High performance of rapid influenza diagnostic test and variable effectiveness of influenza vaccines in Mexico.

OBJECTIVES: To evaluate the performance of rapid influenza diagnostic tests (RIDT) and influenza vaccines' effectiveness (VE) during an outbreak setting. METHODS: We compared the performance of a RIDT with RT-PCR for influenza virus detection in influenza-like illness (ILI) patients enrolled during the 2016/17 season in Mexico City. Using the test-negative design, we estimated influenza VE in all participants and stratified by age, virus subtype, and vaccine type (trivalent vs quadrivalent inactivated vaccines). The protective value of some clinical variables was evaluated by regression analyses. RESULTS: We enrolled 592 patients. RT-PCR detected 93 cases of influenza A(H1N1)pdm09, 55 of AH3N2, 141 of B, and 13 A/B virus infections. RIDT showed 90.7% sensitivity and 95.7% specificity for influenza A virus detection, and 91.5% sensitivity and 95.3% specificity for influenza B virus detection. Overall VE was 33.2% (95% CI: 3.0-54.0; p = 0.02) against any laboratory-confirmed influenza infection. VE estimates against influenza B were higher for the quadrivalent vaccine. Immunization and occupational exposure were protective factors against influenza. CONCLUSIONS: The RIDT was useful to detect influenza cases during an outbreak setting. Effectiveness of 2016/17 influenza vaccines administered in Mexico was low but significant. Our data should be considered for future local epidemiological policies.

Respuesta al tratamiento antituberculosis en pacientes con historia de tratamientos previos en el Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas / Response to antituberculous therapy in patients previously treated for TB at the National Institue for Respiratory Diseases Ismael Cosío Villegas

Antecedentes y objetivos: El Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas (INER), como centro de referencia nacional de enfermedades respiratorias, recibe pacientes con tuberculosis pulmonar (TBp) que ya han recibido múltiples tratamientos. El objetivo de este estudio fue evaluar los resultados del tratamiento antituberculosis en pacientes previamente tratados que fueron supervisados por el INER durante un nuevo retratamiento. Métodos: Estudio retrospectivo con análisis de los expedientes clínicos mediante un cuestionario estandarizado de los pacientes con TBp con antecedente de tratamiento previo, y cuyo nuevo tratamiento fue supervisado en el INER de 1994-2001. La respuesta al tratamiento fue analizada de acuerdo al número de tratamientos previos, al antecedente de fracaso al tratamiento antes de ingresar al INER, y de acuerdo a la presencia o no de tuberculosis multifarma-corresistente (TB-MFR). Resultados: Se incluyeron a 147 pacientes diagnosticados con TBp que habían recibido tratamiento previo. Las tasas de curación en el INER para los pacientes con uno, dos y tres o más tratamientos previos fueron 68.2%, 40.4%, 8.8% (p = 0.009); de abandono 6.8%, 4.3%, 3.1% (p = 0.7) y de fracaso 18.2%, 27.7%, 25.0% (p = 0.6) para cada uno de los grupos, respectivamente. La proporción de TB-MFR fue de 64.4% 86.3% y 94.4% en cada grupo (x² de tendencia, p = 0.0004). El fracaso previo fue predictor independiente de fracaso actual [RM = 2.4 (IC95% 0.9-6.4) p = 0.04]. Las tasas de curación de acuerdo al patrón de resistencia fueron: monorresistencia 71.4%; multifarmaco-rresistencia 44.9% y polirresistencia 30.8%, (x² de tendencia, p = -03). Conclusiones: En pacientes con TBp con múltiples tratamientos previos y que recibieron un retratamiento supervisado por el INER, hubo bajas tasas de curación, una proporción persistente de fracasos al tratamiento y una alta tasa de TB-MFR.

Background: The National Institute of Respiratory Diseases Ismael Cosío Villegas (INER) is a national third level referral center for all respiratory diseases, including multitreaded pulmonary tuberculosis patients (PTb). The purpose of this study was to evaluate the results of supervised PTb retreatment at the INER in patients previously treated for PTb. Methods: Retrospective review of clinical charts by a standardized questionary of previous treated PTb patients and whose new treatment was given and supervised al the INER from 1994 to 2001. The response was analyzed according to the number of previous treatments, history of failure to previous treatments and presence or absence of MDR PTb. Results: One hundred and forty seven patients had previously received treatment for PTb. The cure rates for patients with one, two, three or more previous PTb treatments were 68.2%, 40.4%, and 8.8% (p = 0.009); desertion 6.8%, 4.3%, and 3.1% (p = 0.7); failure 18.2%, 27.7%, and 25 % (p = 0.6) for each one of the groups, respectively. The proportion of MDR- PTb was 64.4%, 86.3%, and 94.4% in each group (X² trend, p = 0.0004). A previous treatment failure was a predictor of failure of treatment at the INER [OR = 2.4 (CI95% 0.9-9.64), p = 0.04]. According to resistance, cure rates were 71.4% for one drug resistance, MDR 44.9% and poly resistance 30.8% (X² trend, p= -03). Conclusions: For patients with one or more failed previous treatments for PTb, receiving a new supervised treatment regime at the INER, there were low cure rates, a high proportion of treatment failures and a high rate of MDR-PTb.