Clinical signs of early localized infection include bulls-eye rash (erythema migrans), muscle and joint aches, fever, headache, swollen lymph nodes, etc. Other than the bulls-eye rash, most of the symptoms of Lyme disease can occur with other diseases. Clinical signs of early disseminated infection include severe headaches, shooting pains, other neurological problems (e.g., facial palsy, meningitis) or cardiac problems (e.g., heart block). Clinical signs of late disseminated infection include severe arthritis and swelling of large joints (mostly knees), occurring in about 60% of untreated patients. Chronic neurological disorders may occur in about 5% of untreated patients and may include cognitive disorders (e.g. memory and concentration problems), shooting pains, numbness or tingling of hands and feet, and encephalitis. **Early treatment of Lyme disease will prevent disease progression to more severe stages of infection. Persons can be infected with Lyme disease and never have symptoms during their lifetime. Not every person presents with same symptoms in each stage nor does everyone go through all the stages of disease.
There are three different tick species that commonly bite people in Virginia (lone star tick, blacklegged tick, and American dog tick). The most common species to bite people in Virginia is the lone star tick. All three tick species can transmit various diseases, but only one species, the blacklegged tick (a.k.a., deer tick, latin name Ixodes scapularis ) transmits Lyme disease. It is the only human biting tick in Virginia with black legs. The VDH brochure “Preventing Tick-borne Diseases in Virginia” provides information on the other tick-borne diseases and is available on the website at http://www.vdh.virginia.gov/epidemiology/DEE/Vectorborne/TickBrochure.pdf
Among blacklegged ticks, the tiny nymph stage causes the most Lyme disease transmission to people. Blacklegged tick must be ATTACHED (and feeding) for at least 36 hours to transmit the Lyme disease agent. The nymphal stage blacklegged tick is typically about 1/16 of an inch in length (about the size of a pin head).
In the spring, adult blacklegged ticks lay eggs. By summer, larval ticks hatch from eggs and are infected with the Lyme disease agent by feeding on infected white-footed mice which typically are found in forest environments. In the 2nd spring & summer, previous season’s larvae become nymphs. Nymphs feed on rodents, dogs, cats & people and infected nymphs transmit Lyme disease to people during the late spring and summer. In 2nd fall & winter, infected nymphs become infected adults. Adult ticks feed mostly on deer & use deer blood to nourish a batch of eggs. Infected adult ticks will sometimes bite people or pets and then transmit Lyme disease.
Zones of Lyme disease activity have expanded from where they initially occurred in the Northeastern and North Central U.S. Virginia is now on the front line of this expansion.
A. Tracking involves monitoring the annual number and geographic distribution of “newly identified”* Lyme disease cases in Virginia. B. Prevention involves preventing Lyme disease through educational efforts directed at the public and health care providers. C. VDH has looked for human Lyme disease cases in Virginia since 1982 and Lyme disease has been a reportable by law in Virginia since 1989. Related Question and Answer Q. Can I get a new case of Lyme disease every year? A. Studies have shown that infection with LD produces an antibody response that is protective for about three years. Thus, a person cannot be re-infected with LD more often than about every three years.
A. Tracking enables VDH to identify Lyme disease activity trends over time and to identify Lyme disease risk areas across the state. Tracking efforts also help VDH target public awareness and prevention efforts to areas with Lyme disease activity.
A. The surveillance case definition is designed to standardize case counting across the U.S. It is not intended to influence the diagnosis of cases by health care providers. B. The surveillance case definition now requires two-tiered laboratory evidence of infection because recent studies have shown that the primary serological tests for Lyme disease (i.e., ELISA/IFA serology and Western Blot IgM serology) yield enough false positive results that reliance on one test provides insufficient evidence.
Since 2000, Virginia has had a steady increase in its annual number of newly identified Lyme disease cases. In 2007, Lyme disease increased dramatically and has remained high since that time. The recent increase in Lyme disease has coincided with a progressive geographic spread of activity southward and westward from northern regions of the state.
These maps show the progressive spread of Lyme disease in Virginia since 2003. Overall, it would seem that Lyme disease is expanding southward and westward.
Because it is not currently economically or technically possible to eliminate tick or deer populations in Virginia, VDH must work to prevent Lyme disease through educational outreach. Prevention involves educating the public on: 1) avoiding tick habitats, 2) dressing appropriately, 3) using proper repellents, 4) conducting tick checks, 5) removing ticks promptly, and 6) knowing the early signs of Lyme disease. Related Question and Answer Q: Will reducing the local deer population reduce Lyme disease? A: Studies have shown that reducing deer populations by more than 80% can cause a sufficient reduction of tick populations to reduce Lyme disease transmission. However, there are limitations to our ability to reduce deer numbers because: 1. Normal deer hunting activities by citizens cannot reduce deer by anywhere close to 80%, and access to hunt on private properties will always be an issue. 2. Birth control programs for deer are only effective in confined deer populations; treating free ranging deer is not technically possible. 3. Fencing deer out is effective, but must be done over large areas of land to be effective, is very expensive, and deer may still enter or leave fenced areas where roads cross the fence-line. Note: VDH is not responsible for the regulation of deer populations or hunting activities. This falls under the responsibility of VA Dept. of Game and Inland Fisheries.
