It’s hard to believe, with all of the new, highly effective topical preventive flea and tick products we have used for the past 20 years, that the Centers for Disease Control is reporting human illness from mosquito, tick and flea bites has tripled over the past decade.
Don’t think because we live in the high altitude and dry climate of Colorado we are immune. At the peak of the summer season you will see plenty of mosquitoes, fleas and ticks.
To refresh your memory, these pests can transmit things like the plague, Lyme disease, cat-scratch disease, Rocky Mountain Spotted Fever; the list is long and scary.
In a CDC press release, Lyle Petersen, MD, MPH, director of the Division of Vector-Borne Diseases in the CDC's National Center for Emerging and Zoonotic Infectious Diseases, said, “The data show that we're seeing a steady increase and spread of tick-borne diseases, and an accelerating trend of mosquito-borne diseases introduced from other parts of the world. We need to support state and local health agencies responsible for detecting and responding to these diseases and controlling the mosquitoes, ticks, and fleas that spread them.”
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. CDC Director Robert Redfield, MD, said, “We don’t know what will threaten Americans next.”
CDC scientists analyzed trends in the cases of 16 nationally reportable insect-borne diseases during 2004–2016. During the study period, a total of 642,602 cases of insect-borne illness were reported, although it is well-known that these cases are under-reported. Even so, the numbers are three times higher than previously reported.
Tick-borne disease more than doubled during the study period. Tick-borne diseases made up 77 percent of all insect-borne disease cases, and some of these can be severe. Lyme disease accounted for 82 percent of all tick-borne cases, but cases of spotted fever rickettsioses, babesiosis and anaplasmosis/ehrlichiosis also increased.
Reported cases of mosquito-borne disease jumped ten-fold. The most common mosquito-borne viruses were West Nile, dengue and Zika. While rare in most of the country, plague was the most common disease resulting from the bite of an infected flea. But as you may know from local news, plague is endemic in Colorado all along the Front Range. Those cute little prairie dogs carry the fleas that transmit the disease.
What is causing the increase?
The increase in these insect-borne diseases in the United States is likely due to many factors. Mosquitos and ticks are moving into new areas nationwide. Overseas travel is common, and a traveler can get infected from a mosquito-borne disease like Zika in one country and easily return home infected, which puts other people at risk. Hurricanes cause rescue groups to move abandoned dogs north to find homes, and illegal immigration is not helping the situation.
Warm weather is a big factor. The mosquito-borne diseases tend to get worse during heat waves. Increasing temperatures tend to make mosquitoes more infectious, which favors outbreaks. For tick-borne diseases, increasing temperatures expand the range of these ticks farther north; and it increases the length of tick season.
The study also revealed that nine insect-borne human diseases were reported for the first time in the United States during the 13-year period. "The discovery or introduction of novel insect-borne agents will be a continuing threat," the experts noted, as these diseases have been difficult to prevent and control.
IDSA takes action
The Infectious Diseases Society of America is taking steps to address this serious issue by urging Congress to provide "increased funding for surveillance and prevention of insect-borne diseases, including research on the most effective methods for preventing tick-borne infections.” They have also advocated for federal investments in the research and development of new vaccines to prevent Zika, Lyme disease and other serious insect-borne diseases.
What can you do? Be serious about all the precautions you already know when hiking or camping to prevent ticks from getting on your legs and clothing. Keep these insects off pets by using the topical (on the skin) controls like Advantage®, Frontline® and the latest product that covers fleas and ticks and prevents mosquito bites, which is Vectra 3-D.
I do not recommend any product that requires the insect to bite your pet first before it is killed. These products have never worked well and your pet still suffers the insect bite; and, of course, disease transmission can still occur. You will know them as they are oral (by mouth) and not topical. I’d stay with these top three well-proven topical treatments. Ask your veterinarian for these products. If you find them in an online store like eBay or Amazon, I can tell you that often these are counterfeit drugs made to look like the real thing, which could cause you and your pets to be vulnerable to these awful diseases. Saving a few dollars is not worth getting one of these insect-borne diseases in either your pets or your family.
Dr. Jim Humphries is a veterinarian in Colorado Springs and also serves as a visiting professor at the College of Veterinary Medicine at Texas A&M University. He provides hospice and end-of-life care for pets. He lives in Falcon with his wife, horses and Great Danes. www.HomeWithDignity.com.