Mapping the hidden epidemic: A scoping review of sexually transmitted diseases in Southeast Asia

Background: Sexually transmitted diseases (STDs) pose a significant global health challenge, with Southeast Asia bearing a disproportionately high burden due to socio-demographic vulnerabilities, disparities in healthcare access, and prevailing cultural stigmas. Despite growing research interest in the region, a comprehensive synthesis of disease burden, risk factors, and intervention strategies remains limited. Objectives: This study aimed to systematically review research trends, study populations, and pathogen distributions of STDs in Southeast Asia to identify evidence gaps and inform future policy and intervention strategies. Methods: A systematic literature search was conducted using Scopus, Web of Science, and PubMed databases in accordance with PRISMA guidelines. Eligible studies were those focusing on STDs in Southeast Asia and included high-risk populations such as men who have sex with men (MSM), sex workers, youth, heterosexual men and women, transgender individuals, and people living with HIV (PLHIV). The review encompassed key STDs including HIV/AIDS, syphilis, gonorrhea, chlamydia, HPV, trichomoniasis, and hepatitis B & C. Results: From 2,867 records, 58 studies met the inclusion criteria. HIV/AIDS was the most frequently studied STD (80%), while bacterial STDs and transgender populations were significantly underrepresented. Most studies employed cross-sectional designs (60%), with few longitudinal or interventional studies. Geographically, research was concentrated in Malaysia, Thailand, and Singapore, with limited representation from Cambodia, Vietnam, and Indonesia. Discussion: The findings underscore substantial research gaps, particularly in bacterial STDs, studies involving heterosexual and transgender populations, and the application of intervention-based designs. Inconsistencies in reporting standards and population definitions further limit the comparability of findings across studies. Conclusion: This review highlights the need for more inclusive and methodologically diverse research on STDs in Southeast Asia. Future efforts should prioritize standardized data collection frameworks, improved surveillance systems, and greater emphasis on intervention studies to strengthen evidence-based public health responses in the region.