The Trouble with Ticks: Distribution, Burden, and Prevention of Tickborne Disease in Humans

National Center for Emerging and Zoonotic Infectious Diseases The Trouble with Ticks: Distribution, Burden, and Prevention of Tickborne Disease in Humans Paul Mead, MD, MPH Integrated Tick Management Symposium 17 June, 2016

Tick-associated diseases in the United States Anaplasmosis Babesiosis Borrelia miyamotoi infection Colorado tick fever Ehrlichiosis Heartland virus infection IgE-mediated anaphylaxis Lyme disease STARI Spotted fever rickettsiosis Powassan virus infection Tick paralysis Tickborne relapsing fever Tularemia

Reported cases of tickborne disease, United States, 2014 Disease Cases Lyme disease 33,461 Spotted fever rickettsiosis 3,647 Ana. phagocytophilum 2,800 Babesia 1,759 Ehrlichia chaffeensis 1,475 Tularemia 180 Powassan virus 8

Reported cases of tickborne disease, United States, 2014 Disease Cases Lyme disease 33,461 Spotted fever rickettsiosis 3,647 Ana. phagocytophilum 2,800 Babesia 1,759 Ehrlichia chaffeensis 1,475 Tularemia 180 Powassan virus 8 Top notifiable diseases, United States, 2014 Disease Cases Chlamydia 1,441,789 Gonorrhea 350,062 Syphilis 63,450 Salmonellosis 51,455 HIV diagnoses 35,606 Lyme disease 33,461 Pertussis 32,971

Reported cases of tickborne disease, United States, 2014 Disease Cases Lyme disease 33,461 Spotted fever rickettsiosis 3,647 Ana. phagocytophilum 2,800 Babesia 1,759 Ehrlichia chaffeensis 1,475 Tularemia 180 Powassan virus 8 Top notifiable diseases, Northeast US, 2014 Disease Cases Chlamydia 227,609 Gonorrhea 47,391 Lyme disease 25,801 Syphilis 11,081 Salmonellosis 7,199 HIV diagnoses 6,202 Pertussis 3,422

Geographic distribution of key tickborne diseases

Reported cases Reported cases of tickborne disease by year United States, 2001-2014 50,000 45,000 40,000 35,000 30,000 25,000 20,000 15,000 10,000 5,000 0 2001 2003 2005 2007 2009 2011 2013 Babesia* Lyme Ehrlichiosis Anaplasmosis Rickettsioses

Geographic expansion of Lyme disease risk United States, 1993-2012 High-incidence counties identified for each of four 5-year time periods High-incidence defined as county in high-risk spatial cluster with county-specific RR >2.0 Method does not capture all counties with Lyme disease transmission Time period when county first reached high-incidence threshold: 1993-1997 1998-2002 2003-2007 2008-2012 Kugeler et al. Emerg Infect Dis 2015;21:1455-57

Estimates of Lyme disease under-reporting State Year Underreporting Method CT 1992 6-9 X MD survey 1 MD 1992-3 10-12 X MD survey 2 NY 1991-4 4 X Tick bite model 3 WI 1992-8 3 X Record review 4 Refs: 1) Meek 1996 2) Coyle 1996 3) Campbell 1998 4) Nalaway 2002

Lyme disease testing by large commercial laboratories in the United States, 2008 Hinckley A, et al. CID 2014; 59:676-81 Survey of 7 large, national clinical diagnostic laboratories ~2,400,000 patient samples tested in 2008 Estimated cost of testing = $492,000,000 Corrected for test performance and clinical stage, true infection rate among samples ~ 12% Estimated 288,000 infected source patients (range 240,000-444,000)

Incidence of clinician diagnosed Lyme disease in the United States, 2005-2010 Nelson C, et al. EID 2015; 9:676-81 Analysis of large medical claims database using diagnostic codes and prescription information insured persons <65 years old 103,647,966 person-years of observation 44,445 outpatient and 985 inpatient Lyme disease diagnoses identified Estimated 329,000 patients treated for Lyme disease annually (range 296,000-376,000)

