Source: UNIV OF CALIFORNIA (VET-MED) submitted to
CHARACTERIZATION OF HUMAN GRANULOCYTIC EHRILICHIA
 
PROJECT DIRECTOR: Madigan, J. E.
 
PERFORMING ORGANIZATION
MEDICINE AND EPIDEMIOLOGY
UNIV OF CALIFORNIA (VET-MED)
DAVIS,CA 95616
 
NON TECHNICAL SUMMARY:
 
OBJECTIVES: The PI intends to perform serology on tick exposed human beings from northern California for evidence of exposure to the agent of Human Granulocytic Ehrlichiosis (HGE). This infectious agent has been demonstrated to be tick borne and may be transmitted as a co-infection with Borrelia burgdorferi the agent of Lyme disease or be transmitted alone and produce significant and occasionally fatal disease. The PI has determined the infectious agent of HGE is identical to or indistinguishable from Ehrlichia equi, a common infection of horses in northern California. The objective is to determine the seroprevalent of this infection in tick exposed humans from northern California in order to determine the potential public health importance of this zoonotic infection.
 
APPROACH: Antibody test for granulocytic Ehrlichiosis: Briefly antigen slides are made using ehrlichia equi antigen obtained from experimentally infected horses and isolated and placed on stand 16 well antigen slides as described in previous publications. Huma plasma is assayed using indirect florescence assay system and with a negative control and positive control for each assay. Polymerase Chain Reaction for HGE and E equip: The laboratory has developed the PCR technique for Ehrlichia equi and HGE. Briefly a 16S Ribosomal RNA amplification system will be utilized on patient serum for detection of the E. equi ribosomal DNA.
 
CRIS NUMBER: 0177541 SUBFILE: CRIS
PROJECT NUMBER: CALV-HOPKINS-96-12 SPONSOR AGENCY: CSVM
PROJECT TYPE: STATE PROJECT STATUS: TERMINATED MULTI-STATE PROJECT NUMBER: (N/A)
START DATE: Aug 1, 1996 TERMINATION DATE: Sep 30, 2005

GRANT PROGRAM: (N/A)
GRANT PROGRAM AREA: (N/A)

CLASSIFICATION
Knowledge Area (KA)Subject (S)Science (F)Objective (G)Percent
722601011304.250%
722601010904.250%

CLASSIFICATION HEADINGS
KA722 - Zoonotic Diseases and Parasites Affecting Humans
S6010 - Individuals
F1130 - Entomology and acarology
F1090 - Immunology
G4.2 - Reduce Number and Severity of Pest and Disease Outbreaks


RESEARCH EFFORT CATEGORIES
BASIC 100%
APPLIED (N/A)%
DEVELOPMENTAL (N/A)%

KEYWORDS: human diseases; bacterial diseases; ixodidae; disease vectors; ehrlichia equi; granulocytes; serology; ehrlichiosis; disease prevalence; zoonoses; antibodies; serological tests; polymerase chain reaction; disease detection

PROGRESS: Aug 1, 1996 TO Sep 30, 2005
Following intravenous inoculation with horse blood-infected with the agent of human granulocytic ehrlichiosis (HGE) from a human fatality, two rhesus macaques (Macaca mulatta) exhibited pyrexia and lethargy on days 4-12 postinfection (PI). Hematology revealed neutropenia, thrombocytopenia, and anemia, with ehrlichial morulae in monocytes and neutrophils on days 4-12. Blood was polymerase chain reaction (PCR)-positive on days 4-12 and bone marrow was PCR-positive on day 11. There was a minor increase in gamma-glutamyl transpeptidase on day 12 and serum interferon-gamma levels increased by day 18. Seroconversion occurred on day 20 PI to a titer of 100 by day 22. Western blot bands characteristic of HGE included 25-, 44-, 80-, 94-, 105-, and 125-kD bands. There was generalized lymphohistiocytic infiltration in the liver, spleen, lymph nodes, and other tissues. The liver had focal hepatocyte apoptosis. There was HGE DNA (by PCR) only in the spleen. Comparable findings were not observed in a monkey that received uninfected horse blood as a control.

IMPACT: 1996-08-01 TO 2005-09-30 This animal model of human disease is important for further studies of HGE diagnosis, management, and pathogenesis.

PUBLICATION INFORMATION: 1996-08-01 TO 2005-09-30
Foley JE, Lerche NW, Dumler JS, Madigan JE. 1999. A simian model of human granulocytic ehrlichiosis. Am J Trop Med Hyg 1999 Jun;60(6):987-93

PROJECT CONTACT INFORMATION
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