ABSTRACT
OBJETIVO: Evaluar el desempeño de los datos clínicos y la prueba rápida (PR) en el diagnóstico de influenza H1N1, y analizar el costo-beneficio que representa el uso de esta herramienta diagnóstica. MÉTODOS: Se aplicó la PR a pacientes que acudieron a cuatro hospitales en la ciudad de México con sintomatología similar a influenza (SSI) durante el período octubre y noviembre de 2009. Se comparó el desempeño diagnóstico de la SSI más la PR contra el de la reacción en cadena de la polimerasa en transcripción reversa en tiempo real (rRT-PCR). La rRT-PCR fue procesada en un laboratorio de referencia y cegado al resultado de la PR. Además, se llevó a cabo una evaluación económica a partir de la cual se estimó el impacto presupuestal relacionado con la utilización de la PR RESULTADOS: Se incluyó a 78 pacientes, de los cuales 39 fueron positivos para influenza H1N1 y 6 para influenza A estacional, de acuerdo al resultado de la rRT-PCR. La SSI mostró una sensibilidad de 96 por ciento y una especificidad de 21 por ciento, la PR de 76 por ciento y 82 por ciento y el conjunto de SSI más PR de 96 por ciento y 100 por ciento, respectivamente. El Cociente de Verosimilitud positivo de la SSI-cefalea fue de 31,5 y el de SSI-odinofagia fue de 330. El uso de PR mostró un ahorro de US$ 12,6 por cada caso sospechoso. CONCLUSIONES: El uso de la PR como auxiliar en el diagnóstico de influenza H1N1 incrementa la certeza y reduce el costo promedio por paciente sospechoso e infectado.
OBJECTIVE: Evaluate the performance of clinical data and the rapid influenza diagnostic test (RIDT) in diagnosing influenza H1N1, and analyze the cost-benefit of using this diagnostic tool. METHODS: The RIDT was used for patients who came to four hospitals in Mexico City with an influenza-like illness (ILI) in October and November 2009. The diagnostic performance of the ILI clinical data and the RIDT was compared to that of the real-time reverse transcription polymerase chain reaction (rRT-PCR) test. The rRT-PCR test was conducted in a reference laboratory and blinded to the results of the RIDT. An economic evaluation also was conducted to estimate the budgetary impact of using the RIDT. RESULTS: The study included 78 patients, 39 of whom tested positive for influenza H1N1 and 6 tested positive for seasonal influenza A, according to the results of the rRT-PCR. The ILI clinical data yielded a sensitivity of 96 percent and specificity of 21 percent; the RIDT yielded a sensitivity of 76 percent and specificity of 82 percent; and the ILI clinical data and RIDT together yielded a sensitivity of 96 percent and specificity of 100 percent. The positive likelihood quotient for ILI-headaches was 31.5 and that of ILI-odynophagia, 330. The use of RIDT yielded savings of US$12.6 per each suspected case. CONCLUSIONS: Use of the RIDT to aid in the diagnosis of influenza H1N1 increases certainty and lowers the average cost per suspected and infected patient.
Subject(s)
Adolescent , Adult , Aged , Child , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Young Adult , Immunoassay/economics , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/diagnosis , Physical Examination/economics , Ambulatory Care/economics , Antigens, Viral/analysis , Antiviral Agents/economics , Antiviral Agents/therapeutic use , Computer Systems/economics , Cost-Benefit Analysis , Diagnostic Errors , Early Diagnosis , Hospitalization/economics , Hospitals, Urban , Immunoassay/methods , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H1N1 Subtype/immunology , Influenza, Human/drug therapy , Influenza, Human/virology , Mexico , Surveys and Questionnaires , Reverse Transcriptase Polymerase Chain Reaction/economics , Single-Blind Method , Time FactorsABSTRACT
Rotavirus represents the major cause of dehydrating diarrhea among infants and young children on worldwide scale and has recently become the target of research aimed at developing a vaccine. To that end, screening tests of clinical specimens ought to provide high sensitivity and specificity. Hence, in order to achieve that aim we compared a commercially available latex agglutination (LA) kit with reverse transcription polymerase chain reaction (RT-PCR) using primers amplifying the gene for the major neutralization antigen in 71 stool samples of children with acute gastroenteritis during November 1998-April 1999. Based on accuracy (76.05%), specificity (86.8%) and sensitivity (63.6%) determined for LA with RT-PCR serving as the gold standard, we recommend LA for field studies where speed and simplicity are crucial. Yet, for the purpose of further studies as to epidemiology and vaccine trials RT-PCR with its higher specificity and sensitivity will be required.