Correspondence

Cryptosporidiosis

N Engl J Med 2002; 347:1287October 17, 2002

Article

To the Editor:

We wish to elaborate on the risks and prevention of nosocomial cryptosporidiosis, briefly discussed in the review of cryptosporidiosis by Chen and colleagues (May 30 issue).1 Multiple nosocomial outbreaks of cryptosporidiosis have resulted from direct and indirect person-to-person transmission; one outbreak was due to spread of the parasite from an ice chest contaminated by a patient.2 Cryptosporidiosis in adults should be managed with the use of standard precautions; in incontinent or diapered children less than six years of age, it should be managed with contact precautions. This recommendation of the Centers for Disease Control and Prevention was recently validated in a retrospective cohort study of 37 hospitalized patients that failed to identify roommate-to-roommate transmission of cryptosporidia.3

Cryptosporidium parvum has been shown to be resistant to the germicides used for disinfection, including quaternary ammonium compounds, phenolic compounds, 70 percent ethyl alcohol, and 2.4 percent glutaraldehyde.4 The absence of outbreaks due to use of gastrointestinal endoscopes probably results from physical removal of the organisms by cleaning and rapid inactivation of C. parvum by drying.4 Proper cleaning before disinfection is therefore crucial to the prevention of cross-transmission by gastrointestinal endoscopes, since cleaning removes approximately 10,000 organisms.

C. parvum is relatively resistant to chlorine at the levels used in potable water. For this reason, it has been recommended that patients who are infected with the human immunodeficiency virus5 and those who have received hematopoietic stem-cell transplants6 minimize their risk of acquiring cryptosporidiosis from water by drinking either filtered water or water that has been boiled for at least one minute. It may be prudent for hospitals to provide all immunocompromised persons with sterile water and sterile ice.

David J. Weber, M.D., M.P.H.
University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7030
dweber@unch.unc.edu

William A. Rutala, M.P.H., Ph.D.
University of North Carolina School of Public Health, Chapel Hill, NC 27599

6 References

1. 1

   Chen X-M, Keithly JS, Paya CV, LaRusso NF. Cryptosporidiosis. N Engl J Med 2002;346:1723-1731
   Full Text | Web of Science | Medline

2. 2

   Weber DJ, Rutala WA. The emerging nosocomial pathogens Cryptosporidium, Escherichia coli O157:H7, Helicobacter pylori, and hepatitis C: epidemiology, environmental survival, efficacy of disinfection, and control measures. Infect Control Hosp Epidemiol 2001;22:306-315
   CrossRef | Web of Science | Medline

3. 3

   Bruce BB, Blass MA, Blumberg HM, Lennox JL, del Rio C, Horsburgh CR Jr. Risk of Cryptosporidium parvum transmission between hospital roommates. Clin Infect Dis 2000;31:947-950
   CrossRef | Web of Science | Medline

4. 4

   Barbee SL, Weber DJ, Sobsey MC, Rutala WA. Inactivation of Cryptosporidium parvum oocyst infectivity by disinfection and sterilization processes. Gastrointest Endosc 1999;49:605-611
   CrossRef | Web of Science | Medline

5. 5

   1999 USPHS/IDSA guidelines for the prevention of opportunistic infections in persons infected with human immunodeficiency virus. MMWR Morb Mortal Wkly Rep 1999;48:1-59, 61
   Medline

6. 6

   Guidelines for preventing opportunistic infections among hematopoietic stem cell transplant recipients: recommendations of the CDC, the Infectious Diseases Society of America, and the American Society of Blood and Marrow Transplantation. MMWR Morb Mortal Wkly Rep 2000;49:1-125
   Medline