To this day, dengue is one of the most significant healthcare issues globally. Roughly half the world’s population is at risk dengue, and the economic burden caused by the disease is estimated to be almost 9 billion USD annually.1
In the Philippines, 29,885 cases were reported between December 25, 2022 and March 15, 2023. This is 85% more cases than the same period in 2022.2
Because of the number of people affected by dengue, and the costs associated with the disease, governments everywhere have worked to combat the disease, but it continues to persist year after year. So what makes this virus so difficult to deal with?
The Virus
One reason that dengue is difficult to control is because of the virus itself.
There are four different strains of the dengue virus: DENV-1 through DENV-4. When someone is infected with dengue, they gain lifelong immunity to the strain they were infected with, but only temporary immunity to the other strains. This means our body’s natural defenses cannot completely protect us from reinfection, especially in a country like the Philippines where all four strains are found.
This also makes vaccine development difficult, as any vaccine will have to consider all four strains of dengue.3
Compounding this is a phenomenon called antigen-dependent enhancement (ADE). In dengue, very high levels of antigens can protect against infection, but moderate levels of antigens can actually make some infections worse.4
These factors combine to make dengue vaccine development a unique challenge.
The Vector1,3
Another part of controlling dengue means controlling how it spreads, which brings its own challenges.
Dengue mainly spreads through a mosquito: Aedes aegypti. This species is well-suited towards living in human environments like cities. They breed in containers of standing water like tires or jars, which means they are frequently found near or in homes.3 The eggs of these mosquitoes are resilient as well. They can survive for months without water and hatch after when the eggs come into contact with water once again, like after it rains.1
Human Behavior1,3
Human behavior also plays a role in how dengue can spread. For example, human trade and travel is a major reason that dengue has been able to spread all over the world.
Factors not directly related to health like low quality housing, poor water access, and a lack of sanitation could all put people at greater risk of being infected. This means that dengue control measures should include consider these, as well as other socioeconomical factors that can affect the spread of disease.
Keeping Yourself Safe
These are only some of the reasons why dengue continues to be a major public health threat. But while experts continue to make progress in fighting dengue, remember to take measures to keep yourself safe like using effective mosquito repellants and emptying containers near your house that collect water.5
References:1. Ebi KL, Nealon J. Environ Res. 2016;151:115–123. 2. WHO Western Pacific Region. Dengue Situation Update 671. Available at: https://apps.who.int/iris/bitstream/handle/10665/365676/Dengue-20230511.pdf. Accessed 13 July 2023. 3. Bäck AT, Lundkvist A. Infect Ecol Epidemiol. 2013;3:19839. 4. Tan HD, et al. PLoS Pathog. 19(3):e1011223. 5. Centers of Disease Control and Prevention. Avoid Dengue by Preventing Mosquito Bites. Available at: https://www.cdc.gov/ncezid/dvbd/media/avoid-dengue.html. Accessed 1 Aug 2023.
