Americas

Dengue Infections Cause Cardiovascular Complications

Karen McClorey Hackett — Tue, 22 Apr 2025 08:59:41 +0000

Reviewer:

When vacationers return with symptoms similar to a cold, most associate their illness with influenza. However, when visiting most countries in the Americas in 2025, one can also be exposed to the mosquito-transmitted dengue virus.

In the United States, dengue infections are often misdiagnosed. They can cause a range of symptoms, from a mild febrile illness to severe conditions such as dengue hemorrhagic fever and shock, which can result in cardiovascular collapse.

Recently, there have been more reports of atypical presentations following infection by any of the four dengue virus (DENV) serotypes, including cardiac manifestations such as electrocardiographic abnormalities, myocarditis, and pericarditis, which require further investigation.

This review, published on April 18, 2025, discusses our current understanding of the cardiovascular manifestations of dengue and their management, explores the proposed pathogenesis, and concludes with potential future research directions.

The global incidence of dengue has been increasing, partly due to higher travel volumes to areas where dengue is endemic and climate change, which has expanded the range of Aedes mosquito vectors, found at elevations below 2,500 feet.

Last year, more than 13 million dengue cases were reported, the highest year on record.

As of April 16, 2025, the U.S. CDC has reported 1,481 travel-related dengue cases in 30 jurisdictions this year. One locally acquired case in southeast Florida has been confirmed.

In 2024, 53 jurisdictions, led by Arizona, California, Florida, New Jersey, New York, and Puerto Rico, reported 9,391 dengue cases.

To reduce these dengue infections, the ideal DENV vaccine would elicit a balanced and highly protective immune response against all four serotypes of DENV.

Current tetravalent live-attenuated DENV vaccines have faced challenges due to the uneven replication of vaccine virus strains, which stimulate a strong immune response to one serotype and weak responses to the other three serotypes.

While forty countries have enabled access to a second-generation dengue vaccine by 2025, the United States government has not.

Which means it's best to avoid mosquito bites to prevent infection while vacationing in the Americas, including Miami Beach.

Sub Title:

Second generation dengue vaccines are available outside of the U.S.

References:

Cardiovascular Complications of Dengue Virus

Major acute cardiovascular events after dengue infection–A population-based observational study

Cardiovascular manifestations of the emerging dengue pandemic

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Oropouche Outbreaks in the Americas at Infection Point

Karen McClorey Hackett — Sat, 19 Apr 2025 15:02:00 +0000

Reviewer:

Robert Carlson, MD

For unknown reasons, the Region of the Americas has been experiencing an Oropouche virus (OROV) outbreak of unprecedented magnitude since 2023.

As of April 2025, ORIV outbreaks have been identified in ten countries in the Americas, with visitors from those countries bringing the virus into the United States.

According to an open-access article published by The Lancet Infectious Diseases on April 14, 2025, data suggest that climatic factors are major drivers of OROV spread and may have been potentially exacerbated by recent weather events.

These researchers wrote, "While other studies on the 2023–24 OROV outbreak have typically focused on analyzing country-level geographical spread, individual socioecological predictors of OROV infection, or viral genomes..." Our analyses rely on an unprecedented serological OROV dataset comprising over 9,000 samples from six countries and multiple ecozones.

We show that OROV is a common arboviral infection in the South American Amazon.

Specifically, OROV and OROV reassortants, but not individual OROV strains, might represent distinct serotypes.

A strain from the 2023–24 OROV outbreak (IRCCS-SCDC_1/2024) did not stand out from either a historical or another contemporary strain in terms of its replication capacity or antigenicity.

Our evidence indicates that OROV infections are significantly underreported in the Americas.

As climate predictors were the most critical predictors in our OROV transmission risk models, the risk of OROV infection is likely to evolve dynamically in the coming decades, with the potential for large-scale future outbreaks.

These researchers suggest preparedness for OROV outbreaks requires enhanced diagnostics, surveillance, and vector control in current and future endemic areas, which could all be informed by the risk predictions presented in this Article.

To alert international travelers of the OROV health risk, the U.S. CDC has issued Level 1 and Level 2 Travel Health Advisories in 2025, which identify outbreaks in various countries.

As of April 19, 2025, no OROV vaccines are available, meaning the best defense against OROV infections is to prevent mosquito bites.

