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Extent of tuberculosis contact investigation
Letters
75
to the Editor
References 1. Barrie D. How hospital linen and laundry services are provided. J Hasp Infect 1994; 27: 219-235. 2. Barrie D, Hoffman PN, Wilson JA, Kramer JM. Contamination of hospital linen by Bacillus cereus. Epidemiol Infect 1994; 113: 297-306.
Sir, Extent
of tuberculosis
contact
investigation
Because of the increase in tuberculosis among hospitalized patients there has been renewed emphasis on the importance of infection control precautions in preventing the spread of Mycobacterium tuberculosis (TB). Protocols exist for managing exposure to TB, but guidelines for the investigation of contacts are unhelpful when exposure is not well-defined.’ We report a skin test conversion in a patient exposed to another patient who had not been isolated because of negative chest X-rays and negative sputum microscopy, but who subsequently yielded TB from bronchial washings. Patient A is a 3 1 -year-old Hispanic male who presented to the Emergency Department with fever (40”(Z), a one month history of weakness, myalgia, cough, and a five day history of diarrhoea. On admission, he was placed in respiratory isolation; his PPD skin test was negative, but an anergy panel was not done. There was a past history of hepatitis B infection, and a previous positive Mantoux (PPD) skin test. An HIV test was positive, with a CD, count of 10. Chest X-rays were repeatedly negative, and after three sputum smears and bronchial washings were negative for acid-fast bacilli (AFB), respiratory isolation was discontinued. One of two stool specimens was AFB positive. The patient used the patient lounge between 17-25 February 1993. On 3 April 1993, the infection control team was notified that mycobacteria were growing from sputum, bronchial washings and stool, and respiratory isolation was reinstituted. The patient was started on five anti-TB drugs. Contact investigation revealed that 232 hospital employees and 38 patients had had exposure to patient A. One patient (patient B) and three hospital employees developed positive skin test (one nursing assistant, one radiology technician, one dietary aide). Patient A and patient B (who had just been admitted to the unit) shared air space in a patient lounge for only 1 h. Patient B had a PPD skin test on 25 February 1993 unrelated to any exposure: it was negative. His post-exposure PPD test was negative on 18 March (no booster effect noted). A PPD test done on 24 May (10 weeks post-exposure) was positive, but there were no changes seen on chest Xray. The dietary aide had no direct contact with the index case but only transported food trucks to and from the unit.
Letters to the Editor
76
The importance of thorough post-exposure follow-up is emphasized by the patient-to-patient conversion rate of 2.6% (one out of 38). The patient/ employee conversion rate was l-5%, while the overall infection rate for this exposure was 1.7%. These numbers are based on the Center for Disease Controls Tuberculosis Risk Assessment Guidelines.’ This case illustrates the value of maintaining respiratory isolation in AIDS patients until culture results are known. Even though sputa and repeated chest X-rays were negative, patient A had a high risk of disseminating TB since he had AIDS, and AFB were demonstrated in the faeces. This also emphasizes the importance of extended contact investigation. Should the contact investigations be limited to room exposure, floor exposure, or vicinity airborne exposure? Because patient A had negative chest X-rays and sputum microscopy, we were chided by some for insisting that complete vicinity airborne exposure be included in the contact investigation. However, this case demonstrates that even when the inoculum appears minimal, contact investigation for TB should include those exposed to room, floor and vicinity airspace.
Infection Control Section Winthrop- University Hospital, Mineola, NY 11501, USA
E. Jacobsen I. Gurevich B. A. Cunha
References Guidelines for preventing transmission of tuberculosis in 1. Centers for Disease Control. health care setting with special focus on HIV-related issues. MMWR 1990; 39 (RR-l 7): l-29. and Prevention. Draft guidelines for preventing the trans2. Centers for Disease Control mission of tuberculosis in health care facilities. Fed Reg 1993; 58: 5281&52854.
Sir, Identification
of MRSA incidents
in hospitals
Staphylococcus In recent years several epidemic methicillin-resistant (EMRSA) have emerged in many hospitals in the UK.‘p2 The Laboratory of Hospital Infection (LHI) identifies MRSA and offers advice to affected hospitals; indeed this process is an integral part of the revised guidelines for MRSA control.3 Tracing affected patients when outbreaks occur is becoming more difficult due to an increasing trend to transfer patients between several wards.4 A recent incident illustrates several additional
75
to the Editor
References 1. Barrie D. How hospital linen and laundry services are provided. J Hasp Infect 1994; 27: 219-235. 2. Barrie D, Hoffman PN, Wilson JA, Kramer JM. Contamination of hospital linen by Bacillus cereus. Epidemiol Infect 1994; 113: 297-306.
