Active Public Health Outbreaks in the WHO Americas Region
As of late 2024, the Pan American Health Organization (PAHO) region is navigating a complex "polycrisis" of simultaneous outbreaks. While Dengue has shattered historical records with over 11 million cases, the region faces the emergence of Oropouche virus in new territories, the northward spread of New World Screwworm, and the precarious resurgence of Measles threatening the region's elimination status.
CRITICAL Dengue: A Record-Breaking Year
2024 is the worst year on record for Dengue in the Americas. PAHO reports an unprecedented surge, driven by climate factors and urbanization. Cases have exceeded 11 million, more than double the total for all of 2023. Brazil accounts for the vast majority of the burden, but significant outbreaks are active in Argentina, Peru, and Colombia.
Dengue Cases: 2024 vs. Historical Average
*Data reflects suspected and confirmed cases reported to PAHO as of late 2024. Simultaneous circulation of all four serotypes (DENV-1, 2, 3, 4) has been detected in Brazil, Costa Rica, Guatemala, Honduras, Mexico, and Panama.
Oropouche Virus Expansion
Historically confined to the Amazon basin, Oropouche virus has expanded significantly in 2024. Cuba reported its first-ever outbreak, leading to travel-associated cases in the US and Europe.
- ? Total Cases: >11,600 confirmed (Brazil, Bolivia, Peru, Colombia, Cuba).
- ? New Risk: Vertical transmission confirmed in Brazil (fetal deaths & congenital anomalies).
- ? US Impact: >90 imported cases (mostly Florida residents returning from Cuba).
Yellow Fever Resurgence
Activity has increased in late 2024, with cases appearing in non-traditional areas, raising concerns about urban spillover.
- ? Hotspots: Colombia (Tolima), Brazil (São Paulo), Peru, Bolivia.
- ? Stats: ~50-60 confirmed cases, with a high case fatality rate (~40-50%).
- ? Alert: PAHO issued an alert in late 2024 regarding the spread to areas outside the Amazon basin.
Measles: Threat to Elimination Status
The Americas, once declared measles-free, is facing a resurgence. In 2024, over 14,000 suspected cases were reported. The US and Canada have seen significant clusters, largely driven by unvaccinated travelers and pockets of low immunization.
| Country | Confirmed Cases (2024 Est.) | Primary Driver |
|---|---|---|
| United States | 270+ | Imported cases & unvaccinated clusters |
| Canada | 140+ | Community transmission in Quebec/Ontario |
| Argentina | 10+ | Imported (Europe/Asia) |
| Bolivia | < 5 | Re-introduction risk |
Emerging & Migrating Threats
New World Screwworm
A major veterinary and public health setback. After decades of control, the parasite has migrated north from Panama, through Central America, reaching Mexico (Chiapas) in November 2024. The US has halted some cattle imports from Mexico in response.
Mpox (Clade Ib)
While Clade IIb cases have declined, the more severe Clade Ib (the focus of the global emergency) was detected in the Americas for the first time in late 2024. Single travel-related cases were confirmed in the United States and Canada (travelers from East Africa).