Sub Title:

Oropouche vaccines are unavailable in 2025

References:

The spatiotemporal ecology of Oropouche virus across Latin America

US CDC - Oropouche in the Americas April 2025

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The Lancet - Characteristics of the 9420 serum samples tested for Oropouche virus-specific IgG class antibodies

Oropouche Travel Advisory Reissued for the Americas

Karen McClorey Hackett — Wed, 09 Apr 2025 18:59:01 +0000

Reviewer:

Robert Carlson, MD

During the summer of 2024, the Pan American Health Organization (PAHO) issued several epidemiological alerts regarding Oropouche outbreaks in the Americas.

Oropouche is a disease caused by the Oropouche virus that is spread primarily to people through the bites of infected biting midges and mosquitoes.

Without a vaccine, public health leaders are very concerned about the ongoing transmission of the virus in 2025.

To reaffirm that this disease is a health risk to travelers, the U.S. Centers for Disease Control and Prevention (CDC) today reissued a Level 1—Practice Usual Precautions, Travel Health Advisory.

As of April 9, 2025, the CDC has listed ten countries in the Americas reporting Oropouche cases.

Previously, a Level 2 Travel Health Notice has been issued for Oropouche cases reported in parts of Brazil and Panama.

Last year, 103 cases of Oropouche were reported in Florida by individuals who had traveled to an endemic area such as Cuba. The majority of these cases were in Miami-Dade County (61).

The CDC says that the Oropouche virus has been found in semen, but it is unknown if Oropouche can be spread through sex.

However, there were also concerns about a rise in potential cases of the Oropouche virus being transmitted from pregnant women to their fetuses, which could be linked to fetal deaths and congenital abnormalities.

The CDC is collaborating with PAHO and other international partners to understand better the potential risks of the Oropouche virus during pregnancy.

According to the CDC, healthcare providers should inform pregnant women considering travel to areas with reported Oropouche virus transmission of the possible risks to the fetus.

If a woman who is pregnant decides to travel, counsel her to prevent bug bites.

A CDC publication in 2024 describes a patient with Oropouche virus disease with virus and viral RNA detected in bodily fluids, including semen. The CDC has interim recommendations for how to counsel patients on possible sexual transmission.

Sub Title:

Florida Reported 103 Oropouche Cases in 2024

References:

US CDC - Level 1

US CDC - Level 2

Competent Oropouche Virus in Semen of Traveler Returning to Italy from Cuba, 2024

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by Andy Leung April 9, 2025

South America's Zika Outbreaks Disrupt Summer Vacations

Karen McClorey Hackett — Thu, 03 Apr 2025 17:19:54 +0000

Reviewer:

Robert Carlson, MD

As of early April 2025, there is no active Travel Health Notice from the U.S. CDC to inform international travelers about health risks related to Zika virus outbreaks. This means thousands of travelers are visiting affected countries, unaware of the Zika's resurgence.

Since the peak of Zika in 2016, outbreak media coverage has significantly decreased, leaving travelers uncertain where to plan their next vacation.

To fill this information gap, the UK Travel Health Pro recently identified countries reporting unusually high mosquito-transmitted Zika cases.

By the end of 2024, 90 countries across Africa, Europe, the Americas, Southeast Asia, and the Western Pacific reported locally acquired cases of the Zika virus.

According to the Pan American Health Organization's Zika case dashboard as of April 3, 2025, Argentina, Brazil, and Bolivia are the South American countries with the highest number of Zika virus disease cases. In total, the Americas have reported 6,014 this year.

In Argentina, a total of 497 cases of Zika have been reported in 2025.

In Bolivia, 31 cases of Zika virus disease have been reported.

And in Brazil, a total of 5,517 Zika cases have been reported since the start of 2025. Last year, Brazil reported over 42,000 Zika cases.

Furthermore, the UK has confirmed that an increasing number of returning travelers have been infected with Zika. The most frequently reported country of travel was Thailand, followed by India.

In 2024, 16 Zika virus disease cases were reported in England, Wales, and Northern Ireland, a 100% increase from 2023.

The UK says most people infected with the Zika virus do not develop symptoms.

However, Zika infections in pregnant women can cause congenital Zika Syndrome, such as microcephaly and neurological complications, such as Guillain-Barré Syndrome.

These serious health concerns also apply to returning U.S. travelers, as 18 Zika cases were confirmed in 2024.

A recent discovery published in the journal Nature Communications helps explain why many people develop a weaker immune response to the Zika virus.

Published on March 25, 2025, these researchers identified the effects of Zika on the host T cell response, highlighting the need to factor such differences into the design of anti-flavivirus vaccines.

Since no approved Zika vaccines exist, the CDC and the UK advise travelers visiting Zika-endemic areas to avoid mosquito bites. Moreover, pregnant women are advised to postpone visiting at-risk regions.

