Transcript
Page 1: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Vector-borne diseases

S. Sears, MD

Page 2: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Lyme disease

• Multisystem inflammatory disease• Causes by spirochetes

– Borrelia burgdorferi

• Spread by Ixodes ticks– I. scapularis

• Eastern,North central and Southern United States

– I. pacificus• Western United States

– I. ricinus• Europe

– I. persulcatus• Asia

• Transmission– Bite of an infected nymph in the spring-really small, barely even know

you’ve been bitten

• Preferred host– White-tailed deer

Page 3: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Borrelia burgdorferi

Page 4: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Ixodes scapularis

Page 5: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Clinical manifestations

• Early localized disease– Occurring few days to one month after the tick bite

• Early disseminated disease– Occurring days to 10 months after the tick bite

• Late or chronic disease– Occurring months to years after the tick bite

Page 6: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Early localized disease

• Erythema migrans– 50-70% of patients– Found

• Near axilla• Inguinal region• Behind the knees• Belt line

– Asymptomatic– May burn or itch– Expands over the course a few days with central clearing

• Associated symptoms– Fatigue– Malaise– Lethargy– Headache– Stiff neck– Myalgias– Arthralgias– Lymphadenopathy

Page 7: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Erythema migrans

Page 8: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Early disseminated disease

• Carditis : 8 -10% of patients– Conduction defects– Cardiomyopathy or myopericarditis

• Neurologic disease :10% of patients– Lymphocytic meningitis– Encephalitis– Cranial neuropathy (often bilateral facial)– Peripheral neuropathy– Radiculoneuropathy– Myelitis

• Musculoskeletal involvement : 50% of patients– Migratory polyarthritis

• Skin involvement– Erythema nodosum

• Lymphadenopathy• Eye involvement

– Conjunctivitis– Iritis– Retinitis– Vitritis– Choroiditis

• Hepatitis• Microhematuria with proteinuria

Page 9: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Late or chronic disease

• Musculoskeletal symptoms– 50% : migratory polyarthritis– 10% : chronic monoarthritis (knee)

• Neurologic disease (incidence not established)– Neuroborrelosis

• Encephalopathy• Neurocognitive dysfunction• Peripheral neuropathy

– Encephalopathy– Encephalomyelitis– Peripheral neuropathy– Ataxia– Dementia– Psychiatric disturbances

• Cutaneous involvement– Acrodermatitis chronica atrophicans– Morphea (localized scleroderma-like lesions)

Page 10: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Acrodermatitis chronica atrophicans

Page 11: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Diagnosis

Centers of Disease Control and Prevention criteria• Presence of erythema migrans• OR• At least one late manifestation• Plus laboratory confirmation• Late manifestations can include if not explained by another disease

– Musculoskeletal system– Chronic arthritis– Not

• Chronic progressive arthritis• Chronic symmetrical arthritis• Fibromyalgia

– Nervous system– Lymphocytic meningitis– Cranial neuritis– Encephalomyelitis – CSF confirmation of antibody against B. burgdorferi– Not

• Headache• Fatigue• paresthesias

Page 12: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Diagnosis

• Serologic tests• Used to confirm the diagnosis• Diagnosis make on clinical grounds• Two-rest step approach

– Sensitive enyzme-linked immunosorbent assay (ELISA)– Followed by Western immunoblot

• If ELISA positive-test Western blot• If ELISA negative-no Western blot• Same sample tested by each test• If < 4 weeks illness - IgM and IgG tested• If > 4 weeks illness - IgG tested• Synovial fluid or CSF• Tested for the antibodies to B.burgdorferi• Antibiotics in early disease may prevent seroconversion• Prior vaccine interferes with the test (vaccine no longer available)

Page 13: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Treatment

Early disease• Erythema migrans• < 10% do not respond• Do not use macrolides• For areas also endemic for human ehrlichiosis use doxycycline

– Doxycycline 100mg po bid for 10-21 days– Amoxicillin 500mg po tid for 14-21 days– Cefuroxime 500mg po bid for 14-21 days

