Toxoplasma gondii. J. Clin. Microbiol. 25:100-105.

8. Hughes, H. P. A. 1985. To×oplas- mosis: the need for improved diagnostic techniques and accurate risk assess- ment. Curt. Top. Microbiol. Immunol. 120:105- 139

9. Kean, B. H. 1972. Clinical toxoplas- mosis: 50 years. Trans. R. Soc. Trop Med. Hyg. 66:549-571.

10. Lindenschmidt, E. G. 1985. Enzyme- linked immunosorbent assay for detec- tion of soluble Toxoplasma gondii antigen in acute-phase toxoplasmosis. Eur. J. Clin. Microbiol. 4:488-492.

11. Lindenschmidt, E. G. 1986. Demon- stration of immunoglobulin M class an- tibodies to toxoplasma gondii antigenic component p35000 by enzyme-linked antigen immunosorbent assay. J. Clin. Microbiol. 24:1045-1049.

12. Mack, D. G., and R. McLeod. 1984. New micromethod to study the effect of antimicrobial agents on Toxoplasma gondii: comparison of sulfadoxine and sulfadiazine individually and in combi- nation with pyrimethamine and study of clindamycin, metronidazole, and cyclo- sporin A. Antimicrob. Agents Che- mother. 26:26-30.

13. McGregor, C. G. A. et al. 1984. Dis- seminated toxoplasmosis in cardiac transplantation. J. Clin. Pathol. 37:74- 77.

14. Mills, J. 1986. Pneumocystis carinii and toxoplasma gondii infections in pa- tients with AIDS. Rev. Infect. Dis. 8:1001- 1011.

15. Navia, B. A. et al. 1986. Cerebral toxoplasmosis complicating the ac- quired immune deficiency syndrome:

clinical and neurological findings in 27 patients. Ann. Neurol. 19:244-238.

16. Neu, H. C. 1967. Toxoplasma trans- mitted at autopsy. JAMA 202:844- 845.

17. Nistal, M. et al. 1986. Testicular toxo- plasmosis in two men with acquired immunodeficiency syndrome (AIDS). Arch. Pathol. Lab. Med. 110:744-746.

18. Piazza, E. et al. 1986. Intracerebral mass lesions in patients affected by AIDS. Acta Neurochir. (Wien) 83:116- 120.

19. Potasman, I. et al. 1986. Analysis of Toxoplasma gondii antigens recognized by human sera obtained before and after acute infection. J. Infect. Dis. 154:650-657.

20. Remington, J. S. 1974. Toxoplasmosis in the adult. Bull. NY Acad. Med. 50:211-227.

21. Remington, J. S., and G. Desmonts. 1983. Toxoplasmosis, pp. 143-263. In J. S. Remington and J. O. Klein (eds.), Infectious diseases of the fetus and newbom infants. W. B. Saunders, Philadelphia.

22. Remington, J. S., W. M. Eimstad, and F. G. Araujo. 1983. Detection of im- munoglobulin M antibodies with an- tigen-tagged latex particles in an immunosorbent assay. J. Clin. Micro- biol. 17:939-941.

23. Siegel, S. E. et al. 1971. Transmisson of toxoplasmosis by leukocyte transfu- sion. Blood 37:388-394.

24. Sklenar, I. et al. 1986. Association of symptomatic human infection with Toxoplasma gondii with imbalance of monocytes and antigen specific T-cell subsets. J. Infect. Dis. 153:315-324.

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29. Van Knapen, F., S. O. Panggabean, and J. Van Leusden. 1986. Evaluation of laboratory diagnosis of toxoplas- mosis by means of an ELISA-triple test. Antonie van Leewenhoek. 52:5-13.

