Outbreak of Pertussis in Ajdabiya among infants under one year old: Epidemiology, vaccination status and disease severity

Abstract

Pertussis, commonly known as whooping cough, remains a significant global public health challenge, with infants under one year old facing the highest risk of severe complications and mortality. This retrospective descriptive study aimed to analyze the epidemiology, vaccination status, and disease severity during a pertussis outbreak in Ajdabiya, Libya, from October 2025 to April 2026. The study included 65 infants diagnosed with pertussis at the Central Hospital of Ajdabiya. Data were collected from medical records and laboratory results and analyzed using SPSS. The results revealed that infants under three months old were the most affected (70.8%). A substantial immunity gap was identified, as 100% of the infants' mothers had not received the Tdap vaccine during pregnancy, and 69.2% of the infants were unvaccinated. Clinical analysis showed that 87.7% of infants exhibited paroxysmal coughing, while 60% experienced life-threatening apnea and cyanosis. Malignant pertussis occurred in 20% of cases, with mortality reaching 10.8%. Statistical analysis indicated a strong correlation between the quality of supportive care and survival outcomes (p=0.000, Spearman correlation=0.815). The findings underscore the critical vulnerability of newborns due to the absence of maternal antibodies and delayed primary vaccination. The study strongly recommends incorporating the Tdap vaccine into the national immunization program for pregnant women, alongside strict adherence to vaccination schedules and the implementation of standardized supportive care protocols to reduce morbidity and mortality in resource-limited settings.