Lyme Disease Epidemiology & Surveillance in Virginia David Trump, MD, MPH, MPA State Epidemiologist Director, Office of Epidemiology Virginia Department of Health History of Lyme Disease • Illness first described in Lyme, CT in 1975 • By 1977, the Ixodes scapularis (black-legged) tick was linked with illness transmission • In 1981, Borrelia burgdoferi was identified as the causative organism • In 1984, CT initiated surveillance for Lyme disease • In 1985, reported incidence of Lyme disease for all CT residents was 22/100,000 • In 1989, Lyme disease became reportable by law in VA • In 1991, Lyme disease became a nationally notifiable condition in the US Lyme Disease in the United States • Most commonly reported vector-borne illness in the US • In 2011, 6th most common nationally notifiable disease • Does not occur nationwide • Mostly concentrated in the Northeast and Upper Midwest Reported Cases of Lyme Disease in USA 1999 2011 Reported Cases of Lyme Disease by State • In 2011, Virginia ranked 10th in the nation for number of annual cases reported to CDC • That same year, Virginia ranked 14th for incidence of Lyme disease • Pennsylvania currently reports the most cases to CDC each year • Delaware currently reports the greatest incidence each year *Incidence measured by confirmed and probable cases per 100,000 population Lyme Disease Incidence in Virginia, 2005 in & Virginia, 2011 2005 & 2012 2012 2005 Cases per 100,000 population 0.1 to 4.9 5 to 9.9 10 to 24.9 25 to 49.9 50 to 99.9 100+ Cases per 100,000 Population Lyme Disease Incidence in Virginia, 1990-2012 16 14 12 10 8 6 4 2 0 Year Cases per 100,000 Population Lyme Disease Incidence by Age Group, Virginia, 2012 30 25 20 15 10 5 0 Age Group 90 Reported Lyme Disease Cases By Sex and Age, Virginia, 2012 80 Female [48%] Male [52%] Number of Cases 70 Unknown 60 50 40 30 20 10 0 Age Group Reported Lyme Disease Cases by Month, Virginia, 2012 180 Number of Cases 160 Cases with Recorded Onset Dates 140 Cases with Event Dates Only 120 100 80 60 40 20 0 Month Understanding Surveillance Data • Surveillance case definitions establish uniform criteria for disease reporting • Data on cases that meet the national surveillance case definition are shared with CDC • Case definition should not be used as the sole criteria for clinical diagnosis • Policies regarding case definitions, reporting, and data release are determined by states under the auspices of the Council of State and Territorial Epidemiologists (CSTE) Surveillance Case Definition Confirmed A case of erythema migrans (EM) with a known exposure OR A case of EM with laboratory evidence of infection and without a known exposure OR A case with at least one late manifestation that has laboratory evidence of infection Probable Any other case of physician-diagnosed Lyme disease that has laboratory evidence of infection Suspected A case of EM where there is no known exposure and no laboratory evidence of infection OR A case with laboratory evidence of infection but no clinical information available (e.g., laboratory report only). Surveillance Case Definition • “Exposure” – Defined as having been (less than or equal to 30 days before onset of EM) in wooded, brushy, or grassy areas (i.e., potential tick habitats) in a county in which Lyme disease is endemic. A history of tick bite is not required. • “Endemnicity” – A county in which Lyme disease is endemic is one in which at least two confirmed cases have been acquired in the county or in which established populations of a known tick vector are infected with B. burgdorferi. Lyme Disease Endemic Localities in Virginia for 2013 Surveillance Two or more Confirmed Cases (2005 – 2012) Franklin Brunswick Galax Case Definition: “Laboratory Evidence of Infection” • Positive Culture for B. burgdorferi, OR • Two-tier testing - IFA/EIA positive or equivocal plus IgM Western Blot (WB) positive: • Positive two tier test is sufficient only when blood was drawn ≤30 days from symptom onset, OR • Single-tier IgG WB seropositive (interpreted by established criteria); sufficient at any point during illness, OR • CSF antibody positive for B. burgdorferi by enzyme immunoassay (EIA) or immunofluorescence assay (IFA), when the titer is higher than it was in serum Limitations of Surveillance Data • Under-reporting and misclassification are features common to all surveillance systems. • Not every case of Lyme disease is reported to CDC, and some cases that are reported may be due to another cause. • Under-reporting is more likely to occur in highly endemic areas, whereas over-reporting is more likely to occur in non-endemic areas. • Surveillance data is captured by county of residence, not county of exposure. • Surveillance data are subject to each state's abilities to capture and classify cases. • States may close their annual surveillance dataset at a different time than CDC. Thus, the final case counts published by CDC may not exactly match numbers published by each state agency for a given year. Reporting Requirements • By law, Lyme disease is a reportable condition in Virginia • Report Lyme disease – when suspected or confirmed – to your local health department within three days Reporting Requirements Lyme Disease is a reportable condition in Virginia: • Code of Virginia 32.1-36 and 32.1-37 • 12-VAC 5-90-80 and 12-VAC 5-90-90 of the Board of Health Regulations for Disease Reporting and Control Local Health Department Directory: http://www.vdh.virginia.gov/lhd/ § 54.1-2963.2. Lyme disease testing information disclosure. This new law places a requirement on practitioners who order tests for Lyme disease. As of July 1, 2013, “every licensee or his in-office designee who orders a laboratory test for the presence of Lyme disease shall provide to the patient or his legal representative” certain information. § 54.1-2963.2. Lyme disease testing information disclosure. "ACCORDING TO THE CENTERS FOR DISEASE CONTROL AND PREVENTION, AS OF 2011 LYME DISEASE IS THE SIXTH FASTEST GROWING DISEASE IN THE UNITED STATES. YOUR HEALTH CARE PROVIDER HAS ORDERED A LABORATORY TEST FOR THE PRESENCE OF LYME DISEASE FOR YOU. CURRENT LABORATORY TESTING FOR LYME DISEASE CAN BE PROBLEMATIC AND STANDARD LABORATORY TESTS OFTEN RESULT IN FALSE NEGATIVE AND FALSE POSITIVE RESULTS, AND IF DONE TOO EARLY, YOU MAY NOT HAVE PRODUCED ENOUGH ANTIBODIES TO BE CONSIDERED POSITIVE BECAUSE YOUR IMMUNE RESPONSE REQUIRES TIME TO DEVELOP ANTIBODIES. IF YOU ARE TESTED FOR LYME DISEASE, AND THE RESULTS ARE NEGATIVE, THIS DOES NOT NECESSARILY MEAN YOU DO NOT HAVE LYME DISEASE. IF YOU CONTINUE TO EXPERIENCE SYMPTOMS, YOU SHOULD CONTACT YOUR HEALTH CARE PROVIDER AND INQUIRE ABOUT THE APPROPRIATENESS OF RETESTING OR ADDITIONAL TREATMENT." Where can I find Lyme disease statistics? • CDC Webpage: http://www.cdc.gov/lyme/ • VDH Reportable Disease Surveillance Data http://www.vdh.virginia.gov/Epidemiology/Surveillanc e/SurveillanceData/ • Morbidity and Mortality Weekly Report (MMWR) http://www.cdc.gov/mmwr/mmwr_wk/wk_cvol.html Role of Public Health: Prevention and Control VDH CDC • Contribute to the understanding of Lyme disease • Education of public and providers • Conduct surveillance for Lyme disease in Virginia • Emphasis on prevention • Primary prevention • Secondary prevention • Maintaining and analyzing national surveillance data for Lyme disease • Conducting epidemiologic studies • Offering diagnostic and reference laboratory services • Developing/testing strategies for the control and prevention Lyme disease in humans • Supporting education of the public and health care providers Thank You!