Blacklegged ticks are forest creatures - not normally found in open fields. To avoid blacklegged ticks, you should: 1. Avoid leaf litter in shady forest environments, 2. Avoid tall weeds, grass and brush along forest trails and forest margins, 3. Avoid wood piles, rock piles, stone walls and rock outcrops that provide cover for rodents and ticks.
Dressing appropriately means: Wearing light colored clothing. - The dark colored blacklegged ticks are easier to spot and remove from light colored clothing. Tuck pants legs into socks and shirts into pants. - Ticks typically get on a person’s feet first and crawl up the leg. If your pants are tucked into legs, the ticks will be forced to crawl up the outside of the pants where they can be seen and removed. If your shirt is tucked into pants the ticks will not have easy access skin on your belly, back, or chest. Button shirt and long shirt sleeves tightly at wrists to prevent easy access to your body and arms by ticks. Remove clothing immediately upon return from tick habitat to prevent carrying ticks into the house. Promptly wash clothing in hot water and dry on high heat (hot water and high heat will kill ticks on clothing).
CDC recommends the use of DEET or Permethrin products as repellents for ticks. a. For exposed skin, use products containing DEET. b. For clothing including socks and shoes, use permethrin. -Permethrin may last up through 6-7 laundry cycles and does not stain clothes. c. Ticks usually get on a person’s feet first, so treating shoes and socks will repel the majority of ticks. d. It is important to follow label instructions on any repellent package, especially those for children. Repellents should not be applied to skin under clothing. Related Question and Answer Q: If I do not like to use DEET products or they irritate my skin, are there any other effective repellent products I can use on my skin? A. Repellents containing either IR3535 or BioUD have shown some efficacy against ticks, but need more testing. Other repellent products containing Picaridin, oil of lemon eucalyptus, citronella or other active ingredients have not been proven effective against ticks.
On returning from potential tick habitats: a. Promptly take a bath or shower and wash with soap and hot water. b. Request assistance from a spouse or friend to check self for ticks, or use a full length mirror and/or a hand- mirror. c. Thoroughly examine children after they have been in tick habitats. *The sooner ticks are found and removed, the less likely they are to transmit disease. Blacklegged ticks require a minimum of 36 hours attachment (feeding) before Lyme disease transmission may occur. Related Question and Answer Q: Why does it take 36 hours for a feeding tick to transmit Lyme disease? A: Blacklegged ticks have only three blood meals during their 2 year life cycle, and pass through long quiescent periods without feeding while transitioning from one development stage to the next. The Lyme disease agent has complex physiological requirements and its numbers decline and become inactive in response to extended periods of low metabolic activity within the tick. The Lyme disease agent resides in the tick's midgut, and during a blood meal on a warm host, the warmth of the host and the presence of ingested blood causes the bacteria to reactivate, multiply, pass through the gut wall into the tick's hemolymph, and infect the tick's salivary glands. This process takes about 36 hours. Infection of the salivary glands allows the Lyme disease agent to be transmitted to the tick's host in salivary fluids.
A. Careful tick removal reduces the chance of disease transmission. B. Do not squeeze the tick’s body - removal must be done carefully to prevent tick from regurgitating into the wound. C. Do not jerk or twist the tick out – this may cause tick mouthparts to break off and remain in the wound. D. We recommend saving the tick in a jar of alcohol so you can properly identify it. VDH can assist with identifying the tick if needed (you may use the “Tick Identification Chart” in the “Preventing Tick-borne Diseases” brochure or look up Dr. Gaines contact info on the VDH website to have him assist with tick identifications).
A. Early recognition of Lyme disease allows it to be easily treated and cured. B. The most recognizable early sign of Lyme disease is the EM (erythema migrans) rash (a.k.a. bulls-eye rash) - most people infected with Lyme disease will have an EM rash. EM rashes cause little or no sensation or pain (if present on person’s back side, it may go un-noticed). The EM rash presents as rings of darker colored skin on African Americans or persons with darker skin color.
