INVESTIGATION OF AN EPIDEMIC OF INVASIVE ASPERGILLOSIS - UTILITY OF MOLECULAR TYPING WITH THE USE OF RANDOM AMPLIFIED POLYMORPHIC DNA PROBES

When seven immunocompromised patients developed invasive aspergillosis during construction at a hospital, new methods were performed to comp are fungal isolates and a case-control study was conducted to determin e risks for infection. Typing of Aspergillus flavus with the use of re striction endonuclease analysis and restriction fragment length polymo rphism using random amplified polymorphic DNA reactions to generate DN A probes revealed different patterns between isolates from two patient s and a similar pattern among those from one patient, a health care wo rker, and an environmental source. Case patients were more likely than controls to have longer periods of hospitalization (median, 83 vs. 24 days; P < 0.01), neutropenia (median, 33 vs. 6 days; P < 0.05), and e xposure to broad spectrum antimicrobials (median, 56 vs. 15 days; P = 0.08). No patients restricted to protected areas developed aspergillos is. Risk of exposure of immunocompromised patients to opportunistic or ganisms stirred up by construction activity may be decreased by admitt ing these patients to protected areas away from construction activity and by restricting traffic from construction sites to these areas. Alt hough typing of A. flavus isolates did not reveal a single type or sou rce of organism responsible for infection, this method may facilitate epidemiologic investigation of possible nosocomial sources and transmi ssion in similar settings.