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Infection Prevention in the Laboratory: Rationale and Implementation of a New Strategy

Patricia Lynch, R.N., B.S.N. M. Jeanne Cummings, R.N., B.S.N. Nancy Michalson, M.A. Epidemiology Department Harborview Medical Center Seattle, Washington 98104

Linda McDonald, R.N., M.S.P.H. Veterans Administration Medical Center Seattle, Washington 98104

Infection prevention practices to pro- tect health care workers (HCW) from acquiring nosocomial infections are

firmly established in most hospitals. In laboratories, the practices usually in- volve routine handling and processing of most patient specimens and special handling of specimens from isolation patients. This traditional two-tiered approach, one system for isolation pa- tients and another system for all other patients, needs examination for risk to laboratory personnel from previously unseen and unknown infectious agents, e.g., human immunodeficiency virus (HIV).

Infection Risk to Laboratory Personnel

In 1982, Dienstag and Ryan (2) pub- lished a study of HCW hepatitis B virus (HBV) profiles by occupational cate-

gory; the study showed that laboratory workers had hepatitis B markers in theii serum about five times more frequently than control populations and ward nursing personnel. Frequency of hepa- titis B markers increased as a function of contact with blood but not contact with patients. Presumably, routine practices of laboratory workers and other high risk employees were not sufficient to protect them and/or they were not notified to use special precau- tions often enough. The fact that labo- ratory personnel were more likely to acquire HBV infection implies that they are also at greater risk of contracting other diseases transmitted by blood such as acquired immunodeficiency syndrome (AIDS).

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Several researchers have studied the mechanisms of transmission of infec- tious agents in the clinical laboratory setting. In 1976, Pike reviewed 3921 cases of laboratory-associated infections (5). Of these, 703 (18%) were be- lieved to be the result of recognized accidents. In 21% it was known that the victim worked with the infective agent. For the balance of the infec- tions, the individual was unaware of working with the agent and no accident was recognized. Of those infections from recognized accidents, 27% re- suited from contact with infectious ma- terial in aerosol-associated events such as spatters or sprays. In that same series aerosols were presumed to be the source of 522 (13%) other infections.

The role of contamination from un- detected aerosols generated during lab- oratory procedures was described by Stern (7). In terms of number of or- ganisms, surface contamination from these inapparent aerosols was greater than direct inoculation of the respira- tory mucosa. Exposure to the or- ganisms on surfaces could be transferred to the mouth or nose by di- rect contact contamination or inoculated through cuts/abrasions.

Infection Precautions Based on Diagnosis

Many of the practices used for "iso- lation patients" were derived from nursing procedures, some of which were developed 25 to 50 years ago, and have never received scientific valida- tion (3). Most such practices are based on the theory that infected patients are recognized clinically and therefore these special procedures will protect the HCW from acquiring infection. Such infection prevention practices are "diagnosis driven," meaning that the diagnosis of the disease is the trigger that initiates a special practice. The underlying implication is that routine HCW practices are not sufficient to present disease transmission.

Infection prevention practices that depend on a diagnosis are successful when the diagnosis is established early and there is a high degree of certainty about that diagnosis. Obviously, most infections must be diagnosable for this to be effective. However, unidentified

cases of diseases always exist and con- stitute a major source for the spread of many infectious diseases. The propor- tion of identified to unidentified cases varies from disease to disease. For ex- ample, approximately 90% of measles cases are clinically apparent, whereas only about one-third of HBV cases are symptomatic; the proportion of recog- nized cases is even less for HIV, cyto- megalovirus (CMV), or herpes simplex virus (HSV) seropositive patients.

Infection Precautions Based on Interactions

Laboratory personnel are at high risk for acquiring infections because of their frequent contact with blood and other body substances. If precautions are initiated only after disease diag- nosis, laboratory workers will be ex- posed to substances from a large number of patients with infections, in- cluding asymptomatic individuals, and those in the prodromal phase of illness.

Feces, airway secretions, drainage from open wounds, nonintact skin, and mucous membranes are always colon- ized with large numbers of organisms. Urine from catheterized patients is likely to become colonized rapidly. Most individuals with bloodborne viral agents such as HIV or HBV do not manifest symptoms of infection. Knowledge of which patient has what infectious agent at any given time is, at best, uncertain.

