Aplicación de los métodos moleculares al diagnóstico y el estudio epidemiológico de las infecciones respiratorias causadas por virus

Abstract

To date, more than two hundred viruses, belonging to six different taxonomic families, have been associated with human respiratory tract infection. The widespread incorporation of molecular methods into clinical microbiology laboratories has not only led to notable advances in the etiological diagnosis of viral respiratory infections but has also increased insight into the pathology and epidemiological profiles of the causative viruses. Because of their high sensitivity, molecular techniques markedly increase the efficiency of viral detection in respiratory specimens, particularly those that fail to propagate successfully in common cell cultures, thus allowing more rapid etiologic diagnosis. However, there are also some disadvantages in the use of these new technologies such as detection of viruses that merely colonize the respiratory tract of healthy people, or those found in the nasopharyngeal secretions of patients who have recovered from respiratory infections, due to longterm viral shedding, when the viruses are unlikely to act as pathogens. Additionally, sequencing of the amplification products allows further characterization of detected viruses, including molecular epidemiology, genotyping, or detection of antiviral resistance, to cite only a few examples.

Métodos moleculares de diagnóstico de infecciones respiratorias. ¿Ha cambiado el esquema diagnóstico?

“…La identificación rápida del virus causante de la infección permite instaurar un tratamiento adecuado y precoz, así como prevenir la transmisión y mejorar el control de brotes. Sin embargo, las técnicas moleculares también presentan una serie de inconvenientes: posibles inhibiciones; variabilidad de los virus que obliga a revisar periódicamente las dianas de cebadores y sondas; falsos positivos por la detección de virus que colonizan la mucosa respiratoria en personas asintomáticas, o virus no viables excretados de forma prolongada después de la resolución de la infección 23,24 .…”