Larissa Otero

Publications (4)19.28 Total impact

• Article: A Diagnostic Accuracy Study of Xpert®MTB/RIF in HIV-Positive Patients with High Clinical Suspicion of Pulmonary Tuberculosis in Lima, Peru.

  Gabriela Carriquiry, Larissa Otero, Elsa González-Lagos, Carlos Zamudio, Eduardo Sánchez, Pamela Nabeta, Miguel Campos, Juan Echevarría, Carlos Seas, Eduardo Gotuzzo
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  ABSTRACT: Diagnosis of pulmonary tuberculosis (TB) among human immunodeficiency virus (HIV) patients remains complex and demands easy to perform and accurate tests. Xpert®MTB/RIF (MTB/RIF) is a molecular TB diagnostic test which is rapid and convenient; the test requires minimal human resources and reports results within two hours. The majority of performance studies of MTB/RIF have been performed in high HIV burden settings, thus TB diagnostic studies among HIV patients in low HIV prevalence settings such as Peru are still needed. From April 2010 to May 2011, HIV-positive patients with high clinical suspicion of TB were enrolled from two tertiary hospitals in Lima, Peru. Detection of TB by MTB/RIF was compared to a composite reference standard Löwenstein-Jensen (LJ) and liquid culture. Detection of rifampicin resistance was compared to the LJ proportion method. We included 131 patients, the median CD4 cell count was 154.5 cells/mm(3) and 45 (34.4%) had TB. For TB detection among HIV patients, sensitivity of MTB/RIF was 97.8% (95% CI 88.4-99.6) (44/45); specificity was 97.7% (95% CI 91.9-99.4) (84/86); the positive predictive value was 95.7% (95% CI 85.5-98.8) (44/46); and the negative predictive value, 98.8% (95% CI 93.6-99.8) (84/85). MTB/RIF detected 13/14 smear-negative TB cases, outperforming smear microscopy [97.8% (44/45) vs. 68.9% (31/45); p = 0.0002]. For rifampicin resistance detection, sensitivity of MTB/RIF was 100% (95% CI 61.0-100.0) (6/6); specificity was 91.0% (95% CI 76.4-96.9) (30/33); the positive predictive value was 66.7% (95% CI 35.4-87.9) (6/9); and the negative predictive value was 100% (95% CI 88.7 -100.0) (30/30). In HIV patients in our population with a high clinical suspicion of TB, MTB/RIF performed well for TB diagnosis and outperformed smear microscopy.
  PLoS ONE 01/2012; 7(9):e44626. · 4.09 Impact Factor
• Source

  Available from: Carlos Seas

  Article: High prevalence of primary multidrug resistant tuberculosis in persons with no known risk factors.

  Larissa Otero, Fiorella Krapp, Cristina Tomatis, Carlos Zamudio, Francine Matthys, Eduardo Gotuzzo, Patrick Van der Stuyft, Carlos Seas
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  ABSTRACT: In high multidrug resistant (MDR) tuberculosis (TB) prevalence areas, drug susceptibility testing (DST) at diagnosis is recommended for patients with risk factors for MDR. However, this approach might miss a substantial proportion of MDR-TB in the general population. We studied primary MDR in patients considered to be at low risk of MDR-TB in Lima, Peru. We enrolled new sputum smear-positive TB patients who did not report any MDR-TB risk factor: known exposure to a TB patient whose treatment failed or who died or who was known to have MDR-TB; immunosuppressive co-morbidities, ex prison inmates; prison and health care workers; and alcohol or drug abuse. A structured questionnaire was applied to all enrolled participants to confirm the absence of these factors and thus minimize underreporting. Sputum from all participants was cultured on Löwenstein-Jensen media and DST for first line drugs was performed using the 7H10 agar method. Of 875 participants with complete data, 23.2% (203) had risk factors for MDR-TB elicited after enrolment. Among the group with no reported risk factors who had a positive culture, we found a 6.3% (95%CI 4.4-8.3) (37/584) rate of MDR-TB. In this group no epidemiological characteristics were associated with MDR-TB. Thus, in this group, multidrug resistance occurred in patients with no identifiable risk factors. We found a high rate of primary MDR-TB in a general population with no identifiable risk factors for MDR-TB. This suggests that in a high endemic area targeting patients for MDR-TB based on the presence of risk factors is an insufficient intervention.
  PLoS ONE 01/2011; 6(10):e26276. · 4.09 Impact Factor
• Article: Predictors of CD4+ cell count response and of adverse outcome among HIV-infected patients receiving highly active antiretroviral therapy in a public hospital in Peru.

