What month is Lyme disease most common?
Ticks and Lyme Disease: Symptoms, Treatment, and Prevention
Tick-borne diseases, such as Lyme disease, are on the rise in people and dogs. Reported cases in people in the U.S. increased from about 12,000 annually in 1995 to approximately 35,000 in 2019, according to the Centers for Disease Control and Prevention. However, not all diagnosed cases are reported and the CDC believes the true number of human infections is likely closer to 476,000 per year.
The U.S. Food and Drug Administration regulates products that are used to help prevent, diagnose, and treat this complex disease.
Who Gets Lyme Disease, What Time of Year?
Lyme disease is a bacterial infection most commonly transmitted via the bite of infected ticks, which attach to any part of the body.
The CDC recommends you check your dog daily, especially after they spend time outdoors. Pay particular attention to the collar area and around the eyelids, ears, tail, under the front legs, and between the back legs and toes.
On people, you will most often find ticks in moist or hairy areas such as the groin, armpits, scalp, and other hard-to-see areas of the body. And while everyone is susceptible to tick bites, campers, hikers, and people who work in gardens and other woody, and brushy areas with high grass and leaf litter, are at the greatest risk of tick bites. As many a suburban gardener can attest, with the expansion of the suburbs and a push to conserve wooded areas, deer populations are thriving. Deer are important sources of blood for ticks and are important to tick survival and movement to new areas, increasing the contact between people and ticks that carry the bacteria. Read more about the lifecycle of the bacteria and how it is transmitted to people and dogs.
In most cases, a tick must be attached for 36 to 48 hours or more before the Lyme disease bacterium can be transmitted. If you remove it within 24 hours, the risk is greatly reduced. Symptoms of Lyme disease may take 3-30 days or longer to appear.
In the majority of cases, tick bites are reported in the summer months when ticks are most active and people spend more time outdoors. But this can extend into the warmer months of early autumn, or even late winter if temperatures are unusually high. Similarly, a mild winter can allow ticks and other insects to thrive and emerge earlier than usual.
How to Safely Remove a Tick
- Using fine-tipped tweezers, grasp the tick as close to the skin’s surface as possible.
- Pull upward with steady, even pressure. Don’t twist or jerk the tick. Your goal is to remove the entire tick, ideally in one piece, including the mouth parts embedded under the skin.
- Thoroughly clean the bite area and your hands with rubbing alcohol, an iodine scrub, or soap and water.
Not all ticks carry Lyme disease, and some ticks carry other diseases. To avoid infecting yourself, never crush a tick with your fingers. For more information on the safe removal, disposal and identification of ticks visit CDC.gov/ticks.
Lyme Disease in People
Prevention
What can I do to prevent Lyme disease?
- Avoid wooded, brushy, and grassy areas, especially during warmer months (April – September), although tick exposure can occur anytime.
- Wear light-colored clothing so that you can see ticks that get on you.
- Treat clothing and gear with products containing 0.5% permethrin.
- Apply insect repellents on uncovered skin, and ensure the products are registered by the Environmental Protection Agency.
- Wear long pants and long-sleeved shirts, and shoes that cover the entire foot.
- Tuck pant legs into socks or shoes, and tuck shirts into pants.
- Wear a hat for extra protection.
- Walk in the center of trails to avoid brush and grass.
- Remove your clothing after being outdoors, and wash and dry them at high temperatures.
- Do a careful body check for ticks after outdoor activities.
There are no licensed vaccines available in the U.S. to aid in the prevention of Lyme disease in people.
Symptoms and Stages
Symptoms of early-stage Lyme disease include:
- muscle and joint aches
- headache
- fever
- chills
- fatigue
- swollen lymph nodes
Another common symptom of Lyme disease is a rash (referred to as “Erythema migrans”). As many as 80% of infected people may develop a rash, however the characteristic “bull’s-eye” rash appears only 20% of the time.
Later-stage symptoms may not appear until weeks or months after a tick bite. They include:
- irregular heartbeat and/or heart palpitations
- arthritis (usually seen as pain and swelling in large joints, especially the knee)
- nervous system abnormalities
When left untreated, the bacterial infection can spread to joints, the heart, and the nervous system and cause permanent damage. Lyme disease is rarely fatal.
