Dengue sometimes gets overshadowed by Malaria as the infectious disease travelers fear the most. But here in Mexico, Dengue fever is far more common.
For expats who choose to live in Mexico, you need to know that Dengue is endemic to nearly 90% of the country. In other words, the risk is ever-present — and growing.
Mexico’s Dengue cases now likely reach hundreds of thousands per year, whereas its malaria cases are less than 200 annually.
Dengue Cases Hit New Record in 2024 – With Jalisco Seeing a Huge Surge
Following a record year in 2023 when confirmed cases tallied 54,403 and probable cases reached 278,000, 2024 is on track to blow those numbers out of the water.
2024 is likely to be the worst year on record for Dengue cases in Mexico, with some interesting shifts in hotspots.
Overall, Dengue cases have been reported in 28 of 32 Mexican states, with the humid, low-lying coastal areas the notable hotspots.
Interestingly, Veracruz and the Yucatán along the Gulf and Caribbean had the most confirmed cases last year. In 2024, however, the worst outbreaks are happening in the western coastal states Guerrero and Oaxaca, based on probable case tallies.
Reduced Dengue infections in the Yucatán are attributable to spraying efforts to reduce the mosquito population, something many other high-risk states haven’t been doing consistently.
Data in the table below show confirmed and probable cases year-to-date through August 5 versus the same period a year ago.
From a growth perspective, the two states that have seen the greatest surge in Dengue cases year over year are two more western states – Jalisco and Nayarit. Cases in these neighboring states have exploded.
What is Dengue Fever?
Dengue is a viral infection that infects humans via mosquito bites. Every year across tropical and sub-tropical climates, up to 400 million people are infected.
There are an astonishing 3,500 different species of mosquito on the planet, but only three carry deadly pathogens you need to worry about – Aedes, Culex, and Anopheles.
The Dengue virus is spread through the bite of an infected female mosquito of the Aedes species.
How Dengue Spreads
As noted above, not all mosquitos pose a risk to humans. You must be bitten by an A. egypti mosquito to become infected with Dengue.
But since there aren’t any distinguishing characteristics for this mosquito, the only way to protect yourself is to avoid being bitten by any type of mosquito.
For the tropical virus wonks out there (myself included), there are four strains of the Dengue virus — with all four present in Mexico.
How Dangerous is Dengue Fever?
The good news is that only about 1 in 4 people infected with Dengue suffer symptoms.
For these unlucky people, symptoms may include a high fever, intense pain throughout the body, abdominal discomfort, nausea or vomiting, severe headache, body rashes, and fatigue.
According to the National Institutes of Health, the incubation period for Dengue is 4 to 7 days, with symptoms typically lasting from 3 to 10 days.
But the different types of Dengue are not equally risky. The strain known as DENV-2 is the most lethal. Unfortunately, it’s also the most prevalent type of Dengue in Mexico.
This helps explain why Mexico sees roughly 20% of total deaths worldwide due to Dengue. The fourth strain known as DENV-4 is the least dangerous—and the least common in Mexico.
One of Dengue’s informal names is “bone break fever.” This is because those suffering its worst symptoms report severe joint pain that feels like their bones are breaking.
A small minority of patients also suffer bleeding from the nose and gums, which indicates Dengue hemorrhagic fever — the most serious form of the disease.
For the 5% of people whose infection progresses to severe Dengue, the mortality rate can reach 20%, with most deaths attributable to lack of timely health care. The overall death rate from Dengue is not high though — at roughly 0.4%.
If you are suffering from any of the symptoms described above, seek medical help immediately! The only way to confirm a Dengue infection is via a blood test.
Why Are Dengue Cases Increasing?
Climate change is expanding the range of disease-carrying mosquitos in the Americas. New research from the University of Toronto uses models to forecast how Dengue will spread across Mexico (and Brazil).
Compared to 2023, Mexico is now seeing its first cases in the central highlands of Zacatecas, with a big increase in infections in neighboring Guanajuato. Previously, these states had few or no infections.
As you can see in the map below, Dengue has expanded inland and north in recent years, encroaching on zones where it previously couldn’t survive.
Year to date, only Mexico City, Chihuahua, Tlaxcala, and Baja California North have been Dengue-free, based on confirmed cases. (some of them have probable cases) These states are too dry and/or too cold for the A. egypti mosquito to survive.
The bad news for Mexico is that Dengue is not just becoming more prevalent – it’s also becoming more severe due to the spread of variant 2, as noted above.
How to Protect Yourself from Dengue
One key to living well in Mexico is staying healthy.
Unfortunately, there is no cure for Dengue and no vaccine to prevent infection, with the exception of Sanofi’s 3-dose regimen available only to children living in endemic areas for the virus.
For everyone else, treatment is merely pain meds to alleviate symptoms. That said, new R&D by Janssen Pharmaceuticals to find an effective vaccine for adults is showing promise.
Until there’s a vaccine for all, there are several things you can do to reduce your odds of being infected. These include:
- Wearing long sleeves and long pants when visiting natural areas
- Applying an effective insect repellent
- Eliminating all standing water around your home.
- Putting screens (mosqueteros) on your windows.
- Getting the heck out of any place that’s infested with mosquitos.
- Installing a mosquito net around your bed for sleeping (especially if you don’t have window and door screens).
- Avoiding natural settings in the evenings when mosquitos are more active.
And if you haven’t yet chosen where to live in Mexico, you should consider moving to drier central and northern states and areas at higher elevation, with the caveat that these states have more issues with water scarcity.
In the meantime, stay safe out there — and maybe have another shot of Tequila.
Sources: National Institutes of Health, Centers for Disease Control, Secretaria de Salud (Mexico), PBS, Open Access Government