Disseminated disease• Cardiac• First degree AV block

– Doxycycline 100mg po bid for 14-21 days– Amoxicillin 500mg po tid for 14-21 days– Cefuroxime 500mg po bid for 14-21 days

• Late disease– Ceftriaxone 2g IV daily for 14-21 days

Page 14: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Treatment

Disseminated disease• Neurologic disease• Early

– Isolated facial nerve palsy– Doxycycline 100mg po bid for 14-21 days– Amoxicillin 500mg po tid for 14-21 days– Cefuroxime 500mg po bid for 14-21 days

• More serious disease– Early or late– Meningitis– Radiculopathy– Encephalitis– Ceftriaxone 2 g IV daily for 14-28 days

• Arthritis• No evidence of neurologic disease

– Doxycycline 100mg po bid for 28 days– Amoxicillin 500mg po tid for 28 days– Cefuroxime 500mg po bid for 28 days

• With neurologic disease– Ceftriaxone 2g IV daily for 14-28 days

Page 15: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Outcome

• Treatment with standard antibiotics generally successful• 10 % experience treatment failure• Non-specific symptoms may linger• Asymptomatic seropositive patients

– Recommendation not to treat

Page 16: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Human ehrlichiosis

Ehrlichiae• Obligate intracellular bacteria• Grow in membrane bound vacuoles

– Human and animal leukocytes• Diseases

– Human monocytic ehrlichiosis (HME)• Caused by Ehrlichia chaffeensis

– Human granulocytic anaplasmosis (HGA)• Caused by Anaplasma phagocytophilum

• Occurs in spring and summer– In southeastern, southcentral,mid-Atlantic United States

• Tick vector– E.chaffeensis - Lone star tick (Amblyomma americanum)– A.phagocytophilum - Ixodes scapularis

• Animal reservoir – HME - white tail deer– HGA - deer and white-footed mouse

Page 17: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Ehrlichia chaffeensis

Page 18: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Lone star tick

Page 19: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Clinical manifestations

• Incubation period 1-2 weeks prior to presentation of symptoms• Fever can persist for 2 months• Nonspecific

– Malaise– Myalgia– Headache– Chills– Nausea– Vomiting– Arthralgias– Cough

• Maculopapular or petechial rash• Neurologic

– Mental status changes– Stiff neck– Clonus

• Complications– Seizures – Coma– Congestive heart failure– Pericardial effusion

Page 20: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Rash

Page 21: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Investigations

• Laboratory findings– Leukopenia– Thrombocytopenia– Anemia– Increased liver function tests

• CSF lymphocytic pleocytosis• Diagnosis

– Indirect fluorescent antibody (IFA) test– Examination of peripheral blood or buffy coat– PCR for HME and HGA– Immunochemical staining of ehrlichial/anaplasmal antigens in

tissue

Page 22: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Treatment

• Drug of choice• Doxycycline IV or oral• 100 mg bid for 10 days• Intolerance to doxycycline• Use rifampin 300mg po bid for 7-10 days

Page 23: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Outcome

Mortality rates• HME - 2 to 5 percent• HGA - 7 to 10 percentLife-threatening disease• In patients co-infected with HIV• Solid organ transplant recipientsPrevention• Tick repellants• Tick removal

Page 24: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Babesiosis

• Tick borne illness• Protozoa of the family Babesiidae• Animal reservoir

– Rodents and cattle

• Human disease– Due to Babesia microti– Enters the red blood cells and causes hemolysis

• Vector– Ixodid tick

• Occurs northeast coast of the United States

Page 25: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Clinical manifestations

• Incubation period– Following a tick bite

• 1-3 weeks– After blood transfusion

• 6-9 weeks

• Symptoms– Fever– Chills– Sweats– Myalgia– Arthralgia– Nausea– Vomiting– Fatigue

