Examinando por Autor "Quintana Alfaro, Luis Alberto"

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Acceso abierto
Usefulness of the chromagar orientation medium, for the identification of Streptococcus agalactiae in urine cultures of pregnant women at the San Bartolomé hospital, January 2016 to March 2019, Lima - Peru
(Universidad Privada Norbert Wiener, 2020-11-20) Francia Salvador, Erika Frida; Pérez Luján, Carolina Marisol; Quintana Alfaro, Luis Alberto
Introduction: Streptococcus agalactiae is the primary cause of infection in pregnant women and can lead to miscarriages. The aim of this study was to determine the diagnostic utility, in terms of sensitivity and specificity, of the CHROMagar Orientation medium for identifying S. agalactiae in urine cultures of pregnant women at Hospital San Bartolomé from January 2016 to March 2019, Lima, Peru. Materials and Methods: A retrospective cross-sectional study was designed involving hospitalized or outpatient pregnant patients with positive S. agalactiae urine cultures. CHROMAGAR ORIENTATION and the Vitek system were used as the standard method. Diagnostic tests were determined to assess sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and Kappa correlation index. Results: The most frequent age group was 31-40 years, with 70.8%, and 82.5% were in the third trimester of pregnancy. A total of 36,600 urine samples were included, with 6,626 isolates, of which 372 (5.6%) were S. agalactiae. We determined a sensitivity of 55.4% (95% CI 50.3 to 60.3), specificity of 99.9% (95% CI 98.8 to 100), PPV of 97.2% (95% CI 94 to 98.7), NPV of 97.4% (95% CI 97 to 97.8), and good agreement (κ=0.70). Conclusion: The CHROMAGAR ORIENTATION medium demonstrated moderate sensitivity and high specificity for the identification of S. agalactiae in urine cultures of pregnant women at Hospital San Bartolomé from January 2016 to March 2019, Lima, Peru.
Acceso abierto
Yield of the bactec-mgit 960 liquid culture in the recovery of mycobacterium tuberculosis in extrapulmonary samples of the Hipólito Unanue National Hospital. Lima-Peru, 2018.
(Universidad Privada Norbert Wiener, 2020-08-07) Llerena Pimentel, Myrian; Oroncoy Asto, Nancy; Quintana Alfaro, Luis Alberto
Materials and Methods: Descriptive, retrospective, cross-sectional study. 208 extrapulmonary samples processed during 2018 at CENEX-HNHU were included, meeting the selection criteria. Descriptive and analytical statistics were used, considering a p value <0.05 as significant. Results: The recovery rate of mycobacteria in liquid medium BACTEC-MGIT 960 was 11.5%, while the Ogawa-Kudoh culture rate was 5.3%. The sensitivity of the BACTEC-MGIT 960 liquid culture was 90.91%, specificity was 93.33%, and the Youden index was 0.84. There were false positives and negatives. The agreement between liquid culture results and the gold standard was "Moderate" (k=0.573; p<0.05), and there was a significant difference in microorganism growth times (p<0.05). The mean growth time was 15.33 days for BACTEC-MGIT 960, while the Ogawa-Kudoh culture took 31.28 days. Conclusion: The BACTEC-MGIT 960 liquid culture performed well in recovering Mycobacterium tuberculosis from extrapulmonary samples obtained at the National Hipólito Unanue Hospital.