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Tick-borne Diseases in Ohio. Christina Davey Regional Epidemiologist Serving Lawrence, Pike, Ross, and Scioto Counties. Overview. Rocky Mountain Spotted Fever Lyme Disease Ehrlichiosis/Anaplasmosis Tick Submission. Rocky Mountain Spotted Fever (RMSF). Agent/transmission
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Tick-borne Diseases in Ohio Christina Davey Regional Epidemiologist Serving Lawrence, Pike, Ross, and Scioto Counties
Overview • Rocky Mountain Spotted Fever • Lyme Disease • Ehrlichiosis/Anaplasmosis • Tick Submission
Rocky Mountain Spotted Fever (RMSF) Agent/transmission • Rickettsia rickettsii • Maintained and amplified by hard ticks, primarily American dog tick (D. variabilis) and Rocky Mountain wood tick (D. andersoni). • Brown dog tick (Rhipicephalus sanguineus) and Cayenne tick (Amblyomma cajennense) also been implicated as vectors.
Rocky Mountain Spotted Fever (RMSF) Agent/transmission (Continued) • In Ohio, the American dog tick (Dermacentor variabilis) is the vector. • Humans contract RMSF through the bite of dog tick, or by coming in contact with tick secretions or body fluids through careless handling of ticks. • Dogs can transport ticks into the household environment and may also become ill with spotted fever. • Humans are dead-end hosts
Rocky Mountain Spotted Fever (RMSF) Signs/Symptoms • Average incubation 1 week after bite • Fever (acute onset), possibly accompanied by • Headache • Malaise • Myalgia • Nausea/vomiting • Neurologic signs • Fatal in 5-10% of untreated cases • Severe fulminant disease possible
Rocky Mountain Spotted Fever (RMSF) Signs/Symptoms (Continued) • Characteristic spotted rash • Macular or maculopapular rash in most (about 80% of) patients • 4-7 days post-onset, • Rash often present on palms and soles.
Rocky Mountain Spotted Fever (RMSF) Occurrence • 71/88 counties in Ohio • Almost half of all cases from Clermont, Franklin and Lucas (from 1999-2007) • 19 deaths since 1964 • April through July
Rocky Mountain Spotted Fever (RMSF) Diagnosis (CDC Laboratory Criteria for Surveillance Purposes) Laboratory Confirmed: • Serological evidence of a fourfold change in IgG-specific antibody titer reactive with R. rickettsii antigen by indirect IFA between paired serum specimens*, or • Detection of R. rickettsii DNA in clinical specimen via amplification of a specific target by PCR assay, or • Demonstration of spotted fever group antigen in biopsy or autopsy specimen by IHC, or • Isolation of R. rickettsii from clinical specimen in cell culture
Rocky Mountain Spotted Fever (RMSF) Diagnosis (CDC Laboratory Criteria for Surveillance Purposes) Laboratory Supportive: • Serologic evidence of elevated IgG or IgM antibody reactive with R. rickettsii antigen by IFA, ELISA, dot-ELISA, or latex agglutination*
Rocky Mountain Spotted Fever (RMSF) Case Definitions for Surveillance • Confirmed: A clinically compatible case (meets clinical evidence criteria*) that is laboratory confirmed. • Probable: A clinically compatible case (meets clinical evidence criteria*) that has supportive laboratory results. • Suspect: A case with laboratory evidence of past or present infection but no clinical information available (e.g. a laboratory report).