However, if not treated properly, Lyme disease can become a chronic illness where symptoms might continue for weeks, months, or even years after the initial tick bite.
Lyme Disease in Dogs
Dogs can get Lyme disease, too. Typical symptoms in dogs include swollen joints and lameness, fever, and loss of appetite. Experts in the FDA’s Center for Veterinary Medicine say dogs with Lyme disease occasionally develop serious kidney disease that can be fatal.
There are ways you can reduce your dog’s risk for tick bites and Lyme disease, which also reduces the risk of infection for you.
- Regularly check your dog for ticks.
- Avoid allowing your dog to roam in tick-infested areas.
- Treat your dog year-round with topical, oral and/or collar tick products. Talk to your veterinarian about which product is best for your dog.
Lyme disease occurs much less frequently in cats than in dogs, and cats’ susceptibility to the disease continues to be the subject of research. However, the same precautions for dogs apply to cats, especially if your cat goes outside, because ticks on cats can be transferred to people and ticks carry other diseases besides Lyme disease that are harmful to cats.
There are several FDA-approved products that treat and control tick infestations. A couple of tick products are also approved in dogs to specifically prevent infections with the bacteria that causes Lyme disease by killing the ticks that carry the bacteria.
Lyme disease vaccines are available for dogs, but not for cats. Talk to your veterinarian to see if vaccination is appropriate for your dog.
Lyme Disease Tests and Treatment
If you think you or your dog may have Lyme disease, contact your physician or veterinarian right away.
Your doctor or veterinarian may test for Lyme disease, and/or they may immediately begin antibiotic treatment, depending on the symptoms you or your dog exhibit.
Most blood tests check for the antibodies produced by the body to fight Lyme disease. CDC experts report it may take several weeks after a tick bite for initial antibodies to develop. Because of this, the blood tests may not be accurate if done soon after a tick bite.
For this reason, your doctor or veterinarian may recommend treatment with antibiotics before the diagnostic tests are complete. According to the CDC and other experts, people treated with appropriate antibiotics in the early stages of Lyme disease usually recover rapidly and completely.
In dogs, the more subtle early stages of Lyme disease often go unnoticed. Even if your dog appears healthy, your veterinarian may recommend yearly screening for Lyme disease, especially if you live in an area where Lyme disease is common. If your dog’s blood test is positive, your veterinarian may recommend additional testing, such as a urinalysis.
About Lyme Disease
Lyme disease is a bacterial infection caused by the bite of an infected blacklegged tick (also known as the deer tick or bear tick). The disease affects both humans and animals. The health department is monitoring the spread of the disease across the state and working with residents to limit exposure to the ticks causing the disease.
Fact Sheets
- Lyme Disease Fact Sheet (PDF)
Basic information about Lyme Disease.- Hmong (PDF)
- Karen (PDF)
- Somali (PDF)
- Spanish (PDF)
Transmission
- Lyme disease is one of several tickborne diseases in Minnesota.
- In order to get Lyme disease, a person must be bitten by a blacklegged tick (also known as deer tick or bear tick) that is infected with the Lyme disease bacteria.
- On average, about 1 in 3 adult blacklegged ticks and 1 in 5 blacklegged tick nymphs (immature stage) are infected with Lyme disease bacteria.
Prevention
- Preventing Tickborne Diseases
Learn how to minimize your risk to Lyme disease and other tickborne diseases.
Signs and symptoms
The signs and symptoms of Lyme disease vary among individuals. A person may not have all of these symptoms. People often feel like they have «the flu.»
- Three to 30 days after a blacklegged tick bite, look for:
- A distinctive rash
- Fever
- Chills
- Headache
- Muscle and joint pain
- Fatigue
- Joint swelling from arthritis in one or more joints, usually the knees
- Arthritis can also have other causes.
Diagnosis
- If a person suspects Lyme disease, he or she should contact a doctor immediately.
- Diagnosis includes:
- Physical examination (signs and symptoms, presence of a rash)
- History of possible exposure to blacklegged ticks
- Blood tests may be performed
- CDC: Lyme Disease Laboratory Testing
CDC detailed info for the public on Lyme disease tests.
