Clinical Focus

  • Clinical Pathology
  • Microbiology

Academic Appointments

Professional Education

  • Residency:Stanford Hospital and Clinics (2011) CA
  • Board Certification: Clinical Pathology, American Board of Pathology (2011)
  • Medical Education:Johns Hopkins School of Medicine (2006) MD
  • MD, Johns Hopkins School of Medicine (2006)
  • MPH, Johns Hopkins School of Public Health (2005)
  • BA, Harvard University (2001)

Research & Scholarship

Current Research and Scholarly Interests

Infectious disease diagnostics, Mycobacterium tuberculosis, Global health


Journal Articles

  • Alerting Physicians during Electronic Order Entry Effectively Reduces Unnecessary Repeat PCR Testing for Clostridium difficile. Journal of clinical microbiology Luo, R. F., Spradley, S., Banaei, N. 2013; 51 (11): 3872-3874


    Hospital information systems (HIS) alerts restricting repeat Clostridium difficile PCR ordering by physicians in patients with a prior result within 7 days eliminated 91% of repeat tests, from 14.5% (282/1,949) repeats preintervention to 1.3% (135/10,285) postintervention. HIS alerting is an effective, targeted, patient-specific tool for improving the quality and utilization of C. difficile results.

    View details for DOI 10.1128/JCM.01724-13

    View details for PubMedID 23985918

  • Molecular Approaches and Biomarkers for Detection of Mycobacterium tuberculosis. Clinics in laboratory medicine Luo, R. F., Banaei, N. 2013; 33 (3): 553-566


    Tuberculosis (TB) continues to be a public health emergency, compounded by the lack of adequate diagnostic testing in many regions of the world. New advances in the molecular detection of Mycobacterium tuberculosis, including faster and simpler nucleic acid amplification tests, have resulted in rapid and cost-effective methods to diagnose TB and test for drug resistance. Ongoing research on biomarkers for TB infection may lead to new tests for blood, urine, breath, and sputum. Sustained investment in the development and dissemination of diagnostic tests for TB is critical for increasing TB case finding, placing patients on appropriate treatment, and reducing transmission.

    View details for DOI 10.1016/j.cll.2013.03.012

    View details for PubMedID 23931838

  • Notes from the field: tuberculosis cluster associated with homelessness--Duval County, Florida, 2004-2012. MMWR. Morbidity and mortality weekly report 2012; 61 (28): 539-540


    Despite a decrease in incidence of tuberculosis (TB) in Duval County, Florida, from 102 cases (11.2 per 100,000 population) in 2008 to 71 cases (8.2 per 100,000) in 2011,* analysis of Mycobacterium tuberculosis genotyping data revealed a substantial increase in the percentage of TB cases with the same genotype.† That percentage increased from 27% (10 of 37) of genotyped cases in 2008 to 51% (30 of 59) of genotyped cases in 2011 (Florida Department of Health, unpublished data, 2012). During this period, the percentage of patients with this genotype who were homeless or who abused substances also increased. Because of concern over potential ongoing TB transmission involving these hard-to-reach populations, the Duval County Health Department, Florida Department of Health, and CDC conducted an investigation during February 15-March 13, 2012. As of March 13, review of medical records and interviews with TB patients had identified 99 cases related to the cluster based on matching genotype results and epidemiologic links (48 cases), matching genotype only (22), epidemiologic links only (22), or common social risk factors for TB (e.g., homelessness, incarceration, or substance abuse within 1 year of TB diagnosis) and suspected epidemiologic links (seven). The first known case with a matching genotype occurred in 2004.

    View details for PubMedID 22810268

  • Supraorbital Postmortem Brain Sampling for Definitive Quantitative Confirmation of Cerebral Sequestration of Plasmodium falciparum Parasites JOURNAL OF INFECTIOUS DISEASES Milner, D. A., Valim, C., Luo, R., Playforth, K. B., Kamiza, S., Molyneux, M. E., Seydel, K. B., Taylor, T. E. 2012; 205 (10): 1601-1606


