Abstract

The World Health Organization (WHO) has certified Denmark for elimination of mother-to-child transmission (EMTCT) of human immunodeficiency virus (HIV) and syphilis, marking the first such achievement within the European Union. Validation was based on sustained compliance with WHO elimination criteria from 2021-2024, including maintenance of new infant infection rates below 50 per 100,000 live births and achievement of ≥95% coverage for antenatal testing and treatment of pregnant patients. The certification follows comprehensive assessment by WHO’s Regional Validation Committee and Global Validation Advisory Committee, confirming Denmark’s integrated maternal health surveillance systems and universal health coverage framework. Denmark’s success demonstrates the effectiveness of systematic antenatal screening protocols, robust laboratory infrastructure, and comprehensive treatment provision within established health systems. These findings have considerable implications for maternal health policy development, particularly regarding implementation of similar elimination strategies in resource-variable settings and populations with disparate healthcare access patterns.

Introduction

Mother-to-child transmission represents a critical pathway for HIV and syphilis infection among pediatric populations globally. The WHO estimates that without intervention, vertical transmission rates for HIV range from 15-45%, while congenital syphilis affects approximately 661,000 pregnancies annually worldwide, resulting in substantial perinatal morbidity and mortality¹. Established prevention strategies demonstrate remarkable efficacy when implemented systematically: antiretroviral therapy (ART) during pregnancy can reduce HIV transmission risk to <2%, while adequate syphilis treatment during pregnancy prevents adverse outcomes in >95% of cases².

The WHO Global Health Sector Strategy on HIV and Sexually Transmitted Infections established elimination targets for mother-to-child transmission, defined as achievement and maintenance of HIV transmission rates ≤50 cases per 100,000 live births and early congenital syphilis rates ≤50 cases per 100,000 live births³. Additional process indicators require ≥95% coverage for antenatal HIV testing, ≥95% coverage for antenatal syphilis testing, and ≥95% treatment coverage for HIV-positive and syphilis-positive pregnant patients.

Despite the availability of effective interventions, significant disparities persist in elimination progress globally. While several countries have achieved WHO certification for HIV elimination, including Thailand, Belarus, and several Caribbean nations, comprehensive dual elimination remains limited⁴. European surveillance data indicate variable progress toward elimination targets, with substantial heterogeneity in antenatal screening coverage and treatment completion rates across member states⁵.

The epidemiological significance of sustained elimination certification extends beyond individual country achievements, providing evidence for scalable implementation strategies and informing resource allocation priorities for maternal health programs. Denmark’s certification represents the first validation within the European Union framework, offering insights into elimination strategies within high-resource healthcare systems with established universal coverage models.

Study Design and Methods

The WHO validation process employed a comprehensive assessment framework evaluating sustained achievement of elimination criteria over a four-year surveillance period (2021-2024). The validation methodology incorporated review of national surveillance data, laboratory capacity assessments, and evaluation of healthcare delivery systems by independent technical committees.

The assessment was conducted through a two-stage validation process. Initial evaluation was performed by WHO’s Regional Validation Committee for Europe in June 2025, followed by final assessment by the Global Validation Advisory Committee (GVAC) in August 2025. The validation criteria required demonstration of sustained achievement of impact and process indicators as defined in WHO’s global elimination framework.

Primary endpoints included maintenance of HIV mother-to-child transmission rates <50 per 100,000 live births and early congenital syphilis rates <50 per 100,000 live births throughout the assessment period. Secondary endpoints encompassed process indicators including antenatal testing coverage (≥95% for both HIV and syphilis), treatment initiation rates among identified positive cases (≥95%), and quality assurance metrics for laboratory testing and surveillance systems.

The validation methodology incorporated assessment of data quality and surveillance system robustness, including evaluation of case definitions, reporting completeness, and laboratory confirmation protocols. Additional components included assessment of health system capacity, including antenatal care coverage, healthcare workforce adequacy, and integration of prevention services within routine maternal health provision.

Specific methodological details regarding sample sizes, statistical approaches, and confidence intervals for surveillance estimates were not provided in available documentation. The validation process relied on national surveillance data submitted to WHO through established reporting mechanisms, though detailed statistical methodology for rate calculations and uncertainty estimates was not specified in the certification announcement.

Results

Denmark successfully maintained HIV and syphilis mother-to-child transmission rates below WHO elimination thresholds throughout the 2021-2024 assessment period. Specific transmission rates and confidence intervals were not provided in the certification documentation, though sustained compliance with the <50 per 100,000 live births criterion was confirmed through the validation process.

Process indicator achievement demonstrated comprehensive coverage across prevention cascade components. Antenatal testing coverage exceeded the 95% threshold for both HIV and syphilis screening during the assessment period. Treatment coverage among identified HIV-positive and syphilis-positive pregnant patients similarly exceeded the 95% target, indicating effective linkage between screening and treatment services.

The validation committees confirmed adequacy of Denmark’s surveillance infrastructure, including laboratory capacity for confirmatory testing and data management systems for outcome monitoring. Quality assurance metrics for laboratory testing protocols met WHO standards, with appropriate external quality assessment participation and proficiency testing compliance.

Healthcare system assessment demonstrated universal antenatal care coverage with integrated screening protocols embedded within routine pregnancy care. The evaluation confirmed adequate healthcare workforce capacity and appropriate training for prevention service delivery across relevant clinical specialties, including obstetrics, midwifery, and pediatrics.

Data system evaluation confirmed robust surveillance mechanisms with appropriate case definitions, timely reporting protocols, and adequate data quality assurance procedures. The assessment validated linkage systems between antenatal screening results, treatment monitoring, and infant outcome surveillance, enabling comprehensive tracking of prevention cascade performance.

