March 2000 volume 16 number 3 Division of Public Health http://health.state.ga.us The Georgia Epidemiology Report is a publication of the Epidemiology Section of the Epidemiology and Health Information Branch, Division of Public Health, Georgia Department of Human Resources Tick-borne diseases in Georgia The medical and economic importance of ticks has long been recognized due to their ability to transmit disease to humans and animals. Ticks are vectors of a variety of pathogenic agents, including species of bacteria (Borrelia burgdorferi, Rickettsia rickettsii, Ehrlichia ssp.), viruses (tick-borne encephalitis virus - family Flaviviridae), and parasites (Babesia microti, Anaplasma marginale). Five tick-borne diseases are known to occur among humans in the southeastern United States: Rocky Mountain spotted fever (RMSF), human monocytic ehrlichiosis (HME), tularemia, Southern tick associated rash illness (STARI), and Lyme disease. While RMSF and tularemia have long been recognized as causes of human disease in this region, STARI and several forms of human ehrlichiosis have only recently emerged. Alterations in vector-host ecology are at least partly responsible for the emergence of tick-borne diseases. The public health importance of these illnesses will become more significant as human behaviors continue to alter the habitats of tick and reservoir species, resulting in increased transmission of known tick-borne diseases and the emergence of previously unrecognized zoonotic infections in humans. Diagnosis and treatment: The prompt diagnosis and early treatment of tick-borne infections is often associated with a reduced risk of severe complications or fatalities. Unfortunately, clinical recognition of most tick-borne diseases is difficult because many cases do not initially present with a rash or other distinguishing clinical feature, and few patients recollect a tick bite (Table 1). Moreover, laboratory tests that are currently available offer little assistance to clinicians in making a prompt and accurate diagnosis because serologic tests are usually negative during the acute stage of disease (Table 2). Collection of convalescent-phase blood samples from patients with a suspected tick-borne disease is usually required in order to confirm a diagnosis. While empiric therapy for suspect cases of tick-borne diseases is appropriate because of the potential for chronic disease (as with Lyme disease), or severe or fatal illness (as with RMSF or HME), the routine administration of prophylactic treatment after a tick bite is not currently recommended. Director Kathleen E. Toomey, M.D., M.P.H. Epidemiology and Health Information Branch Acting Director Kathleen E. Toomey, M.D., M.P.H. Acting State Epidemiologist Paul A. Blake, M.D., M.P.H. Epidemiology Section Chief Paul A. Blake, M.D., M.P.H. Public Health Advisor Mel Ralston Prevention: The best way to prevent tick-borne disease is to reduce or eliminate exposure to ticks and to promptly remove attached ticks. Studies have shown that transmission of RMSF, HME, or Lyme disease requires at least 10 hours of tick attachment, so the prompt removal of ticks should be emphasized to patients in order to minimize the risk of infection. Patients should also be made aware of the risk factors for tick exposure and should be educated about how to prevent tick bites. An educational brochure for patients is available through the Georgia Division of Public Health (GDPH). Important teaching points to be made include: Avoid overhanging grasses, weeds or brush while hiking, camping, hunting, or doing other activities outdoors. Wear light colored long sleeved shirts and pants that are tight at the wrists and ankles (or tuck shirts into pants and pants into socks). Use chemical acaricides containing DEET (applied to exposed skin) or permethrin (applied to clothing) to deter tick attachment. Inspect yourself and children for attached ticks immediately after spending time outdoors. Ticks are