For these reasons, a change in infec- tion control strategy is recommended: the same handling practices should be used for all specimens (4). Effective precautions for patients and patient specimens need to be "interaction driven," instead of "diagnosis driven." At Harborview Medical Center and Seattle Veterans Adminis- tration Medical Center, we term this system Body Substance Isolation (BSI). The elements of BSI are as follows: 1) gloves for anticipated con- tact with body substances; 2) hand- washing for intact skin contacts and for accidental body substance exposure; 3) gowns, caps, bootees for anticipated soilage of clothing, hair or shoes; 4) masks, eyewear for procedures with likelihood of splash/splatter to the face; 5) private rooms for patients with air-

borne communicable disease; and 6) all sharp needles and sharp instruments are disposed of in puncture-resistant plastic containers.

To implement this strategy, laborato- ries and patient care areas discontinued the approach of using special precau- tions only for specimens from isolated patients. Instead, all body substances must be handled with the same standard of care and a high level of suspicion for infection potential. This strategy is also used at several other hospitals in- cluding the University of California, San Diego and the San Francisco Gen- eral.

Implementing Body Substance Isolation in the Laboratory at Seattle VA Medical Center

After achieving a basic understanding and acceptance of the BSI concept, representatives from laboratory admin- istration and bench personnel met to evaluate the prechange needs. Imple- menting any new strategy or change in practice requires several integral com- ponents. These components are proce- dural, educational, equipment-related, and evaluative. The success of any major change depends on the active support of management.

The identified determinants of hazards associated with laboratory ma- nipulation of pathogens are: number and severity of laboratory infections; modifiers of human susceptibility and resistance (vaccines, therapy, antibody, immunosuppression, sex, race, others); human infectious dose; infection from equipment (generated aerosols); agent excretion in urine, feces, saliva, or other fluids and tissues.

Matching these determinants to the patient populations served by the labo- ratory, the medical histories of the staff (HBV antibody prevalence and immu- nization status), the spectrum of dis- eases identified within the laboratory, and the sophistication of the procedures and equipment used, it was decided to standardize procedures to a Biosafety Level 2 for all areas. 6 This lead would cover most of the blood and body fluid transmissable agents and would prevent transmission of diseases for which lab- oratory workers are historically at risk. We also discontinued "Biohazard" la-

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beling for specimens from patients who were known to have infections such as hepatitis B or AIDS.

Education Two separate training programs on

basic BSI were provided to the existing laboratory staff before implementation. The education was aimed at identifying the weaknesses of the previous diag- nosis driven system and the strengths of the proposed interaction driven precau- tions in terms of personnel protection. The objective was to reinforce the con- cept that the individual HCW is re- sponsible for initiating precautions appropriate to the procedure as well as insuring that available prevention mea- sures, such as immunization, are used.

Some laboratory staff expressed anx- iety and anger at the prospect of re- ceiving unlabeled specimens when the patient was known to be infected, even though they recognized the weakness of diagnosis-dependent precautions. The changes in the laboratories were ac- complished gradually.

Orientation of new personnel, resi- dents, and students was another critical consideration, particularly when these new procedures conflicted with pre- vious practices. Orientation for all new personnel included the following infor- mation: review and documentation of understanding of the BSI concept; re- view of the laboratory safety manual; review of the specific bench procedure manual; and verbal review with the section/bench supervisor.

Procedures Manuals that describe the laboratory

policies and procedures required revi- sion to comply with the BSI concept. These included the laboratory safety manual, the bench procedure manuals, the infection control guidelines for the laboratory and related areas, and the laboratory orientation manual.

All procedure manuals were revised to remove references to labeling or special techniques such as cleaning based on specific diseases. The manuals were edited to reflect a base- line of Biosafety Level 2.

In an effort to maximize the protec- tion provided and to minimize the im- pact of precautions on work flow, each

specific bench and laboratory area was studied to determine its specific high risk functions in relation to contact with whole blood, serum, or tissue. Cate- gories of risk of exposure were strati- fied as: high risk (gloves required); moderate risk (gloves advised; hand- washing required); low risk (gloves not required; handwashing advised).

