Epidemiological & demographic trends of Haemophilus influenzae in Malaysia's southern region: data insights from tertiary level hospital and nearby facilities.

INTRODUCTION

Haemophilus influenzae (HI) is a significant pathogen responsible for respiratory and invasive infections globally. Following the introduction of the Haemophilus influenzae serotype B (Hib) vaccine in Malaysia in 2002, cases of Hib-related diseases declined sharply. Still, the prevalence of nontypeable Haemophilus influenzae (NTHi) emerged as a public health concern. This study investigates epidemiological and demographic patterns of HI infections in Malaysia's southern region.

MATERIALS AND

METHODS

Clinical isolates of HI were recovered during routine diagnostic testing and analysed from June 2023 to December 2024. All isolates were identified using conventional laboratory methods, biochemical assays, and Matrix-Assisted Laser Desorption/Ionisation Time-of-Flight Mass Spectrometry (MALDI-TOF MS). Confirmatory serotyping was outsourced to the National Public Health Laboratory in Sungai Buloh, Selangor. Epidemiological trends were assessed based on demographics, sample types, and seasonal variations.

RESULTS

A total of 281 samples were analysed. NTHi accounted for 96.5% of isolates, with sputum as the dominant sample type (56.4%). Infants and elderly individuals constitute the most vulnerable groups. Peaks in sample submissions correlated with monsoon seasons. Foreign nationals had disproportionately higher mortality rates, reflecting challenges in vaccination access.

CONCLUSION

The study underscores the dominance of NTHi infections in post-Hib vaccination settings in Malaysia. Seasonal trends and demographic disparities emphasise the need for tailored public health interventions and infrastructure strengthening to reduce the burden of HI infections.