Updates on the Epidemiology of Dengue Fever in Chiapas, MX

Well, March 11, 2020 was the date the World Health Organization declared COVID-19 a global pandemic. I recall the director of W.H.O. struggling with the decision for a day or two prior, with the understanding that such a proclamation from W.H.O. carries extreme significance .Last such pandemic was 2009-2010 H1N1 swine flu pandemic, which is already dwarfed by the current pandemic.

That being said, just because a novel virus causes a global pandemic doesn't render the rest of the public health threats obsolete. As a follow up, we are now in week 15 of 2020 and Mexico's Secretaría de Salud has continued to post weekly updates tracking the epidemiology of Dengue Fever throughout the country of Mexico. Thankfully we are currently off-season for Dengue. Here are the last three years of case counts for 2020 (partial), 2019 and 2018:

The seasonal curve for 2018-2019 was significantly higher than the previous year, and I worry that the curve may continue to elevate this year. Of note, the distribution of cases in 2018-2019 was not localized to the state of Chiapas as it was in 2017-2018. It's still too early to tell what will be this year's distribution.

2018-2019 (concentration in Jalisco)

2017-2018 (concentration in Chiapas)

Taking a step back, Macías et al. (2019) observed the hospital burden of Dengue Fever throughout Mexico over 2009-2014 and consolidated this information into a similar graphic, showing a significant and expected distribution of disease burden throughout the southern half of the country.

The troubling aspect of public health is that the most vulnerable populations among us tend to carry the disproportionate weight of disease burdens, and Dengue Fever is no different. As the ecology of the Aedes egypti vector continues to evolve through an ever-changing world, I expect that the COVID-19 crisis will have little influence on the trajectory of Dengue Fever. However, human activity may be significantly altered by the COVID-19 crisis, and that may have myriad possible effects on the ecology of the Aedes egypti mosquitos. As always, only time will tell for sure.


References
1. https://www.gob.mx/cms/uploads/attachment/file/546854/Pano_dengue_15_2020.pdf
2. https://www.gob.mx/cms/uploads/attachment/file/524262/Pano_dengue_52_2019.pdf
3. https://www.gob.mx/cms/uploads/attachment/file/478592/Pano_dengue_sem_52_2018.pdf
4. https://www.medigraphic.com/pdfs/revinvcli/nn-2019/nn193b.pdf