The 2020 Mosquito Season Review

The 2020 Mosquito Season Review

As cold weather settles in over most of the United States and insect activity diminishes, let’s take a look back at some of the happenings with a 2020 mosquito season review. Two of our most dangerous disease vectors, the yellow fever mosquito (Aedes aegypti) and the Asian tiger mosquito (Aedes albopictus) continue to expand their range in the US. These two species are the primary transmitters of the viruses that cause Zika, chikungunya, dengue, and yellow fever. A third species, the Asian bush mosquito (Aedes japonicus) is rapidly spreading in the Eastern US. Its disease-transmitting potential is not well understood.

2020 Mosquito Season Review - CDC Statistics for 2020

The mosquito-borne disease burden for humans and animals was substantial. The numbers below are from CDC’s website. Note that full reporting for 2020 is not yet complete. There was evidence of West Nile virus activity in people, birds, or mosquitoes in 44 states. Also, there were 540 human cases, well below our average of about 2,000 per year; 184 (34%) of the cases occurred in California. There were 9 human cases and a large number of equine cases of Eastern equine encephalomyelitis (EEE), compared to 36 human cases in 2019. Dengue fever made a dramatic reappearance, with 250 total reported cases. 181 of those were travel-related while the rest of the cases (69) were all locally acquired in Florida, primarily in the Florida Keys. Finally, there were 5 cases of a relative rare disease, caused by Jamestown Canyon virus, reported from New Hampshire.

A Rough Year for Mosquito Surveillance

It is really unclear how much actual disease from mosquito bites there was in 2020. Many surveillance and control programs were crippled or actually shut down by the pandemic, and personnel resources were reallocated. One piece of good news, however, is that there is absolutely no scientific evidence that the coronavirus that causes COVID-19 is transmitted by mosquitoes. 2021 will likely bring more outbreaks and surprises in the mosquito universe and CAPT Stan will be here to bring you all the news! Best wishes for the holiday season and new year. Captain Stan Cope (aka the Mosquito Man) is our Vice President of Technical Services and blogs frequently on mosquitoes. In addition to his social media content you can find his blog archives here:

2020 Mosquito Season Review - Additional Resources

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