RESUMEN
Quantification of Leishmania infantum DNA in blood samples by an ultrasensitive quantitative polymerase chain reaction (QPCR) detected parasitemias in different clinical presentations. We observed a large range of parasitemias, more than 9 log values, and could determine the threshold between asymptomatic carriage and disease in the Mediterranean area (approximately one parasite/mL of blood). Based on kinetoplast DNA amplification, this assay had a sensitivity of 0.001 parasite DNA equivalents/mL and detected asymptomatic carriage of Leishmania. It detected parasite DNA in 58% of healthy subjects, while an immunoblot detected specific antibodies in only 16%. For initial diagnosis of disease, this quantitative PCR with blood samples constitutes a non-invasive alternative to bone marrow aspiration. Its main applications are monitoring of drug therapy and follow-up of immunodeficient patients for biologic confirmation of relapses.
Asunto(s)
Leishmania infantum/aislamiento & purificación , Leishmaniasis Visceral/diagnóstico , Parasitemia/diagnóstico , Parasitemia/epidemiología , Reacción en Cadena de la Polimerasa/veterinaria , Anfotericina B/uso terapéutico , Animales , ADN Protozoario/análisis , ADN Protozoario/sangre , Estudios de Seguimiento , Leishmania infantum/genética , Leishmaniasis Visceral/tratamiento farmacológico , Leishmaniasis Visceral/parasitología , Parasitemia/sangre , Parasitemia/parasitología , Reacción en Cadena de la Polimerasa/métodos , Recurrencia , Valores de Referencia , Sensibilidad y EspecificidadRESUMEN
We describe 3 cases of endocarditis after acute Q fever in 3 patients with clinically silent, undiagnosed valvulopathies, including mitral valve prolapse, minimal valvular leak, and biscuspid aortic valve. We conclude that, to prevent endocarditis, these minor valvulopathies must be actively searched for with echocardiography after diagnosis of acute Q fever.
Asunto(s)
Endocarditis Bacteriana/etiología , Enfermedades de las Válvulas Cardíacas/diagnóstico por imagen , Fiebre Q/complicaciones , Válvula Aórtica/anomalías , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/microbiología , Ecocardiografía , Endocarditis Bacteriana/diagnóstico por imagen , Endocarditis Bacteriana/patología , Femenino , Enfermedades de las Válvulas Cardíacas/complicaciones , Enfermedades de las Válvulas Cardíacas/microbiología , Humanos , Masculino , Persona de Mediana Edad , Válvula Mitral/diagnóstico por imagen , Válvula Mitral/microbiología , Válvula Mitral/patología , Prolapso de la Válvula Mitral/complicaciones , Prolapso de la Válvula Mitral/diagnóstico por imagen , Prolapso de la Válvula Mitral/microbiologíaRESUMEN
We isolated a novel spotted fever group rickettsia from a patient coming back from Chad with fever and a maculopapulous rash. In Africa, only six pathogenic spotted fever group rickettsiae have been identified, R. conorii, R. africae, R. akari, R. aeschlimannii, "R. mongolotimonae," and R. felis. Our isolate was identified by PCR amplification and sequencing of the 16S rRNA (16S rDNA), citrate synthase (gltA), and rOmpA (ompA) encoding genes. The 16S rDNA, gltA, and ompA sequences of the isolate were found to be 99.7, 99.6, and 99.5% identical with that of Astrakhan fever rickettsia, respectively. This rickettsia is endemic in the Caspian sea area and has also recently been identified in Kosovo. Using mouse serotyping, the currently accepted method for the identification of spotted fever group rickettsiae, the Chad isolate exhibited a specificity difference of 2 when compared to Astrakhan fever rickettsia and at least 4 when compared with other members of the R. conorii complex. The Chad isolate should be considered a variant of Astrakhan fever rickettsia. This is the first description of Astrakhan fever rickettsia outside Europe and the bacterium may be responsible for cases of spotted fever in Chad. Although Astrakhan fever rickettsia is transmitted by Rhipicephalus ticks in Europe, further studies are indicated to identify its vector in Africa where these ticks are also prevalent.