More Americans are getting sick from bug bites

Randy Kelley
May 2, 2018

Lyle Petersen, director of the CDC division of vector-borne diseases, said increasing temperatures can help such diseases spread, though he declined to say specifically if climate change is the cause.

The number of Americans sickened by bites from infected mosquitoes, ticks or fleas tripled from 2004 to 2016 - a result of rising global temperatures and increased worldwide travel, U.S. health officials said Tuesday.

The numbers of confirmed new transmissions jumped from just 27,000 in 2004 to more than 96,000 in 2016, the CDC said. CDC is working on "rebuilding comprehensive vector control programs that have eroded over time", according to the report authors, in addition to working with health departments and organizations on improving surveillance, developing guidance, and increasing public awareness regarding these diseases.

Though rare, plague was the most common disease resulting from the bite of an infected flea.

Using a national database, researchers analyzed reported cases of 16 different vector-borne diseases (six tick-borne diseases, nine mosquito-borne diseases and one flea-borne disease), from 2004 to 2016.

Other factors leading to the spread of mosquito-borne diseases like Zika include worldwide travel, the CDC said.

West Nile virus was the most common form of mosquito-borne illness, Petersen said, but there has been a recent "accelerating trend" of mosquito-borne disease being introduced to the us, with West Nile in 1999, chikungunya in 2014, and Zika in 2016.

"It enables these ticks to expand to new areas".

The CDC said it is likely that the 640,000 cases of bug-borne illnesses grossly understates the actual number of cases around the US because many other cases are never diagnosed or treated properly. "They are spread by movements of people or animals or vectors, and with expanding global travel and trade, all diseases are basically a plane flight away", he said.

The authors also noted there were nine vector-borne human diseases that were reported for the first time in the US from 2004 to 2016.

More than 642,000 cases of these illnesses were reported during the 13 years studied in the Vital Signs report from the US Centers for Disease Control and Prevention.

The warmer weather of spring and summer means the start of tick and mosquito season and the diseases they transmit, including Lyme disease, Rocky Mountain spotted fever, West Nile and Zika.

The number of Americans sickened each year by bites from infected mosquitoes, ticks or fleas tripled from 2004 through 2016, with infection rates spiking sharply in 2016 as a result of a Zika outbreak, USA health officials said Tuesday.

"What I can say is that any of these diseases are very sensitive to temperatures, so when there are increasing temps, it promotes several things", Petersen said. He added that increasing temperatures can expand the range of ticks further north.

"Why the increase? Mosquitoes and ticks are moving into new areas nationwide", Robert Redfield, MD, director of the CDC said in a media telebriefing.

With added support, these agencies can better test for and track diseases and pests, train staff to conduct prevention and control activities, and educate the public on how to prevent bites, the researchers said.

For example, recent data from clinical and laboratory diagnoses estimate that Lyme disease infects about 300,000 Americans every year, which is eight to 10 times more than the number reported in the CDC analysis.

"After spending time in wooded areas or in parks, always make sure to inspect yourself and your family for ticks", Glatter continued.

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