Equity gaps in neglected tropical disease research in Malaysia: a systematic review, 2014-2024.

backgroundNeglected tropical diseases (NTDs) disproportionately affect marginalised populations, yet the distribution of research attention across pathogens, populations, and settings remains uneven. Malaysia, a middle-income country with strong research capacity and a diverse NTD burden, provides an important case for examining research equity. This review aimed to systematically map NTD research in Malaysia and identify equity gaps across pathogens, population groups, study designs, and geographic settings.

methodsWe conducted a systematic review in accordance with PRISMA guidelines. The Web of Science Core Collection was searched for peer-reviewed studies published between 1 January 2014 and 31 December 2024. Eligible studies reported human NTD data from Malaysia and addressed infectious NTDs of viral, bacterial, helminthic, or protozoal aetiology. Data were extracted on publication characteristics, study design, population age groups, settings, geographic location, and pathogen category. Descriptive analyses, visualisation techniques, and chi-square tests were used to assess equity patterns.

resultsA total of 336 studies were included. Viral and bacterial infections accounted for more than two-thirds of publications, while helminthic and protozoal infections were consistently underrepresented. Among studies reporting age information, adults and adolescents were most frequently studied, whereas children were comparatively underrepresented; however, age was not specified in 35% of studies. Most research employed observational or cross-sectional designs, with few interventional or outbreak-focused studies. Research output was geographically concentrated in urban and high-density states, with limited coverage of rural and indigenous settings. Population–pathogen inequities were statistically significant (χ² = 51.22, df = 9, p < 0.0001).

conclusionsNTD research in Malaysia is characterised by substantial research equity gaps, including pathogen bias towards outbreak-driven diseases, inadequate demographic reporting, limited interventional evidence, and urban-centred research visibility. These inequities in knowledge production may reinforce downstream health inequities by constraining evidence-informed and equity-sensitive policy responses. Addressing these gaps will require rebalancing research priorities towards neglected pathogens and populations, strengthening reporting standards, and aligning national research agendas with the equity principles of the WHO NTD Roadmap 2021–2030.