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Diseases | Science

More mosquitoes and mosquito-borne diseases are the ‘new normal’


Author: Valneva Chief Medical Officer, Dr. Juan Carlos Jaramillo, M.D.

Consider the recent headlines: “Mosquito-borne diseases are surging in Europe,” found in the leading science journal, Nature and, “Mosquito-borne diseases on the rise as insect population thrives,” published in US News & World Report. Further, the Times of India and a globally recognized infectious disease intelligence provider have reported a four-fold increase of the mosquito-borne disease, Chikungunya, in India since last year.

The higher incidence of mosquito-borne diseases is due to the undisputable fact that there are more mosquitoes. The reason for the increase should not surprise us: the earth is warming. In July, our planet experienced its warmest day in recent history. As temperatures rise, the summers are longer, rainfall is heavy, and conditions become increasingly favorable to mosquitoes enabling them to thrive in places they didn’t before.

Mosquitoes are more than a nuisance. A bite from an infected mosquito can lead to diseases like dengue and West Nile, as well as viruses people may find less familiar like Chikungunya, which has been reported in more than 110 countries. Chikungunya can be very serious. Chronic symptoms – experienced by approximately 43% of people with the infection – are characterized by joint pain, arthritis-like symptoms, fatigue and potentially debilitating effects which can last for months or even years. Many who experience severe infection never fully recover.

More mosquitoes and higher incidence of mosquito-borne diseases are becoming the new normal. More awareness and preparation should be, too. What should people do now when traveling to where the mosquitoes are? Here are five considerations:

  • The Nature article says, “don’t get bitten.” The authors recommend using repellant, wearing long-sleeved, light-colored clothing, and keeping windows covered with mosquito screens.
  • Know the destinations where mosquitoes are thriving. You may be surprised. Mosquitoes carrying diseases including Chikungunya are now found in European countries such as France, Croatia, Italy, Portugal and Spain, in addition to popular travel destinations including India, Brazil, Argentina, Central America, Asia, Mexico, and the Caribbean.
  • Make it personal: For example, what blood type are you? Published data show mosquitoes are more likely to bite Type O over A, B, or AB. And, if you’ve ever wondered why mosquitoes seem to target you more than others, it may be your natural fragrance.
  • Plan activities with more awareness: The peak biting activity of the Aedes aegyptimosquito (that carries Chikungunya, dengue, yellow fever, and Zika) is after sunrise and at sunset. Even the presence of a full moon can significantly increase mosquito activity, sometimes by as much as 500%, according to the American Mosquito Control Association.
  • Get a travel health consult: There are many resources such as specialty travel clinics, pharmacies in many states, and healthcare professionals with travel health expertise. You can also check out the US Centers for Disease Control & Prevention Travelers’ Health portal. The good news is several mosquito-borne diseases can be prevented with vaccines.

Americans are traveling internationally in larger numbers. With more attention, prevention and protection, the only thing travelers will return with after a great trip are great memories.

1. https://www.nature.com/articles/d41586-024-03031-y

2. https://www.usnews.com/news/national-news/articles/2024-09-04/mosquito-borne-illnesses-on-the-rise-as-insect-population-thrives

3. https://timesofindia.indiatimes.com/city/pune/chikungunya-cases-rise-four-fold-in-state-this-year/articleshow/113678240.cms?utm_campaign=OutbreakInsider&utm_medium=email&_hsenc=p2ANqtz–R4RQtOx4HDoVRLp7tkpg_hY3-W7nAqafgQZ3vec1nytQOYKNV4Lj5jQKhRiFQfwfnaTErXfH-0dXoUvYBe3o75Di34-ua0UPmJa3W4lYPT0jnYJw&_hsmi=327217652&utm_content=327217014&utm_source=hs_email

4. https://bluedot.global/vaccines-on-the-table-as-chikungunya-outbreak-intensifies-in-india/

5. https://climate.copernicus.eu/new-record-daily-global-average-temperature-reached-july-2024#:~:text=The%20Earth%20has%20just%20experienced,*%2C%20at%2017.16°C.

6. https://www.ecdc.europa.eu/en/news-events/worsening-spread-mosquito-borne-disease-outbreaks-eueea-according-latest-ecdc-figures#:~:text=Background,Netherlands%2C%20Slovakia%20and%20Sweden.

7. Puntasecca CJ, King CH, LaBeaud AD. “Measuring the global burden of chikungunya and Zika viruses: A systematic review.” PLOS Negl Trop Dis 15, no. 3 (2021): e0009055.

8. Paixão, E. S., Rodrigues, L. C., Costa, M., Itaparica, M., Barreto, F., Gérardin, P., & Teixeira, M. G. “Chikungunya chronic disease: a systematic review and meta-analysis.” Transactions of the Royal Society of Tropical Medicine and Hygiene

9. https://www.sciencepublishinggroup.com/article/10.11648/j.aje.20190302.13?fbclid=IwZXh0bgNhZW0CMTAAAR0QBSGtK43QGfr5_c3zbRQIZN2vM8AbsfcEVR9Kd_zgF_LfgDJLkyvbDys_aem_DxSCR1lPAp1qlHUHFYwD7Q

10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10789295/pdf/nihms-1953436.pdf

11. https://wwwnc.cdc.gov/travel/yellowbook/2024/environmental-hazards-risks/mosquitoes-ticks-and-other-arthropods#:~:text=Mosquitoes%20bite%20throughout%20the%20day,and%20at%20sunset%20(dusk).

12. American Mosquito Association. https://www.mosquito.org/fun-facts/

13. https://www.trade.gov/us-international-air-travel-statistics-i-92-data