    The conventional clinical case definition of cerebral malaria (CM) is imprecise but specificity is improved by a definitive clinical feature such as retinopathy or confirming sequestration of parasites in a post-mortem examination of the brain. A full autopsy is often not possible, since it is costly and may encounter resistance of the deceased's family.We have assessed the use of a cytological smear of brain tissue, obtained post-mortem by supraorbital sampling, for the purpose of quantifying cerebral sequestration in children with fatal malaria in Blantyre, Malawi. We have compared this method to histological quantification of parasites at autopsy.The number of parasites present on cytological smears correlated with the proportion of vessels parasitized as assessed by histology of fixed and stained brain tissue. Use of cytological results in addition to the standard clinical case definition increases the specificity of the clinical case definition alone from 48.3% to 100% with a minimal change in sensitivity.Post-mortem supraorbital sampling of brain tissue improves the specificity of the diagnosis of fatal cerebral malaria and provides accurate quantitative estimates of cerebral sequestration. This tool can be of great value in clinical, pathogenetic, and epidemiological research studies on cerebral malaria.

    View details for DOI 10.1093/infdis/jis001

    View details for Web of Science ID 000303329200018

    View details for PubMedID 22291197

  • Transient Facial Swellings in a Patient With a Remote African Travel History JOURNAL OF TRAVEL MEDICINE Richardson, E. T., Luo, R., Fink, D. L., Nutman, T. B., Geisse, J. K., Barry, M. 2012; 19 (3): 183-185


    We present a case of Loa loa infection in a patient, 21 years after visiting an endemic area for only 4 days. To our knowledge, this case represents the longest time for the diagnosis of loiasis to be made post-exposure in a traveler and emphasizes that even short exposures can place travelers at risk.

    View details for DOI 10.1111/j.1708-8305.2012.00612.x

    View details for Web of Science ID 000303197900009

    View details for PubMedID 22530826

  • Brain Abscess Caused by Phaeoacremonium parasiticum in an Immunocompromised Patient JOURNAL OF CLINICAL MICROBIOLOGY McNeil, C. J., Luo, R. F., Vogel, H., Banaei, N., Ho, D. Y. 2011; 49 (3): 1171-1174


    Phaeoacremonium parasiticum is an environmental fungus usually associated with subcutaneous infections. We report the first documented case of central nervous system involvement with brain abscess formation in a patient with chronic granulomatous disease and review the literature on Phaeoacremonium parasiticum infections.

    View details for DOI 10.1128/JCM.00830-10

    View details for Web of Science ID 000287967100072

    View details for PubMedID 21191052

  • Is Repeat PCR Needed for Diagnosis of Clostridium difficile Infection? JOURNAL OF CLINICAL MICROBIOLOGY Luo, R. F., Banaei, N. 2010; 48 (10): 3738-3741


    Patients with diarrhea, defined as loose or watery stool, and two or more Clostridium difficile tcdB PCR tests within 14 days of each other were investigated. Repeat PCR for 293 patients with a prior negative result yielded negative results in 396 (97.5%) of 406 tests. Ten new positives were detected, including one false positive. Repeat PCR within 7 days appears rarely useful, except for patients with evidence of a new infection.

    View details for DOI 10.1128/JCM.00722-10

    View details for Web of Science ID 000282544700042

    View details for PubMedID 20686078

  • Comparison of Single-Copy and Multicopy Real-Time PCR Targets for Detection of Mycobacterium tuberculosis in Paraffin-Embedded Tissue JOURNAL OF CLINICAL MICROBIOLOGY Luo, R. F., Scahill, M. D., Banaei, N. 2010; 48 (7): 2569-2570


    Real-time PCR can rapidly identify Mycobacterium tuberculosis in paraffin-embedded tissue in the absence of microbiological culture. In a comparison of single-copy and multicopy PCR targets in 70 tissue samples, the sensitivities were 26% and 54%, respectively, with 100% specificity. Sensitivity was 75% for newer samples and was not decreased for acid-fast bacillus (AFB) stain-negative specimens.

