Washington, DC, October 31, 2024 (PAHO) – The Pan American Health Organization (PAHO) has issued an epidemiological alert due to the recent identification of clusters and cases of measles in the Americas, urging countries to intensify their vaccination and surveillance efforts.
In the alert published on Monday, PAHO reported that, in 2024 up to October 5, more than 14,000 suspected cases of measles have been registered, with 376 confirmed in eight countries of the Americas, mainly in the United States (267 cases), Canada (82) and Argentina (11). Most of these cases are imported or related to importation. The Americas region was certified as free of rubella in 2015 and of endemic measles in 2016.
Measles is a highly contagious viral disease that primarily affects children and can cause serious complications, including severe diarrhea, ear infections, blindness, pneumonia, and encephalitis (inflammation of the brain). Some of these complications can be fatal.
The most affected age group includes children aged 1 to 9 years and young adults aged 20 to 29 years. Fifty-seven percent of confirmed cases were unvaccinated, and in 28% their vaccination status was unknown, highlighting the urgent need to address gaps in vaccination coverage. Although there has been an increase in cases since mid-February of this year, the overall trend shows a decrease in the weeks following late March; however, cases have continued to be confirmed in subsequent months.
Throughout the year, PAHO warned in January and June about the decline in vaccination coverage against measles, rubella, and mumps (known as MMR or measles-mumps-rubella vaccine). In 2023, the regional coverage for the first dose of the MMR vaccine was 87% and 76% for the second dose, below the ideal threshold of 95% recommended to prevent outbreaks.
In response to the situation, PAHO urges Member States to implement active search strategies to detect cases, as well as to carry out complementary vaccination activities to close existing immunity gaps and strengthen communication with communities to promote vaccine acceptance. Travelers are also advised to get vaccinated before visiting areas where measles transmission has been documented.
PAHO urges countries to continue strengthening surveillance systems, rapid response to any imported cases of measles, and achieving adequate vaccination coverage. It is crucial to address risk factors that could favor the spread of the virus such as low vaccination coverage, gaps in surveillance, the active circulation of the virus in other regions of the world, and the increased movement of people in the region, and dengue outbreaks where some measles cases could be masked, the Organization states in the epidemiological alert.
Globally, measles remains one of the leading causes of death in young children, despite the existence of a safe and effective vaccine to prevent it. According to the World Health Organization (WHO), up to October 15, 2024, more than 502,000 suspected cases of measles were reported in 182 Member States of the six WHO regions, of which more than 283,000 (56%) were confirmed.
PAHO is committed to supporting countries in implementing effective measures to control the spread of the virus and protect the most vulnerable populations. The organization also emphasizes the importance of inter-institutional collaboration to ensure a coordinated response to this public health threat.
While measles continues to be a global health problem, PAHO reiterates that vaccination is the most effective tool to prevent outbreaks and protect communities. It is necessary to maintain surveillance systems for the early detection of imported cases, as well as a rapid response to outbreaks to limit the spread of the virus.
