Molecular and clinical evidence of Ehrlichia chaffeensis infection in Cameroonian patients with undifferentiated febrile illness

• Published in: Annals of allergy, asthma, & immunology asthma, & immunology, 2009-12, Vol.103 (8), p.719-725
• Main Authors: Ndip, L. M., Labruna, M., Ndip, R. N., Walker, D. H., McBride, J. W.
• Format: Article
• Language: English
• Subjects: Acute Disease; Adolescent; Adult; Arthralgia; Bacterial diseases; Biological and medical sciences; Cameroon; Child; Child, Preschool; DNA, Bacterial - analysis; Ehrlichia - genetics; Ehrlichia - isolation & purification; Ehrlichia chaffeensis; Ehrlichiosis; Ehrlichiosis - diagnosis; Ehrlichiosis - genetics; Ehrlichiosis - immunology; Electrophoresis, Agar Gel; Exanthema; Female; Fever; Fever - etiology; Fluorescent Antibody Technique; General aspects; Headache; Human bacterial diseases; Humans; Immunoglobulins - analysis; Infant; Infection; Infectious diseases; Ixodidae; Lung; Male; Medical sciences; Middle Aged; Myalgia; Peripheral blood; Polymerase chain reaction; Polymerase Chain Reaction - methods; Rhipicephalus sanguineus; Rickettsial diseases; Tropical bacterial diseases; Young Adult
• ISSN: 0003-4983; 1081-1206; 1364-8594
• DOI: 10.1179/000349809X12554106963753

In the U.S.A., human monocytotropic ehrlichiosis (HME) caused by Ehrlichia chaffeensis is an emerging tick-transmitted zoonosis. In Cameroon, where E. canis, E. chaffeensis and E. ewingii have recently been detected in dogs and/or ticks (Rhipicephalus sanguineus), the potential exists for human infections. Patients from the coastal region of Cameroon who had acute fevers of unknown aetiology were therefore checked for ehrlichial infection, using a real-time PCR that amplifies part of a genus-specific gene (dsb) that codes for a disulphide-bond formation protein. Ehrlichial blood was detected in the peripheral blood from 12 (10%) of the 118 patients investigated by PCR. When the 12 amplicons from the positive cases were sequenced, they were found to be identical to each other and to the corresponding dsb sequence of an Arkansas strain of E. chaffeensis. The 12 patients who were PCR-positive for E. chaffeensis suffered from fever (100%), headache (67%), myalgia (42%), arthralgia (58%), pulmonary involvement (17%) and/or a diffuse rash (17%).