Lone star ticks can carry and transmit the Ehrlichiosis agent (bacteria). Infected ticks must be attached for a minimum of 24 hours to transmit the disease and typically, fewer than 5% of lone star ticks will be infected with Ehrlichiosis. Blacklegged ticks can carry the Anaplasmosis agent (bacteria). Infected ticks must be attached for a minimum of 24 hours to transmit the disease and typically, fewer than 5% of blacklegged ticks will be infected with Anapalsmosis. Blacklegged ticks can carry the Babesiosis agent (protozoan). However, there have only been three cases of Babesiosis identified in Virginia to date. The American Dog tick may carry the Rocky Mountain spotted fever agent (bacteria). Infected ticks must be attached 4 to 6 hours to transmit the disease and typically, fewer than 1% of ticks are infected with the agent of RMSF. **Lyme disease infection rates measured in Virginia’s ticks have ranged from 1% - 40% depending on geographic location (some of the highest rates have been measured along Virginia’s Atlantic coastline. Although no tick surveys have been done for Ehrlichiosis / Anaplasmosis, tick infection rates typically are less than 5%; RMSF tick infection rates are typically less than 1%. Babesia is even less common.
Lyme Disease Tracking and Prevention in Virginia
Lyme Disease Tracking & Prevention Virginia Department of Health
What is Lyme Disease? 3 Stages of Infection <ul><li>Early Localized Infection (3-30 days) </li></ul><ul><ul><ul><li>Bull’s-eye rash, muscle or joint aches, fever, headache </li></ul></ul></ul><ul><li>Early Disseminated Infection (1- 4 months) </li></ul><ul><ul><ul><li>Severe headaches, pain, </li></ul></ul></ul><ul><ul><ul><li>neurological symptoms </li></ul></ul></ul><ul><li>Late Disseminated Infection (3 months to years) </li></ul><ul><ul><ul><li>Severe arthritis and swelling of large joints, pain, neurological and cognitive disorders </li></ul></ul></ul>A Tick-borne bacterial disease
Common Virginia Ticks Lone Star Tick American Dog Tick Blacklegged Tick
Role of the Virginia Department of Health <ul><li>Preventing disease through Education </li></ul><ul><li>Tracking </li></ul><ul><ul><ul><li>Monitoring the annual number and geographic distribution of newly identified Lyme disease cases in VA </li></ul></ul></ul>
Tracking Lyme disease <ul><li>Reporting cases to local health departments by healthcare providers. </li></ul><ul><li>2. Reporting positive test results to VDH by private laboratories. </li></ul><ul><li>3. Use of the CDC’s Lyme disease case definition to identify new cases. </li></ul><ul><li>4. Entering identified cases in a database. </li></ul>
State Reporting Requirements for Lyme Disease <ul><li>Virginia State Law requires that healthcare providers report Lyme disease cases to the local health department ( Code of Virginia 32.1-36 ). </li></ul><ul><li>Contact information for local health departments can be found at: http:// www.vdh.virginia.gov/lhd / </li></ul>
Lyme Disease Case Reporting Lyme-associated symptoms including erythema migrans (EM) rash (a.k.a., bull’s eye rash) if present <ul><li>Necessary laboratory results: </li></ul>VDH uses the CDC’s Lyme Disease Surveillance Case Definition which requires: Positive or equivocal results from ELISA (or IFA) serology as well as positive Western Blot IgM serology if the blood was drawn within 30 days of onset, or Positive Western Blot IgG serology, if blood was drawn more than 30 days after onset. <ul><li>Necessary case information: </li></ul>Date of onset Complete laboratory testing results
5. Remove ticks promptly Use pointed tweezers to grasp the tick by the head; do not squeeze its body! Pull slowly and steadily until the tick releases; do not jerk or twist the tick.
6. Know the early signs of Lyme <ul><li>Bull’s Eye rash </li></ul><ul><li>Fatigue </li></ul><ul><li>Fever </li></ul><ul><li>Joint or muscle aches </li></ul><ul><li>Headache </li></ul><ul><li>Swollen glands </li></ul>
Other Tick-borne Diseases <ul><li>Ehrlichiosis/Anaplasmosis (tick must be attached 24 hrs) </li></ul><ul><li>Babesiosis (tick must be attached for 36 hrs) </li></ul><ul><li>Rocky Mountain Spotted Fever (tick must be attached only 4-6 hrs) </li></ul>
For more information… <ul><li>Virginia Department of Health </li></ul><ul><li>Centers for Disease Control and Prevention </li></ul>http://www.vdh.virginia.gov http://www.vdh.virginia.gov/epidemiology/DEE/Vectorborne/TickBrochure.pdf http:// www.cdc.gov/ncidod/dvbid/lyme /
Acknowledgements <ul><li>David Gaines, Ph.D., Public Health Entomologist, Virginia Department of Health </li></ul><ul><li>Division of Environmental Epidemiology, VDH </li></ul><ul><li>U.S. Centers for Disease Control and Prevention </li></ul><ul><li>CDC Public Health Images Library </li></ul><ul><li>American Lyme Disease Foundation </li></ul><ul><li>Google Images </li></ul><ul><li>We invite you to complete the following survey: </li></ul><ul><li>http://www.zoomerang.com/Survey/WEB22ALUM8JJD7 </li></ul>