Diphtheria in Critical Care: A Retrospective Case Series (2020-2024) From Pakistan

Introduction: Diphtheria remains a life-threatening illness in low-resource settings, especially where vaccine coverage is low and diphtheria antitoxin (DAT) is not reliably available. Severe cases often require pediatric intensive care due to airway obstruction, myocarditis, and organ failure. We aimed to describe the clinical features, management, and outcomes of children with diphtheria admitted to a PICU in Pakistan.


Methods: We retrospectively reviewed medical records of patients aged 0–18 years admitted to the PICU with diphtheria between January 2020 and November 2024. Eighteen cases were identified; 15 records were available. Seven patients were referred from the emergency department and 8 from outside hospitals. Eleven were unvaccinated, 2 had received primary immunization without boosters, and 2 had unknown status. Fourteen patients were intubated; the only survivor was not. Intubations occurred in the OR (n=8), ER (n=3), bedside (n=1), pre-transfer (n=1), and unspecified (n=1). One patient died during a complicated ER intubation with no further workup.


Results: Of the 15 patients reviewed, 14 died and 1 survived (case fatality rate: 93.3%). Median age was 7 years (range: 1–14); 7 were girls and 8 boys. Median PICU stay was 3 days (range: 1–11). The diagnosis was confirmed in all cases by the isolation of Corynebacterium diphtheriae from throat swabs. The median time from symptom onset to DAT administration was 3 days (range, 1-6 days). Immunization history revealed that 12 patients (80%) were either unimmunized or had an incomplete vaccination history.
Diphtheritic myocarditis was the most common severe complication, affecting 12 patients all of whom were unimmunized. Of 12 with myocarditis, 9 died.


Conclusions: Despite treatment with antitoxin and antibiotics, mortality remained extremely high, primarily due to cardiac complications. Strengthening national vaccination policy, improving immunization coverage, and ensuring reliable DAT availability are urgent priorities in preventing fatal outcomes from diphtheria. Early integration of palliative care should be considered to improve comfort and support families when curative treatment is unlikely. These findings underscore the need for health system preparedness to manage preventable infectious diseases with critical care potential.