attracted to warm, moist areas, such as the under arms, groin, behind the knees, and scalp. Remove attached ticks immediately by grasping them with a tweezers placed as close to the skin as possible and slowly pulling back in a direction perpendicular to the skin surface. Crushing the tick should be avoided. After tick removal, the area of tick attachment and hands should be washed with soap and water. Georgia Epidemiology Report Editorial Board Carol A. Hoban, M.S., M.P.H. - Editor Kathryn E. Arnold, M.D. Paul A. Blake, M.D., M.P.H. Susan Lance-Parker, D.V.M, Ph. D. Kathleen E. Toomey, M.D., M.P.H. Angela Alexander - Mailing List Jimmy Clanton, Jr. - Graphics There is currently no vaccine available in the United States to protect against RMSF, HME, or STARI. Vaccination against tularemia is recommended in the US for people with occupational exposure, such as laboratory workers. Lyme disease vaccine, which was approved for human use in 1998, is recommended only for persons who reside, work or recreate in areas of high risk. Fortunately, all of Georgia is classified as either a low or no risk area. Georgia Department of Human Resources Division of Public Health, Epidemiology Section Epidemiology & Health Information Branch Two Peachtree St., N.W., Atlanta, GA 30303 - 3186 Phone: (404) 657-2588 Fax: (404) 657-2586 Emerging tick-borne diseases: study enrollment, and symptomatic participants will be encouraged to seek Since Ehrlichia chaffeensis was identified as the cause of HME in 1986, two other species of Ehrlichia, both with tropisms for granulocytes, have emerged as causes of human granulocytic ehrlichiosis medical attention. Participants will receive the results of tick testing when they are available. Recommended reading: 1. Walker DH. Tick-transmitted infectious diseases in the United States. Annual Review of Public Health 1998;19:237- (HGE). In 1994, an unnamed Ehrlichia species that is genetically 69. similar or identical to veterinary pathogens E. phagocytophila and 2. Spach DH, Liles WC, Campbell GL, et al. Tick-borne disease in the United States. NEJM 1993;329:936-47. 3. Fritz CL, Glaser CA. Ehrlichiosis. Infectious Disease Clinics of North America 1998;12:123-36. E. equi, was first identified as an agent of HGE in the Northeast and 4. Buller R, Arens M, Hmiel P, et al. Ehrlichia ewingii, a newly recognized agent of human ehrlichiosis. New England the Upper Midwest. Ehrlichia ewingii, which causes canine Journal of Medicine 1999;341:148-155. 5. Dumler JS, Bakken JS. Human ehrlichioses: newly recognized infections transmitted by ticks. Annual Review of ehrlichiosis, was first reported in 1999 to be a cause of HGE in Medicine 1998;49:201-13. Missouri. While disease caused by these three Ehrlichia species 6. Barbour AG. Does Lyme disease occur in the South?: a survey of emerging tick-borne infections in the region. Am J Med Sci 1996;311:34-40. cannot be distinguished clinically, they are epidemiologically 7. Warshafsky S, Nowakowski J, Nadelman R, et al. Efficacy of antibiotic prophylaxis for prevention of Lyme disease. distinct and they can be differentiated via laboratory techniques. J Gen Intern Med 1996;923-933. 8. CDC. Recommendations for the use of Lyme disease vaccine: recommendations of the Advisory Committee on Information regarding testing for human ehrlichiosis can be Immunization Practices (ACIP). MMWR 1999;48(RR-7):1-25. obtained by contacting the GDPH. 9. Kirkland KB, Klimko TB, Meriwether RA, et al. Erythema migrans-like rash illness at a camp in North Carolina. A new tick-borne disease? Arch Intern Med 1995;157:2635-2641. 