title: Cytomegalovirus retinitis and viral resistance. Prevalence of resistance at diagnosis, 1994. Cytomegalovirus Retinitis and Viral Resistance Study Group.
abstract: OBJECTIVE
  To determine the prevalence of cytomegalovirus (CMV) isolates resistant to ganciclovir sodium or foscarnet sodium at the time of diagnosis of CMV retinitis, prior to the initiation of therapy.
  
  
  METHODS
  Prospective epidemiologic study.
  
  
  METHODS
  An acquired immunodeficiency syndrome ophthalmology clinic.
  
  
  METHODS
  Patients with acquired immunodeficiency syndrome and newly diagnosed CMV retinitis.
  
  
  METHODS
  Culturing blood and urine samples for CMV and testing of all positive isolates for sensitivity to ganciclovir and foscarnet.
  
  
  METHODS
  Prevalence of the following: blood culture isolates resistant to ganciclovir (inhibitory concentration 50% [IC50] > 5.5 mumol/L) or foscarnet (IC50 > 400 mumol/L) and urine culture isolates resistant to ganciclovir or foscarnet.
  
  
  RESULTS
  Forty-nine patients were enrolled during a 13-month period. Forty-four patients had blood culture samples that could be evaluated; of these, 66% were positive (59% of patients). Thirty-four patients had urine cultures that were evaluable; of these, 82% were positive (57% of patients). Overall, 78% of patients had either a urine or blood culture sample positive for CMV. No blood culture isolates were resistant to ganciclovir, and only 1 urine culture isolate (2% of patients) was resistant to ganciclovir. Three percent of blood culture isolates and 4% of urine culture isolates (2% and 2% of patients, respectively) were resistant to foscarnet. Overall, 4% of patients had either a blood or urine culture isolate resistant to foscarnet.
  
  
  CONCLUSIONS
  Resistance to ganciclovir or foscarnet at the time of diagnosis of CMV retinitis is uncommon.
authors.affiliation: Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Md., USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Jabs
authors.forename: J P
authors.initials: JP
authors.lastname: Dunn
authors.forename: C
authors.initials: C
authors.lastname: Enger
authors.forename: M
authors.initials: M
authors.lastname: Forman
authors.forename: N
authors.initials: N
authors.lastname: Bressler
authors.forename: P
authors.initials: P
authors.lastname: Charache
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology*; D000328:Adult; D000998:Antiviral Agents / Q000494:pharmacology*; D015142:Baltimore / Q000453:epidemiology; D003587:Cytomegalovirus / Q000187:drug effects* / Q000302:isolation & purification; D017726:Cytomegalovirus Retinitis / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology*; D004352:Drug Resistance, Microbial; D005260:Female; D017245:Foscarnet / Q000494:pharmacology*; D015774:Ganciclovir / Q000494:pharmacology*; D006801:Humans; D015994:Incidence; D008297:Male; D008826:Microbial Sensitivity Tests; D015995:Prevalence; D011446:Prospective Studies; D016036:Seroepidemiologic Studies; D014556:Urine / Q000821:virology; D014766:Viremia / Q000821:virology
chemical_list: D000998:Antiviral Agents; D017245:Foscarnet; D015774:Ganciclovir