The global spread of dengue fever, one of the most notorious and incurable diseases, has reached record levels, prompting governments and public health experts worldwide to raise the alarm. This mosquito-borne virus, once confined to warm climates, is now emerging in regions where it was previously unheard of, including parts of Europe and the United States.
In 2023 alone, there were over five million reported dengue infections across 80 countries and territories, a significant increase from the 500,000 cases recorded in 2000. Tragically, more than 5,500 lives have been lost to this disease so far.
Dengue’s impact has been felt in various parts of the world. California reported its first case of locally-transmitted dengue virus, while Sudan’s capital, Khartoum, experienced its first-ever outbreak, straining an already underfunded healthcare system. In countries where dengue was already endemic, such as Bangladesh and Peru, the virus has spread at an unprecedented scale. Bangladesh witnessed its worst outbreak in history, with cases reported in all 64 districts, infecting nearly 300,000 people and claiming over 1,400 lives. Peru’s health minister even declared a state of emergency to tackle the raging dengue outbreak.
One of the major concerns highlighted in a risk assessment report by the Pan-American Health Organization is the lack of robust dengue surveillance and management systems. This raises concerns about undetected cases and unrecorded travel movements that could contribute to the unnoticed spread of the disease. Currently, there is no antiviral treatment for dengue, but the symptoms can be managed with medication.
Dengue symptoms can vary widely, with up to 80% of cases being asymptomatic. While some infections may only result in flu-like symptoms, severe cases can lead to internal bleeding, potentially causing death. Common symptoms include high fever, nausea, vomiting, severe muscle and joint pain, earning the disease the nickname “breakbone fever.” Early detection and access to medical care can significantly reduce the mortality rate, which is less than 1% for dengue overall but rises to 2-5% for severe cases. However, if left untreated, the mortality rate can reach 20%.
Dengue is primarily spread through infected female Aedes aegypti mosquitoes, which thrive in stagnant water. Mosquito bites are the primary mode of transmission, but the disease can also be passed from pregnant women to their babies or through blood transfusions, organ transplants, or needle injuries. The resurgence of global travel after the COVID-19 pandemic and the El Niño weather phenomenon, which contributes to warmer temperatures, are believed to have contributed to the increase in dengue outbreaks. Additionally, rising global temperatures due to climate change have expanded the regions suitable for Aedes aegypti mosquitoes, posing a threat to parts of the US, Europe, and Africa.
Experts have also highlighted the impact of urbanisation on dengue transmission. The growth of informal urban settlements without proper plumbing networks creates breeding grounds for mosquitoes in stagnant water and exposed litter. Aedes aegypti mosquitoes, already well-adapted to urban environments, thrive in these conditions. The surge in dengue cases has put healthcare systems worldwide to the test, with some struggling to meet the overwhelming demand. Experts have raised concerns about the human costs of inadequate governmental responses to dengue, leading to mounting public anxiety and anger.
Authorities worldwide are taking various measures to combat dengue. Traditional methods such as fumigation, which involves killing mosquitoes, have been widely used but are becoming less effective as mosquitoes develop resistance to chemical compounds. An innovative approach led by the World Mosquito Program involves releasing special mosquitoes bred to carry a bacteria called Wolbachia, which blocks the transmission of dengue and other mosquito-borne viruses. However, this approach has faced opposition in some areas due to concerns about its effectiveness and potential risks.
Countries like Singapore have implemented rigorous inspections to identify and eliminate mosquito breeding grounds, imposing fines or imprisonment for premises found to have mosquito breeding. Efforts are also underway to track dengue clusters and predict the spread of the disease globally. Dengue vaccines, such as Qdenga and Dengvaxia, are available for specific age groups or those living in high-risk areas. However, the confidence in vaccines was impacted by a situation in the Philippines, where the Dengvaxia vaccine was found to increase the severity of the disease for some recipients.
To protect oneself against dengue, authorities recommend using insect repellent, wearing protective clothing, installing insect screens, and regularly checking homes for stagnant water. It is crucial for governments worldwide to share best practices in preventing the spread of dengue, especially as the disease reaches new regions. Funding should be allocated to anticipate extreme weather events and climate shocks to effectively manage the risk posed by dengue.
The global battle against dengue requires collaborative efforts at the local, national, and international levels. With the increasing threat of dengue and its devastating impact on communities, it is essential to prioritise effective surveillance, management systems, and preventive measures. By staying informed, taking necessary precautions, and supporting scientific advancements, we can work towards reducing the burden of this notorious disease and protecting the health and well-being of people worldwide.