Rocky Mountain Spotted Fever (RMSF) Treatment (need based on clinical and epidemiological information) • Tetracycline antibiotics (usually doxycycline) • Treat for at least 3 days after fever subsides and until evidence of clinical improvement • Standard duration of treatment: 5-10 days
Rocky Mountain Spotted Fever (RMSF) Prevention and Control • Avoid ticks in endemic areas • Tuck pants into socks • Use repellents (carefully following label instructions) • Wear light-colored clothing • Regularly inspect for and remove ticks (on humans and pets) • Keep grass and weeds mowed
Lyme Disease Agent/transmission • Borrelia burgdorferi • Reservoir=mice, squirrels, other small animals • Ixodes scapularis (black-legged tick, also known as “deer tick”)=vector in eastern and midwestern states • Ixodes pacificus=vectorin western United States • Other species of ticks not known to transmit Lyme Disease. • No known human-human transmission (though transplacental transmission may occur)
Lyme Disease Signs/Symptoms • Incubation period of up to 30 days after tick bite • Muscle aches • Fever • Swollen lymph nodes • Headache • Joint pain • Fatigue • Late manifestations
Lyme Disease Signs/Symptoms (Continued) • Erythema migrans (“bull’s-eye” rash) • Best clinical marker • Seen in 60-80% of cases • Develops at site of tick attachment after a delay of 3-30 days • Usually appears 7-14 days after exposure • Gradually expands over several days
Lyme Disease Occurrence • Since 1990, 932 cases reported from 83/88 Ohio counties • 48 cases reported to CDC in 2008 • Most commonly reported vector-borne disease in U.S. with 20,000 cases each year • 80% of total U.S. cases from Mid-Atlantic and New England (mostly New York, New Jersey and Pennsylvania) • Black-legged tick rare in Ohio
Lyme Disease Diagnosis (CDC Laboratory Criteria for Surveillance Purposes) • Positive culture for B. burgdorferi, or • Demonstration of diagnostic IgM or IgG antibodies to B. burgdorferi in serum or CSF*, or • Single-tier IgG Western blot / immunoblot seropositivity interpreted using established criteria*
Lyme Disease Case Definitions for Surveillance • Confirmed: a) a case of EM with a known exposure, or b) a case of EM with laboratory evidence of infection (by CDC lab criteria) and without a known exposure or c) 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 (by CDC lab criteria). • Suspected: a) a case of EM where there is no known exposure and no laboratory evidence of infection, or b) a case with laboratory evidence of infection but no clinical information available (e.g. a laboratory report).
Lyme Disease Treatment • Antibiotic therapy during acute phase • Doxycycline, amoxicillin, or cefuroxime axetil • IV ceftriaxone or penicillin for neurological or cardiac • Second 4-week course if symptoms persist or recur
Lyme Disease Prevention, and Control • Vaccine no longer available • Avoid of ticks in endemic areas • Tuck pants into socks • Wear light-colored clothing • Use repellents (carefully following label instructions) • Regularly inspect for and remove ticks (on humans and pets) • Keep grass and weeds mowed • Reduce reservoir populations
Ehrlichiosis/Anaplasmosis Agents/transmission • Ehrlichia chaffeensis - formerly known as human monocytic ehrlichiosis (HME) • Anaplasma phagocytophilum, (aka Ehrlichia equi or Ehrlichia phagocytophila) - formerly known as human granulocytic ehrlichiosis (HGA, HGE) • Ehrlichia ewingii
Ehrlichiosis/Anaplasmosis Agents/transmission • E. chaffeensis is transmitted principally by the Lone Star tick, Amblyomma americanum • A. phagocytophilum appears to be transmitted by the blacklegged ticks, Ixodes scapularis and Ixodes pacificus. • E. ewingii appears to be transmitted by the Lone Star tick, Amblyomma americanum. • Reservoirs for vector ticks: deer, elk, wild rodents and dogs.
Ehrlichiosis/Anaplasmosis • Humans contract Ehrlichiosis/Anaplasmosis through the bite of vector tick, or by coming in contact with tick secretions or body fluids through careless handling of ticks. • Humans are dead-end hosts.
