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, U.S. health officials said on Tuesday, May 1.
The U.S. Centers for Disease Control and Prevention said that some 96,075 diseases caused by bites by mosquitoes, ticks and fleas were reported in 2016, up from 27,388 in 2004, in an analysis of data from the CDC’s National Notifiable Diseases Surveillance System, Reuters reported.
Infections in 2016 went up 73 percent from 2015, reflecting the emergence of Zika, which is transmitted by mosquitoes and can cause severe birth defects. Zika was the most common disease borne by ticks, mosquitoes and fleas reported in 2016, with 41,680 cases reported, followed by Lyme disease, with 36,429 cases, almost double the number in 2004.
“Almost everyone has been bitten by a mosquito, tick, or flea. These can be vectors for spreading pathogens (germs),” noted the CDC.
“A person who gets bitten by a vector and gets sick has a vector-borne disease, like dengue, Zika, Lyme, or plague,” it said, adding that only “state and local health departments and vector control organizations are the nation’s main defense against this increasing threat.”
But, it added, that only 84 percent of “local vector control organizations lack at least 1 of 5 core vector control competencies. Better control of mosquitoes and ticks is needed to protect people from these costly and deadly diseases.”
It said that new infections such as the Chikungunya and Zika viruses “caused outbreaks in the U.S. for the first time,” and “seven new tickborne germs can infect people in the U.S.”
“Zika, West Nile, Lyme and chikungunya—a growing list of diseases caused by the bite of an infected mosquito, tick, or flea—have confronted the U.S. in recent years, making a lot of people sick. And we don’t know what will threaten Americans next,” Dr. Robert R. Redfield, director of the CDC, said in a statement, ABC News reported.
The ABC report noted that the most notable increase was Lyme disease, which has doubled in cases in the 13-year span of the report. It’s because ticks have spread to new areas of the country.
“It enables these ticks to expand to new areas. Where there are ticks, there comes diseases,” said Lyle Petersen, director of the CDC’s Division of Vector-Borne Diseases.
The CDC says that Lyme disease is caused by the bacterium Borrelia burgdorferi and is transmitted to humans through the bite of some ticks.
“The typical symptoms include fever, headache, fatigue, and a characteristic skin rash called erythema migrans. If left untreated, infection can spread to joints, the heart, and the nervous system,” says the CDC.
Warmer summer temperatures also tend to bring outbreaks of mosquito-borne illnesses, officials said, Reuters reported.
While Zika stood out as the latest emerging threat in the report, it also showed a long-term increase in cases of tick-borne Lyme disease, which can attack the heart and nervous system if left untreated.
Researchers warned that their numbers likely do not include every case as many infections are not reported.
These increases are due to many factors, including growing populations of the insects that transmit them and increased exposure outside of the United States by travelers who unknowingly transport diseases back home.
The CDC said more than 80 percent of vector-control organizations across the United States lack the capacity to prevent and control these fast-spreading, demanding illnesses. Petersen said that federal programs are increasing funding for those organizations.