Tick-Borne and Animal-Associated DiseasesDavid Spach, MDProfessor of MedicineDivision of Infectious DiseasesUniversity of Washington, Seattle
Important North American Ticks Ixodes Female (Adult) Ixodes Male (Adult) Ixodes Nymph Amblyomma Female (Adult) Dermacentor Female (Adult) Ornithodoros (Adult) From: Spach DH et al. N Engl J Med. 1993;329:936-47.
Tick Quiz 1 2 From: Spach DH, et al. N Engl J Med. 1993;329:936-47.
Case History: Question • A 17-year-old girl presented to the emergency room with lower extremity weakness. She had prolonged recent outdoor exposure. Her weakness was symmetrical and had begun about 8 hours prior to coming to the ER; sensation is intact. A tick is found embedded in her scalp. The most appropriate course of action is:1. Give IV ceftriaxone x 14 days2. Remove tick and observe closely3. Give IM streptomycin x 10 days4. Arrange for emergent plasmapharesis
Tick ParalysisClinical Features • Early Features- Paresthesias- Leg weakness- Absence of fever • Later Findings- Ascending paralysis- Ataxia- Hyporeflexia/Areflexia • Late Findings- Bulbar signs- Hypoventilation
Case History • A 28-year-old man presented to clinic with a 16 cm erythematous, annular skin lesion on his right flank and flu-like symptoms. He spent the past 30 days hiking in the mountains. • The most appropriate course of action is?
National Lyme Disease Risk From: CDC Lyme Disease Home Page. www.cdc.gov/ncidod/dvbid/lyme/
Erythema Migrans Rash From: Steere AC. N Engl J Med. 2001;345:115-25.
Lyme Disease: General Approach to Treatment • Early Disease (Absence of serious Neurologic/Cardiac)- Doxycycline- Amoxicillin • Late Disease or Serious Neurologic/Cardiac Disease- Ceftriaxone
Case History • A 67-year-old man from Wisconsin develops fever, severe malaise, and dark urine. Two weeks ago he went on a 7-day hunting trip in rural Wisconsin. Labs show hematocrit = 31 and platelet count = 49,000. • The most likely diagnosis and treatment?
Babesiosis: Transmission • Ticks- Ixodes scapularis- Ixodes pacificus • Transfusion-Associated- RBCs- Platelets
Babesiosis: Treatment • First Line- Clindamycin plus Quinine • Second Line- Azithromycin plus Atovaquone
Case History • A 71-year-old geologist presents with a 3-day history of fever, chills, and myalgias. Seven days prior he was in rural eastern Washington and slept in an old cabin. Labs show hematocrit = 42, platelet count 67,000, and an abnormal blood smear. • The most likely diagnosis is:1. Relapsing fever2. Lyme disease3. Leptospirosis4. Colorado tick fever
Ornithodoros Tick From: Spach DH, et al. N Engl J Med. 1993;329:936-47.
Tick-Borne Relapsing Fever: Treatment • First Line- Doxycycline • Second Line- Erythromycin
Case History • A 29-year-old woman is admitted with suspected RMSF. • Which finding is NOT often observed with RMSF:1. WBC > 12,0002. Platelet count < 150,0003. Rash that begins on extremities4. Exposure to a Dermacentor tick
RMSF in US 1981-1992: Average Incidence by County From: ThornerAR, et al. Clin Infect Dis. 1998;27:1353-9.
RMSF: Clinical Manifestations From: Catherine Wilfert (Duke University Medical Center)
Rocky Mountain Spotted Fever: Treatment • First Line- Doxycycline • Second Line- Chloramphenicol
Case History • A 43-year-old man from Westchester county, NY presents with fever and erythema migrans 7 days after a tick bite. He is started on amoxicillin, but 4 days later returns with headache, fever, and myalgias. Labs show leukopenia, thrombocytopenia, and increased hepatic transaminases. The most appropriate course of action is: 1. Give high dose corticosteroids 2. Give PO Doxycycline 3. Give IV Ceftriaxone 4. Give IV Gentamicin
Ehrlichiosis & Anaplasmosis in United States E. chaffeensisA.phagocytophiliumE. ewingii Amblyomma Ixodes Amblyomma Granulocytes/Eos Monocytes Granulocytes HME HGA HGE From: CDC Ehrlichiosis Home Page. www.cdc.gov/ncidod/dvrd/ehrlichia/Index.htm
Ehrlichiosis: Treatment • First Line- Doxycycline: 100 mg PO bid x 7-10 days • Second Line- Chloramphenicol- Rifampin
Case History: Question Silver-Haired Bat • A 29-year-old male is bitten on the shoulder by a bat and the bat escaped. What percent of Rabies Immune Globulin should be given at the wound site?1. 25%2. 50%3. 75%4. 100%
Rabies Postexposure ProphylaxisRabies Immune Globulin • “Administer 20 IU/kg body weight. If anatomically feasible, the full dose should be infiltrated around the wound(s) and any remaining volume should be administered IM at an anatomical site distant from vaccine administration. CDC and Prevention. MMWR. 1999;48 (RR-1): 275-9.