    View details for DOI 10.1128/JCM.02449-09

    View details for Web of Science ID 000279318700040

    View details for PubMedID 20463168

  • Real-Time PCR Testing for mecA Reduces Vancomycin Usage and Length of Hospitalization for Patients Infected with Methicillin-Sensitive Staphylococci JOURNAL OF CLINICAL MICROBIOLOGY Nguyen, D. T., Yeh, E., Perry, S., Luo, R. F., Pinsky, B. A., Lee, B. P., Sisodiya, D., Baron, E. J., Banaei, N. 2010; 48 (3): 785-790


    Nucleic acid amplification tests (NAATs) have revolutionized infectious disease diagnosis, allowing for the rapid and sensitive identification of pathogens in clinical specimens. Real-time PCR testing for the mecA gene (mecA PCR), which confers methicillin resistance in staphylococci, has the added potential to reduce antibiotic usage, improve clinical outcomes, lower health care costs, and avoid emergence of drug resistance. A retrospective study was performed to identify patients infected with methicillin-sensitive staphylococcal isolates who were receiving vancomycin treatment when susceptibility results became available. Vancomycin treatment and length of hospitalization were compared in these patients for a 6-month period before and after implementation of mecA PCR. Among 65 and 94 patients identified before and after mecA PCR, respectively, vancomycin usage (measured in days on therapy) declined from a median of 3 days (range, 1 to 44 days) in the pre-PCR period to 1 day (range, 0 to 18 days) in the post-PCR period (P < 0.0001). In total, 38.5% (25/65) of patients were switched to beta-lactam therapy in the pre-PCR period, compared to 61.7% (58/94) in the post-PCR period (P = 0.004). Patient hospitalization days also declined from a median of 8 days (range, 1 to 47 days) in the pre-PCR period to 5 days (range, 0 to 42 days) in the post-PCR period (P = 0.03). Real-time PCR testing for mecA is an effective tool for reducing vancomycin usage and length of stay of hospitalized patients infected with methicillin-sensitive staphylococci. In the face of ever-rising health care expenditures in the United States, these findings have important implications for improving outcomes and decreasing costs.

    View details for DOI 10.1128/JCM.02150-09

    View details for Web of Science ID 000274996200016

    View details for PubMedID 20071556

  • CD81 protein is expressed at high levels in normal germinal center B cells and in subtypes of human lymphomas HUMAN PATHOLOGY Luo, R. F., Zhao, S., Tibshirani, R., Myklebust, J. H., Sanyal, M., Fernandez, R., Gratzinger, D., Marinelli, R. J., Lu, Z. S., Wong, A., Levy, R., Levy, S., Natkunam, Y. 2010; 41 (2): 271-280


    CD81 is a tetraspanin cell surface protein that regulates CD19 expression in B lymphocytes and enables hepatitis C virus infection of human cells. Immunohistologic analysis in normal hematopoietic tissue showed strong staining for CD81 in normal germinal center B cells, a cell type in which its increased expression has not been previously recognized. High-dimensional flow cytometry analysis of normal hematopoietic tissue confirmed that among B- and T-cell subsets, germinal center B cells showed the highest level of CD81 expression. In more than 800 neoplastic tissue samples, its expression was also found in most non-Hodgkin lymphomas. Staining for CD81 was rarely seen in multiple myeloma, Hodgkin lymphoma, or myeloid leukemia. In hierarchical cluster analysis of diffuse large B-cell lymphoma, staining for CD81 was most similar to other germinal center B cell-associated markers, particularly LMO2. By flow cytometry, CD81 was expressed in diffuse large B-cell lymphoma cells independent of the presence or absence of CD10, another germinal center B-cell marker. The detection of CD81 in routine biopsy samples and its differential expression in lymphoma subtypes, particularly diffuse large B-cell lymphoma, warrant further study to assess CD81 expression and its role in the risk stratification of patients with diffuse large B-cell lymphoma.

    View details for DOI 10.1016/j.humpath.2009.07.022

    View details for Web of Science ID 000276493600015

    View details for PubMedID 20004001

  • Preferential Lower Respiratory Tract Infection in Swine-Origin 2009 A(H1N1) Influenza CLINICAL INFECTIOUS DISEASES Yeh, E., Luo, R. F., Dyner, L., Hong, D. K., Banaei, N., Baron, E. J., Pinsky, B. A. 2010; 50 (3): 391-394


    We report a case of 2009 influenza A(H1N1) virus infection in which virus was detected predominantly in specimens from the lower respiratory tract but was absent or at very low levels in nasopharyngeal swab samples. This presentation suggests that, in certain hosts or for particular variants of 2009 A(H1N1) virus, the lower respiratory tract may be the preferred site of infection.