9. Kirkland KB, Klimko TB, Meriwether RA, et al. Erythema migrans-like rash illness at a camp in Erythema migrans-like rashes that are associated with tick bites occur in the Rocky Mountain spotted fever southeastern portion of the US; however, studies have failed to implicate Pathogen: Rickettsia rickettsii Borrelia burgdorferi as the etiologic agent . It is believed that STARI is caused Vector: Dermacentor variabilis (American dog tick) by a yet uncultivable species of Borrelia called B. lonestari carried by Amblyo- Incubation: 5-7 days (range 2 to 14) mma americanum (Lone Star tick), the most common human-biting tick in the Clinical Classic triad of fever, rash, and history of tick bite in 60-70% at Southeast. STARI is a very mild illness with no known chronic manifestations. description: initial presentation. Acute onset of fever (100%), malaise (95%), severe frontal headache (90%), myalgia (80%), and vomiting (60%). Rash on wrists and ankles spreads centrally and becomes Surveillance of tick-borne diseases in Georgia: petechial, papular or purpuric (60-90%). Other symptoms may include: conjunctivitis, abdominal pain, nausea, cough, renal Lyme disease, RMSF, HME, and tularemia are all physician and dysfunction, meningismus, and mental confusion. laboratory reportable diseases in the state of Georgia. Currently, Case fatality: 13-25% in absence of specific therapy, otherwise 3-5% surveillance data is incomplete and unreliable because convalescent blood Human monocytic ehrlichiosis samples are seldom obtained to confirm diagnoses, and there has been little Pathogen: Ehrlichia chaffeensis follow-up with reporting physicians to encourage collection of convalescent Vector: Amblyomma americanum (Lone star tick) blood and to obtain clinical information. For these reasons, it has been Incubation: 7 days (range 1 to 28) difficult to estimate the true morbidity and mortality associated with tick- Clinical Symptoms from hospital cohort: fever (97%), malaise (84%), borne infections in Georgia. In an effort to enhance surveillance for tick- description: headache (81%), myalgia and arthralgias (68%), chills (61%), borne diseases the GDPH will be initiating several projects. The objectives of nausea (48%), cough (26%), and confusion (20%). Non-specific these projects will be to enhance physician and patient awareness of the rash (30%). Laboratory: thrombocytopenia (74%), leukopenia diseases, to better understand the epidemiology of these diseases, and to (72%), and elevated AST/ALT (80%). detect the emergence of new tick-borne diseases in Georgia. Data will also be Case fatality: Up to 5% used to target public health interventions to populations at greatest risk. Tularemia Projects include: Pathogen: Francisella tularensis 1) An active physician-based surveillance system for Lyme disease Vector: Amblyomma americanum (Lone star tick) and Dermacentor variabilis and STARI. (American dog tick) Dermatologists and healthcare providers at clinics in three distinct regions of Incubation: 3 to 5 days (range 1 to 14) Georgia will be asked to participate in this project. Clinic patients at Clinical Tick-borne tularemia typically presents with ulcer at site of tick participating facilities will be eligible for study admission if they have, 1) description: bite, and painful regional lymphadenopathy. Rarely can present acute onset of an annular, erythematous, expanding EM-like rash that is at with typhoidal form: fever, chills headache, abdominal pain, and least 5 cm in diameter and, 2) a history of a tick bite at the rash site, or prostration. potential exposure to ticks within 14 days prior to rash onset. All partici- Case fatality: Rare cases of fulminant septic shock pants will have a skin biopsy of the rash, urine, whole blood, and acute- and Lyme disease convalescent- sera obtained for testing at CDC. Pathogen: Borrelia burgdorferi 2) Active surveillance for HME and RMSF in the coastal region of Vector: Ixodes scapularis (Black-legged tick) Georgia. Healthcare providers in parts of coastal Georgia will be asked to participate in this project. All patients at participating hospitals and clinics will be eligible for study admission if they have, 1) a fever (temperature > 37.5C) of unknown etiology or, 2) a skin rash plus thrombocytopenia. Patients will be excluded if laboratory tests or procedures obtained