Treatment
- Here are a few general statements about the treatment of Lyme disease:
- The disease is treated with antibiotics. Antibiotics are very effective in killing the bacteria.
- Treatment is most effective early in the course of Lyme disease. Lyme disease detected later is also treatable with antibiotics, but can cause symptoms that may take longer to go away, even after the antibiotics have killed the Lyme disease bacteria.
- CDC: Post-Treatment Lyme Disease Syndrome
CDC detailed information on Post-treatment Lyme disease Syndrome” (PTLDS).
Treatment following a tick bite
- In some circumstances, a single dose of antibiotic (doxycycline) given within 72 hours of a tick bite might prevent the development of Lyme disease. Several criteria must be met:
- The tick must be identified as the blacklegged tick (deer tick).
- The tick must have been attached for at least 36 hours (if it is engorged — puffed up with blood — then it was probably on this long).
- The tick bite occurred in a highly endemic area (see High Risk Areas for Tickborne Diseases in Minnesota)
History
- Lyme disease is the most common tickborne disease in the United States.
More from other web sites:
- CDC Lyme Disease
Centers for Disease Control and Prevention general information about Lyme disease.
Climate Change Indicators: Lyme Disease
This indicator tracks the rate of reported Lyme disease cases across the United States.
- Figure 1. Reported Cases of Lyme Disease in the United States, 1991–2018
This figure shows the annual incidence of Lyme disease, which is calculated as the number of new cases per 100,000 people. The graph is based on cases that local and state health departments report to CDC’s national disease tracking system. Data source: CDC, 2019 10
Web update: April 2021Figure 2. Change in Reported Lyme Disease Incidence in the Northeast and Upper Midwest, 1991–2018
This map shows how reported Lyme disease incidence has changed by state since 1991, based on the number of new cases per 100,000 people. The total change has been estimated from the average annual rate of change in each state. This map is limited to the 15 states where Lyme disease is most common, where annual rates are consistently above 10 cases per 100,000 people. Connecticut, New York, Massachusetts, and Rhode Island have had changes in reporting methods that make it difficult to calculate an accurate trend. Data source: CDC, 2019 11
Web update: April 2021Reported Lyme Disease Cases in 1996 and 2018
These maps show the distribution of Lyme disease cases reported to CDC in 1996 and 2018. Each dot represents an individual case placed according to the patient’s county of residence, which may be different from the county of exposure. The year 1996 was chosen as a reasonable starting point for comparison with recent years. These maps focus on the parts of the United States where Lyme disease is most common. The lack of dots in Massachusetts in 2018 is due to a difference in reporting standards, not an absence of Lyme disease. Data source: CDC, 2019 12
Web update: April 2021Key Points
- The incidence of Lyme disease in the United States has nearly doubled since 1991, from 3.74 reported cases per 100,000 people to 7.21 reported cases per 100,000 people in 2018 (see Figure 1).
- Among the states where Lyme disease is most common and where cases have been tracked consistently since 1991, Maine and Vermont have experienced the largest increases in reported case rates, followed by New Hampshire (see Figure 2). On average, Maine and Vermont report more than 100 additional cases per 100,000 people compared to what they reported in 1991; New Hampshire’s rate has increased by 87 cases per 100,000.
- Driven by multiple factors, the number and distribution of reported cases of Lyme disease have increased over time (see 1996 and 2018 maps).
Background
Lyme disease is a bacterial illness that can cause fever, fatigue, joint pain, and skin rash, as well as more serious joint and nervous system complications. Lyme disease is the most common vector-borne disease (that is, a disease transmitted by mosquitoes, ticks, or fleas) in the United States. In recent years, approximately 20,000–30,000 confirmed cases of Lyme disease per year have been reported to the Centers for Disease Control and Prevention (CDC). 1 However, the actual number of illnesses is likely greater than what is reported to health officials. 2,3 Lyme disease is transmitted through the bite of certain species of infected ticks (referred to commonly as deer ticks) that carry the bacteria that cause Lyme disease. These ticks live not only on deer, but also on rodents, birds, and other host animals. Deer do not harbor the bacteria that cause Lyme disease, but certain other hosts such as white-footed mice do, and ticks pick up the bacteria by feeding on these infected hosts.
