Coronavirus Breaking News

The Republic of Colombia Ministry of Health recently posted on Facebook that it has seen a rise in yellow fever cases over the past two years.

From 2024 to January 4, 2026, Colombian officials reported 142 confirmed cases. This includes 63 deaths.

The mosquito-transmitted disease has been detected in ten departments, each with at least one death from yellow fever. These are Caldas, Caquetá, Cauca, Guaviare, Huila, Meta, Nariño, Putumayo, Tolima, and Vaupés.

While some of these yellow fever cases have occurred in forest areas, others have been reported near Bogotá, the capital city and a tourist destination.

Over the last few years, Tolima, located west of Bogota, has been the most affected area, often accounting for over 80% of yellow fever cases.

According to the World Health Organization and the U.S. Centers for Disease Control and Prevention, the yellow fever vaccine is among the most effective available. It is a live, attenuated vaccine that provides lifelong protection with a single dose for most people.

No booster doses are routinely needed. However, as of January 5, 2026, travel vaccine experts are available to provide insights on yellow fever immunization.

From a security perspective, the United Kingdom (UK) updated its travel advice on January 5, 2026, advising against all but essential travel to parts of Colombia, such as the Colombia-Venezuela border and northern Colombia.

The UK wrote that if you choose to travel to Colombia in 2026, research your destinations and get appropriate insurance. 

The Zika virus, once a major global health emergency, continues to circulate in the Americas, with the Pan American Health Organization (PAHO) confirming local transmission in 52 countries and territories since 2015.

While case numbers have fluctuated in recent years, the Federative Republic of Brazil remains the epicenter, historically reporting the highest number of confirmed cases in the Americas region.

Recent data highlight Brazil's ongoing battle with the mosquito-borne illness.

Brazil recorded 1,801 confirmed Zika cases, maintaining its lead in the Americas.

As of January 2, 2025, PAHO data indicate that Brazil has significantly reduced its number of confirmed Zika cases, with 2,067 cases reported in 2024 and 3,997 in 2023.

Many Zika outbreaks are concentrated in major Brazilian cities, including Rio de Janeiro, a metropolis of millions and a top destination for international travelers. As the city gears up for Carnaval 2026, scheduled from February 13 to 21, concerns about mosquito-borne diseases linger.

PAHO emphasizes that most Zika infections are mild or asymptomatic, but the virus poses serious risks to pregnant women, potentially causing congenital Zika syndrome in newborns. Travelers, especially those planning pregnancies, are advised to take precautions.

With no locally acquired Zika cases in the continental U.S. since 2019, the U.S. Centers for Disease Control and Prevention (CDC) Yellow Book states that international travelers with suspected Zika infection should be tested with real-time polymerase chain reaction or an NS1 antigen test.

This CDC advice is being followed in Hawai'i.

The Hawaiʻi Department of Health announced on May 27, 2025, that it is investigating two travel-related Zika cases.

And in U.S. territories, the CDC says Zika-spreading mosquitoes are found throughout Puerto Rico, where the Department of Health reported 16 cases in 2024, down from 43 in 2023.

From a disease prevention perspective, the CDC says no Zika vaccine candidate has been approved.

However, clinical trials are active in 2026.

Japan has experienced a dramatic resurgence of syphilis since 2010, reaching epidemic rates again in 2025.

The Japan National Institute of Infectious Diseases (NIID) has reported a significant increase in syphilis cases over the past decade, with the last four years averaging over 13,000 cases annually.

In 2025, the NIID confirmed that this unfortunate trend continued for the fourth consecutive year.

Among Japan's prefectures, Tokyo accounted for 25% of the national total of syphilis cases, followed by Osaka, Aichi, Fukuoka, and Kanagawa.

According to a December 2025 analysis, syphilis risk factors among predominantly heterosexual populations in urban Japan have significantly increased. These findings reveal that casual sexual partnerships and diverse sexual networks facilitated by dating applications and commercial sex services create unique transmission dynamics not adequately captured by previous research.

These researchers stated that promoting preventive measures among sex industry workers and patrons is crucial in Japan's cities.

Syphilis is a sexually transmitted infection (STI) that is generally transmitted by contact with infectious sores, through blood transfusions, or through mother-to-child transmission during pregnancy. This bacterial infection is caused by Treponema pallidum.

Syphilis can be treated with antibiotics such as penicillin. Furthermore, patients can become reinfected, so early antibiotic treatment is necessary.

After decades of clinical trial missteps, a December 18, 2025, study found syphilis vaccine development is beginning to gain momentum due to advances in understanding the outer membrane protein of Treponema pallidum, host–pathogen interactions, and the genomics of syphilis.

Preventing vertical transmission of Treponema pallidum subsp pallidum could be the most consequential target for a vaccine, given the global resurgence of congenital syphilis and adverse pregnancy outcomes.

As of late 2025, the U.S. Preventive Services Task Force and the American College of Obstetrics and Gynecology recommend that pregnant women be tested for syphilis. And in 2026, Alabama, Arizona, Colorado, Georgia, Maryland, Mississippi, Missouri, North Carolina, Tennessee, and Texas require syphilis testing during pregnancy.