This is one Zika vaccine candidate conducting clinical research, indicating another form of prevention is on the horizon.

Valneva SE's VLA1601 is a second-generation purified, inactivated, whole Zika virus vaccine candidate, conducting phase 1 research. Insights from this research are expected later in 2025.

Sub Title:

Zika infections can cause microcephaly and neurological complications, such as Guillain-Barré Syndrome

References:

UKHSA

Nature Communications March 2025

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US CDC Zika Case Map 2024

U.S. CDC Under-Discloses Dengue Outbreaks

Donald Hackett — Fri, 21 Mar 2025 14:51:36 +0000

Reviewer:

Robert Carlson, MD

With the World Health Organization (WHO) and over 100 countries reporting Dengue cases in 2025 and classifying Dengue outbreaks as a grade 3 global emergency, the new U.S. CDC Travel Health Advisory appears to be under-highlighting this global health issue.

On March 20, 2025, the CDC only identified 16 countries with higher-than-expected Dengue cases among U.S. travelers returning from those countries.

Previously, the CDC stated that the Dengue virus was endemic in the U.S. territories of Puerto Rico, American Samoa, and the U.S. Virgin Islands. In the continental U.S., Dengue is frequently detected in Florida's Miami-Dade County.

As of March 21, 2025, the WHO/PAHO data dashboard indicates over 1.2 million Dengue cases and 348 related fatalities have already been reported this year in the Region of the Americas, which includes the United States.

In 2024, more than 13 million Dengue cases were reported in the Americas, making it the highest year on record.

The CDC stated today that international 'travelers should practice prevention measures for all areas with a risk of dengue, an acute febrile illness.'

An estimated 40%–80% of DENV infections are asymptomatic.

However, symptoms in perinatally infected neonates typically present during the first week of life and include fever, hemorrhagic manifestations, hypotension, and thrombocytopenia.

A previous study found that 'compared to uninfected mothers, babies born to mothers with dengue are likely to have worse outcomes. Preterm birth and low birth weight are frequently observed in dengue-affected pregnancies, which can have serious effects on the health and development of the child.'

The CDC recommends that visitors to Dengue-risk areas prevent mosquito bites by using an EPA-registered insect repellent, wearing long-sleeved shirts and pants outdoors, and sleeping in rooms with window screens.

While many countries have authorized a second-generation Dengue vaccine (QDENGA) to reduce the number of mosquito-transmitted Dengue infections, this vaccine is unavailable in the U.S.

However, several Dengue vaccine candidates are conducting late-stage clinical trials, which could be authorized in the U.S. in the future.

Sub Title:

Dengue vaccine unavailable in the United States in 2025

References:

US CDC Global Dengue March 20, 2025

Review of Maternal and Perinatal Outcomes of Dengue in Pregnancy

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WHO Dengue Case Map March 2025

Oropouche Virus Has Spread Throughout the Americas

Karen McClorey Hackett — Tue, 04 Mar 2025 10:25:10 +0000

Reviewer:

Robert Carlson, MD

Since first detected in 1955 in the Carribean, Oropouche virus (OROV) has been reported across various countries in the Region of the Americas.

According to an article published in the Journal of Travel Medicine on March 2, 2025, OROV was historically confined to the Brazilian Amazon Basin and was often mistaken for dengue, another mosquito-transmitted virus.

However, since late 2022, OROV cases have also been reported in Bolivia, Ecuador, Guyana, Colombia, Cuba, Panama, and Peru.

Additionally, Florida's Health Department reported over 100 OROV cases in international visitors primarily traveling from Cuba in 2024.

Collaborating with Central Public Health Laboratories across Brazil, researchers integrated epidemiological metadata with genomic analyses from recent cases, generating 133 whole-genome sequences covering the virus’s three genomic segments (L, M, and S).

These include the first genomes from regions outside the Amazon and the first recorded fatal cases.

Phylogenetic analyses show that the 2024 OROV genomes form a monophyletic group with sequences. They identified 21 reassortment events, though it remains unclear whether these genomic changes have facilitated viral adaptation to local ecological conditions or contributed to phenotypic traits of public health significance.

This research's findings demonstrate how OROV has evolved through reassortment and spread rapidly across multiple states in Brazil, leading to the largest outbreak ever recorded outside the Amazon and the first confirmed fatalities.

Additionally, the virus’s recent rapid geographic expansion and the emergence of severe cases emphasize the urgent need for enhanced surveillance across the Americas.