  Diego López de Castilla, Kristien Verdonck, Larissa Otero, David Iglesias, Juan Echevarría, Lynen Lut, Eduardo Gotuzzo, Carlos Seas
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  ABSTRACT: Our aim was to investigate CD4+ cell recovery and adverse outcome after highly active antiretroviral therapy (HAART) under the Peruvian National Program for HIV. A prospective, observational study was conducted between May 2004 and September 2005. Data were collected from records of patients receiving HAART at a public hospital under the Peruvian National Program for HIV. Predictors of CD4+ cell count recovery and adverse outcome were analyzed by multiple regression. Three hundred and twenty-six patients were included in the study. The mean increase in CD4+ cell count at six months was 114 cells/microl (95% confidence interval: 103-126). Patients with a lower CD4+ cell count at baseline and those starting HAART with a didanosine-based regimen had a higher increase in CD4+ cell count at six months. Patients starting HAART with a stavudine-based regimen had a lower increase in CD4+ cell count at six months. World Health Organization clinical stage IV at diagnosis of HIV infection, a low body weight at baseline, and starting HAART with a stavudine-based regimen were independently associated with an adverse outcome. The CD4+ cell response to HAART under Peruvian National Program for HIV was comparable with reports from other countries. However, the fact that advanced clinical disease predicted adverse outcome emphasizes the need for earlier access to HAART.
  International Journal of Infectious Diseases 06/2008; 12(3):325-31. · 1.94 Impact Factor
• Article: Ocular manifestations associated with brucellosis: a 26-year experience in Peru.

  Isaias Rolando, Liset Olarte, Gustavo Vilchez, Marina Lluncor, Larissa Otero, Mark Paris, Carlos Carrillo, Eduardo Gotuzzo
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  ABSTRACT: Brucellosis has unusual clinical manifestations. Ocular involvement caused by brucellosis remains poorly recognized in areas in which brucellosis is endemic. A prospective study was performed to evaluate patients attending the Instituto de Medicina Tropical "Alexander von Humboldt" and the Hospital Nacional Cayetano Heredia (Lima, Peru) from January 1980 through December 2005 who received a diagnosis of brucellosis with ocular involvement. Diagnosis was made on the basis of clinical findings as well as agglutinations and/or culture positive for Brucella melitensis. During a period of 26 years, 1551 patients with brucellosis were seen, including 52 patients with ocular brucellosis. We found that 7 (0.7%) of 965 patients with acute brucellosis and 45 (7.9%) of 570 patients with chronic brucellosis had ocular brucellosis (P<.001). In 16 patients with brucellosis, the disease stage was unclassified. The most frequent ocular presentation was uveitis, which was found in 43 (82.7%) of the 52 patients with ocular brucellosis. Posterior uveitis was the most frequent uveal syndrome (21 cases; 45.7%). Patients with panuveitis had the worst visual prognosis: 8 of 9 patients with panuveitis were legally blind, including 5 patients with no light perception. Brucellosis may involve the eye and can lead to serious complications. In patients with brucellosis, early ophthalmologic evaluation can lead to prompt treatment and might prevent blindness from severe ocular damage.
  Clinical Infectious Diseases 05/2008; 46(9):1338-45. · 9.15 Impact Factor