Program Schedule

457
Actinomyces Infection in Hematologic and Solid Cancer Patients at the University of Texas MD Anderson Cancer Center in 1998-2014

Session: Poster Abstract Session: Transplant Infectious Diseases
Thursday, October 9, 2014
Room: The Pennsylvania Convention Center: IDExpo Hall BC
Posters
  • Actino-IDSA.pdf (773.8 kB)
  • Background:

    Actinomyces species are common human commensal flora that become pathogenic only under certain conditions. Characteristics and treatment of actinomycosis in cancer patients have not been well described. A descriptive analysis of the disease in this population is presented herein.

     

    Methods:

    Actinomyces-positive cultures for any source were identified at The University of Texas MD Anderson Cancer Center microbiology laboratory from 1998 to 2014. A retrospective review of the patients' medical records was carried out, and case definitions were created to classify the infection as proven, probable, or possible based on clinical presentation, culture site, and pathologic findings. Patient characteristics were collected, including known risk factors for actinomycosis noted in the literature.

     

    Results:

    We identified a total of 156 cases of actinomycosis after excluding 582 contaminants. The patients' median age was 58 years. According to our definitions, 14 (9%) of the cases were proven, 60 (38%) were probable, and 82 (53%) were possible. Most of the patients (66%) had solid tumors, whereas 21% had hematologic malignancies and 12% had no cancer diagnosis. The presentations by anatomical site were the thorax (45%), abdomen-pelvis (29%), and face-neck (20%). Other patient characteristics are listed in Table 1. In terms of treatment, aminopenicillins were used most frequently (71%) followed by tetracyclines (37%). The mean duration of treatment was 6 weeks, and 74% of the cases responded to therapy.

     

    Variable

    Patients (%)

    History of local trauma or surgery (at the site of infection)

    52

    Lymphopenia (<1000 cells/mm3)

    40

    Radiation therapy

    34

    Steroid use (within 1 month)

    8

     

    Conclusion:

    Actinomycosis in cancer patients has a variety of presentations, with the thorax being the most common site of infection. Disruption of mucosal barriers is an important factor in the pathogenesis of the infection as evidenced by the high number of patients with a history of local trauma/surgery and radiation therapy. Penicillins continue to be the most used antibiotics, with a good success rate. Diagnosis is complicated by frequent colonization by Actinomyces spp., necessitating a high level of clinical suspicion for an early diagnosis.

    Andres Gutierrez, MD, Internal Medicine - Infectious Diseases, Baylor College of Medicine, Houston, TX, Ella Ariza-Heredia, MD, Infectious Diseases, Infection Control and Employee Health, University of Texas MD Anderson Cancer Center, Houston, TX, Jeffrey J. Tarrand, MD, Department of Laboratory Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, TX and Dimitrios Kontoyiannis, The University of Texas M.D. Anderson Cancer Center, Houston, TX

    Disclosures:

    A. Gutierrez, None

    E. Ariza-Heredia, None

    J. J. Tarrand, None

    D. Kontoyiannis, Pfizer, Astellas Pharma US, Gilead, and Merck & Co.,Inc: Research support, Research support

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