• Physical exam– Splenomegaly– Hepatomegaly– Jaundice

Page 26: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Severe disease

• High-level parasitemia (> 10 percent)• Significant hemolysis ( plus DIC)• Renal ,hepatic, pulmonary compromiseRisk factors• Age over 50 years• Asplenia• Underlying malignancy• Immunosuppressive therapy• HIV/AIDS

Page 27: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Diagnosis

Laboratory • Anemia• Thrombocytopenia• Conjugated hyperbilirubinemiaConfirmation• Blood smear

– Intraerythrocytic parasites

• PCR• Serology

– Indirect immunofluorescent antibody test

Page 28: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Babesia microti

Page 29: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Treatment

• First-line treatment• 7-10 days

– Clindamycin-quinine– Or atovaquone-azithromycin

• Dosing– Atovaquone - 750 mg po q 12 hrs– Azithromycin - 500-1000 mg po x1 then 250 mg po daily– Clindamycin - 600 mg po tid or 300 mg IV qid– Quinine - 650 mg po q6hrs

• Severe disease– Antibiotics– Plus exchange transfusion

• Until parasitemia is < 5 percent

• Outcome is variable with level of disease

Page 30: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Malaria

• Human malaria caused by species Plasmodia– P. falciparum– P. vivax– P. ovale– P. malariae

• Predominates– Tropical Africa– Southeast Asia– Haiti– South America– Dominican Republic– Central America– Middle East– India

• Transmission– Bite of Anopheles mosquito– Congenital– Blood transfusion– Contaminated needles– Transplantation

Page 31: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Anopheles mosquito

Page 32: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Malaria

All four malaria parasites• Digest red blood cell proteins and hemoglobin• Results in hemolysis and increased splenic clearance

Liver and spleen enlarge over time• Thrombocytopenia from increased splenic clearanceP. Falciparum• Forms stick knobs• Forms rosettes• Results in obstruction of blood flow

Protection against malaria• Sickle cell genetic alterations• Alpha thalassemia • Beta thalassemia• Ovalocytes

Immunity• Partial immunity may occur in those in endemic areas

Page 33: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Cycle of malaria

Page 34: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Clinical manifestations

Incubation period• 1-4 weeksSymptoms• Chills• Sweats• Headache• Myalgias• Fatigue• Nausea• Abdominal pain• Vomiting• Diarrhea• Cough• Signs• Anemia• Thrombocytopenia• Splenomegaly• Hepatomegaly• Jaundice• Splenic rupture

Page 35: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Clinical manifestations

P. falciparum• Associated with transient increases in HIV viral load• Cerebral malaria• Impaired state of consciousness• SeizuresRisk factors• Age• Pregnancy• Poor nutritional status• HIV infection• Prior splenectomyComplications• Renal failure• ARDS• Hypoglycemia• Anemia• Bleeding• GastroenteritisP. vivax and ovale• Liver forms-late relapsesP. malariae• GN from chronic immune complex formation and deposition

Page 36: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Diagnosis

Light microscopy• Stained thick and thin blood smear

– Thick smear• Malaria

– Thin smear• Morphologic features

• Parasite density estimation• Fluorescent microscopy• Antigen detection• PCR- DNA / RNA

Page 37: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Blood smear

Page 38: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Treatment

Supportive measuresAntimalarial medicationsMechanisms of antimalarial drugs• Quinoline derivatives

– Chloroquine,quinine,quinidine,mefloquine• Inhibit heme polymerase activity• Accumulation of free heme is toxic to parasites

– Antifolates• Pyrimethamine,sulfonamides,dapsone• Kill intrahepatic forms of the parasite

– Artemisinin derivatives• Artemisinin,artemether,artesunate• Produce free radical that damage parasite proteins

– Antimicrobials• Clindamycin,atovaquone,tetracyclines• Kill blood parasites

Page 39: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Treatment

Chloroquine-sensitive• P.vivax• P.ovale• P. malariae

– Chloroquine 10mg base/kg (max 600mg base)– Followed by 5mg/kg base (max 300mg base)– At 6, 24,and 48 hours– Cure rates 95%

