Anaplasma phagocytophilum is not an aetiological agent of fever of intermediate duration in Gran Canaria (Spain)

Abstract

Laboratorio de Espiroquetas y Pato´genos Especiales, Centro Nacional deMicrobiologi´a-ISCIII, Madrid, SpainINTRODUCTIONFever of intermediate duration (FID) is defined asnon-localised fever occurring in the community,lasting from 1 to 4 weeks, and having no diag-nostic orientation after basic clinical, analyticaland radiological evaluations are completed. [1]. InSpain, the most frequent causes of FID (70%) aresystemic infectious diseases (mainly rickettsioses,brucellosis, bartonellosis, anaplasmosis andagents of infectious mononucleosis), localisedinfections (i.e. intraabdominal abscesses or pros-tatitis), vasculitis and neoplasms, and other aeti-ological agents.In Gran Canaria (Spain), the most frequentcauses of FDI are Coxiella burnetii [2], Rickettsiatyphi [3] and Rickettsia felis [4]. However, manypatients with FDI, without data suggestive ofoccult bacterial infections, vasculitis or neo-plasms, have a clinical response to the useof doxycycline but no microbiological diagnosis.So, the aim of this work was to evaluate theaetiological role of Anaplasma phagocytophilumin patients with FDI in Gran Canaria.PATIENTS, MATERIAL ANDMETHODSAll autochthonous adult outpatients with FIDevaluated in the Infectious Diseases Unit from 1October 2004 to 31 December 2006 were investi-gated for their aetiological diagnosis. Demo-graphic, clinical and laboratory data werecollected for all patients. Chest X-ray, three sets ofblood cultures and urine culture were systemati-cally performed. Antibodies against Coxiella bur-netii (immunofluorescence (IFA); IgG and IgM(bioMe´rieux, Marcy l’Etoile, France)), Rickettsiatyphi (IFA; IgG and IgM (bioMe´rieux)), Rickettsiaconorii (IFA;IgG and IgM (bioMe´rieux)), Leptospiraspp. (MAT, bioRad, Marnes la Coquette, France),Epstein-Barr virus (EBV) (enzymeimmunoassay(EIA); IgG-VCA (Trinity Biotech, Bray Co. Wick-low, Ireland), IFA; IgM (Palex Medical, MeridianBioscience, Cincinnati, OH, USA)), Cytomegalovi-rus (CMV) (EIA; IgG and IgM (Abbott Laborato-ries, Delkenheim, Germany)), Toxoplasma gondii(EIA; IgG and IgM (Abbott Laboratories), IgA(diaSorin, Milano, Italy)), human immunodefi-ciencyvirus(HIV)(EIA,AbbottLaboratories),withpositive results confirmed by immunoblot test(INNOLIA, Innogenetics, Gent, Belgium),hepatitis A (EIA, Abbott Laboratories), hepatitis B(EIA; surface antigen—BsAg-antibodies for core -antiHBc- (Abbott Laboratories)) and hepatitis C(EIA, Abbott Laboratories) virus were tested for inall patients. Serological evaluation of Brucella spp.wasnotincludedbecausethisinfectionisabsentinGran Canaria. A definite diagnosis of these dis-eases was the presence of a compatible clinicalpicture and conventional serological criteria. FDIpatients with epidemiological characteristics sug-gestive of imported diseases, and⁄or with only aserum sample, were excluded.Anaplasma phagocytophilum antibodies (IgG andIgM) were evaluated in patients without a definitediagnosiswhentwoserumsampleswereavailable(acute and convalescent phase). A commercial