Search API
The ongoing chikungunya epidemic in France's Réunion Department has resulted in 39,532 cases and nine associated deaths since the beginning of 2025.
This includes 4,304 new cases from April 7 to April 13, 2025.
On April 23, 2025, ARS Réunion stated that 'the chikungunya epidemic continues across the island. Although the number of chikungunya-related primary care consultations is stabilizing, the number of emergency room visits is increasing.'
Local health authorities, the World Health Organization, and the U.S. Centers for Disease Control and Prevention (CDC) are urging heightened vigilance for travelers to Réunion.
Visitors are advised to take preventive measures against mosquito bites, such as using insect repellent, wearing long-sleeved clothing, and staying in accommodations with screened windows or air conditioning.
Additionally, international travelers may pose a risk of introducing chikungunya to other regions where Aedes mosquito vectors are present. It is recommended that they monitor for symptoms, such as fever, joint pain, and rash, for up to two weeks and seek medical attention if symptoms arise.
The CDC says if you are pregnant, consider reconsidering travel to the affected states, especially if you are nearing the delivery of your baby. Mothers infected around the time of delivery can pass the virus to their baby before or during delivery.
Newborns infected in this way or by a mosquito bite are at risk for severe illness, including poor long-term outcomes.
The vaccination campaign, which started on April 7, 2025, is available for individuals aged 18 to 64 with comorbidities. Health authorities emphasize the importance of monitoring for allergic reactions within 72 hours of vaccination and seeking immediate medical attention if any symptoms occur.
The CDC's Level 2 Travel Advisory recommends vaccination against chikungunya for adults traveling to a destination with a current chikungunya outbreak. The vaccine should not be administered to individuals with weakened immune systems or those who have experienced a severe allergic reaction to any component of the vaccine.
In the United States, chikungunya vaccination services are available as of April 30, 2025, at travel clinics and pharmacies.
According to the Pan American Health Organization (PAHO), a total of 21 measles cases have been confirmed in the Autonomous City of Buenos Aires and the Province of Buenos Aires, Argentina.
As of April 16, 2025, three of these measles cases were imported and 18 were locally acquired.
The Buenos Aires National Health Service has reported that the majority of cases are concentrated in Commune 14, which is home to approximately 248,000 people.
The PAHO stated that the index case of this outbreak was reported in January 2025 in a child with a history of international travel.
Twelve of the cases were confirmed with genotype B3, and one of the imported cases, associated with recent international travel to Thailand, was identified as genotype D8.
Throughout 2025, a total of 2,318 measles cases, including three deaths, have been confirmed in six countries in the Region of the Americas, which includes the United States.
This PAHO data represents an 11-fold increase compared to the same period in 2024.
The PAHO wrote 'Measles is a highly contagious, airborne viral disease that can lead to severe complications and death. This disease is preventable with two doses of the MMR vaccine, which is highly recommended for most people.
As of April 29, 2025, the regional risk is currently assessed as high, while the global risk remains moderate.'
However, the Argentine Republic was not included in the U.S. CDC's recent Global Measles Advisory that identified 58 countries reporting measles outbreaks.
The Yellow fever outbreak in South America now includes the Republic of Ecuador, home to approximately 17 million residents.
As of April 28, 2025, Ecuador's Public Health Minister, Edgar Lama, announced that there are three confirmed cases, with a fourth case under investigation.
The first case was detected in the province of Zamora Chinchipe, located at the southeastern end of the Amazon Basin.
Furthermore, Minister Lama stated in a media release, "We remain vigilant and are not in any situation similar to Colombia and Peru, which have had so many cases of yellow fever," he stated.
As of the end of April 2025, yellow fever outbreaks have been reported throughout South America.
Ecuador is a popular tourist destination that features the Galápagos Islands in the Pacific Ocean.
To alert international travelers to the Yellow fever health risk, the U.S. CDC states that proof of vaccination is not required for direct travel from the United States, or when traveling to areas above 7,550 ft in elevation, or the cities of Guayaquil or Quito, or the Galápagos Islands.
However, the CDC has included Ecuador in recent Dengue and Oropouche in Level 1 Travel Health Advisories.
In the United States, yellow fever vaccination appointments are offered at certified travel clinics and pharmacies.
In the Republic of Peru, the sudden upswing in Yellow fever cases has caused outbreak alerts to be issued for this western South American country in 2025.
As of April 25, 2025, 32 human cases of yellow fever have been confirmed, including eleven fatal cases.
Last year, Peru reported 19 confirmed cases of yellow fever, resulting in nine deaths for the entire year.
In 2025, cases were confirmed in most Peruvian departments, with the district of Imaza reporting the highest number of cases (12, including three fatal cases).
Most of the confirmed cases were males (90.6%), with a history of exposure in wild and/or wooded areas, due to agricultural work activities.