To alert healthcare providers and travelers, the Pan American Health Organization and the U.S. CDC have issued various Travel Health Advisories, confirming OROV is spread primarily by the bite of infected midges and mosquitoes.

However, the Oropouche virus has been found in semen.

There have been possible cases of Oropouche being passed from a pregnant woman to her fetus.

The CDC says visitors to impacted areas should consider using condoms or not having sex during travel and for 6 weeks after returning from travel.

Additionally, the CDC says healthcare providers should inform women who are pregnant and considering travel to areas with reported Oropouche virus transmission of the possible risks to the fetus. If a pregnant woman decides to travel, counsel her to prevent bug bites.

Since no Oropouche vaccines are available as of March 4, 2025, the CDC's advice is the easiest to implement to prevent infections and severe disease.

Sub Title:

Oropouche travel advisories active in 2025

References:

Travel-associated international spread of Oropouche virus beyond the Amazon

US CDC Oropouche in the Americas

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US CDC 2025

Can Fractional Yellow Fever Vaccinations Decrease Deaths in the Americas

Karen McClorey Hackett — Fri, 21 Feb 2025 10:09:57 +0000

Reviewer:

Robert Carlson, MD

While the Yellow fever vaccine has been found highly effective when administered as a single dose, researchers have continued to examine the minimum dose requirements for seroconversion.

These researchers say the potential advantages of offering fractional doses are increased vaccinations and reduced under-vaccination, which have become a measurable health concern in the Region of the Americas over the past few years.

For example, 61 human cases of yellow fever were confirmed in the Region of the Americas in 2024, of which 30 were fatal (case fatality ratio, 50%).

According to a new study, fractional dosing can protect people similarly to a full dose.

On February 19, 2025, the NEJM published an Orginal Article that concluded that Institut Pasteur de Dakar 17D-204 yellow fever vaccination fractional dose of 500 IU was noninferior to the standard dose of 13,803 IU for producing seroconversion within 28 days.

Noninferiority was shown if the lower boundary of the 95% confidence interval for the difference in the incidence of seroconversion between the fractional dose and the standard dose was higher than -10 percentage points.

Previously, The Lancet Infectious Diseases published an Opinion on April 28, 2023, saying fractional dose yellow vaccination in an emergency or reactive mass vaccination campaign has become essential in stretching the limited vaccine stockpile over a much larger population.

The Lancet also published results from a clinical study in January 2021 (updated Feb. 2022), concluding, 'Fractional doses of all WHO-prequalified yellow fever vaccines were non-inferior to the standard dose in inducing seroconversion 28 days after vaccination, with no major safety concerns. These results support using fractional dosage in the general adult population for outbreak response in a vaccine shortage.'

Moreover, the WHO's initial position on fractional yellow fever vaccine was set out in the 2013 position paper.

According to the Pan American Health Organization (PAHO) rapid risk assessment on February 14, 2025, yellow fever under vaccinations remains a public health concern.

Between 2014 and 2023, yellow fever vaccine coverage declined in about half of the countries with yellow fever endemic areas in the Americas. Six countries had less than 80% coverage: Argentina, Bolivia, Brazil, Panama, Peru, and Venezuela.

This under-vaccination rate is associated with the increase of yellow fever cases in late 2024 and the beginning of 2025 in endemic countries of the Americans, such as Brazil and Columbia.

PAHO says the overall risk of this event in the Americas Region, especially in endemic countries, is classified as ¨High¨ with a ¨High¨ level of confidence based on the available information.

Regardless of the vaccine's dosage, the PAHO and the U.S. Centers for Disease Control and Prevention recommend international travelers be fully protected against the mosquito-transmitted Yellow fever virus before visiting endemic areas in 2025.

In the United States, travel clinics and pharmacies offer the U.S. FDA-approved yellow fever vaccine YF-VAX.

Sub Title:

Yellow Fever Vaccine Fractional Dosage Found Protective

References:

Low-Dose Yellow Fever Vaccine in Adults in Africa

Public Health Risk Assessment related to yellow fever: implications for the Americas Region

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WHO 2025

Zika Returns to Eight Countries in 2025

Donald Hackett — Tue, 18 Feb 2025 17:36:27 +0000

Reviewer:

Robert Carlson, MD

Following a record-setting number of Zika virus outbreaks in 2024, the Pan American Health Organization (PAHO) today reported eight counties have confirmed cases in 2025.

On February 18, 2025, the PAHO's data dashboard revealed that 333 Zika cases had already been confirmed in 2025.

