RESUMEN
Shigella flexneri is one of the agents most frequently linked to diarrheal illness in developing countries and often causes outbreaks in settings with poor hygiene or sanitary conditions. Travel is one of the means by which S. flexneri can be imported into developed countries, where this pathogen is not commonly seen. A robust and discriminatory subtyping method is needed for the surveillance of S. flexneri locally and regionally, and to aid in the detection and investigation of outbreaks. The PulseNet International network utilizes standardized pulsed-field gel electrophoresis (PFGE) protocols to carry out laboratory-based surveillance of foodborne pathogens in combination with epidemiologic data. A multicenter validation was carried out in nine PulseNet laboratories located in North and South America, Europe, and Asia, and it demonstrated that a new protocol is highly robust and reproducible for subtyping of S. flexneri. This protocol, already approved for PulseNet laboratories, applies NotI and XbaI as primary and secondary restriction enzymes, respectively, under electrophoresis conditions of initial switch time of 5 s to final switch time of 35 s, at 6 volts/cm.
Asunto(s)
Técnicas de Tipificación Bacteriana , ADN Bacteriano/metabolismo , Shigella flexneri/clasificación , Técnicas de Tipificación Bacteriana/normas , ADN Bacteriano/química , Dinamarca , Desoxirribonucleasas de Localización Especificada Tipo II/metabolismo , Disentería Bacilar/diagnóstico , Disentería Bacilar/microbiología , Electroforesis en Gel de Campo Pulsado , Hong Kong , Medio Oriente , América del Norte , Control de Calidad , Reproducibilidad de los Resultados , Shigella flexneri/aislamiento & purificación , Shigella flexneri/metabolismo , América del Sur , Factores de TiempoRESUMEN
The epidemiology of serogroup X meningococcal meningitis in Africa is unknown. During a serogroup X meningococcus outbreak in Kenya, case finding involved record review at health facilities and interviews with health workers and community leaders in West Pokot district. An age- and location-matched case-control study for risk factors was done. From December 2005 to April 2006, 82 suspect cases of meningitis were reported; the epidemic threshold was surpassed within two administrative divisions. Most (58%) cases were 5-24 years old; the case-fatality ratio was 21%. Serogroup X meningococcus was the most common serogroup - 5 (63%) of eight isolates serogrouped. Living in the same compound as another case, preceding upper respiratory tract infection and cooking outside the house were significant risk factors for disease. Serogroup X meningococcus caused an outbreak with similar epidemiology and risk factors as other serogroups. Serogroup-specific laboratory-based surveillance for meningococcus in Africa to detect serogroup X disease should be enhanced.