Rabies: Post-Exposure Prophylaxis Not Previously Vaccinated • Wound cleansing • *Rabies Immune Globulin • +Rabies Vaccine: day 0,3,7,14 *Administer vaccine as IM in deltoid+Administer full dose of RIG around wound if possible; remaining volume give at site distant from vaccine site *Note: Number of recommended doses of rabies vaccine changed from 5 to 4 (ACIP June 24, 2009) From: CDC. MMWR 2008;57:1-26.
Case History: Question • What is the main reservoir for Hantavirus in the United States? 1. Deer mice2. Deer3. Mosquitoes4. Horned nose black fly
Case History: Question • A 49-year-old woman is admitted to the hospital with a suspected diagnosis of hantavirus pulmonary syndrome. Which of the following would be LEAST characteristic of the clinical presentation of hantavirus pulmonary syndrome? 1. CSF pleocytosis 2. Increased hematocrit 3. Increased white blood cell count with immature forms 4. Thrombocytopenia
Hantavirus Pulmonary Syndrome: Reservoir Peromyscus maniculatusDeer Mouse Source: CDC and Prevention
*Hantavirus Pulmonary SyndromeThrough November 11, 2009 Source: CDC and Prevention *By State of Exposure
Hantavirus Pulmonary Syndrome: Chest Radiograph Severe Early Stage CDC Later Stage Interstitial
Hantavirus Pulmonary SyndromeProgression of Disease Recovery Prodrome Cardiopulmonary Death Picture
Hantavirus Pulmonary SyndromeTherapy • Careful volume replacement (PAP=12-15 mm) • Vasopressors -Dopamine -Dobutamine • Extracorporeal membrane oxygenation (ECMO) • Intravenous Ribavirin? - NIH Trial (1-888-866-7257)
Case History: Question • 52-year-old previously healthy woman presents to urgent care following a macaque monkey bite? The patient works as a researcher at a primate laboratory at the UW. • What is the name of the organism you are concerned about that she may have acquired from this macaque bite? • What therapy would you recommend?1. Amoxicillin-clavulanic acid + Zidovudine2. Amoxicilin-clavulanic acid + Valacyclovir3. Moxifloxacin + Interferon-alpha4. Moxifloxacin + Entecavir + Ribavirin
B Virus (Cercopithecineherpesvirus 1) • Endemic among macaque monkeys • Shedding from oral, conjunctival, or genital mucosa • Incubation: 2-35 days (most 5-21 days after exposure) • Clinical infection: vesicular rash, peripheral NS, CNS • Mortality rate if untreated: 80% From: Cohen JI. Clin Infect Dis 2002;35:1191-203.
B Virus (Ceropithecineherpesvirus 1) • Prophylaxis(1) Valacyclovir: 1g PO q8h x 14 days(2) Acyclovir: 800 mg PO 5x/day x 14 days • Treatment (NO CNS Symptoms)(1) Acyclovir: 12.5-15.0 mg/kg IV q8h(2) Ganciclovir: 5 mg/kg IV q12h • Treatment (CNS Symptoms Present)(1) Ganciclovir: 5 mg/kg IV q12h From: Cohen JI. Clin Infect Dis 2002;35:1191-203.
Case History • A 28-year-old healthy woman is scratched on her neck by cat and 1 week later develops a scab at the site. Three weeks later she develops preauricular and postauricularadenopathy. • The most likely organism and appropriate treatment are:
Cat Scratch Disease: Azithromycin Therapy From: Bass JW et al. Pediatr Infect Dis 1998;17:447-52.
Case History: Skin & Soft Tissue • A 26-year-old woman is bitten on her leg by her dog while trying to break up a dog fight. One day later her wound is red and painful and she comes to the ER for evaluation. Which of the following is TRUE? 1. Her risk of getting rabies from this dog bite is about 15%2. Pasturella is rarely involved in dog bites3. Cat bites become infected more often than dog bites4. Anaerobic organisms are more common in dog bite than cat bite infections
Microbiology of Infected Dog Bites From: Talan DA, et al. NEJM 1999;340:85-92.
Microbiology of Infected Cat Bites From: Talan DA, et al. NEJM 1999;340:85-92.
Dog & Cat Bites Wound Infections: Therapy • Therapy (Oral) - Amoxicillin-CA (Augmentin) x 7-14 days • Therapy (Intravenous - Ampicillin-sulbactam (Unasyn) - Ertapenem (Invanz) • Therapy (Penicillin-Allergic) - Clindamycin plus Fluroquinolone