title: Invasive and Complicated Pneumococcal Infection in Patients with Cancer.
abstract: BACKGROUND
  In susceptible patients, Streptococcus pneumoniae can cause complicated pneumonia and invasive pneumococcal disease. The aim of this study was to assess the clinical and antimicrobial features of complicated and invasive pneumococcal disease in patients with cancer.
  
  
  METHODS
  We conducted a retrospective study including all S. pneumoniae isolates between January 1, 2007 and December 31, 2015 in an oncology center. Capsular serotyping was done in isolates from sterile sites.
  
  
  RESULTS
  There were 103 episodes: 69 with invasive pneumococcal disease and 34 with complicated pneumonia. Sixty-two patients were male (60%); mean age was 50 years. Eighty-four isolates were susceptible to penicillin (81.6%), 11 (10%) were intermediate, and eight (8.3%) were resistant. Serotyping was performed in 64 isolates; the main serotypes identified were 3 (n = 13) and 19A (n = 11). No patient had a record of vaccination. Mortality at seven days attributed to pneumococcal infection was different in invasive pneumococcal disease (n = 18, 28.6%) vs. pneumonia (n = 3, 8.9%; p = 0.04). Thirty-day mortality related with the infectious process was statistically different between both groups: 21 patients with invasive pneumococcal disease (30.4%) and six with pneumonia (17.6%; p = 0.04). By logistic analysis, the risk factor associated with mortality was not having received appropriate antimicrobial treatment in the first 48 hours.
  
  
  CONCLUSIONS
  S. pneumoniae is a pathogen related with high mortality in patients with cancer. Pneumococcal immunization needs to be reinforced in this population.
authors.affiliation: Microbiology Laboratory Instituto Nacional de Cancerología (INCan), Mexico City, Mexico.
authors.forename: Sugehily
authors.initials: S
authors.lastname: Zarco-Márquez
authors.affiliation: Department of Infectious Diseases, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico.
authors.forename: Patricia
authors.initials: P
authors.lastname: Volkow-Fernández
authors.affiliation: Microbiology Laboratory Instituto Nacional de Cancerología (INCan), Mexico City, Mexico.
authors.forename: Consuelo
authors.initials: C
authors.lastname: Velázquez-Acosta
authors.affiliation: Infectious Diseases Research Center, Instituto Nacional de Salud Pública (INSP), Cuernavaca, Morelos, Mexico.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Echániz-Avilés
authors.affiliation: Infectious Diseases Research Center, Instituto Nacional de Salud Pública (INSP), Cuernavaca, Morelos, Mexico.
authors.forename: María Noemí
authors.initials: MN
authors.lastname: Carnalla-Barajas
authors.affiliation: Infectious Diseases Research Center, Instituto Nacional de Salud Pública (INSP), Cuernavaca, Morelos, Mexico.
authors.forename: Araceli
authors.initials: A
authors.lastname: Soto-Noguerón
authors.affiliation: Department of Infectious Diseases, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico.
authors.forename: Patricia
authors.initials: P
authors.lastname: Cornejo-Juárez
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications*; D010403:Penicillin Resistance; D010406:Penicillins / Q000494:pharmacology; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000209:etiology / Q000382:microbiology; D011018:Pneumonia, Pneumococcal / Q000453:epidemiology / Q000209:etiology / Q000382:microbiology; D012189:Retrospective Studies; D012307:Risk Factors; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents; D010406:Penicillins