RESUMEN
BACKGROUND: Chikungunya virus (CHIKV) and Dengue virus serotype 2 (DENV-2) were recently introduced in central Africa, along with Aedes albopictus. Simultaneous outbreaks of CHIKV and DENV-2 have subsequently occurred, in Cameroon in 2006 and Gabon in 2007. METHODS: To study the spread of the 2 viruses, we conducted active surveillance of acute febrile syndromes throughout Gabon between 2007 and 2010. Diagnostic methods included quantitative real-time reverse-transcription polymerase chain reaction, and molecular characterization was based on partial envelope gene sequences. RESULTS: Between 2007 and 2010, 4287 acutely febrile patients were investigated for CHIKV and DENV-2 infections, of whom 1567 were CHIKV-positive, 376 DENV-2-positive, and 37 coinfected. We diagnosed 153 CHIKV and 11 DENV-2 cases in 2008, and 5 CHIKV and 9 DENV-2 cases in 2009. In 2010, CHIKV and DENV-2 caused a second large simultaneous outbreak. Among 2826 acutely febrile patients examined during this outbreak, 1112 were CHIKV-positive, 288 DENV-2-positive, and 28 coinfected. Mosquitoes were collected near the homes of coinfected patients, and 1 Aedes albopictus specimen was found to be positive for both CHIKV and DENV-2. CONCLUSIONS: These findings show the rapid dissemination of CHIKV and DENV-2 within a nonimmune population in a tropical African country, probably facilitated by the spread of Aedes albopictus. This has resulted in major simultaneous outbreaks with numerous coinfections in both human and mosquito.
Asunto(s)
Aedes/virología , Infecciones por Alphavirus/epidemiología , Virus Chikungunya/aislamiento & purificación , Coinfección , Virus del Dengue/aislamiento & purificación , Dengue/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Infecciones por Alphavirus/virología , Animales , Virus Chikungunya/clasificación , Virus Chikungunya/genética , Niño , Preescolar , Dengue/virología , Virus del Dengue/clasificación , Virus del Dengue/genética , Brotes de Enfermedades , Femenino , Gabón/epidemiología , Humanos , Lactante , Masculino , Persona de Mediana Edad , Epidemiología Molecular , Datos de Secuencia Molecular , Reacción en Cadena en Tiempo Real de la Polimerasa , Análisis de Secuencia de ADN , Proteínas del Envoltorio Viral/genética , Adulto JovenRESUMEN
An isocratic high-performance liquid chromatography (HPLC) method with on-line extraction has been developed to determine linezolid in Mueller-Hinton broth. The loading mobile phase consisting of water-acetonitrile 99:1 (v/v) allowed retention of the analyte on a LiChrocart 4-4 pre-column filled with a LiChrospher 100 RP-8, 5 microm. The transfer of the analyte by a backflush mode to a 150 mm x 4.6 mm I.D. Kromasil C8 5 microm column was performed using a mobile phase of water-acetonitrile 80:20 (v/v). UV detection at 254 nm allowed a quantification limit of 0.39 microg/mL with a 50-microL sample size. The method was successfully applied to in vitro pharmacokinetic-pharmacodynamic studies.