    View details for DOI 10.1086/649875

    View details for Web of Science ID 000273500300014

    View details for PubMedID 20047483

  • Pathology Quiz Case 1 Glomangiopericytoma (sinonasal-type hemangiopericytoma [HPC]) ARCHIVES OF OTOLARYNGOLOGY-HEAD & NECK SURGERY Worden, B., Getz, A., Luo, R., Hwang, P. H. 2009; 135 (5): 520-?

    View details for Web of Science ID 000266207600018

    View details for PubMedID 19451477

  • Age-bridging among young, urban, heterosexual males with asymptomatic Chlamydia trachomatis SEXUALLY TRANSMITTED INFECTIONS Jennings, J. M., Luo, R. F., Lloyd, L. V., Gaydos, C., Ellen, J. M., Rietmeijer, C. A. 2007; 83 (2): 136-141


    To determine the prevalence of age-bridgers among urban males aged 14-24 years, asymptomatically infected with chlamydia and to determine factors that distinguish age-bridgers from non age-bridgers. An index was defined as an age-bridger if within 2 months, he had had at least two sexual partners who differed from him in age by > or =2 years.Infected males provided data about themselves and up to four sexual partners in the past 2 months. Bivariate and multivariable logistic regression was used in the analysis.The prevalence of age bridging was 21% in Baltimore and 26% in Denver. In both cities, in bivariate analysis, age-bridgers and their partners engaged in significantly more risky sexual behaviours. In adjusted multivariable analysis after controlling for number of sexual partners, age bridging was associated with having a sexual partner in the past 2 months, who, at time of last sexual intercourse, was drinking.Age-bridgers represented major proportions of the study populations and, along with their sexual partners, were more likely to engage in risky sexual behaviours. Male age-bridgers may be key players in the transmission of sexually transmitted infections among youth linking age-disparate sexual networks.

    View details for DOI 10.1136/sti.2006.023556

    View details for Web of Science ID 000245686500016

    View details for PubMedID 17151025

  • Body composition, gender, and illicit drug use in an urban cohort AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE Cofrancesco, J., Brown, T. T., Luo, R. F., John, M., Stewart, K. J., Dobs, A. S. 2007; 33 (3): 467-474


    This cross-sectional study of adult (137 male, 128 female), urban, community dwelling users and nonusers of illicit drugs evaluated associations of demographic, medical, and drug factors with body composition. The population was 49% HIV-positive and 94% African-American. In multivariate analysis, there were no body composition differences among males based on drug use. Among females, the highest tertile of drug use had less fat (12.3 vs.19.9 kg, p = .01) and lower body mass index (21.9 vs. 25.1, p = .01) versus less frequent or nonusers. These data suggest a sex difference in body composition associated with drug use.

    View details for DOI 10.1080/00952990701301616

    View details for Web of Science ID 000246964900013

    View details for PubMedID 17613974

  • Injection drug use and HIV transmission in Russia AIDS Luo, R. F., Cofrancesco, J. 2006; 20 (6): 935-936

    View details for Web of Science ID 000236713500020

    View details for PubMedID 16549981

  • Use of the computer program GIDEON at an inpatient infectious diseases consultation service CLINICAL INFECTIOUS DISEASES Luo, R. F., Bartlett, J. G. 2006; 42 (1): 157-158

    View details for Web of Science ID 000233698900036

    View details for PubMedID 16323112

  • Diagnosis of sputum-scarce HIV-associated pulmonary tuberculosis in Lima, Peru LANCET Vargas, D., Garcia, L., Gilman, R. H., Evans, C., Ticona, E., Navincopa, M., Luo, R. F., Caviedes, L., Hong, C., Escombe, R., Moore, D. A. 2005; 365 (9454): 150-152


    Sputum induction, bronchoalveolar lavage, or gastric aspiration are often needed to produce adequate diagnostic respiratory samples from people with HIV in whom tuberculosis is suspected. Since these procedures are rarely appropriate in less-developed countries, we compared the performances of a simple string test and the gold-standard sputum induction. 160 HIV-positive adults under investigation for tuberculosis, and 52 asymptomatic HIV-positive control patients underwent the string test followed by sputum induction. The string test detected tuberculosis in 14 patients in whom this disease was suspected; sputum induction detected only eight of them (McNemar's test, p=0.03). These preliminary data suggest that the string test is safe and effective for retrieval of useful clinical specimens for diagnosis of pulmonary tuberculosis, and is at least as sensitive as sputum induction.

