Director’s Remarks - PAHO Press Briefing on Dengue, Oropouche, and Avian Flu (H5N1) - 10 December 2024

Washington, DC

Good morning. Thank you for joining today’s press briefing.

This year marks the first since 2020 without COVID-19 as a global health emergency. It has been a year of achievements in our Region's efforts toward disease elimination. In 2024, the Americas regained its status as free of endemic measles, with Brazil recently reverified as free of the disease. Additionally, Belize, Jamaica, and St. Vincent and the Grenadines eliminated mother-to-child transmission of HIV and syphilis, and Brazil eliminated lymphatic filariasis as a public health problem.

Our Region continues to lead in key health areas. While global measles cases surged by 20% in 2023, the Americas was the only region to see a decline, with only 73 confirmed measles cases, the lowest number in its history. Additionally, vaccination coverage for the measles, rubella, and mumps (MMR1) vaccine reached 87%, the highest since 2019.

While we celebrate these milestones, we also face significant challenges. Today, I’d like to update you on three diseases currently impacting the Region of the Americas: dengue, Oropouche, and H5N1, also known as avian influenza.

Each of these is unique and poses a different level of threat to the Region, yet there are important lessons in how we track and respond to these diseases, helping to keep our populations safe now and in the future.

This year, we’ve faced the largest dengue epidemic in the Americas since tracking began in 1980.

Over 12.6 million cases have been reported, nearly three times the record set in 2023. More than 21,000 of these cases have been severe, and more than 7,700 deaths have been reported.

Argentina, Brazil, Colombia, and Mexico have accounted for 90% of dengue cases and 88% of dengue-related deaths in the Region this year, with Brazil representing the largest share.

Dengue is also posing a higher-than-normal risk to children. Children under 15 have accounted for over one-third of dengue cases in Costa Rica, Mexico, and Paraguay.  In Guatemala, 70% of dengue-related deaths have occurred in children.

The geographic area susceptible to dengue transmission is also expanding in countries like Argentina and Uruguay, and in countries not typically impacted by dengue. This includes the United States, where most cases have been imported by travelers, with some limited local transmission in Florida, Hawaii, Texas, Arizona, and California.

This increase in cases is directly associated with climate events, including droughts, floods, and warmer climates that favor the proliferation of mosquito breeding sites. Rapid population growth, unplanned urbanization, and poor living conditions with inadequate water supply, sanitary services, and waste disposal are also driving the spread of the disease.

Despite the challenges, we are not powerless against dengue.

The PAHO Integrated Management Strategy for Arboviral Disease Prevention and Control has been implemented with our Member States. This strategy includes vector surveillance, improved case management, training of health providers, and community engagement. The strategy has been crucial in keeping severe and fatal cases relatively low through better case management.

Dengue vaccines have been introduced in Argentina, Brazil, and Peru. Honduras plans to do so in 2025.

While the current dengue vaccine may be a valuable tool for improving community protection and individual outcomes, it will not stop the spread of the virus in the short or medium term, and does not provide immediate relief during an outbreak. Additionally, global supplies of this vaccine remain limited.

We are also seeing a rise in Oropouche virus across the Americas.

Oropouche is a vector-borne virus that has historically been confined to the Amazon Basin. But like dengue, cases are now being detected in new areas.

This year, 12 countries and territories in the Americas have reported more than 11,600 cases of Oropouche, mainly in Brazil, with more than 9,500 cases.

Though the Oropouche outbreak is a small-scale one, it requires our attention due to its increasing geographic spread. Two deaths have been reported in Brazil, and the possibility of mother-to-child transmission, including fetal deaths and congenital anomalies, is being investigated.

Countries must strengthen their surveillance and continue to share information. We must work across borders to monitor new cases and support the response of health systems.

Finally, I would like to update you on H5N1, or avian influenza.

H5N1 is a virus most commonly found in birds, however, it is now infecting other species as well—most recently dairy cattle in the United States.

In 2024, 58 human cases have been reported in the United States and one in Canada. This contrasts with the three cases reported in the previous two years for the entire Region. Animal cases have been reported in an additional 17 countries since this outbreak began in 2021.

With a moderate number of cases, most of them related to occupational exposure to sick poultry and dairy cattle, the public health impact remains limited.

Surveillance, including genomic characterization, is crucial to track the virus across species, understand its evolution and risks to humans, and guide our actions.

Countries should continue to collect and share information with public health agencies and official veterinary services. Those at high risk of infection—such as farm workers dealing with birds and cattle—must be adequately protected.

Intersectoral collaboration on avian influenza is also critical to enable early detection and timely interventions in animals. This year, PAHO convened its 35 Member States to establish the Commission for the Prevention and Control of Zoonotic Influenza, to bolster cooperation across human, animal, and environmental health sectors. These efforts under the One Health approach need redoubling in 2025 and beyond.

PAHO is in contact with officials and partners in the human and animal health fields in the United States and Canada to track the outbreak in cows. We will provide guidance for the Region as new information becomes available.

Disease outbreaks are not new but the challenges we face today require attention and collaboration.

Our Region’s response to dengue underscores the power of disease surveillance to plan, prepare, and act. When countries share information, and coordinate and support disease responses, it saves lives and guides us as we tackle the rising threats of dengue, Oropouche, and avian influenza.

As we address the impacts of climate and health, urbanization, and inequality, PAHO continues to work with every Member State to leverage our collective capacity to prepare and respond to current and future health challenges.

Thank you.

Dr. Jarbas Barbosa