400
A 3 year old patient presents with a cough, fever, and runny nose for 5 days. The patient's preschool is requiring that all students have TB testing before attending. This is the measurement (in mm) of the area of induration after 48-72 hrs that would indicate LTBI and a need for subsequent INH therapy
10 mm, as the patient is in a moderate risk group due to age (<4y/o)
Measurements that indicate LTBI:
- 5mm = HIV+, abnormal CXR, close contacts of documented TB infected individuals, severely immunocompromised
- 10 mm = Homeless, travel to or birth in endemic area, IVDU but HIV-, prisoners, health care workers, nursing home pts and staff, diabetes or CRF, immunosuppressed, <4 y/o.
- 15 mm = >/= 4 y/o and no clear risk factors