[Morphologic identification of Ehrlichia sp. in the platelets of patients infected with the human immunodeficiency virus in Venezuela]

Abstract

Objective: To determine the frequency of infection by bacteria of the genus Ehrlichia in a population of patients infected with the human immunodeficiency virus (HIV). As is widely recognized, HIV infection is usually followed by the acquired immunodeficiency syndrome (AIDS) after a variable period during which the individual can develop different types of opportunistic infections whose severity depends on his/her immune status. Human ehrlichiosis is a newly-recognized tick-borne infectious disease caused by Ehrlichia spp., which are obligate intracellular, Gram-negative bacteria showing tropism for blood cells (leukocytes and platelets). In Venezuela, the disease was first recognized in humans in 1994, when intra-cytoplasmic microcolonies (morula) were found in human platelets.

Methods: We collected peripheral blood samples from 87 HIV-positive persons that were received at the Immunology Laboratory of the Oncology and Hematology Institute in Caracas, Venezuela, one of the country's referral centers for cases of HIV infection. Slides prepared from buffy coat that had been stained with Wright's solution and sealed with resin for preservation were examined retrospectively under the light microscope.

Results: Ehrlichia spp. were found in the platelets of 12 of the 87 (13.8%) patients whose slides were examined.

Conclusion: The presence of Ehrlichia sp. in the platelets of HIV-positive patients suggests that ehrlichiosis should be among the differential diagnoses of opportunistic infection in this group of patients.