Tickborne Diseases

Tickborne Diseases

9/9/2015 OBJECTIVES TICKBORNE • Describe the epidemiology, origin, treatment, and prevention of tick borne DISEASES diseases. • Solve case studies. Lynda Britton, Ph.D., MLS(ASCP)CM, SM LSU Health Shreveport TICK LIFE CYCLE BLACKLEGGED TICKS HOW TICKS SPREAD DISEASE MOUTH PARTS • Preparing to feed 10 min to 2 hrs • Cuts skin surface & inserts feeding tube • Secrete saliva to modulate host defenses – Pain and itch – Hemostatis – Inflammation and wound healing • Transmits pathogen while feeding for days • Drops off to complete next life stage 1 9/9/2015 • Emerging Infections Program • CDC in 2007 • Coordinate surveillance – Public health impact –Cost – Tick density and acaridice treatment – Trap rodents and treat with fipronil – Identify novel pathogens molecularly WWW.CDC.GOV/PUBS RESEARCHER DRAGS FOR TICKS CASE 1 • 12 y. o. from Santa Cruz, CA • Swollen painful right knee and hip • Recurrent knee swelling & pain lasting several days every 4-5 months • Treated with herbs instead of antimicrobials • WBC = 7000, HCT 33%, ESR 73mm/h • Knee aspirate: 59,000 WBCs and protein of 5 g/dL • No growth on bacterial cultures but positive by PCR 2 9/9/2015 WHAT DO YOU SUSPECT IS THE LYME DISEASE PATHOGEN? • Most common tick-borne disease in North America 25% 25% 25% 25% • Caused by Borrelia burgdorferi A. Rickettsia • >21,000 cases reported during 2014 rickettsii • 5th among all nationally notifiable conditions B. Borrelia • 90% cases occur in 12 states burgdorferi • Tick vectors: Ixodes scapularis C. Borrelia hermsii I. pacificus D. Ehrlichia sii ri sii chafeensis orfe d herm rickett chafeensis burg ia l Borrelia Rickettsia Borre Ehrlichia I. SCAPULARIS I. PACIFICUS STAGE 1: LOCALIZED LYME DISEASE INFECTION • Erythema migrans • Seasonal (April-September) • Occurs in ~90% • Low risk of disease if tick • Begins 7-10 days after tick attached <36 hrs bite • Signs/symptoms begin 7-10 • Expands over days to weeks days after bite (range 3-30 days) • Central clearing occurs in • May be asymptomatic minority • Rarely fatal • Constitutional: flu-like and lymphadenopathy 3 9/9/2015 DISSEMINATED STAGE DISSEMINATED: • Multiple skin lesions RHEUMATOLOGIC MANIFESTATIONS •Generalized • 60% untreated 20 yrs ago developed joint lymphadenopathy swelling –10% •Malaise, fatigue, – Synovial fluid 24,000 WBC with granulocytes • 5% develop cardiac • Migratory transient intermittent arthritis and effusions involvement • Pain in muscles, bones, – Conductional abnormalities—atrio- tendons, bursa ventricular node block • Baker’s cyst – Myocarditis – Pericarditis DISSEMINATED EARLY NEUROLOGIC LATE NEUROLOGICAL LYME MANIFESTATIONS DISEASE--RARE • Cranial neuropathy • Encephalomyelitis – Bell’s palsy – Parenchymal inflammation of brain and/or spinal • Meningitis-lymphocytic cord – CSF= lymphocytic, mod • Cognitive difficulties ↑ protein, normal glucose • Peripheral neuropathy • Memory, mood, – Intermittent ↓ vibratory sensaon of legs and feet • Sleep disturbances • Encephalopathy – Memory and cognitive impairment – CSF normal HOW IS LYME DISEASE BEST DIAGNOSIS DIAGNOSED? • Characteristic clinical A. Culture in Kelly 25% 25% 25% 25% picture medium • Serology: 2-step B. Histochemical – 1) Polyvalent ELISA: 60- examination of tissue 70% positive by wk 4 C. Peripheral blood – if equivocal or + smear – 2) Western blot (IgG and D. EIA followed by separate IgM): requires 5 Western blot of 10 bands .. .. n. dium at