Chloroquine resistant• P. vivax

– Mefloquine or quinine PLUS doxycyclinePrevention of relapse• Liver forms of malaria• P. vivax and P. ovale

– Primaquine 30mg/day for 14 days– Start immediately after completing chloroquine– Screen for glucose-6-phosphate-dehydrogenase to prevent hemolysis

Page 40: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

P. Falciparum malaria

Chloroquine-sensitive• Treat like other forms of malaria for the chloroquineMost cases are chloroquine-resistant• Uncomplicated disease

– One of the following:• Quinine-based• Atovaquone-proquanil• Mefloquine• Artemisinin derivative combinations

Quinine-based• Quinine sulfate 10mg/kg salt (max 650 mg) q8hrs for 3-7days• Combined with

– 3 tabs of pyrmethamine-sulfadoxine(25/500mg) on day three– Or doxycycline 100mg po bid for seven days

• Quinine causes reversible tinnitus and reversible high-tone hearing loss

Page 41: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

P. Falciparum malaria

Atovaquone-proquanil• 250mg atovaquone plus 100mg proguanil• Four tablets for 3 days

– Common side-effects gastrointestinalMefloquine• 25 mg/kg base as a single dose

– Side-effects– Vomiting,nightmares,ataxia,delirium,seizures

Artemisinin derivatives• IV ,IM or oral• Given for 5-7 days• 4mg/kg on day 1• 2mg/kg on days 2,3• 1mg/kg on days 4-7

– Combined with• Mefloquine-750mg then in 12 hrs 500mg• Or doxycycline 100mg po bid for 7 days

• No serious toxicities from artenisinin derivatives have been observed in humans

Page 42: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Severe Falciparum malaria

Definition• Parasitemia of > 5 percent• Altered consciousness• Oliguria• Jaundice• Severe normocytic anemia• Hypoglycemia• Organ failureAdditional features• Seizures• Acute renal failure• Electrolyte abnormalities• Metabolic acidosis• ARDS• Shock• Hemoglobinuria• bleeding

Page 43: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Treatment-severe disease

Use intravenous medications• Quinine-based

– IV quinidine gluconate 10mg/kg over 2 hrs the 0.02mg/kg/min• Artemisinin-based

– Artesunate 2.4 mg/kg IV followed by 1.2mg/kg at 12 and 24 hrs the 1.2mg/kg daily for 6 days

• Quinine-resistant– Artenisinin-based– Plus tetracycline or mefloquine

• Artenisinin not in the United states– Need to use quinine plus tetracycline/doxycycline

• Supportive measures• Exchange transfusion

– For parasitemia > 10%– Or MSOF

• Transfusion• Removes parasitized red blood cells• Parasitic toxins• Cytokines• Replaces with fresh plasma• Continue until parasitemia < 5 %

Page 44: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Prognosis

Mortality• Untreated-100%• Treated -10-40 %Indicators of poor prognosis

– Age < 3 years– Deep coma– Convulsions– Papilledema– Absent corneal reflexes,decorticate/decerebrate rigidity– Organ dysfunction,ARDS,shock– Parasitemia > 5%– Peripheral mature pigmented parasites– Hematocrit <15 %, hemoglobin < 5 g/dL– Peripheral WBC > 12,000– Blood glucose < 40 g/dL– BUN > 60 mg/dL or creatinine > 3mg/dL– Lactate > 5 mmol/L– Increased liver function test 3 times normal– High CSF lactate >6 mmol/L– Low antithrombin III levels– High plasma TNF concentration

Page 45: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Rocky Mountain Spotted Fever

Causative agent rickettsia• Gram-negative bacteria-coccobacillus• Intracellular parasite• Grows in the nucleus and cytoplasm of host cellsVector• Dermacentor variabilis-American dog tick

– Eastern and south central United States• Dermacentor andersonii-Rocky Mountain wood tick

– Mountain states west of Mississippi• Brown dog tick (Rhipicephalus sanguineus)