Once again, the Federative Republic of Brazil, which has led this unfortunate list in the Region of the Americas for years, has 271 cases, followed by Bolivia, Columbia, Costa Rica, El Salvador, Guatemala, Mexico, and Peru.

Since Zika was first detected in the continent of the Americas in May 2015, the PAHO has identified 52 countries and territories in the Americas that have reported cases and related fatalities.

The large Zika virus outbreaks that occurred during 2015 and 2016 in the Americas have subsided, but the Zika virus continues to be a severe health risk. The PAHO and other health agencies have confirmed that Zika infections can cause microcephaly, Guillain-Barré syndrome, and other central nervous system malformations in infected children.

While the PAHO says the best way to avoid these diseases is to avoid being bitten by an infected mosquito, an innovative vaccine candidate is progressing in clinical development.

Valneva SE announced today that phase 1 results for its Zika vaccine candidate are expected in the first half of 2025. This news indicates a Zika vaccine could become available in the future.

Before traveling to at-risk areas, check the U.S. CDC's Travelers' Health website for active Zika Travel Health Notices to determine if your destination is at risk of Zika virus transmission.

Sub Title:

Zika vaccine candidate advanced to Phase 1 clinical development

References:

PAHO 2025

US CDC - Zika

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While Pregnant, Chikungunya Infection Can Disrupt Infant Development

Karen McClorey Hackett — Mon, 27 Jan 2025 15:33:30 +0000

Reviewer:

Robert Carlson, MD

Over the past few decades, mosquito-driven outbreaks of Chikungunya disease have occurred in approximately 100 countries, and many adults have been diagnosed with severe cases.

For example, in the Region of the Americas, there were 236 Chikungunya-related fatalities in 2024.

And in 2025, the Pan American Health Organization has already reported 523 Chikungunya cases in Brazil.

Furthermore, questions remain unanswered about whether pregnant women are likely to transmit the virus to unborn infants and the virus's impact on infected children's development.

A recent study published on January 24, 2025, examined the effects of intrauterine and perinatal exposure to the Chikungunya virus (CHIKV) on neurodevelopment in infants and toddlers in Rio de Janeiro, a known hotspot for outbreaks.

In an Orginal Arucale published by The Journal of Pediatrics, researchers concluded abnormal neurodevelopmental outcomes were observed in both infected and uninfected children who had been exposed to CHIKV either during pregnancy or around the time of birth.

At 11 to 42 months, 35 exposed children and 78 unexposed controls had Bayley-III assessments. Compared with controls, exposed children had higher rates of Developmental Delay (DD) (7 [20%] vs. 2 [3%], p=0.004) driven by the language domain and greater risk of DD driven by motor and cognitive domains scores (10 [29%] vs. 10 [13%], p=0.03 and 8 [23%] vs. 5 [6%], p=0.02, respectively).

Eight of 35 (23%) CHIKV-exposed children screened positive for autism spectrum disorder (ASD).

CHIKV-exposed uninfected children had 2 (9.5%) cases of DD and 5 (23.8%) cases of ASD.

These researchers and many public health leaders believe monitoring newborn health during the first week of life in CHIKV outbreak zones is essential for the offspring of pregnant travelers who visited outbreak zones.

Additionally, expecting mothers should avoid mosquito bites and speak with a travel vaccine expert about vaccination options.

In 2023, the U.S. FDA approved a vaccine to prevent chikungunya infections, which is available at travel clinics and pharmacies in the United States.

Sub Title:

Women should consider vaccination before traveling to chikungunya outbreaks

References:

Neurodevelopmental Follow-Up in Children with Intrauterine and Perinatal Exposure to Chikungunya Virus

Perinatal and Neonatal Chikungunya Virus Transmission: A Case Series

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65 Million Vaccinations Administered in Latin America and the Caribbean

Karen McClorey Hackett — Tue, 14 Jan 2025 17:52:37 +0000

Reviewer:

Robert Carlson, MD

The 2024 Vaccination Week in the Americas (VWA) announced today that it administered more than 65 million vaccine doses in 34 Latin America and the Caribbean countries.

Since PAHO initiated VWA in 2002, the initiative has reached over 1.2 billion people, reinforcing its role as a cornerstone of immunization efforts in Latin America and the Caribbean.

The 22nd annual VWA was conducted in late April 2024, underscoring the Region's commitment to combatting vaccine-preventable diseases. Key Achievements of VWA 2024 include, but are not limited to, the following:

Over 30 million doses of influenza vaccines were administered in 23 countries,

VWA successfully vaccinated 3.8 million individuals against polio,

4.3 million against measles,

2.7 million people against the human papillomavirus.

