SAN JUAN, Puerto Rico (AP) — Dengue is sweeping across the Western Hemisphere in numbers not seen since record-keeping began more than four decades ago, with experts warning that rising temperatures and rapid urbanization are accelerating the pace of infections.

Officials from countries in the Americas and Caribbean, such as the Bahamas and Brazil, are warning of overcrowded clinics and a daily increase in new infections as the region has surpassed a record of over 4 million reported cases this year. This number exceeds a previous record set in 2019, and there have also been more than 2,000 reported deaths in this region.

“This year marks the highest number of dengue cases ever recorded,” stated Thais dos Santos, who serves as an advisor for monitoring and managing arboviral diseases at the Pan American Health Organization, the regional branch of the World Health Organization in the Americas. She pointed out that data collection for dengue began in 1980. “Diseases transmitted by vectors, particularly those carried by mosquitoes, serve as a useful indicator of the impact of climate change.”

Insufficient sanitation and inadequate healthcare infrastructure have played a role in the increase of cases. However, specialists suggest that climate change-induced droughts and floods are also contributing to the spread of the virus. This is due to the presence of stagnant water and increased mosquito activity during heavy rainfall.

Gabriela Paz-Bailey, the head of the dengue department at the U.S. Centers for Disease Control and Prevention in Puerto Rico, observed that rising temperatures are expanding the mosquito’s living space and accelerating the development of the virus within the mosquito. This results in increased levels of the virus and a higher likelihood of transmission.

Dr. Jeremy Farrar, chief scientist of the World Health Organization, stated that these infections are a result of major underlying trends that are occurring globally. He also mentioned that addressing climate change is a challenging task and with a growing number of urbanized countries, diseases like dengue are becoming more frequent and difficult to manage.

According to Dos Santos, there has been an increase in dengue cases and new patterns emerging, such as higher temperatures and longer seasons. The virus is also spreading to areas typically not affected, with California and Florida reporting their first local cases and Florida setting a new record with 138 cases this year compared to 65 last year.

The summer of the Northern Hemisphere in this year has been the warmest ever recorded. In August, the temperature was 1.5 degrees Celsius (2.7 degrees Fahrenheit) higher than the average temperature before industrialization. According to the European climate service, Copernicus, 2023 is currently the second hottest year on record.

As of early November, there have been over 4.5 million reported cases of dengue worldwide, with 4,000 deaths recorded in 80 countries. Farrar suggests that this year’s number of reported cases could exceed the global record of 5.2 million set in 2019.

According to him, dengue is a growing concern for the Americas, but it has become a global issue.

Countries like Bangladesh are seeing a record number of cases and deaths. The government in the South Asian country has reported more than 313,700 cases and more than 1,600 deaths, the majority of them occurring within three days of hospitalization, according to published data.

The mosquito responsible for transmitting dengue has been detected in 22 European countries, and cases of the disease have been observed in France, Italy, and Spain. In August, Chad, a country in central Africa, reported its first recorded outbreak of dengue.

According to the World Health Organization, Dengue is present in approximately 129 countries and poses a risk to around half of the global population. The primary method of transmission is through bites from infected female Aedes aegypti mosquitoes, as they require protein from their hosts for their eggs. Symptoms of the virus include intense headaches, fever, vomiting, and a skin rash. Although many infected individuals do not experience symptoms, severe cases can result in plasma leakage and potential fatality.

According to experts, having multiple infections increases the chances of developing severe dengue, making it even more concerning.

According to Paz-Bailey, the mosquito that transmits dengue is also responsible for spreading chikungunya and Zika virus. However, the prevalence of the latter two viruses is lower due to previous immunity. Paz-Bailey noted that it is uncommon for a mosquito to carry multiple viruses simultaneously.

In January, the World Health Organization issued a warning about the potential global impact of dengue, a rapidly spreading disease transmitted by mosquitoes. Although vaccines and genetically modified mosquitoes carrying Wolbachia bacteria have been developed to combat dengue, there is currently no targeted treatment for those who have already contracted the virus.

The number of countries that have requested vaccines from manufacturers is unknown. However, the Pan American Health Organization has stated that their immunization technical advisory group has discussed dengue vaccines and will release recommendations once they are finalized.

Earlier this year, the Americas set a new regional record for dengue. Brazil, Argentina, Paraguay, and Peru had the highest number of cases globally. Peru declared a state of emergency in certain regions due to a historic number of cases.

The Caribbean is currently facing a rise in cases, as the region has seen a 15% rise in confirmed cases in early October compared to the same time frame last year. This information comes from the Caribbean Public Health Agency.

Authorities in Guadeloupe and Martinique, French Caribbean islands, announced a current epidemic in August that remains ongoing. For instance, Martinique has recorded an average of 800 infections per week on the island, which has a population of approximately 394,000.

In September, Jamaica and the Bahamas announced an outbreak, which was followed by Barbados in October.

The Caribbean Public Health Agency released a statement emphasizing the dangers and consequences of outbreaks of dengue and other diseases transmitted by mosquitoes. These outbreaks pose a major threat to health, tourism, and overall social and economic development.

Impoverished countries struggle the most with dengue, with poor sanitation creating fertile breeding grounds for infected mosquitoes, a lack of air conditioning and screened windows allowing the insects to roam freely and rickety health systems groaning under a growing caseload.

According to Farrar, who is the chief scientist at the World Health Organization, treating dengue is a challenging task due to patients’ tendency to delay seeking medical attention and the rapid progression of the virus. Providing care for patients can be complicated as it involves closely monitoring their fluid intake, which is a time-consuming process.

“Consider a scenario where you have a thousand individuals in need of such sensitive clinical attention. This could easily overpower a system,” he stated.

Claude Burton, a retiree from Jamaica who is 70 years old, has personal experience with the burden placed on healthcare facilities. In the previous month, his health deteriorated and he eventually sought medical attention from a doctor.

Following his positive test result, he traveled by taxi from Ocho Rios to Kingston for an hour to be hospitalized per his doctor’s recommendation. The initial hospital he sought treatment at was unable to admit him due to a lack of available beds. He then spent two nights in a wheelchair at the second hospital before a bed became available.

He remembered, “I was in a really bad state.” He also mentioned that he had blood in his urine and had to stay in the hospital for four nights.

According to Dr. Georgiana Gordon-Strachan, the director of the Tropical Metabolism Research Unit at the University of the West Indies in Jamaica, the island’s summer in 2023 created ideal circumstances for its most recent outbreak.

According to her, dengue fever is influenced by heat.

The most concerning aspect is that the current strain of dengue circulating in Jamaica is the most severe out of the four strains, according to her statement.

In order to combat the virus, trucks are traveling through Jamaica, Barbados, and other Caribbean islands and using a product that has a small quantity of insecticide to fog designated areas. Health authorities are also continuously reminding individuals to dispose of old tires, plastic containers, and other objects that can collect rainwater. They are also recommending the use of bed nets while sleeping and wearing long pants and shirts with sleeves.

Paz-Bailey emphasized the need for proactive discussion about dengue as it poses a significant risk to public health.