r e smear e in st m m d • PCR lly We exa bloo y Ke b n i ical ed re m u w lt llo • Culture: low yield (27%) che o Cu o Peripheral f ist H EIA 4 9/9/2015 SOUTHERN TICK-ASSOCIATED RASH ILLNESS • Seronegative Lyme Disease • Southern Lyme Disease • “One of the more obtuse diseases. .” SOUTHERN TICK-ASSOCIATED AMBLYOMMA RASH ILLNESS AMERICANUM • Red, expanding-3” • 7 days of bite • Long star tick • Geography • Cause unknown LONE STAR TICK CLINICAL MANIFESTATIONS • Range and abundance ↑over past 20-30 years • Large numbers in Maine and as far west as • Early Lyme Disease central Texas and Oklahoma – Fatigue, headache, fever, and muscle pains • All life stages will feed on humans— • No arthritis, neurological disease or aggressive chronic symptoms • Feed readily on dogs and cats • Saliva can be irritating; redness and discomfort at a bite site does not necessarily indicate an infection 5 9/9/2015 DIAGNOSIS DIFFERENCE WITH LYME DISEASE • Clinically: symptoms, geographical • STARI patients recall tick bite location and tick bite • Time from bite to symptoms shorter • No blood tests because don’t know • Patients with rash less likely to have etiological agent symptoms • Smaller and fewer lesions • More likely to have central clearing CASE #2 WHAT SHOULD BE INCLUDED IN THE DIFFERENTIAL DIAGNOSIS? A. Meningococcemia B. RMSF 13% 13% 13% 13% 13% 13% 13% 13% • In June, 5 y.o. female C. HME • Taken to an ED in Missouri D. Enterovirus • 3-day history of intermittent fever, E. Kawasaki disease headache, mild nausea, and a sore throat F. Drug reactions ° º • Fever of 105 F (40.6 C) G. Streptococcal • Maculopapular rash on her legs, including a F E e n infection i ase v MS HM io R se tions ct bo c a ccem di fe e co rea in h the soles of her feet. t go Enterovirus al f asaki rug o H. All of the above in cc ll n aw D e K A M ptoco re St FURTHER INFO NEEDED CASE CONTINUED • Rash began on the arms and legs same • How long has rash been there? day • Where it appeared before onset of fever? • Did not own a dog • Medications? • No history of recent travel out of the local • Immunocompromising conditions? area • Recent activities? • No history of a tick bite but ticks in the • Ill contacts? area around their house 9 •Travel? • 8.8 x 10 WBC with 5% bands, 70% neutrophils • Tick exposures? • 50 x 109 platelets 6 9/9/2015 ROCKY MOUNTAIN SPOTTED FEVER • Etiologic agent: Rickettsia rickettsii • Vectors: – Dermacentor variabilis (dog tick) – D. andersoni (wood tick) – Amblyomma americanum (lone star tick) RMSF • 91 cases in 2014 • Spring and summer • Incubation period: ~ 7 days (2-14) • Abrupt onset severe HA, F/C, prostration, myalgias, nonproductive cough (later) • GI manifestations very common • CNS: meningitis, meningoencephalitis • Death: 1-2 weeks after symptom onset in 4- 8% (untreated) RASH • Macular rash develops day 2-6 (90%): wrists, ankles, palms, & soles then centrally • Lesions become petechial, hemorrhagic • Vasculitis 7 9/9/2015 WHAT IS THE PREFERRED METHOD DIAGNOSIS TO DIAGNOSE RMSF IN THE LAB? • Clinical & epidemiologic A. Blood culture 25% 25% 25% 25% • Nonspecific lab findings: B. Direct fluorescent – anemia, hyponatremia, low plts, ↑AST antibody • RMSF PCR from rash site C. PCR of rash biopsy is now preferred D. Immunohisto- • IFA: IgM +: 1-2 w but may chemical staining of be false + blood y sy ... • IgG +: 4-6 w iop st culture b d antibod ical t ash r m Bloo f o ‐che escen o • Immunostaining: skin r CR t P is h fluo