The Pan American Health Organization (PAHO) announced on January 14, 2025, this data reflect a substantial increase of 2 million doses administered during VWA 2023.

"Vaccination week has been a flagship initiative of our organization for more than 20 years," PAHO Director Dr. Jarbas Barbosa commented in a media statement.

"Historically, our Region has been a leader in disease elimination. However, for over a decade, vaccination coverage has declined significantly due to several factors, including the false perception that diseases that have been eliminated or controlled no longer pose a risk to people's health."

In December 2024, the PAHO reported on transmissible diseases affecting the Region. Countries reported more than 12.6 million dengue cases, nearly three times the number reported in 2023.

These included 21,000 severe cases and over 7,700 deaths.

Argentina, Brazil, Colombia, and Mexico account for 90% of dengue cases and 88% of deaths, with Brazil having the largest share.

The PAHO also confirmed Chikungunya, a viral disease transmitted by the bite of infected mosquitoes, impacted over 425,000 people in the Americas in 2024, a new record.

In 2025, PAHO plans to collaborate with countries in the Latin American and Caribbean Region to expand access to vaccines, particularly for vulnerable communities.

As of January 14, 2024, the U.S. CDC published Travel Health Advisories for the Americas, which include vaccine recommendations for international visitors.

Sub Title:

Vaccination Week 2024 in the Americas increased 2 million administered doses

References:

Vaccination Week Through the Years

PAHO - Dengue Outbreak 2024

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Additional Evidence From Brazil Suggests Blood Transfusion-Transmitted Dengue Virus

Karen McClorey Hackett — Sat, 30 Nov 2024 11:31:19 +0000

Reviewer:

Robert Carlson, MD

Over the past decade, clinical evidence has suggested a potential route of blood transfusion-transmitted dengue virus (TT-DENV).

On November 29, 2024, the Lancet Infectious Disease published a Correspondence reporting six dengue cases from two pediatric cardiovascular intensive care units (CICUs) in São Paulo, Brazil.

These children were transfused multiple times following cardiac surgeries for complex congenital heart diseases during the peak of Brazil's current dengue outbreak. Most patients developed fever and thrombocytopenia, and dengue infection was confirmed by NS1 antigen test and serology (IgM positive).

There were four deaths, two of which were complicated by severe hepatitis and two by bacterial sepsis.

These researchers wrote that the blood donors were not screened for dengue but concluded TT-DENV was the most likely source of infection.

Furthermore, 'these cases raise considerable concerns about transfusion safety during dengue outbreaks.'

TT-DENV has been documented in previous epidemics, where dengue RNA-positive blood donations led to confirmed transmissions.

Studies have shown that asymptomatic blood donors with DENV viremia represent a potential source of TT-DENV transmission. Asymptomatic infections account for a substantial proportion of cases during large outbreaks, making them difficult to detect through routine screening.

According to these researchers, nucleic acid testing (NAT) has proven to be a more reliable method for detecting early-stage infections when viral load is present. Yet, widespread implementation of NAT remains limited in dengue-endemic regions, such as the Americas.

With DENV viremia rates reported in up to 5.5% of blood donors during outbreaks, 'it is imperative that we reevaluate current blood safety protocols.

Given Brazil's status as a hotspot for mosquito-transmitted diseases such as chikungunya, dengue, and zika, 'we urge health authorities to prioritize introducing more rigorous blood screening measures during outbreaks, such as targeted NAT, to safeguard transfusion recipients.'

'Failure to address this risk could result in a hidden epidemic of TT-DENV during dengue outbreaks in patients receiving blood products, particularly those who are more susceptible to severe disease.'

This new study and the previous studies may impact blood donation activity on Florida's southeast coast, Texas, and throughout Puerto Rico, where dengue has become endemic.

On November 25, 2024, the Texas Department of State Health Services reported the first locally acquired case of dengue virus in Cameron County. Also, there have been 106 travel-associated dengue cases, including one death reported in Texas this year.

Just across the Rio Grande River in south Texas, Mexico has reported about 500,000 dengue cases in 2024.

According to the Red Cross website, as of November 30, 2024, blood donations are tested for multiple disease markers, but not dengue, chikungunya, or zika.

Note: This article was fact-checked, edited for tone, and updated on Dec. 2, 2024.

