Commonwealth _ Dengue fever is currently surging across the Western Hemisphere at an unprecedented rate, marking a stark escalation since record-keeping began over four decades ago. Experts are sounding alarms, attributing the swift spread of infections to rising temperatures and rapid urbanization. With a staggering count of over 4 million reported cases across the Americas and the Caribbean this year, surpassing the previous record set in 2019, authorities from various regions, such as the Bahamas and Brazil, are grappling with overwhelmed healthcare facilities and a steady stream of new cases. Tragically, the region has witnessed over 2,000 deaths linked to dengue. Thai’s dos Santos, an adviser on surveillance and control of arboviral diseases at the Pan American Health Organization, highlighted this year as unprecedented in dengue history since record-keeping began in 1980. She emphasized the significance of vector-borne diseases, like those transmitted by mosquitoes, as crucial indicators of the impacts of climate change. Factors such as poor sanitation and fragile healthcare systems have contributed to the surge, but climate change-induced droughts, floods, and subsequent mosquito proliferation are amplifying the virus’s transmission.
Dr. Gabriela Paz-Bailey from the U.S. Centers for Disease Control and Prevention underscored how higher temperatures expand the mosquito habitat and accelerate the virus’s development within mosquitoes. This results in higher viral loads, elevating the chances of transmission. Dr. Jeremy Farrar, chief scientist at the World Health Organization, emphasized the broader global trends driving these infections. He pointed to the difficulty in addressing climate change and the rapid urbanization occurring in many countries, foreseeing increasing complexity in dealing with diseases like dengue. As dengue cases spike, officials are observing unprecedented occurrences, including record temperatures, prolonged seasons, and the virus’s spread to regions farther north and south than usual. Notably, California and Florida reported their first locally acquired dengue cases this year, with Florida hitting a record of 138 cases compared to 65 cases the previous year. The Northern Hemisphere experienced its hottest summer on record, with August temperatures surpassing pre-industrial averages by 1.5 degrees Celsius (2.7 degrees Fahrenheit). 2023 stands as the second hottest year recorded globally, according to Copernicus, the European climate service.
Globally, over 4.5 million dengue cases were reported by early November, with over 4,000 deaths across 80 countries. Farrar warned that the global record of 5.2 million cases set in 2019 might be exceeded this year, underlining that while the Americas should be particularly concerned, dengue has become a worldwide concern. The mosquito responsible for carrying dengue has been identified in 22 European countries, and localized transmission of the disease has been observed in France, Italy, and Spain. In an unprecedented occurrence, Chad, located in central Africa, reported its first-ever outbreak of dengue in August.
Compounding the issue, experts warn that recurrent infections heighten the risk of developing severe dengue. While the mosquito carrying dengue also transmits chikungunya and the Zika virus, there’s lower circulation of these viruses due to previous immunity. Dr. Paz-Bailey noted the rarity of mosquitoes carrying two viruses simultaneously. The World Health Organization cautioned in January about the pandemic threat posed by dengue, branding it as the fastest-spreading mosquito-borne disease globally. Despite the existence of vaccines and specially engineered mosquitoes with Wolbachia bacteria to combat dengue, there are no specific treatments available once someone contracts the virus. The extent of vaccine requests from manufacturers remains unclear across countries. However, the Pan American Health Organization indicated that its immunization advisory group convened to discuss dengue vaccines and intends to release recommendations upon finalization. The Caribbean region is grappling with a surge in cases, with a 15% increase in confirmed cases by early October compared to the same period the previous year, as reported by the Caribbean Public Health Agency. Highlighting the grave implications, the Caribbean Public Health Agency emphasized that dengue outbreaks and other mosquito-borne diseases pose significant threats to health, tourism, as well as social and economic development. The impact of dengue is particularly severe in impoverished nations, where inadequate sanitation fosters breeding grounds for infected mosquitoes. Moreover, the absence of amenities like air conditioning and screened windows allows these insects to freely proliferate, burdening already fragile healthcare systems.