Examples of procedures performed at these levels in terms of work flow are: handling and processing fresh tissue (high); processing parafin imbedded tissue (moderate); logging results (low). Thus, in the same functional area, several levels of risk are encoun- tered by bench personnel.

To assist in identifying the physical areas where the functions performed are deemed high or moderate risk, a system was devised to color code and visibly identify the precautions expected ("Gloves Required" versus "Gloves Advised") for individuals working within those boundaries. In addition, automated devices and related equip- ment were labeled with the expected precaution.

Equipment The laboratory representatives re-

viewed the existing equipment and de- scribed the following additions or modifications that would be required before implementing the program:

1. A disposable glove dispenser placed at each bench location determined to be most accessible by the users.

2. Standardized and easily accessible location for goggles, masks, and aprons. Note: After review of avail- able literature, only the centrifuge and the cryostat were identified as aerosol generators.

3. Approved impervious disposal con- tainers for sharps at each bench.

4. Biohazard reminder signs placed at each bench and area as a reminder/ reinforcer of the BSI concept.

5. Standardized chemical disinfectant (chlorine based) for both routine cleaning and accidental spills for all bench areas.

6. Standardized cleaning routine and schedules for all equipment, e.g., cryostat and pathology equipment;

eliminating special cleaning for "known" cases.

7. Modi fy ing t e l ecommunica t ions equipment, allowing for smoother work flow while gloved (speaker phones to replace hand-held re- ceivers for STAT calls, etc.).

8. Identifying computers and equip- ment used while gloved as "bio- hazard" to alert repair personnel. Computer keyboards are covered with a plastic "skin."

9. Addit ional biosafety hoods for working with specimens during aerosol-generating procedures.

It should be noted that these recom- mendations exceed those of Biosafety Level 2.

Federal, state, and professional orga- nization recommendations and regula- tions were reviewed for any specific prohibitions to the proposed changes, including College of American Pathol- ogists, Centers for Disease Control, Joint Commission on the Accredition of Hospitals, and the Veterans Adminis- tration Central Office, Infectious Dis- eases Advisory Committee Chair- person.

Evaluation To know that change has actually

occurred, the indicators or the evalua- tion tools must be identified before the change is implemented, and they must be used to evaluate program effective- ness at meaningful frequencies. Visual monitoring of glove use by bench per- sonnel was suggested as a simple method of monitoring compliance. If glove usage fell below a predetermined acceptable level, supervisory level managers would act. At this point, laboratory management was crucial to making the change successful. Because responsibility for implementing the change in knowledge and behavior rests ultimately with the users, identification of obstacles and problem solving must include these "front line" participants. Change in practice involves a signifi- cant emotional element.

Conclusion The Amercian Hospital Association

(1) has recently recommended that all health care facilities implement uni-

170 0196-4399/87/$0.00 + 02.20 (~3, 1987 Elsevier Science Publishing Co., Inc. Clinical Microbiology Newsletter 9:21,1987

versal infection precautions. They fur- ther suggested that hospitals may wish to discontinue labeling "infectious" specimens as we have done. We offer our rationale and experience as a model for others who wish to implement a similar strategy.

References 1. American Hospital Association. 1987.

Statement of the Advisory Committee on Infections Within Hospitals on Pro- tection of Health Care Workers. Amer Hosp Assn, Chicago, IL

2. Dienstag, J. L., and K. M. Ryan. 1982. Occupational exposure to hepa- titis B virus in hospital personnel: in- fection or immunization. Am. J. Edpidemiol. 115:26-39.

3. Jackson, M. M., and P. Lynch. 1985. Isolation practices: a historical perspec- tive. Am. J Infect Control 13:21-31.

4. Lynch, P. et al. Rethinking the role of isolation practices in preventing noso- comial infections. Ann. Intern. Med. (in press).