within 72 hours of hospital admission or clinic visit provide an explanation for their illness. Acute- and convalescent-phase sera (collected 4-6 weeks apart) will be sent to the CDC for testing. Incubation: 7 to 14 days (range 3 to 30) Clinical Erythema migrans (EM) rash (an expanding, erythematous, bulls description: eye-shaped rash) 60-90% of cases. Acute onset of fever, headache, malaise, arthralgias, and/or myalgias. If not adequately treated may become disseminated disease: multiple secondary EM lesions (2550%), arthritis (60%), CNS manifestations (including facial palsy and meningitis) (15%) and carditis (5%). Case fatality: Rarely, if ever, fatal Southern tick-associated rash illness Pathogen: Probably Borrelia lonestari (thus far uncultivated) 3) Identification of infectious agents in ticks that have been Vector: Probably Amblyomma americanum (Lone Star tick) attached to Georgia residents. Incubation: Approximately 12 days (range 2 to 21) Public health professionals throughout the state will be asked to encourage Clinical Tick bite-associated annular, expanding, erythematous, EM-like Georgia residents who have removed an attached tick to call the Georgia description: lesions. Symptoms other than a rash are rare and are usually very Poison Control Center. Callers will be asked to send the tick to the CDC to mild, but may include headache, musculoskeletal pain, fatigue, and be identified and tested for the presence of the agents of Lyme disease, HME, nausea. Fever is not a characteristic feature of the illness. and RMSF. A brief questionnaire that includes questions about tick exposures and current health status will be administered two weeks after Case fatality: No deaths have been reported -2 - Diagnostic Criteria for Tick-borne Diseases in Georgia Rocky Mountain spotted fever (Rickettsia rickettsii) Probable case A clinically compatible case with single sera antibody titer: IFA > 1: 64 OR CF > 1:16 OR LA, IHA or MA > 1:128 OR Proteus OX-19 or OX-2 test > 1:320 OR a four-fold rise in titer in paired sample using same test Serum: 5 mL (in red-top tube) collected both at disease onset and >3 weeks later Confirmed case A clinically compatible case with either: Serum: 4-fold or greater rise in antibody titer in paired samples to R. rickettsii by IFA, CF, LA, IHA, or MA OR Whole blood: positive PCR assay to R. rickettsii OR Skin biopsy: positive IFA to R. rickettsii OR Clinical specimen: isolation and culture of R. rickettsii Specimen Requirements Whole blood: 5 mL (in purple-top tube) Skin biopsy: 2-4 mm skin lesion in transport media collected in acute phase of the illness Clinical specimen: (skin biopsy or whole blood) see instruction above Human Monocytic Ehrlichiosis (Ehrlichia chaffeensis) Probable case A clinically compatible case with either: Serum: single antibody titer > 1: 64 by IFA OR Intracytoplasmic morulae identified in white blood cells Confirmed case A clinically compatible case with either: Serum: 4-fold or greater rise in antibody titer in paired samples to Ehrlichia species by IFA OR Whole blood: positive PCR assay to Ehrlichia species OR Skin biopsy: positive IFA to Ehrlichia species OR Clinical specimen: isolation and culture Ehrlichia species OR Serum: single antibody titer > 1: 64 by IFA plus intracytoplasmic morulae identified in white blood cells Tularemia (Francisella tularensis) Serum: 5 mL (red-top tube) collected both at disease onset and 4 to 6 weeks later Whole blood: 5 mL (purple-top tube) Skin biopsy: 2-4 mm skin lesion in transport media collected in acute phase of the illness Clinical specimen: (skin biopsy or whole blood) see instruction above Probable case A clinically compatible case with either: Serum: single elevated antibody titer >1:160 to F. tularensis in patient without previous tularemia vaccination OR Clinical specimen: FA positive for F. tularensis Confirmed case A clinically compatible case with either: Serum: 4-fold or greater rise in antibody titer to