According to the WHO’s chief scientist, Dengue fever is poised to emerge as a significant threat in the southern United States, southern Europe, and new parts of Africa during this decade. This escalation is attributed to rising temperatures that facilitate the spread of infection-carrying mosquitoes.
Traditionally, dengue fever has been a pervasive issue in much of Asia and Latin America, leading to an estimated 20,000 fatalities each year.
Surge in dengue cases
Global dengue rates have surged eightfold since 2000, largely driven by climate change, increased human mobility, and urbanization. Although many cases remain unreported, the year 2022 witnessed 4.2 million documented cases worldwide, with health authorities cautioning that near-record transmission levels are expected in the current year. Bangladesh, for instance, is grappling with its most severe outbreak to date, with more than 1,000 fatalities.
Jeremy Farrar, an infectious diseases specialist, who recently joined the World Health Organization, emphasized the necessity for proactive discussions and preparation concerning dengue fever. He highlighted the need to equip countries for the forthcoming challenges in many major cities.
Farrar, with 18 years of experience in Vietnam working on tropical diseases including dengue, and as the former head of the Wellcome Trust global health charity, as well as an advisor to the UK government on its COVID-19 response, has unique insights into the matter. He cautioned that Dengue infection is likely to become endemic in parts of the United States, Europe, and Africa where limited local transmission has already occurred. This will place substantial strain on healthcare systems in numerous countries.
Dengue is a disease that often goes unnoticed, with most individuals showing no symptoms. Consequently, case rates are presumed to be significantly higher than the officially reported numbers. Those who do exhibit symptoms may experience high fever, muscle spasms, and severe joint pain, often referred to as “break-bone fever.” In less than 1% of cases, Dengue can prove fatal.
Presently, there is no specific treatment for dengue, although a vaccine is available. Recently, the WHO endorsed the Qdenga vaccine from Takeda Pharmaceuticals for children aged 6 to 16, especially in regions where dengue poses a significant public health threat. While the vaccine is approved in the EU, Takeda encountered setbacks in the United States, with the vaccine’s application withdrawal due to data collection issues. Discussions with the U.S. Food and Drug Administration regarding the vaccine are ongoing.
Preparing new regions for dengue involves targeted allocation of public health funds, focusing on areas such as mosquito control. Dengue is transmitted by infected Aedes aegypti mosquitoes, which differ from the malaria-carrying variety in their behavior. They bite indoors throughout the day rather than at night and breed in shallow water.
Farrar emphasized that effective prevention strategies must encompass hospital triage plans, scientific innovation, urban planning, and the mitigation of standing water near or within homes. Collaboration across various sectors is imperative to tackle this growing health challenge effectively.