What is PAHO and how does it relate to WHO?: PAHO is the Pan American Health Organization, the WHO's regional office for the Americas. Founded in 1902, it coordinates disease surveillance and outbreak response across 35 member states.
Did PAHO warn about hantavirus before the MV Hondius outbreak?: Yes. PAHO issued an Epidemiological Alert on 19 December 2025 flagging elevated Southern Cone hantavirus cases with increased lethality, five months before the MV Hondius cluster surfaced.Source: PAHO
How many H5N1 human cases has PAHO recorded in the Americas?: PAHO logged 75 cumulative human H5N1 cases in the Americas since April 2022, 2 deaths, in 5 countries, with no new human case reported since 24 November 2025.Source: PAHO Epidemiological Update, 11 March 2026
Why does PAHO's hantavirus alert matter for Antarctic tourism?: The December 2025 alert flagged elevated Andes-virus risk in Patagonia, the departure zone for Antarctic cruises. Operators who read it should have briefed passengers before boarding in Ushuaia.Source: PAHO

Background

PAHO (Pan American Health Organization) is the WHO's regional office for the Americas, headquartered in Washington, D.C. Founded in 1902 as the International Sanitary Bureau, it is the world's oldest international health organisation, predating WHO itself. PAHO coordinates public health surveillance, outbreak response, vaccine procurement, and health systems strengthening across 35 member states in North, Central, and South America, and the Caribbean. Its Epidemiological Alert and update system is the primary formal channel through which WHO-tier risk assessments reach the Americas. PAHO operates through a network of country offices and works with national ministries of health, providing technical guidance, laboratory support, and early-warning bulletins on emerging infectious disease.

PAHO issued an Epidemiological Alert on 19 December 2025 warning of elevated hantavirus cases across the Southern Cone, with increased lethality in some countries; Argentina's caseload ran at roughly twice the prior year's rate. That alert sat unacted-on for five months before the MV Hondius sailed from Ushuaia in early 2026, carrying passengers into Andes-virus-endemic Tierra del Fuego. PAHO also issued an H5N1 update on 11 March 2026 logging 75 cumulative human cases in the Americas since 2022, across 5 countries, with no new human case since 24 November 2025. On 14 April 2026 PAHO expanded a partnership with CEPI for regulatory and vaccine-safety capacity in the Americas, part of the H5N1 mRNA preparedness effort.

Source Material

PAHO — Official Website Pan American Health Organization

How the World Sees Them

Latin America

PAHO is the primary formal health channel for the region; its December alert carried direct operational implications for Argentine provincial health authorities and port operators in Ushuaia.

United States

PAHO is hosted in Washington and its alerts feed into CDC situational awareness; the gap between the December warning and cruise-operator action reflects a broader advisory-to-industry communication failure.

European Union

EU travellers aboard MV Hondius were covered retrospectively by ECDC monitoring; PAHO's original alert did not reach European travel health agencies before departure.

Global health community

PAHO's December 2025 alert demonstrates that early-warning systems are functioning; the failure was in translating institutional alerts into operator-level biosecurity action.