Ehrlichiosis/Anaplasmosis Signs/symptoms • Incubation period: 5-14 days after tick bite for Ehrlichia chaffeensis infection and E. ewingii infection; 5-21 days for Anaplasma phagocytophilum infection • Fever (acute onset) and one or more of the following: • Headache • Myalgia • Malaise • Anemia • Leuokpenia • Thrombocytopenia • Hepatic transaminase elevation • Nausea • Vomiting • Rash (uncommon for HME, rare for HGE) • Case fatality rate of 2-3% for E. chaffeensis, less than 1% for A. phagocytophilum, and not documented for E. ewingii
Ehrlichiosis/Anaplasmosis Occurrence • Found primarily in the South and Mid-Atlantic, North/South Central United States, and isolated areas of New England, E. chaffeensis is transmitted principally by the Lone Star tick, Amblyomma americanum. • A. phagocytophilum is more likely to be found in the New England, North Central and Pacific States, and appears to be transmitted by the blacklegged ticks, Ixodes scapularis and Ixodes pacificus. • Found primarily in the South Atlantic and South Central United States with isolated areas of New England, E. ewingii appears to be transmitted by the Lone Star tick, Amblyomma americanum. • Lone Star ticks becoming more common in Ohio, especially Southern Ohio.
Ehrlichiosis/Anaplasmosis Diagnosis (CDC Laboratory Criteria for Surveillance Purposes) – E. chaffeensis (HME) Laboratory Confirmed: • Serological evidence of fourfold change in IgG-specific antibody titer to E. chaffeensis antigen by indirect IFA between paired serum samples*, or • Detection of E. chaffeensis DNA in clinical specimen via amplification of specific target by PCR assay, or • Demonstration of ehrlichial antigen in biopsy or autopsy sample by immunohistochemical methods, or • Isolation of E. chaffeensis from clinical specimen in cell culture
Ehrlichiosis/Anaplasmosis Diagnosis (CDC Laboratory Criteria for Surveillance Purposes) – E. chaffeensis (HME) Laboratory Supportive: • Serological evidence of elevated IgG or IgM antibody reactive with E. chaffeensis antigen by IFA, ELISA, dot-ELISA, or assays in other formats*, or • Identification of morulae in the cytoplasm of monocytes or macrophages by microscopic examination
Ehrlichiosis/Anaplasmosis Diagnosis (CDC Laboratory Criteria for Surveillance Purposes) – E. ewingii Laboratory Confirmed: • E. ewingii DNA detected in clinical specimen via amplification of a specific target by PCR assay
Ehrlichiosis/Anaplasmosis Diagnosis (CDC Laboratory Criteria for Surveillance Purposes) – A. phagocytophilum (HGE) Laboratory Confirmed: • Serological evidence of fourfold change in IgG-specific antibody titer to A. phagocytophilum antigen by indirect IFA in paired serum samples*, or • Detection of A. phagocytophilum DNA in clinical specimen via amplification of a specific target by PCR assay, or • Demonstration of anaplasmal antigen in biopsy/autopsy sample by immunohistochemical methods, or • Isolation of A. phagocytophilum from clinical specimen in cell culture
Ehrlichiosis/Anaplasmosis Diagnosis (CDC Laboratory Criteria for Surveillance Purposes) – A. phagocytophilum (HGE) Laboratory Supportive: • Serological evidence of elevated IgG or IgM antibody reactive with A. phagocytophilum antigen by IFA, ELISA, dot-ELISA, or assays in other formats*, or • Identification of morulae in the cytoplasm of neutrophils or eosinophils by microscopic examination
Ehrlichiosis/Anaplasmosis Case Definitions for Surveillance • Confirmed: A clinically compatible case (meets clinical evidence criteria) that is laboratory confirmed. • Probable: A clinically compatible case (meets clinical evidence criteria) that has supportive laboratory results. • Suspect: A case with laboratory evidence of past or present infection but no clinical information available (e.g. a laboratory report).
Ehrlichiosis/Anaplasmosis Treatment • Begin immediately upon strong suspicion of ehrlichiosis through clinical and epidemiological findings • Doxycycline or other tetracyclines (fever generally subsides within 24-72 hours) • Minimal course of 5-7 days • Patients with anaplasmosis should be treated with doxycycline for 10-14 days because of possible Lyme disease coinfection
Ehrlichiosis/Anaplasmosis Prevention and Control • Avoid ticks in endemic areas • Tuck pants into socks • Use repellents (carefully following label instructions) • Wear light-colored clothing • Regularly inspect for and remove ticks (on humans and pets) • Keep grass and weeds mowed