Studies provide evidence that climate change has contributed to the expanded range of ticks, 4 increasing the potential risk of Lyme disease, such as in areas of Canada where the ticks were previously unable to survive. The life cycle and prevalence of deer ticks are strongly influenced by temperature. 5 ,6 For example, deer ticks are mostly active when temperatures are above 45˚F, and they thrive in areas with at least 85-percent humidity. Thus, warming temperatures associated with climate change are projected to increase the range of suitable tick habitat and are, therefore, one of multiple factors driving the observed spread of Lyme disease. 7 Because tick activity depends on temperatures being above a certain minimum, shorter winters could also extend the period when ticks are active each year, increasing the time that humans could be exposed to Lyme disease. Unlike some other vector-borne diseases, tick-borne disease patterns are generally less influenced by short-term changes in weather (weeks to months) than by longer-term climate change.
Climate is just one of many important factors that influence the transmission, distribution, and incidence of Lyme disease. Other factors that affect the number of Lyme disease cases include changes in the populations of host species (particularly deer), which affect tick population size. The percentage of ticks that are infected depends on the prevalence and infection rates of white-footed mice and certain other hosts. Host species populations and habitats can be affected by climate change and other ecosystem disturbances. Human exposure to infected ticks is also influenced by factors such as changes in the proximity of human populations to ticks and other hosts, increased awareness of Lyme disease, and modified behaviors, such as spending less time outdoors, taking precautions against being bitten, and checking more carefully for ticks. Occupation influences exposure, as people who work outdoors, like farmers and landscapers, may be especially at risk. 8 Lyme disease is one of many diseases transmitted to humans by ticks or mosquitoes that CDC tracks. 9
About the Indicator
This indicator looks at the incidence of Lyme disease, which reflects the rate of new cases contracted in a given geographic area and time period. Incidence is typically calculated as the number of cases per 100,000 people per year. Annual Lyme disease totals and rates for each state were provided by CDC. The original data were collected by state and local health departments, which track confirmed cases of Lyme disease that are diagnosed by health care providers and report these cases to the National Notifiable Diseases Surveillance System. Nationwide reporting of Lyme disease began in 1991.
Figure 1 shows the national incidence of Lyme disease since 1991, and Figure 2 shows trends in incidence over time in 15 states that collectively account for about 95 percent of the nation’s reported cases. To illustrate changes in the distribution of reported cases over time, maps of the years 1996 and 2018 are presented side by side.
About the Data
Indicator Notes
For consistency, this indicator includes only data for confirmed cases of Lyme disease that are reported to CDC, not cases that are considered “probable.” Changes in diagnosing practices and awareness of the disease over time can affect trends. Cases are reported based on the patient’s county of residence, which is not necessarily the place where they were infected. Risk of infection is focused in certain regions of the country, and confirmed reports from low-incidence states are often the result of travel to an area of higher incidence. Evidence suggests that expanding ranges of ticks in certain northern states may be more related to a warming climate than expanding ranges in southern states. 13,14 Because of the many factors affecting tick populations and reporting of Lyme disease, though, this indicator does not provide sufficient information to determine what proportion of the observed changes in Lyme disease incidence is directly driven by climate change. Further study is critical to improving the usefulness of this indicator and informing decisions affecting public health. For information on prevention, symptoms, and treatment of Lyme disease, see: www.cdc.gov/lyme.
Data Sources
All three figures are based on publicly available Lyme disease data compiled by CDC at: www.cdc.gov/lyme/stats/index.html. Incidence was calculated using mid-year population estimates from the U.S. Census Bureau. 15
Technical Documentation
- Download related technical information PDF
References
1 CDC (Centers for Disease Control and Prevention). 2019. Lyme disease data tables: Historical data. Updated November 22, 2019. Accessed January 2021. www.cdc.gov/lyme/stats/tables.html.
2 CDC (Centers for Disease Control and Prevention). 2013. CDC provides estimate of Americans diagnosed with Lyme disease each year. www.cdc.gov/media/releases/2013/p0819-lyme-disease.html.
3 CDC (Centers for Disease Control and Prevention). 2021. How many people get Lyme disease? www.cdc.gov/lyme/stats/humancases.html.
