The 2021 Mosquito Season Review

The 2021 Mosquito Season Review

For most of the United States, ‘mosquito season’ is over, making it the perfect time for a 2021 mosquito season review. The overwhelming majority of adult mosquitoes have been killed by the cold weather, while others are overwintering in protected areas such as animal burrows, inside buildings, cracks and crevices, etc. Let’s take a look at a few of the headlines from 2021.

2021 Mosquito Season Review - CDC Statistics for 2021

West Nile virus (WNv) continues to be the most commonly reported mosquito-transmitted virus in the US. Since WNv was first detected in New York City in 1999, 51,801 human cases and 2,390 deaths have been reported to the Centers For Disease Control and Prevention (CDC). The averages per year are 2,467 cases and 114 deaths. In 2021, as of December 14th, CDC has reported 2,445 cases and 165 deaths from WNv. Sixty-nine percent of the cases were the more severe forms, known collectively as ‘neuroinvasive’, while the other 31% were ‘non-neuroinvasive’. Interestingly, Arizona alone accounted for 1,426 (58.3%) of the cases and 96 (58.2%) of the deaths. As of December 1st, CDC has reported 86 travel-related cases of dengue fever but no locally acquired cases. There have been 470 locally acquired cases of dengue reported from Puerto Rico. One other note of interest is that New Hampshire reported four human cases of Jamestown Canyon virus.

Are All Mosquitoes Vectors for Disease?

One of the most frequent questions I get is ‘do all mosquito species transmit pathogens to humans’?. The answer is a resounding ‘no’! In fact, most of the estimated 3,600 species of mosquitoes in the world don’t bite humans but instead prefer the blood of large mammals, birds, reptiles, amphibians, and other creatures. In 2020, CDC stated “Over 200 types of mosquitoes live in the continental United States and US territories; of these 200, about 12 types spread germs that can make people sick. Other mosquitoes bother people and are considered nuisance mosquitoes.” What does 2022 hold for the world of mosquitoes and mosquito-transmitted diseases? Whatever happens, CAPT Stan will be here to report on it. Best wishes for the New Year ahead! 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:

2021 Mosquito Season Review - Additional Resources

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