o t n u m biopsy prior to therapy Direc Im RICKETTSIA PARKERI CASE 3 • Healthy 2 y.o. female southeast Missouri • Mild form of RMSF • Fever 104⁰F, vomitting and diarrhea • Confirmed 2002 • Red maculopapular rash that blanched began on cheek • Amblyomma maculatum tick • 4.9 x 109 WBC, 10.9 g/dL Hgb, 102 x 109 plt • Cattle on Gulf Coast of Texas • Hyponatremia and mildly elevated liver enzymes • Virginia • Inclusion bodies in cytoplasm of monocytes • Antibodies cross react with RMSF • PCR confirmed diagnosis WHAT IS THE SUSPECTED EHRLICHIOSIS PATHOGEN IN THIS CASE? • Obligate intracellular bacteria form A. Anaplasma 25% 25% 25% 25% distinct microcolonies called morulae B. Rickettsia rickettsii • Diseases: C. Ehrlichia • Human Monocytotropic Ehrlichiosis chafeensis • Human Granulotropic Anaplasmosis D. Borrelia hermsii • E. ewingii • “Rocky Mountain Spotless Fever” ii • Ehrlichia muris-like (EML)—MN & WI sis sma ts a een hermsii ricket haf Anapl ia c tts e Borrelia ck Ri Ehrlichia 8 9/9/2015 EHRLICHIOSIS • Southeastern and south-central US • Lone star tick • OK, MO, AR 35% cases • Ehrlichia muris-like in upper midwest • 966 reported case in 2014 SIGNS AND SYMPTOMS BLOOD TRANFUSION AND ORGAN TRANSPLANTATION • Fever, headache • Chills, malaise • Survive for > 1week in refrigerated blood • Muscle pain • Leukoreduced blood • Nausea, diarrhea, anorexia • Infected within 1 mo • Confusion • No cases confirmed by organ • Conjuctival injection transplantation • Rash—more common in children 9 9/9/2015 GENERAL LAB FINDINGS LABORATORY DIAGNOSIS • Serology (IFA) – Negative in first 7-10 days • Anemia – Minimum peak of 1:80 • Leukopenia – Fourfold change • Thrombocytopenia – Positive: week 3 • Elevated AST – Peak: week 6 – Cross-reactivity • Elevated ALT • Morulae detected in 20% • PCR LABORATORY DIAGNOSIS IF MORULAE WERE SEEN IN SEGMENTED NEUTROPHILS, WHAT WOULD BE THE AGENT? • Antibody titer to Ehrlichia chaffeensis 25% 25% 25% 25% antigen by IFA in paired serum samples A. Ehrlichia •PCR chaffeensis • Identification of morulae in leukocytes and B. Anaplasma a positive IFA titer phagocytophilia • Immunostaining of E. chaffeensis antigen C. Rickettsia ricketsii in a biopsy or autopsy sample ii lia D. Borrelia ensis hi p ffe rickets yto cha sia urgdorferi b • Culture from a clinical specimen agoc a burgdorferi chia h li p ickett rreli r a R o Eh sm B la nap A ANAPLASMA PHAGOCYTOPHILUM • Human granulocytotropic ehrlichiosis • Fever, shaking chills • Severe headache • Malaise, myalgia • Nausea, vomiting, diarrhea, anorexia • Cough • Mild self-limiting in most • Fatal if advanced age or immunosuppressed, malignancy or chronic inflammatory • Rash 60% children; 30% adults • More likely to have morulae 10 9/9/2015 • Persons aged >70 and 60–69 years • <1% fatality • Ixodes scapularis and Ixodes pacificus (blacklegged ticks) • New England, North Central and Pacific states LABORATORY DIAGNOSIS EHRLICHIA EWINGII • IgG antibody titer by IFA in paired serum samples • Canine granulocytotropic ehrlichiosis (first week and 2-4 weeks later) • 20 human cases • Positive PCR whole blood in 1st week and •Vector: A. americanum confirmation • First 4 cases of human infection reported • Identification of morulae in leukocytes and a July, 1999 positive IFA titer • Immunocompromised patients from Missouri, • Immunostaining in a biopsy or autopsy sample Oklahoma, and Tennessee • Culture of A.

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