Sub Title:

Dengue

References:

Dengue: a hidden threat in blood transfusions amidst Brazil's largest outbreak

Dengue virus transmission risk in blood donation: Evidence from Thailand

Transfusion-Transmitted Dengue and Associated Clinical Symptoms During the 2012 Epidemic in Brazil

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Red Cross 2024

One-Dose HPV Vaccinations Save More Women from Cervical Cancer

Karen McClorey Hackett — Sun, 17 Nov 2024 18:48:21 +0000

Reviewer:

Robert Carlson, MD

Four years ago to the day, 194 countries resolved to eliminate cervical cancer, with the World Health Organization (WHO) leading a global strategy. Since then, significant progress has been made.

According to the WHO, on November 17, 2024, at least 144 countries had introduced a human papillomavirus (HPV) vaccine, and over 60 countries now include HPV testing in their cervical screening programs, the fourth most common cancer in women.

As world leaders arrive in Brazil for the G20 Summit this weekend, health prevention advocates are joining the WHO to mobilize efforts on a worldwide "Day of Action for Cervical Cancer Elimination."

"I thank all the health workers who are playing a critical role in this global effort," said Dr Tedros Adhanom Ghebreyesus, WHO Director-General, in a media release.

"Only with strong leadership and sustained investment can we achieve our shared goal of equitable access for communities most in need."

In 2022, the WHO aimed to fully vaccinate 90% of women with the HPV vaccine by age 15.

While the 90% vaccination goal has not been achieved, the WHO has led an expansion in access to HPV vaccines and a reduction in the suggested number of doses.

Data released in July 2024 indicates that the one-dose HPV vaccine coverage among young women increased from 20% in 2022 to 27% in 2023.

In 2023, 37 countries were implementing the single-dose schedule.

WHO estimates that the single-dose schedule adoption has resulted in at least 6 million additional young women being reached with HPV vaccines in 2023.

And as of late 2024, 57 countries are implementing the single-dose schedule.

Furthermore, the WHO took action to increase HPV vaccine supply.

WHO announced in October that a fourth WHO-prequalified HPV vaccine product, Cecolin®, has been confirmed for use in a single-dose schedule. This important milestone will contribute to improving the sustainable supply of HPV vaccines—allowing more women to be reached with the vaccines that prevent cervical cancer, says the WHO.

Dr Kate O'Brien, Director of the Department of Immunization, Vaccines and Biologicals at WHO, commented in a previous press release, "Given the continuing supply challenges, this addition of single-dose vaccine product means countries will have greater choice of vaccines to reach more girls."

In the United States, HPV causes about 37,800 cancer cases. In addition to cervical cancer, HPV causes cancers of the vagina, vulva, penis, anus, rectum, and oropharynx.

HPV vaccinations are recommended for two and three doses and are available at health clinics and pharmacies.

Sub Title:

37 countries offer one dose HPV vaccines for young women

References:

2020 - Global strategy to accelerate the elimination of cervical cancer

WHO and partners rally cervical cancer elimination efforts

WHO adds an HPV vaccine for single-dose use

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by Keith Johnston

Dengue Outbreaks Continue in the Caribbean

Karen McClorey Hackett — Wed, 10 Apr 2024 14:40:49 +0000

Reviewer:

Robert Carlson, MD

The Pan American Health Organization (PAHO) recently joined the U.S. CDC in issuing dengue outbreak warnings for the Region of the Americas.

As of March 26, 2024, over 3.5 million cases and more than 1,000 deaths have been reported in the Americas.

"This is cause for concern, as it represents three times more cases than those reported for the same period in 2023, a record year with more than 4.5 million cases reported in the region," PAHO Director Jarbas Barbosa said during a recent press briefing.

While dengue is on the rise throughout Latin America, the Caribbean is seeing an uptick in dengue cases in countries such as Barbados, Costa Rica, Guadeloupe, Guatemala, Martinique, and Mexico, where transmission is usually higher in the second half of the year.

For example, over 5,400 dengue cases have been confirmed in Costa Rica this year.

The PAHO Director also noted the presence of the mosquito vector and cases in new geographical areas, raising concerns that some countries may not be prepared to face an increase in transmission.

Dr. Barbosa noted, "the dengue case fatality rate in the region remained below 0.05%."

Once infected, dengue can take up to two weeks to develop, with illness generally lasting less than a week. However, dengue can become severe within a few hours. According to the CDC, severe dengue is a medical emergency, usually requiring hospitalization.

In February 2024, the CDC highlights dengue outbreaks in 18 countries in its Level 1 - Practice Usual Precautions, Travel Health Advisory.

In the United States, Florida and Puerto Rico have reported locally-transmitted dengue cases in 2024.

The CDC says travelers to areas of risk should protect themselves by preventing mosquito bites and speaking with a travel vaccine expert about dengue vaccination options one month before departing.