Estimates of Lyme disease under-reporting State Year Underreporting Method CT 1992 6-9 X MD survey 1 MD 1992-3 10-12 X MD survey 2 NY 1991-4 4 X Tick bite model 3 WI 1992-8 3 X Record review 4 All 2008,10 8-10 X Lab survey, 5 claims data 6 Refs: 1) Meek 1996 2) Coyle 1996 3) Campbell 1998 4) Nalaway 2002 5) Hinckley 2014 6) Nelson 2015

Cost estimates for Lyme disease United States Author Period Mean cost per case Cost description Pauly et al. 1 1990 $ 6,196 Total medical, non-medical, productivity losses Zhang et al. 1997-2000 $ 1,965 2 Total medical, non-medical, productivity losses Adrion et al. 2006-2010 $ 2,968 Excess medical costs 1 Unpublished report 2 Median cost = $281

Prevention Clin Infect Dis 2011;52:S271-5

Hayes and Piesman, N Engl J Med 2003;348:2424-30 Avenues for prevention

Hayes and Piesman, N Engl J Med 2003;348:2424-30 Avenues for prevention

Effectiveness of repellent for preventing Lyme disease Reference P value Effect* Variable 2008 Vázquez 1 0.05 OR 0.8 Use on skin or clothing 1990 Schwartz 0.05 OR 0.5 Use of repellent 2001 Smith G 1 0.02 OR 0.7 Use away from home 2001 Smith G 1 NS OR 1.2 Use in yard 2009 Connally 1 NS OR 0.6 Wore in yard 2001 Phillips 2 NS - Usually or always use 1998 Orloski 1 NS OR 1.0 Use of repellent 1996 Klein 1 NS - Use of repellent 1995 Ley 1 NS OR 1.5 Use in past month 1998 Smith P 2,3 NS RR 0.5 On skin at work 1998 Smith P 2,3 NS RR 0.7 On skin at leisure * OR = Odds Ratio, RR Relative Risk 1 case control, 2 cross-sectional, 3 odds ratios presented as inverse

Effectiveness of tick checks for preventing Lyme disease Reference P value Effect* Variable 2009 Connally 1 0.02 OR 0.5 within 36 hrs of exp. 2009 Connally 1 0.03 OR 0.4 Bath within 2 hrs of exp. 2001 Smith G 1 0.001 OR 0.6 Check during activities 2001 Smith G 1 NS OR 1.2 after activities 2008 Vázquez 1 NS OR 1.0 Check body after exposure 2001 Phillips 2 NS - Usually or always check 1998 Orloski 1 NS OR 0.5 Performed tick check 1996 Klein 1 NS - Use of tick checks 1995 Ley 1 NS OR 0.8 Always vs. never checking 1988 Smith P 2,3 NS RR 1.1 Check for ticks at work 1988 Smith P 2,3 NS RR 0.8 Check for ticks at leisure * OR = Odds Ratio, RR Relative Risk 1 case control, 2 cross-sectional, 3 odds ratios presented as inverse

Personal protective measures Inexpensive and unlikely to be harmful Insect repellent Tick checks Protective clothing Showering promptly after exposure Insufficient at population level

Hayes and Piesman, N Engl J Med 2003;348:2424-30 Avenues for prevention

Effectiveness of residential acaricides to prevent Lyme and other tickborne diseases in humans Randomized, double-blinded, placebo-controlled trial of single springtime pesticide application bifenthrin vs. water barrier spray Hinckley A, et al. JID 2016; e -pub 2,727 households in 3 northeastern states Questing ticks >60% lower on acaricide-treated properties No comparable reduction in human exposure to ticks or tickborne illness

Conclusions Tickborne diseases continue to emerge as an important public health problem in the United States Disease burden substantial Case counts increasing Geographic expansion Existing prevention methods inadequate

Acknowledgments State & Local Health Departments TickNet Emerging Infections Program Partners For more information, contact CDC 1-800-CDC-INFO (232-4636) TTY: 1-888-232-6348 www.cdc.gov Alison Hinckley, Sarah Hook, Kiersten Kugeler, Christina Nelson, Anna Perea, Amy Schwartz, Ryan Max, Ben Beard The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.