Aspergillus

Aspergillus is a group of molds that are ubiquitous in nature and common to water environments.They are also resistant to many water disinfection treatment methods.Failure of disinfection methods to eradicate waterborne Aspergillus can lead to dissemination of their spores.In water distribution systems, Aspergillus can quickly flourish at sites of biofilm development(1,2).Invasive aspergillosis is now considered to be the second most common fungal infection requiring hospitalization in the United States(3).In patients with positive fungal cultures, Aspergillus spp. are the second most common isolates after Candida sp.(3).Invasive aspergillosis has been associated with a 60% overall mortality rate, and a mortality rate of 80-90% among severely immunocompromised patients(4).

Aspergillus Facts:

  • In a three-year prospective study conducted by Anaissie et al. at a 350-bed teaching hospital, a total of 416 water samples were drawn from both municipal and hospital water sites.Aspergillus species were recovered from 33% of municipal water sites, 55% of hospital water sites, and 21% of patient care area faucet and shower sites(5).Data from the same study indicated that in patient rooms with properly functioning laminar airflow systems, the concentrations of airborne Aspergillus in the bathrooms adjoining patient rooms was six-fold higher than the concentrations in the rooms themselves.This finding suggested that Aspergillus-containing aerosols generated by the bathroom showers produced the elevated concentrations of airborne Aspergillus.
  • The 2003 Centers for Disease Control Guidelines for Infection Control in Health Care Facilities suggests minimizing the exposure of severely immunocompromised patients to activities that might result in their exposure to fungal spores(6).It stands to reason that point-of-use water sources such as faucets and showers should also be a matter of concern.

Aspergillus and Point-Of-Use Filtration:

  • Point-of-use 0.2 micron filters on faucets and showers can assist in managing patient exposure to waterborne pathogens such as Aspergillus sp.

Infections caused by Aspergillus spp. are associated with high rates of morbidity and mortality, especially in the following patient populations:

  • Allogeneic hematopoietic stem cell transplant recipients
  • Patients receiving chemotherapy for non-hematologicmalignancies.
  • Heart and lung transplant recipients
  • AIDS patients
  • Severe burn patients

参考:
1.Warnock, D.W. Preventing fungal infections:in hospital and beyond.In Infections in patients with hematologic malignancies:meeting the challenge.CME Program, http://www.medscape.com/.
2.Geldreich, E.E. 1996.Biological profiles in drinking water.In Microbial quality of water supply in distribution systems.p.103-158. CRC Lewis (Boca Raton, FL).
3.Sigler, L. and P.E. Verweij.2003.Aspergillus, Fusarium, and other opportunistic monilaceous fungi. p.1728-1733. In (ed.)Baron, E.J., J.H. Jorgensen, M.A. Pfaller, and R.H. Yolken.Manual of
Clinical Microbiology, 8th ed.ASM Press, Washington, D.C.
4.Patterson, T. 2003.Recent advances in the management of invasive aspergillosis.International symposium on antimicrobial agents and ressistance (Seoul, Korea).http://www.ansorp.org/.
5.Anaissie, E.J. and S.L. Stratton, C. Dignani, R.C. Summerbell, J.H. Rex, T.P. Monson, T. Spencer, M. Kasai, A. Francesconi, and T.J. Walsh.2002.Pathogenic Aspergillus species recovered from a hospital water system:a three-year prospective study.Clin.Infect.Dis. 34:780-789.
6.Schulster, L. and R.Y. W. Chin.2003.Guidelines for environmental infection of control in health-care facilities, recommendations of CDC and the healthcare infection control practices advisory committee.MMWR.52:1-44.


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