– Arizona• Ricksettsia

– Induces cell death and necrosis• Leads to vasculitis• Hemorrhage• Increased vascular permeability• Edema• Activation of humoral immunity

Page 46: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Rickettsia rickettsii

Page 47: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

American dog tick

Page 48: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Brown dog tick

Page 49: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Clinical manifestations

Occurs in spring and summer• Fever-common• Severe headache• Malaise• Arthralgias• Nausea• Between 3-5 days• Rash

– Begins on the ankles and wrists– Spreads to hands and feet– Spreads centrally– Maculopapular and becomes petechial

• Abnormal mentation• Seizures• Focal neurologic deficits

Page 50: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Rash

Page 51: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Petechial rash

Page 52: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Diagnosis

Laboratory• Thrombocytopenia• Hyponatremia• Increased liver function tests• AzotemiaCSF-WBC <100, increased protein, normal glucoseSkin biopsy• Direct immunofluorescenceSerologic• Indirect fluorescent antibody

Page 53: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Serum-indirect fluorescent antibody

Page 54: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Treatment

• Orally or IV• Doxycycline 100mg bid• Continued for at least three days after patient afebrile• Usual length• 5-7 days

Page 55: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Outcome

• Severe RMSF sequelae• Peripheral neuropathy• Hemiparesis• Deafness• Mortality• < 4 years• 3-4 %• > 60 years• 4-9 %• Host factors associated with severe disease• Male gender• Black race• Chronic alcohol abuse• Glucose-6-phosphate dehydrogenase deficiency

Page 56: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Tularemia

Caused by a gram-negative coccobacilli• Francisella tularensisPredominantly in the Northern hemisphereCan persist in water,mud or animal carcasses for weeksReplicates in macrophages/leukocytesNatural infections found in• Ticks,mosquitoes,horse flies,fleas,liceHuman infections• Vectors (ticks,biting flies,mosquito)• Handling of infected animals (cleaning rabbits)• Undercooked meat• Drinking contaminated water• Cat scratches or bites• Splashing infected material in the eye

Page 57: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Francisella tularensis

Page 58: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Clinical manifestations

Abrupt onset• Fever• Chills• Headache• MalaiseIncubation period 2-10 daysSix clinical syndromes• Ulceroglandular• Glandular• Thyphoidal• Pneumonia• Oropharyngeal• Oculoglandular

Page 59: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Syndromes

• Ulceroglandular– Single erythematous papuloulcerative lesion– Central eschar– Tender regional lymph nodes

• Glandular– Enlargement of single of multiple lymph nodes

• Typhoidal– Febrile septic illness– Lack of exposure history

• Pneumonic– Pulmonary infection– Airborne or hematogenous spread– Unilateral of bilateral infiltrates– Infiltrates are nodular– Hilar adenopathy,pleural effusions

• Oropharyngeal– Ingestion of poorly cooked meat– Severe painful pharyngitis– Cervical lymphadenopathy

• Oculoglandular– Conjunctival erythema– Periorbital edema

Page 60: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Ulceroglandular

Page 61: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Pneumonic

Page 62: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Oropharyngeal

Page 63: Vector-borne diseases S. Sears, MD. Lyme disease Multisystem inflammatory disease Causes by spirochetes –Borrelia burgdorferi Spread by Ixodes ticks –I

Tularemia

Diagnosis• Serologic

– Tube agglutination– ELISA– PCR

Treatment• Streptomycin-drug of choice

– 10mg/kg IM q 12hrs for 7-10 days– Recommended for meningitis– Severe disease

• Other options– Gentamicin : 3-5mg/kg IM/IV q8hrs for 7-10days– Tetracycline: 500mg po qid for 14 days– Doxycycline : 100mg po bid for 14 days– Chloramphenicol : 25-60mg/kg per day in 4 doses for 14 days

• Mortality 2-4 percent• Complications

– Drainage of lymph nodes– Pericarditis– Meningitis– ARDS– Rhabdomyolysis/renal failure


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