4 Beard, C.B., R.J. Eisen, C.M. Barker, J.F. Garofalo, M. Hahn, M. Hayden, A.J. Monaghan, N.H. Ogden, and P.J. Schramm. 2016. Chapter 5: Vector-borne diseases. In: The impacts of climate change on human health in the United States: A scientific assessment. U.S. Global Change Research Program. https://health2016.globalchange.gov.
5 Beard, C.B., R.J. Eisen, C.M. Barker, J.F. Garofalo, M. Hahn, M. Hayden, A.J. Monaghan, N.H. Ogden, and P.J. Schramm. 2016. Chapter 5: Vector-borne diseases. In: The impacts of climate change on human health in the United States: A scientific assessment. U.S. Global Change Research Program. https://health2016.globalchange.gov.
6 Leighton, P.A., J.K. Koffi, Y. Pelcat, L.R. Lindsay, and N.H. Ogden. 2012. Predicting the speed of tick invasion: An empirical model of range expansion for the Lyme disease vector Ixodes scapularis in Canada. J. Appl. Ecol. 49(2):457–464.
7 Beard, C.B., R.J. Eisen, C.M. Barker, J.F. Garofalo, M. Hahn, M. Hayden, A.J. Monaghan, N.H. Ogden, and P.J. Schramm. 2016. Chapter 5: Vector-borne diseases. In: The impacts of climate change on human health in the United States: A scientific assessment. U.S. Global Change Research Program. https://health2016.globalchange.gov.
8 Gamble, J.L., J. Balbus, M. Berger, K. Bouye, V. Campbell, K. Chief, K. Conlon, A. Crimmins, B. Flanagan, C. Gonzalez-Maddux, E. Hallisey, S. Hutchins, L. Jantarasami, S. Khoury, M. Kiefer, J. Kolling, K. Lynn, A. Manangan, M. McDonald, R. Morello-Frosch, M.H. Redsteer, P. Sheffield, K. Thigpen Tart, J. Watson, K.P. Whyte, and A.F. Wolkin. 2016. Chapter 9: Populations of concern. The impacts of climate change on human health in the United States: A scientific assessment. U.S. Global Change Research Program. https://health2016.globalchange.gov.
9 Rosenberg, R., N.P. Lindsey, M. Fischer, C.J. Gregory, A.F. Hinckley, P.S. Mead, G. Paz-Bailey, S.H. Waterman, N.A. Drexler, G.J. Kersh, H. Hooks, S.K. Partridge, S.N. Visser, C.B. Beard, and L.R. Petersen. 2018. Vital signs: Trends in reported vectorborne disease cases—United States and territories, 2004–2016. MMWR 67(17):496–501. www.cdc.gov/mmwr/volumes/67/wr/mm6717e1.htm?s_cid=mm6717e1.
10 CDC (Centers for Disease Control and Prevention). 2019. Lyme disease data tables: Historical data. Updated November 22, 2019. Accessed January 2021. www.cdc.gov/lyme/stats/tables.html.
11 CDC (Centers for Disease Control and Prevention). 2019. Lyme disease data tables: Historical data. Updated November 22, 2019. Accessed January 2021. www.cdc.gov/lyme/stats/tables.html.
12 CDC (Centers for Disease Control and Prevention). 2019. Lyme disease data tables: Historical data. Updated November 22, 2019. Accessed January 2021. www.cdc.gov/lyme/stats/tables.html.
13 Diuk-Wasser, M.A., A.G. Hoen, P. Cislo, R. Brinkerhoff, S.A. Hamer, M. Rowland, R. Cortinas, G. Vourc’h, F. Melton, G.J. Hickling, J.I. Tsao, J. Bunikis, A.G. Barbour, U. Kitron, J. Piesman, and D. Fish. 2012. Human risk of infection with Borrelia burgdorferi, the Lyme disease agent, in eastern United States. Am. J. Trop. Med. Hyg. 86(2):320–327.
14 Stromdahl, E.Y., and G.J. Hickling. 2012. Beyond Lyme: Aetiology of tick-borne human diseases with emphasis on the south-eastern United States. Zoonoses Public Hlth. 59(Supplement 2):48–64.
- Diagnosis includes: