Introduction: A resurgence of pertussis has been reported in numerous countries. This study aimed to determine the incidence, clinical characteristics, and outcome of pertussis among infants in Sarawak, Malaysia.
Methodology: We conducted a descriptive retrospective study of infants aged < 12 months with laboratory-confirmed pertussis admitted to Bintulu Hospital in Sarawak, Malaysian Borneo, from 2015 until 2021. Pertussis was confirmed in all patients using a polymerase chain reaction of nasopharyngeal aspirates.
Results: Of 588 infants who had a nasopharyngeal aspirate, 108 (18%) had laboratory-confirmed pertussis. The average annual incidence was 482 per 100,000 infants aged < 12 months between 2015 and 2019, with a marked decline in 2020 and 2021. Eighty-two (76%) were < 3 months of age. Seventy-eight (72%) were unvaccinated for pertussis, including 75 (96%) who were too young to receive the first dose. A third of the cases had atypical presentations. Severe disease characterized by hypoxemia, pulmonary hypertension, recurrent apnea, encephalopathy, or cardiovascular dysfunction occurred in 32%. Forty-eight percent required humidified high-flow nasal cannula oxygen therapy and 22% required invasive ventilation. Twenty-four percent overall needed intensive care. One (1%) infant had a fatal outcome. Nearly all cases of severe disease or those that required invasive ventilation or intensive care had received ≤ 1 dose of pertussis vaccination.
Conclusions: A high incidence of pertussis with a high rate of severe disease was observed in Sarawak, Malaysia, predominantly among infants too young to be vaccinated. Additional vaccination strategies such as maternal vaccination or cocooning should be considered.
Keywords: Bordetella pertussis; Malaysia; Pertussis; infants; vaccination; whooping cough.
Copyright (c) 2024 Anand Mohan, Yee-Yen Tan, Rohaidah Hashim, David Chun-Ern Ng, Veronica Huey-Shin Wong, Da-Wei Liew, Su-Lin Chien, Lee-See Tan, Peter Sie-Teck Lau, Thilagam Rajandran, Yuwana Podin, Mong-How Ooi.