    View details for Web of Science ID 000226170700030

    View details for PubMedID 15639297

  • Understanding the threat of HIV/AIDS JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION Luo, R. F. 2002; 288 (13): 1649-1649

    View details for Web of Science ID 000178314000028

    View details for PubMedID 12350199

  • Rewriting the body: the origins of anatomical dissection in ancient Greece. The Pharos of Alpha Omega Alpha-Honor Medical Society. Alpha Omega Alpha Luo, R. F. 2002; 65 (4): 29-33

    View details for PubMedID 12592978

  • Genetic and neuroradiological heterogeneity of double cortex syndrome ANNALS OF NEUROLOGY Gleeson, J. G., Luo, R. F., Grant, P. E., Guerrini, R., Huttenlocher, P. R., Berg, M. J., Ricci, S., Cusmai, R., Wheless, J. W., Berkovic, S., Scheffer, I., Dobyns, W. B., Walsh, C. A. 2000; 47 (2): 265-269


    Mutations in the X-linked doublecortin gene appear in many sporadic cases of double cortex (DC; also known as subcortical band heterotopia), a neuronal migration disorder causing epilepsy and mental retardation. The purpose of this study was to examine why a significant percentage of sporadic DC patients had been found not to harbor doublecortin mutations and to determine whether clinical features or magnetic resonance imaging scan appearance could distinguish between patients with and without doublecortin mutations. Magnetic resonance imaging scan analysis differentiated patients into the following four groups: anterior biased/global DC with doublecortin mutation (16 of 30; 53%), anterior biased/global DC without mutation (8 of 30; 27%), posterior biased DC without mutation (3 of 30; 10%), and limited/unilateral DC without mutation (3 of 30; 10%). The presence of these atypical phenotypes suggests that other genetic loci or mosaicism at the doublecortin locus may be responsible for this diversity of DC cases.

    View details for Web of Science ID 000085120300022

    View details for PubMedID 10665503

  • Characterization of mutations in the gene doublecortin in patients with double cortex syndrome ANNALS OF NEUROLOGY Gleeson, J. G., Minnerath, S. R., Fox, J. W., Allen, K. M., Luo, R. F., Hong, S. E., Berg, M. J., Kuzniecky, R., Reitnauer, P. J., Borgatti, R., Mira, A. P., Guerrini, R., Holmes, G. L., Rooney, C. M., Berkovic, S., Scheffer, I., Cooper, E. C., Ricci, S., Cusmai, R., Crawford, T. O., Leroy, R., Andermann, E., Wheless, J. W., Dobyns, W. B., Ross, M. E., Walsh, C. A. 1999; 45 (2): 146-153


    Mutations in the X-linked gene doublecortin, which encodes a protein with no dear structural homologues, are found in pedigrees in which affected females show "double cortex" syndrome (DC; also known as subcortical band heterotopia or laminar heterotopia) and affected males show X-linked lissencephaly. Mutations in doublecortin also cause sporadic DC in females. To determine the incidence of doublecortin mutations in DC, we investigated a cohort of eight pedigrees and 47 sporadic patients with DC for mutations in the doublecortin open reading frame as assessed by single-stranded conformational polymorphism analysis. Mutations were identified in each of the eight DC pedigrees (100%), and in 18 of the 47 sporadic DC patients (38%). Identified mutations were of two types, protein truncation mutations and single amino acid substitution mutations. However, pedigrees with DC displayed almost exclusively single amino acid substitution mutations, suggesting that patients with these mutations may have less of a reproductive disadvantage versus those patients with protein truncation mutations. Single amino acid substitution mutations were tightly clustered in two regions of the open reading frame, suggesting that these two regions are critical for the function of the Doublecortin protein.

    View details for Web of Science ID 000078466100003

    View details for PubMedID 9989615

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