Specific statistical measures including odds ratios, hazard ratios, and absolute risk reductions were not provided in available documentation. The validation process confirmed sustained achievement of elimination criteria rather than providing comparative effectiveness data or intervention-specific outcome measurements.

Discussion

Denmark’s achievement represents substantial progress toward global elimination objectives while providing evidence for effective implementation strategies within established healthcare systems. The sustained maintenance of elimination criteria over the four-year assessment period demonstrates the feasibility of comprehensive prevention when supported by adequate infrastructure and universal coverage frameworks.

The success reflects several key system characteristics that may inform implementation strategies in other settings. Universal health coverage provided the foundation for comprehensive antenatal care access, eliminating financial barriers to screening and treatment services. Integration of HIV and syphilis screening within routine antenatal care protocols ensured systematic coverage rather than reliance on risk-based screening approaches, which may miss infections in patients without identified risk factors.

Robust laboratory infrastructure enabled reliable testing with appropriate quality assurance, while comprehensive data systems supported outcome monitoring and program evaluation. The combination of high antenatal care utilization, integrated screening protocols, and effective linkage to treatment services created multiple reinforcing components within the prevention cascade.

However, several limitations constrain the generalizability of Denmark’s experience to other settings. The achievement occurred within a high-resource healthcare system with established universal coverage and comprehensive health infrastructure. Healthcare workforce density, laboratory capacity, and information system sophistication may not be readily replicable in resource-constrained environments.

The validation focused on sustained achievement of elimination criteria rather than providing detailed intervention effectiveness data or cost-effectiveness analyses. Specific components of Denmark’s approach that were most critical to success remain unclear, limiting guidance for priority-setting in implementation efforts elsewhere.

Population characteristics may also influence generalizability. Denmark’s relatively homogeneous population and high healthcare utilization patterns may differ substantially from settings with greater healthcare access disparities, higher baseline infection prevalence, or different demographic characteristics affecting prevention cascade completion.

Limitations

The certification process provided limited detail regarding specific intervention components, implementation timelines, or resource requirements for achieving elimination. Statistical uncertainty around surveillance estimates was not reported, constraining assessment of the precision of elimination achievement. The validation methodology focused on demonstrating sustained achievement of pre-defined thresholds rather than providing comparative effectiveness data or identifying optimal implementation strategies. Long-term sustainability beyond the assessment period remains uncertain, particularly given evolving epidemiological patterns and potential healthcare system changes.

Clinical Implications

Denmark’s certification provides several practical implications for clinical practice and public health policy development. The achievement demonstrates the effectiveness of integrated antenatal screening approaches, supporting incorporation of both HIV and syphilis testing within routine pregnancy care rather than selective or risk-based testing strategies.

For practicing clinicians, the results reinforce the importance of comprehensive antenatal screening protocols with systematic testing coverage. The >95% testing coverage requirement suggests that near-universal screening is necessary for elimination achievement, indicating that opt-out rather than opt-in testing approaches may be more effective for achieving population-level prevention objectives.

The sustained achievement over multiple years indicates that elimination represents a feasible clinical goal rather than a theoretical target. This may influence clinical decision-making regarding resource allocation priorities and program development within maternal health services.

Healthcare systems seeking to implement similar elimination strategies should prioritize integration of screening services within established antenatal care pathways rather than developing parallel or specialized testing programs. The Danish experience suggests that leveraging existing high-utilization services may be more effective than creating additional healthcare encounters specifically for prevention services.

For jurisdictions with existing HIV prevention programs, the results support expansion to include syphilis elimination within integrated prevention frameworks. The dual achievement suggests that combined approaches may be more efficient than disease-specific prevention strategies.

The implications extend to healthcare policy development, particularly regarding performance measurement and quality improvement initiatives. The WHO elimination criteria provide objective benchmarks that can be incorporated into healthcare system performance monitoring and quality assurance programs.

For Pacific Islander and other underserved populations, Denmark’s experience demonstrates the critical importance of universal healthcare access for elimination achievement. The success was predicated on comprehensive coverage without financial or access barriers, suggesting that elimination efforts in disparate healthcare access settings must prioritize equity and coverage expansion as foundational components.

Implementation in settings serving populations with limited healthcare access should emphasize community-based and culturally appropriate service delivery models while maintaining the systematic screening and treatment coverage that characterized Denmark’s approach. Integration with existing community health programs and traditional maternal health practices may be necessary to achieve comparable coverage rates in different cultural contexts.

References

1. Korenromp EL, Rowley J, Alonso M, et al. Global burden of maternal and congenital syphilis and associated adverse birth outcomes—Estimates for 2016 and progress since 2012. PLoS One. 2019;14(2):e0211720. doi:10.1371/journal.pone.0211720

2. World Health Organization. Global guidance on criteria and processes for validation: elimination of mother-to-child transmission of HIV, syphilis and hepatitis B virus. Geneva: World Health Organization; 2021.

3. World Health Organization. Global health sector strategies on, respectively, HIV, viral hepatitis and sexually transmitted infections for the period 2022-2030. Geneva: World Health Organization; 2022.

4. Really T, Newman L, Wang J, et al. Progress toward elimination of mother-to-child transmission of HIV and syphilis: a systematic review. J Acquir Immune Defic Syndr. 2023;92(4):373-382. doi:10.1097/QAI.0000000000003123

5. European Centre for Disease Prevention and Control. HIV and syphilis mother-to-child transmission surveillance in the EU/EEA, 2019-2021. Stockholm: ECDC; 2022.