conducted among children aged 0–14 years hospitalized with PCR-confirmed pertussis between 2023 and 2025. Disease severity was classified using an operational Pertussis Severity Score (PSS), with PSS > 5 indicating severe disease. Descriptive statistics summarized demographic characteristics, clinical presentation, laboratory findings, management, and outcomes. Unadjusted exploratory analyses were performed to assess associations between vaccination status and categorical severity-related outcomes using Pearson’s chi-square test or Fisher’s exact test, as appropriate. Effect estimates were reported with 95% confidence intervals where applicable.
ResultsThe study included 50 children with a median age of 2.0 months (IQR 1.0–3.0); 50.0% were male. Common clinical features included cough (94.0%), paroxysms (88.0%), cyanosis (70.0%), recurrent apnoea (64.0%), vomiting (64.0%), hypoxemia (58.0%), and pneumonia (40.0%). Most patients had no documented pertussis-containing vaccine dose at admission (86.0%). Severe pertussis (PSS > 5) was identified in 52.0% of cases; 58.0% required oxygen therapy and 54.0% required ICU admission. In-hospital mortality occurred in 20.0% of admissions, reflecting the high-acuity tertiary referral setting. In unadjusted exploratory Fisher’s exact analysis, severe pertussis occurred in 25 of 43 children with no documented pertussis-containing vaccine dose before admission compared with 1 of 7 children with at least one documented dose (58.1% vs. 14.3%; OR = 8.33, 95% CI: 0.92–75.36; p = 0.045). This association was borderline and imprecise, as reflected by the wide confidence interval.
ConclusionHospitalized pertussis at KSMC primarily affected very young infants and was characterized by substantial clinical severity, high ICU utilization, and notable in-hospital mortality within this tertiary referral setting. Children with no documented pertussis-containing vaccine dose were over-represented among severe cases; however, this unadjusted exploratory finding should be interpreted cautiously because age and vaccination eligibility were closely related in this very young admission sample. Larger prospective studies are needed to clarify vaccination-related predictors of pertussis severity while accounting for age eligibility and other potential confounders.