5. Pike, R. M. 1976. Laboratory asso- ciated infections: summary and analysis of 3921 cases. Health Lab Sci 13:105- 114.

6. Richardson, J. H., and Barkley, W. E. (eds.). 1984. Biosafety in microbiolog- ical and biomedical laboratories, U.S. Department of Health and Human Ser- vices, Public Health Service, Wash- ington. D.C.

7. Stem, E. L. et al. 1974. Aerosol pro- duction associated with clinical labora- tory procedures. Am. J. Clin. Pathol. 62:591-600.

Editor 's Note: Recently the National Committee for Clinical Laboratory Standard (NCCLS) established as task force to draft guidelines for the protec- tion of laboratory workers from infec-

tious diseases transmitted by blood and tissue. Their recommendations are similar in approach to the above article and recent CDC recommendations I in that primary responsibility for protec- tion is placed on the individual labora- tory worker, all samples received in the laboratory are to be considered poten- tially infectious, and "universal pre- cautions" should be followed to prevent skin and mucous membrane contact with blood and body fluids from all patients. NCCLS plans for a rapid publication and dissemination of these guidelines (M-29P).

References 1. CDC. 1987. Recommendations for

prevention of HIV transmission in health care setting. MMWR 36(Suppl): 1 S- 18S.

Case Report

Cedecea lapagei Isolated from Lung Tissue

Philip E. Coudron, Ph.D. Sheldon M. Markowitz, M.D. McGuire Veterans Administration Medical

Center and Medical College of Virginia Richmond, Virginia 23249

A 60-year-old male presented to the McGuire VA Medical Center in De- cember of 1984 for evaluation. The patient, a heavy smoker, had pulmo- nary tuberculosis in 1973 at which time he received an 18-month regimen of isoniazid and ethambutol. He had per- sistent left upper lobe cavitary disease with recurrent hemoptysis and eventu- ally underwent a left upper lobectomy. Severe hemoptysis, often estimated to be greater than 200 mL per day, re- curred intermittently until the time of admission. An admission chest x-ray showed a 5 × 6 cm filled cavity in the left lower lung and a soft tissue mass in the dependent portion of the cavity, consistent with a fungus ball. A dense zone of consolidation surrounded the

cavity. Fiberoptic bronchoscopy re- vealed a narrow and distorted left lower lobe bronchus with blood emanating from the orifice. A bronchial washing, three sputa, and a urine sample col- lected within the first 3 days after ad- mission, were smear and culture negative for mycobacteria. Three sputum samples collected on separate days were negative for fungus. A bronchial washing yielded Torulopsis glabrata and Candida albicans and was negative for tumor cells. Four days after admission, the patient developed a low-grade fever of 101°F and under- went a thoracotomy and a left pneumo- nectomy. Histologic examination of lung sections revealed fibrosis, nu- merous foamy macrophages, two gran- ulomas and an inflammatory infiltrate of eosinophils, lymphocytes, and plasma cells. Sections stained for fungi and acid fast bacteria were negative. Lung tissue was also sent for routine culture.

Because a concomitant bacterial pneumonia could not be entirely ex- cluded on clinical grounds, the patient was given parenteral cephradine peri- operatively and, for 7 days, postopera- tively. The patient had an uneventful

postoperative course and was dis- charged on no medication. He has re- mained asymptomatic for the last 2 years.

A nonlactose fermenting gram- negative bacillus was isolated in pure culture on blood and MacConkey agar from two lung tissue specimens. The same organism was also recovered with normal respiratory flora from a bron- chial washing and two sputum samples. The organism was identified as Cedecea lapagei by the API 20E (Analytab Products, Inc., Plainview, NY) and MicroScan (American Micro- Scan, Mahwah, NJ) systems with the profile numbers 3204001 and 40000264, respectively. The Vitek system (Vitek Systems, Hazelwood, MO) was unable to identify the or- ganism.

Biochemical studies were also per- formed using conventional methods (2). Our results were identical to pre- vious descriptions of this organism (4) with the exception of a negative Voges-Proskauer result; most strains (80%) of C. lapagei are positive. Our isolate showed weak pink color devel- opment only after the recommended 5 to 10 min waiting period following ad-

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