TB skin test convertors, especially clusters of 2 or more, are important events for health care facilities because they indicate there may be an unidentified infectious TB case in the facility and therefore warrant investigation. Please see the below definitions for TB skin test convertor, TB skin test convertor cluster, TB symptom assessment and TB source case. Listed below are the South Dakota TB Control Program recommendations for investigation of TB skin test convertors identified in health care, long-term care and correctional facilities as well as recommendations for their household members. Department of Health staff will confirm all reports of TB skin test convertors prior to conducting an investigation by obtaining the patient’s TB skin test history to include the date and reaction of the positive TB skin test, the date and reaction of the last negative TB skin test, the date and reaction of each step of the patient’s 2-step TB skin test and the date of entrance into the facility.
DEFINITIONS TB skin test convertor: An increase of 10 mm or more of induration on a TB skin test in a 2-year time period. Patients who are negative on the 1st step of the 2-step TB skin test are not considered convertors. TB skin test convertor cluster: A TB skin test convertor cluster is defined as either of the following: a) Two or more TB skin test convertors in the same facility within a 6-month time period OR b) Two or more convertors who can be epidemiologically linked with-in a 6- month time period. TB symptom assessment: A medical assessment (usually completed by nursing staff in a facility) in which the patient is assessed for the following symptoms: 1) productive cough of 3 or more weeks duration, 2) unexplained night sweats, 3) unexplained fever and 4) unexplained weight loss. Patients identified with any of these symptoms should be referred for additional medication evaluation to rule out or confirm TB disease. TB source case: A person with infectious TB disease who is responsible for transmitting M. tuberculosis to others but who is probably not diagnosed and therefore does not know they have TB. |
1. Investigation of household members if TB skin test convertor
Disease Intervention Specialists (DIS) staff (located in field offices around the state) will conduct a TB symptom assessment and recommend TB skin testing to all household members who have resided with a TB skin test convertor for 7 or more days in the last 6 months since the conversion. If any household members are identified to have a positive TB skin test and/or symptoms compatible with TB, they will be referred for further medical evaluation to confirm or rule out active TB.
2. Investigation of isolated TB skin test convertors at facilities
Individual reports of TB skin test convertors who reside or work in a health care, long-term care or correctional facility are the responsibility of the facility to investigate. DIS staff will only investigate TB skin test convertor clusters (see #3 below). Facilities should take into consideration the following issues when determining whether to investigate isolated TB skin test convertors:
In addition, facility staff will want to reference the CDC document “Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Settings, 2005”. (Click the link or request a hard copy by contacting the TB Control Program at (605) 773-3737 or 1-800-592-1861). If the facility decides to investigate the isolated TB skin test convertor, they can use the investigation steps listed below in #3. If the facility decides not to investigate the isolated convertor, it is recommended to increase the surveillance activities so staff or residents who have symptoms compatible with TB disease are promptly identified. Any additional TB skin test convertors identified within 6 months of the first convertor will be immediately reported to the TB Control Program.
3. Investigation of TB skin test convertor clusters
DIS staff will initiate an investigation for TB skin test convertor clusters that will include the following:
4. Failure to comply with TB Control Program recommendations
If the facility does not comply with the recommendations provided by the DIS staff for follow-up activities for the reported TB skin test convertor clusters, this information will be reported to the TB Control Program who will work with the Office of Licensure and Certification to ensure the recommendations are followed.