With the global spreading of the Chikungunya virus expected to continue in 2026, Valneva SE and Serum Institute of India today announced that they have mutually agreed to discontinue their license agreement for Valneva's IXCHIQ® single-shot chikungunya vaccine.

As of December 31, 2025, Valneva's strategic intent in regaining full rights is to assume direct control over its supply chain and commercialization for endemic high-risk countries, thereby accelerating access for regions most affected by the disease.

According to the European Medicines Agency, IXCHIQ was shown to be effective at triggering the production of antibodies against the chikungunya virus in two primary studies. This is expected to reduce the risk of getting this mosquito-transmitted disease caused by the Chikungunya virus.

Supporting access to the vaccine in low-and middle-income countries falls within the framework of the funding agreement Valneva signed with the Coalition for Epidemic Preparedness Innovations in July 2024, with co-funding from the European Union.

Currently, the U.S. CDC has issued various Travel Health Notices for Chikungunya outbreaks, including a Level 2 alert for China in mid-December 2025.

The CDC advises international travelers to speak with a travel vaccine consultant regarding immunization options before visiting outbreak areas in 2026.

As an Arctic blast brings cold weather to North America, many travelers are planning vacations to warmer climates in 2026. While dreaming of sandy beaches, travelers need to research areas where mosquito-related illnesses might be common.

After a record-setting year in 2024, when global Dengue fever cases reached nearly 14 million and resulted in over 9,000 deaths across 106 countries and territories, new data shows that infections have significantly declined this year.

As of early December 2025, the World Health Organization (WHO) has recorded just over 5 million dengue cases and about 3,000 dengue-related fatalities, marking a notable decline in outbreaks from the previous year.

This WHO data represents roughly a 65% drop from 2024's total.

WHO experts attribute the reduction partly to improved vector control measures, shifts in herd immunity, and varying seasonal patterns.

In the United States, both travel-related and locally acquired dengue cases were also reduced in 2025.

However, according to the U.S. CDC data as of December 31, 2025, seven jurisdictions reported 3,325 local Dengue cases this year, including warm weather destinations.

The unfortunate leader is Puerto Rico, which has reported 3,154 Dengue cases, followed by Florida (58) and California (6).

From a disease-prevention perspective, Puerto Rico continued to administer the first-generation Dengue vaccine, Dengvaxia, to 82 people this year. 

Currently, neither Florida nor California offers Dengue vaccinations in high-risk areas, such as Florida's southeast coast.

With the arrival of a third Dengue vaccine (Butantan-DV) in 2026, even more people will have the chance to stay safe from this serious, preventable disease!

South Carolina's Department of Public Health (DPH) today announced it is actively responding to a measles outbreak centered around Spartanburg County.

Seven of the new cases were known household exposures; five resulted from a previously reported school exposure; two resulted from an exposure at church; and one resulted from an exposure at either school or church. The sources of four cases are unknown, and one is still being investigated, stated DPH.

As of December 30, 2025, DPH is reporting 179 cases of measles since early July, with 176 in the upstate area.

DPH wrote that some cases are travel-related exposures or close contacts of known cases. Other cases have no identified source, suggesting that measles is circulating in the community and could spread further.

We have seen measles spread quickly in unvaccinated households here in South Carolina. We also know that it can spread rapidly in unvaccinated communities based on outbreaks in other states, added the DPH.

Nationally, the U.S. CDC reported 2,012 confirmed measles cases across 44 jurisdictions as of December 23, 2025. Most of these cases were confirmed in Texas earlier this year.

Internationally, measles is an ongoing risk around the world, and more international travelers are getting infected. Both Canada and Mexico continue to report an excessive number of measles cases in 2025.

The CDC recommends that most international travelers ensure they have received an MMR vaccination before departing abroad.

The World Health Organization (WHO) today announced updated figures on the chikungunya virus (CHIKV) outbreak, revealing a significant resurgence in 2025 with 502,264 reported cases, including 208,335 confirmed cases and 186 associated deaths.

As of December 29, 2025, this Rapid Risk Assessment says WHO regions have seen declines in cases compared to 2024, others are experiencing sharp increases, and the mosquito-transmitted virus is emerging in previously unaffected populations.

This uneven pattern makes it challenging to assess the overall global trend, but points to localized outbreaks and resurgences in specific areas.

The Region of the Americas recorded the highest number of confirmed cases, closely followed by the European Region, where the majority stem from French Overseas Departments in the Indian Ocean.

The WHO warns that the risk of further geographic spread remains high as infected travelers can introduce the virus to new areas, where local transmission can establish if competent Aedes mosquitoes are present.

In the United States, the leading states reporting travel-related chikungunya cases include southeast Florida (250) and Texas (6).

WHO advises travelers to affected areas to use insect repellent, wear protective clothing, and consider preventive measures such as vaccination.

Previously, the U.S. CDC has issued Level 2 - Practice Enhanced Precautions, Travel Health Notices focused on chikungunya outbreaks in China, Cuba, and France's overseas departments.

As of December 30, 2025, two chikungunya vaccines are available globally, including in the USA at travel clinics.