W hile Lyme disease is the fastest growing vector-borne disease in the United States, many other bacteria, parasites, and viruses can also be transmitted by ticks.
These are generally referred to as “co-infections” of Lyme, since people often have them at the same time as Lyme disease. While U.S. cases of Lyme disease are estimated to be over 300,000 per year, no one really knows the incidence of co-infections.
In a LymeDisease.org survey of over 3,000 patients with chronic Lyme disease, more than half reported laboratory-confirmed co-infections, with 30% having two or more. According to Dr. Richard Horowitz, “The existence of these co-infections explains why some people with Lyme remain chronically ill even after treatment.”
The most common co-infections reported with Lyme disease are Babesia (32%), Bartonella (28%), and rickettsial illnesses (26%). Rickettsial illnesses include ehrlichiosis (15%), Rocky Mountain spotted fever (6%), and anaplasmosis (5%).
Ticks Transmit 94% of Vector-Borne Diseases
Most vector-borne diseases (VBDs) in the United States are transmitted by ticks. Of the nearly 50,000 cases of VBDs reported to the Centers for Disease Control (CDC) in 2014, 94% were tick-borne, with most of those being Lyme disease. Only 6% of VBDs were from mosquitoes. Yet, Lyme receives only a fraction of the research funding given to Zika and West Nile virus.
The recognition of tick-borne pathogens that are responsible for human illness is accelerating.
Eleven new ones have been discovered since 1960, with over half of those found since 2000.
Several factors contribute to the increase of TBDs:
- improved diagnostics,
- climactic changes (warm wet weather),
- reforestation and population increases of mice/deer,
- range expansion and population increases of ticks,
- lack of a single, effective, widely accepted preventative strategy.