# Factors associated with pertussis infection and suspected cases in the Aseer Region, Saudi Arabia: a retrospective cross-sectional analysis study

## TL;DR

This study examines factors linked to pertussis in children in Saudi Arabia's Aseer region, finding low vaccination rates and a resurgence in 2024.

## Contribution

The study identifies low maternal Tdap vaccination and infant vaccination coverage as key factors in pertussis resurgence in the Aseer region.

## Key findings

- 41.5% of suspected pediatric cases tested positive for pertussis, with infants under four months being most affected.
- Maternal Tdap vaccination significantly reduced pertussis positivity rates (38.9% vs. 77.8%).
- Pertussis positivity dropped in 2022 but surged to 69.3% in 2024, indicating a recent resurgence.

## Abstract

Pertussis is a major cause of vaccine-preventable morbidity and mortality in children globally. In Saudi Arabia, the incidence has risen despite high immunization rates and maternal Tdap recommendations. This study aims to identify the incidence and key factors associated with laboratory-confirmed pediatric pertussis in the Aseer region from 2020 to 2024.

A retrospective analysis was conducted on suspected pediatric pertussis cases at Sarat Ubaida General Hospital, Aseer region, from 2020 to 2024. Data from medical records included age, gender, vaccination history, symptoms, and lab results. Descriptive statistics summarized characteristics, with Chi-square and Fisher's Exact tests for comparisons, and multivariable logistic regression for adjusted odds ratios (95% CI).

Of 388 suspected cases, 41.5% tested positive. Infants under four months made up 58.3% of cases, and males accounted for 51.3%. Fewer than 42% had received any pertussis vaccine, with only 28.6% of mothers receiving Tdap in the third trimester. Annual positivity dropped from 37.1% in 2020 to 5.9% in 2022, then rose to 69.3% in 2024. Maternal Tdap immunization significantly reduced positivity rates: 38.9% in unvaccinated mothers compared to 77.8% in vaccinated mothers (p = 0.003). Classic respiratory symptoms helped distinguish positive from negative cases.

Pediatric pertussis in the Aseer region has seen low vaccination coverage and a resurgence in 2024, especially in infants under four months. It's crucial to boost maternal Tdap uptake, improve infant vaccination access, target low-coverage communities, and maintain surveillance to monitor trends and vaccine effectiveness.