A Greek expert epidemiologist sounded the alarm about a potential increase in dengue fever cases in Europe due to climate change. Dengue is a viral infection transmitted to humans through the bite of infected mosquitoes.
Addressing a public health seminar in Athens on Monday, Athens Medical School professor Sotiris Tsiodras said that in South America, every hospital bed has a mosquito net to prevent the transmission of dengue fever between patients.
Brazil, where the incidence of the disease has increased by 450 percent in the last five years, plans to produce billions of mosquitoes infected with a special parasite that will prevent the transmission of dengue fever, he said.
In the first months of 2024, he added, France, Italy and Spain have recorded a 250 percent increase in dengue cases compared to the corresponding period in 2023, which has been attributed to climate change.
“I find it difficult to imagine that every bed in Greek hospitals will need its own mosquito net,” Tsiodras, who advised the Health Ministry on Covid-19 during the pandemic, said.
The epidemiologist said that climate change has had multiple effects on the spread of communicable diseases in terms of the distribution and ecology of transmitters (such as mosquitoes), water quality and quantity as well as food safety.
Half of the world’s population is at risk of dengue fever
The World Health Organization (WHO) says that about half of the world’s population is now at risk of dengue with an estimated 100–400 million infections occurring each year. While many dengue infections are asymptomatic or produce only mild illness, the virus can occasionally cause more severe cases, and even death.
The highest number of dengue cases was recorded in 2023, affecting over 80 countries in all regions of WHO. Since the beginning of 2023 ongoing transmission, combined with an unexpected spike in dengue cases, resulted in a historic high of over 6.5 million cases and more than 7300 dengue-related deaths reported.
Several factors are associated with the increasing risk of spread of the dengue epidemic, WHO notes:
-the changing distribution of the vectors (chiefly Aedes aegypti and Aedes albopictus mosquitoes), especially in previously dengue naïve countries;
-the consequences of El Niño phenomena in 2023 and climate change leading to increasing temperatures and high rainfall and humidity;
-fragile health systems in the midst of the COVID-19 pandemic; and
-political and financial instabilities in countries facing complex humanitarian crises and high population movements.
According to WHO, One modeling estimate indicates 390 million dengue virus infections per year of which 96 million manifest clinically. Another study on the prevalence of dengue estimates that 3.9 billion people are at risk of infection with dengue viruses.
The disease is now endemic in more than 100 countries in the WHO Regions of Africa, the Americas, the Eastern Mediterranean, Southeast Asia, and the Western Pacific. The Americas, Southeast Asia, and Western Pacific regions are the most seriously affected, with Asia representing around 70% of the global disease burden.
Tasos Kokkinidis
