Global Dengue Observatory Launched as Cases Reach Historic Highs

A new international platform, the Global Dengue Observatory, is now operational, providing monthly monitoring of dengue trends across 88 countries. This initiative aims to bolster the global response to a disease that reached unprecedented levels in 2024, with over 14 million cases reported worldwide .

Dengue’s Global Reach and Increasing Threat

Dengue is now endemic in over 100 countries, putting approximately half of the world’s population at risk, according to the World Health Organization (WHO). While traditionally concentrated in tropical regions, outbreaks are increasingly occurring in unexpected locations, including high-altitude cities .

The Global Dengue Observatory: A New Tool for Surveillance

Developed by the London School of Hygiene & Tropical Medicine (LSHTM), the Global Dengue Observatory leverages data from the WHO and LSHTM’s OpenDengue Project to provide a comprehensive view of dengue activity. The platform is intended for use by researchers, policymakers, and the public .

“It could enable those managing programmes, departments and ministries to make better decisions, particularly when the figures show a worrying or escalating situation,” says Tomás Orduna, an infectious diseases specialist at Muñiz hospital in Buenos Aires .

Addressing Delays in Data Reporting

A significant challenge in tracking dengue’s global impact is the time lag between case occurrence and reporting to international databases. Katie Milligan Susong, an infectious diseases researcher at LSHTM, explains that cases must be identified locally, reported to national authorities, and then shared with organizations like the WHO, a process that can accept days or months .

To mitigate this, LSHTM researchers have developed algorithms to estimate the final number of cases, accounting for reporting delays and missing data. Currently, these corrections are applied to data from Latin America, the region most affected by dengue .

Expanding Surveillance and Regional Coordination

The platform currently tracks countries reporting at least five cases per month over the past five seasons, excluding countries with emerging but low case numbers, such as France, and Italy. Doris Kemunto Nyamwaya, an LSHTM expert on Africa, believes the observatory has the potential to significantly strengthen surveillance efforts on the continent .

Orduna suggests that adding features to facilitate regional comparisons could assist neighboring countries coordinate preventive measures .

Record Cases in 2024 and Shifting Dynamics

By the end of February 2025, the observatory recorded 314,783 cumulative dengue cases worldwide, with 235,075 in South America. However, the WHO reported a record 14.6 million dengue cases globally in 2024, a significant increase from the 7 million cases observed in 2023 and .

The WHO attributes this surge to factors including expanding mosquito habitats, climate change, weak health systems, and political instability .

A study in Virology Journal highlights how these dynamics are driving dengue into new environments. In 2024, Cochabamba, Bolivia (2,550 meters above sea level), experienced its largest outbreak to date, demonstrating the virus’s ability to circulate at high altitudes .

Regional Variations and Future Outlook

While Latin America saw a 66% decrease in cases in 2025 (4.4 million cases) due to short-term immunity following the 2024 outbreaks, some countries continue to report high infection levels, including Cuba, Guyana, and Suriname .

Milligan notes that localized spikes underscore the importance of real-time monitoring, as regional averages can mask dangerous local increases .