Beyond the Cough: A Rare Case of Severe Pertussis With Hyperleukocytosis in a 30-day-old Malay Infant

Abstract

Pertussis infection can lead to hyperleukocytosis, characterized by a significant increase in white blood cell count. Hyperleukocytosis in pertussis is associated with disease severity and poor outcomes, particularly in young infants. Pertussis leukocytosis is caused by pertussis toxin released by Bordetella pertussis during infection, but the exact mechanisms are still unclear. We present a case of severe pertussis with hyperleukocytosis in a 30-day-old Malay infant, ultimately resulting in fatality due to severe complications. This case illustrates the severity and variability of pertussis in infants, particularly with the rare presentation of hyperleukocytosis. It demonstrates the link between leukocytosis treatment and outcomes, reinforcing the need for early detection and treatment, and highlights the critical role of vaccinations in preventing and mitigating the severity of pertussis infections.