Sir, Extent
of tuberculosis
contact
investigation
Because of the increase in tuberculosis among hospitalized patients there has been renewed emphasis on the importance of infection control precautions in preventing the spread of Mycobacterium tuberculosis (TB). Protocols exist for managing exposure to TB, but guidelines for the investigation of contacts are unhelpful when exposure is not well-defined.’ We report a skin test conversion in a patient exposed to another patient who had not been isolated because of negative chest X-rays and negative sputum microscopy, but who subsequently yielded TB from bronchial washings. Patient A is a 3 1 -year-old Hispanic male who presented to the Emergency Department with fever (40”(Z), a one month history of weakness, myalgia, cough, and a five day history of diarrhoea. On admission, he was placed in respiratory isolation; his PPD skin test was negative, but an anergy panel was not done. There was a past history of hepatitis B infection, and a previous positive Mantoux (PPD) skin test. An HIV test was positive, with a CD, count of 10. Chest X-rays were repeatedly negative, and after three sputum smears and bronchial washings were negative for acid-fast bacilli (AFB), respiratory isolation was discontinued. One of two stool specimens was AFB positive. The patient used the patient lounge between 17-25 February 1993. On 3 April 1993, the infection control team was notified that mycobacteria were growing from sputum, bronchial washings and stool, and respiratory isolation was reinstituted. The patient was started on five anti-TB drugs. Contact investigation revealed that 232 hospital employees and 38 patients had had exposure to patient A. One patient (patient B) and three hospital employees developed positive skin test (one nursing assistant, one radiology technician, one dietary aide). Patient A and patient B (who had just been admitted to the unit) shared air space in a patient lounge for only 1 h. Patient B had a PPD skin test on 25 February 1993 unrelated to any exposure: it was negative. His post-exposure PPD test was negative on 18 March (no booster effect noted). A PPD test done on 24 May (10 weeks post-exposure) was positive, but there were no changes seen on chest Xray. The dietary aide had no direct contact with the index case but only transported food trucks to and from the unit.
Letters to the Editor
76
The importance of thorough post-exposure follow-up is emphasized by the patient-to-patient conversion rate of 2.6% (one out of 38). The patient/ employee conversion rate was l-5%, while the overall infection rate for this exposure was 1.7%. These numbers are based on the Center for Disease Controls Tuberculosis Risk Assessment Guidelines.’ This case illustrates the value of maintaining respiratory isolation in AIDS patients until culture results are known. Even though sputa and repeated chest X-rays were negative, patient A had a high risk of disseminating TB since he had AIDS, and AFB were demonstrated in the faeces. This also emphasizes the importance of extended contact investigation. Should the contact investigations be limited to room exposure, floor exposure, or vicinity airborne exposure? Because patient A had negative chest X-rays and sputum microscopy, we were chided by some for insisting that complete vicinity airborne exposure be included in the contact investigation. However, this case demonstrates that even when the inoculum appears minimal, contact investigation for TB should include those exposed to room, floor and vicinity airspace.
Infection Control Section Winthrop- University Hospital, Mineola, NY 11501, USA
E. Jacobsen I. Gurevich B. A. Cunha
References Guidelines for preventing transmission of tuberculosis in 1. Centers for Disease Control. health care setting with special focus on HIV-related issues. MMWR 1990; 39 (RR-l 7): l-29. and Prevention. Draft guidelines for preventing the trans2. Centers for Disease Control mission of tuberculosis in health care facilities. Fed Reg 1993; 58: 5281&52854.
Sir, Identification
of MRSA incidents
in hospitals
Staphylococcus In recent years several epidemic methicillin-resistant (EMRSA) have emerged in many hospitals in the UK.‘p2 The Laboratory of Hospital Infection (LHI) identifies MRSA and offers advice to affected hospitals; indeed this process is an integral part of the revised guidelines for MRSA control.3 Tracing affected patients when outbreaks occur is becoming more difficult due to an increasing trend to transfer patients between several wards.4 A recent incident illustrates several additional