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A 51 year old male presented at the ER with fever and confusion, 5 days earlier an acute syndrome had developed which was characterized by fever malaise, myalgia, and headache. Physical examination revealed a critically ill man. His temp. was 39.7 C, pulse 110 bpm, respiration rate was 28. BP 100/60). Chemistry BUN 21.1 (1.8-7.1) Creatinine 848.6 (53-106) LDH 1975 (100-200) ALT 403 (6-37) AST 768 (5-30) ALK Phos 173 (30-95) Bilirubin 51.3 (0.2-1.0) Hematuria CBC Hemoglobin 12 (13-18) Hematocrit 38 (45-52) WBC 4600 (4300 - 10,800) with left shift platelets 18,000 (150,000 - 350,000) PT - norm PTT - prolonged Neurological consult was normal
Presentationmatches which of the following? A-Thrombocytopenia purpura B- Rocky Mountain Spotted Fever C- Renal Failure D- Lyme Disease E- Babesiosis F- Ehrlichia G- Any of the above
Vector-borne Diseases • Urban sprawl • Greater exposure to etiologic agents that until now were not considered a risk for human illness • Frequently go unrecognized and go undiagnosed • Delays in diagnosis= greater morbidity and mortality
PATHOGENS TRANSMITTED IN THE U.S. BY TICKS INCLUDE: • Viruses • Bacteria • Rickettsia • Protozoa • What are the most frequently recognized vector-borne diseases in the U.S.?
TICK- BORNE DISEASES Disease EtiologicAgent Type of Tick Orbivirus (virus) Dermacentor spp (Dog or wood tick)
Ehrlichia • Obligate intracellular Gram neg. org. • Infect leukocytes of mammals • Non motile • Replicate within the phagosome of the hosts cells • Divide by binary fission • Form an inclusion body called a morula • Morula matures and ruptures cell • Cycle begins again
Ehrlichia canis: Ehrlichia chaffeensis, Agent for (HME) Ehrlichia muris Ehrlichia canis • Ehrlichia Phagocytophila: E. equi E. phagocytophila E. recently identified yet unnamed, resembling E.equi and E. phagocytophila, agent for (HGE) • Ehrlichia sennetsu: E. sennetsu, first known ehrlichia species to infect humans.(endemic to Asia)
TWO MOST RECENTLY DISCOVERED SPECIES • Ehrlichia chaffeensis, has an affinity for monocytes called Human monocytic Ehrlichiosis • Ehrlichia as yet unnamed, has an affinity for granulocytes called Human Granulocytic Ehrlichiosis
History • Veterinary sciences • E. canis was reported as early as 1935 • Sentry dogs in Vietnam • 200-300 deaths from 1968 to 1970 due to canine tropical pancytopenia
E. sennetsu General self limiting mononucleosis like illness 1953 in Japan E. canis First case of human ehrlichiosis in the U.S. 1986 in Detroit
Center for Disease Control in Atlanta 400 cases of human ehrlichiosis reported death occurred in 2%-3% of total cases death occurred in 5%-10% of cases with HGE
HOST ORGANISMS • White tailed deer • Small rodents • Dogs
RISK FOR CONTRACTING TICK BORNE DISEASES • 68% of cases are from rural areas • Associated with outdoor recreation • Duration of tick attachment
“DEER TICK” DOG TICK
EHRLICHIA MANIFESTS ITSELF AS A SYSTEMIC ILLNESS • Often confused with • Lyme disease • Renal failure • Pulmonary syndromes • RMSF (Rocky Mountain Spotted Fever) • Tuleremia • May be transmitted as a co-infection
THERAPY SHOULD NOT BE DELAYED SEROLOGICAL TESTING ANTIGENTIC RELATEDNESS ANTIGEN ANTIBODY REACTION POSITIVE SEROLOGY MAY INDICATE PAST RATHER THAN CURRENT INFECTION PCR GENETIC SEQUENCING
MORBIDITY AND MORTALITY Potential cost of morbidity posed by these vector-borne diseases is staggering when you think about it minimal cost of treatment RECOMMENDATIONS Any time a patient presents with a febrile illness (of unknown origin) and possible exposure to ticks, even it they don’t remember being bitten, the clinician should question the likelihood of any of the vector-borne illnesses.
Thank You CATHY WALKER TECHNICAL SUPPORT ARKANSAS DEPARTMENT OF HEALTH PRESENTATION BY CHERYL LeDOUX