F. tularensis OR Clinical specimen: isolation of F. tularensis Lyme disease (Borrelia burgdorferi) Serum: 5 mL (red-top tube) collected both at disease onset and 4 to 6 weeks later Clinical specimen: (ulcer exudate or lymph node aspirates) collect in a sterile vial Confirmed case Probable case A clinically compatible case with an erythema migrans rash and history of tick exposure. Confirmed case A clinically compatible case with an erythema migrans rash or a late manifestation history of tick exposure plus: Serum: 2-step process for early disease: 1) EIA or IFA IgG and IgM 2) if positive, do Western blot IgG and IgM. If late disease: IgG Western blot. If neuroborreliosis, EIAIgG serum and CSF. Calculate index if EIA elevated. Skin biopsy: isolation and culture of B. burgdorferi OR CSF: isolation and culture of B. burgdorferi OR Synovial fluid: isolation and culture of B. burgdorferi OR Serum: 5 mL serum (red-top tube) collected both at disease onset and 4 to 6 weeks later Skin biopsy: 2-4 mm skin lesion in transport media collected in acute phase of the illness CSF: 5-10 mL in sterile tube Synovial fluid: 5-10 mL in sterile tube Abbreviations: IFA indirect fluorescent antibody test, CF - compliment fixation, LA - latex agglutination, IHA indirect hemagglutination, MA microagglutination, PCR - polymerase chain reaction, EIA - enzyme-linked immunosorbent assay, WB - Western immunoblot. -3 - The Georgia Epidemiology Report Epidemiology and Health Information Branch Two Peachtree St., NW Atlanta, GA 30303-3186 Bulk Rate U.S. Postage Paid Atlanta, Ga Permit No. 4528 March 2000 Volume 16 Number 3 Reported Cases of Selected Notifiable Diseases in Georgia Profile* for December 1999 Selected Notifiable Diseases Campylobacteriosis Chlamydia genital infection Cryptosporidiosis E. coli O157:H7 Giardiasis Gonorrhea Haemophilus influenzae (invasive) Hepatitis A (acute) Hepatitis B (acute) Legionellosis Lyme Disease Meningococcal Disease (invasive) Mumps Pertussis Rubella Salmonellosis Shigellosis Syphilis - Primary Syphilis - Secondary Syphilis - Early Latent Syphilis - Other Syphilis - Congenital Tuberculosis Total Reported for December 1999 1999 32 1792 9 5 109 1382 6 17 11 0 0 10 0 3 0 123 16 22 34 92 121 3 107 Previous 3 Months Total Ending in December 1997 1998 1999 232 189 142 4227 7841 7763 24 47 38 7 17 14 313 337 357 5065 5426 5686 12 24 21 224 233 76 52 36 48 4 0 2 3 0 0 17 22 19 1 1 0 2 8 7 0 0 0 363 501 476 491 204 52 50 46 52 100 81 92 327 236 198 333 241 236 1 6 3 171 172 200 Previous 12 Months Total Ending in December 1997 1998 1999 766 769 715 16164 25508 30653 74 152 167 46 84 41 916 1215 1355 18525 20832 21153 41 69 80 763 879 478 224 209 203 6 8 4 9 5 0 107 103 72 11 2 4 18 38 46 0 0 0 1380 1839 1959 1204 1138 280 259 125 141 703 230 283 1864 795 703 1156 799 733 24 29 19 694 629 657 * The cumulative numbers in the above table reflect the date the disease was first diagnosed rather than the date the report was received at the state office, and therefore are subject to change over time due to late reporting. The 3 month delay in the disease profile for a given month is designed to minimize any changes that may occur. This method of summarizing data is expected to provide a better overall measure of disease trends and patterns in Ge orgia. ** Other syphilis includes latent (unknown duration), late latent, late with symptomatic manifestations, and neurosyphilis. AIDS Profile Update Report Period Total Cases Reported* Percent Female MSM Risk Group Distribution (%) IDU MSM&IDU HS Blood Unknown Latest 12 Months: 1/99 - 12/99 Five Years Ago: 1/94 - 12/94 Cumulative: 7/81 - 12/99 1693 25.8 33.4 13.1 3.2 17.6 1.4 2352 18.2 44.2 22.9 6.1 13.3 1.6 21477 16.1 49.8 18.9 5.8 13 1.9 MSM - Men having sex with men IDU - Injection drug users * Case totals are accumulated by date of report to the Epidemiology Section 31.4 11.8 10.7 HS - 4- Race Distribution (%) White Black Other 19.3 78.5 2.2 32.7 65.7 1.6 36.9 61.1 2.1 - Heterosexual