Even though the Yellow fever vaccination is recommended, 71.8% of the cases had no history of vaccination against yellow fever.
According to the U.S. CDC, vaccination is not recommended for travel to areas with elevations greater than 7,550 ft, including specific regions west of the Andes, the city of Lima, and the highland tourist areas of Cusco, the Inca Trail, and Machu Picchu.
These Peurivan destinations welcome over 1 million people annually.
When departing for Peru in 2025, travel clinics and pharmacies offer a specific recommendation for the yellow fever vaccination.
While most hikers and campers await the results of a Phase 3 clinical trial of the most advanced Lyme disease vaccine candidate, The Lancet Infectious Diseases recently published an article highlighting very positive data from the Phase 2 study.
On April 25, 2025, results from the NCT04801420 study confirm the previously observed safety and immunogenicity profiles of VLA15 in adults and extend them to children aged five years and older, as well as adolescents.
Additionally, the greater immunogenicity of VLA15 among children and adolescents might translate to increased flexibility in the real-world clinical setting.
According to Vaneva SE and Pfizer Inc., VLA15 is an investigational multivalent protein subunit vaccine that utilizes an established mechanism of action for a Lyme disease vaccine, targeting the outer surface protein A (OspA) of Borrelia burgdorferi, the bacterium that causes Lyme disease.
OspA is a surface protein expressed by the bacteria when present in a tick. Blocking OspA inhibits the bacterium’s ability to leave the tick and infect humans.
The vaccine candidate covers the six most prevalent OspA serotypes expressed by the Borrelia burgdorferi sensu lato species in North America and Europe.
Lyme disease, if left untreated, can cause serious chronic complications affecting the skin, joints, heart, or nervous system.
According to various health agencies, the medical need for vaccination against Lyme disease is steadily increasing as the geographic footprint of the disease widens in the United States and Europe.
Throughout Europe, the bacteria are only transmitted by the bites of the ticks Ixodes ricinus and I. persulcatus. In the most affected regions, tick infection rates may exceed 10%. These areas are primarily located in central Europe.
However, the ECDC says in recent years, the spread of infected ticks has extended toward northern latitudes, including Scandinavia.
In the United Kingdom, the South of England and the Scottish Highlands have been earmarked by the government as high-risk areas for Lyme disease in 2025. Annually, the UK Health Security Agency reports about 1,500 laboratory-confirmed cases of Lyme disease.
With millions of people returning to the woods and mountains this summer, analysts say there is significant pent-up demand for an effective Lyme disease vaccine.
While influenza activity continued to decline across the United States, flu-related fatalities among children increased, now totaling 204 for the 2024-2025 flu season.
This data exceeds the fatality total for each of the last two flu seasons.
The Centers for Disease Control and Prevention (CDC) Influenza Surveillance Report: Key Updates for Week 16, reported on April 25, 2025, that this flu season is classified as a high severity season overall and for all age groups (children, adults, older adults) and is the first high severity season since 2017-2018.
According to the National Center for Health Statistics Mortality Surveillance data, 0.3% of the deaths that occurred during the week ending April 19, 2025 (Week 16), were due to influenza.
This percentage decreased by 0.1% or more compared to Week 15.
The CDC continues to recommend that everyone aged six months and older receive an annual flu vaccine as long as influenza viruses are circulating. As of late April, various flu shots are available at community pharmacies throughout the United States.
Furthermore, suppose your summer vacation plans for 2025 include a trip to the Southern Hemisphere, where the flu season is in full swing. In that case, your pharmacist may recommend an additional flu shot for protection.
Once again, research affirms that healthcare professionals remain the most trusted source of information (73%) and can significantly influence disease prevention efforts, such as vaccination.
A University of Texas Southwestern Medical Center survey published on April 24, 2025, found that 58% of adults say they would be willing to be vaccinated against mpox if their healthcare provider recommended it.
This data represents a 12% increase since 2022.
According to an article published in Vaccine (Volume 56, May 22, 2025, 127141), self-reported knowledge of mpox (40%), as well as perceived self-efficacy (55%) and mean risk perception (3.2), have also increased since the 2022 survey.
Respondents from the Health and Human Services Region 1 (CT, ME, MA, NH, RI, VT) were the least likely to receive the vaccine, even when recommended to do so.
These results highlight the need for ongoing education among adults to improve awareness of and vaccination intention for the mpox vaccine.
The consistently high degrees of trust placed in healthcare professionals and officials should guide future communications about mpox and other infectious diseases, and reinforce the importance of leveraging trusted sources to share essential public health information, wrote these researchers.
In May 2022, an unprecedented global outbreak of mpox Clade IIb prompted the World Health Organization (WHO) to declare a Public Health Emergency of International Concern. Since then, mpox cases, including Clade 1, have been reported in more than 126 WHO Member States.
As of April 28, 2025, mpox vaccination (JYNNEOS) services are commercially offered throughout the United States.