Sub Title:

San Juan Puerto Rico is a dengue hot spot

References:

PAHO calls for collective action in response to record increase in dengue cases 2024

US CDC Level 1 - Practice Usual Precautions - Dengue - 2024

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Wednesday, April 10, 2024 - 17:30

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from Pixabay

More Countries Release Genetically Modified Mosquitoes to Curtail Diseases

Donald Hackett — Sun, 11 Feb 2024 12:25:15 +0000

Reviewer:

Robert Carlson, MD

In 2023, mosquitoes in southeast Brazil transmitted diseases like dengue and Zika, which posed a significant public health issue.

The World Health Organization reported that dengue cases reached an all-time high in 2024, with over 5,000 deaths globally, and Zika cases were once again confirmed in various South American countries.

Unfortunately, recent data indicates that disease outbreaks will be similar in 2024.

However, scientists are working on a genetic-modifying solution to this massive problem.

Waldeir Barbosa da Silva recently explained to his family that he was going to release hundreds of thousands of mosquitoes infected with a bacterium (Wolbachia), which surprised them, as reported by Roberto González in SciDev.Net’s Latin America and Caribbean edition on February 5, 2024.

In 2011, Wolbachia-carrying mosquitoes were released for the first time into a community in the Cairns region of Australia. The Wolbachia strain was transferred to the Aedes aegypti mosquito, which does not carry it naturally.

Since then, the World Mosquito Program (WMP) has devised a strategy to breed large numbers of infected mosquitoes and release them into places with high rates of mosquito-borne diseases.

“The bacterium was injected into the eggs of mosquitoes,” says Sandra Zapata, an environmental technologist who worked with WMP in Barrio Paris, a district of Bogotá, Colombia, during the initiative’s most recent intervention.

To continue reading this article, the full, unedited version is posted below. And a related study is linked as a reference.

In the United States, the City of South Miami, Florida, implemented a test in 2019 in which Wolbachia-infected WB1 Aedes aegypti mosquitoes were released. The Florida Keys have continued these tests.

In 2024, two approved dengue vaccines are being used by various countries, but no Zika vaccines have been aithoried.

Sub Title:

wMel Wolbachia in Aedes aegypti mosquitoes in the Americas

References:

South American cities release mosquitoes to stem disease

wMel Wolbachia in Aedes aegypti mosquitoes throughout the Cities of Bello, Medellín and Itagüí, Colombia

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Brazil Spends Millions Modifying Dengue-Carrying Mosquitoes

Donald Hackett — Sun, 28 Jan 2024 14:45:18 +0000

Reviewer:

Robert Carlson, MD

The Federative Republic of Brazil recently deployed two science-based methods to reduce the impact of its multi-decade dengue virus outbreak.

Dengue re-emerged in Brazil in 1981 and has perpetually increased the number of cases, reaching about 2,909,404 cases and a case fatality rate of 0.049% for 2023.

As Brazil's Ministry of Health offers Takeda's second-generation QDENGA® vaccine, it also deploys a one-time intervention to protect Brazilians from dengue and other mosquito-borne diseases such as Zika.

To support Brazil's states and municipalities. The health department transferred R$256 million (about $500m) to reinforce the fight against dengue.

Brazil uses the Wolbachia method as an additional strategy for controlling dengue outbreaks.

The initiative involves releasing Aedes aegypti mosquitoes infected by an intracellular bacterium of the genus Wolbachia. This process blocks the transmission capacity of dengue viruses by mosquitoes.

According to the World Mosquito Program, Wolbachia is a safe, natural bacteria that has evolved to live inside the cells of up to 50% of insects.

Wolbachia cannot survive outside of insect cells because it does not have the necessary machinery to replicate itself without help from the insect host. This means Wolbachia cannot survive in the real world.

When Wolbachia mosquitoes are released, they breed with wild mosquitoes. Wolbachia-modified mosquitoes eventually replace the local mosquito population.

Once Wolbachia is established in the population, it stays there for many years.

In the United States, the Wolbachia method has been deployed in Florida since 2017. In the U.S., the use of mosquitoes with Wolbachia is regulated by the U.S. Environmental Protection Agency.

During 2023, the Florida Department of Health issued mosquito-borne illness advisories for dengue and malaria.

Sub Title:

Wolbachia method genetically modifies Aedes aegypti mosquitoes

References:

Brazil Ministry of Health 2024

World Mosquito Program 2023

Wolbachia is regulated in Florida by the U.S. EPA

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U.S. CDC Wolbachia bacteria