At the end of March, the Indiana State Department of Health released 2017-18 maps showing collections of black-legged tick, also known as deer tick, nymphs and adults in Indiana counties, and the percentage of those ticks that carried the causative agent for Lyme disease.
Unfortunately, sampling was not conducted in Whitley County, but counties just to the west of us did show significant numbers of ticks, and significant percentages that carried Borrelia burgdorferi, the Lyme disease bacterial pathogen.
According to the report, the highest numbers of ticks and the highest percentages of pathogen-infected ticks tended to occur in northern, northwestern, near-southwestern and random southern Indiana counties. However, the report stated, “it is important to remember that black-legged ticks have been found in most Indiana counties.”
Dr. Timothy J. Gibb, Purdue Extension Entomologist, authored the Purdue Extension publication, “Ticks,” from which I will offer excerpts for further discussion here.
Several species of ticks occur in Indiana. The most frequently encountered outdoor species is the American dog tick, also known as the eastern wood tick. Occasionally, one may also find the lone star tick or the deer tick in outdoor, wooded areas. Another species, the brown dog tick, may sometimes become a problem indoors, primarily in association with an indoor-outdoor dog.
Ticks have four life stages: egg, larva, nymph and adult. Some of our ticks serve as vectors (carriers and transmitters) of human disease pathogens.
The American dog tick is normally found in woods, uncut grassy fields, parks and other areas with wild vegetation. Adults are dark brown to black, with white markings on the dorsal (top of back) side. This tick is considered the most important vector of Rocky Mountain Spotted Fever in the United States.
The lone star tick is commonly found in moist, wooded areas, especially in areas with established deer populations. The adult female has a distinct single white spot on its back. In Indiana, these ticks are more frequently found in wooded areas in southern Indiana. These ticks are suspected in the transmission of tularemia, RMSF and Lyme disease, but they are not considered important vectors of these diseases.
The deer tick, or black-legged tick, is a tick of concern because it serves as the primary vector of Lyme disease. Deer ticks are found in similar habitats as the two previously described ticks. They are small and dark brown in color, with no white markings on their dorsal side. Female black-legged tick adults have a black head, legs and scutum (a plate-like structure behind the head). U.S. Centers for Disease Control and Prevention describes the size of unfed adults of this species as “approximately the size of a sesame seed.” That’s about 3-5 millimeters in length — pretty small compared to other ticks.
Lyme disease is caused by a spirochete (spiral-shaped motile bacteria) the deer tick carries. Early symptoms can be mild and overlooked. Flu-like symptoms, chills, fever and fatigue are often experienced. A first unique symptom is a red, expanding rash. The CDC notes that the rash “sometimes clears as it enlarges, resulting in a target or ‘bull’s-eye’ appearance.”
More than one rash may appear, and they do not always occur at the site of the tick bite. In fact, they may occur anywhere on the body, even in inconspicuous places such as the armpit, groin or back of the knee. More severe symptoms may appear weeks, months or even years after the tick bite. These may include severe headaches, arthritis, and nervous system or cardiac abnormalities.
The brown dog tick differs from other ticks in that they feed almost exclusively on dogs. They are found around pet bedding areas.
If you are bitten by a tick, do not panic. Carefully remove the tick, including its mouth parts, from your skin using tweezers or blunt forceps. Take care not to squeeze, crush or puncture the tick. Disinfect the bite site and wash hands thoroughly with soap and water. Monitor your health the following days. Consult a physician immediately if a rash or flu-like symptoms develop. It might also be wise to save the tick in a sealed plastic bag for reference. According to the CDC, if a tick is attached to your skin for less than 24 hours, your chance of getting Lyme disease is extremely small; however other tickborne diseases may be transmitted more quickly.
This article is not meant to provide medical advice. For recommended treatment, a doctor should be consulted.
For more information, find Purdue Extension’s publication on ticks (with pictures included), plus related publications, online at The Education Store: mdc.itap.purdue.edu. The CDC also has important information at www.cdc.gov. Find the aforementioned ISDH report at in.gov/isdh/28130.htm.