Ask the Experts - TB Screening With Skin Testing Post-BCG Vaccine
Ask the Experts - TB Screening With Skin Testing Post-BCG Vaccine
A private grade school in Moscow, Russia, is having trouble formulating a policy of TB screening with skin testing for students, as some have received bacille Calmette-Guérin (BCG) vaccine at birth, some at age 10 or 12, and some not at all. The school has 700 children from all over the world. Are there any clear guidelines for skin testing this population? Would a reasonable policy be to skin test annually the children who have not been vaccinated, skin test at admission (but not annually) those vaccinated at birth, and not to skin test those who have been recently vaccinated?
Dr. T. J. Meade
It is difficult to apply guidelines published for the United States to other countries. However, most of the general principles are appropriate:
1. Skin test responses to TB should be documented following BCG vaccination at any age.
2. Most positive skin tests following BCG vaccination are in a 5-9-mm range unless the vaccinee has been exposed to TB.
3. A large increase in skin test response for a BCG recipient indicates recent exposure to Mycobacterium tuberculosis.
4. Most children who have received BCG, particularly when received at birth, become skin-test-negative after 1 year if they have not been exposed to TB.
I would offer the following as suggestions for the private grade school in Moscow, Russia:
1. Skin test all children annually, and carefully record the response as measured by a healthcare professional.
2. Treat children with isoniazid if a skin test response increases significantly (usually 10 mm or greater but individual judgment must be used) and the chest x-ray is normal.
3. For children who have not received BCG vaccine or became skin-test-negative after BCG, a 10-mm response warrants investigation and treatment. A 5-mm response if there is a household contact for TB, particularly in a child younger than 4 years, should be investigated and treated.
A private grade school in Moscow, Russia, is having trouble formulating a policy of TB screening with skin testing for students, as some have received bacille Calmette-Guérin (BCG) vaccine at birth, some at age 10 or 12, and some not at all. The school has 700 children from all over the world. Are there any clear guidelines for skin testing this population? Would a reasonable policy be to skin test annually the children who have not been vaccinated, skin test at admission (but not annually) those vaccinated at birth, and not to skin test those who have been recently vaccinated?
Dr. T. J. Meade
It is difficult to apply guidelines published for the United States to other countries. However, most of the general principles are appropriate:
1. Skin test responses to TB should be documented following BCG vaccination at any age.
2. Most positive skin tests following BCG vaccination are in a 5-9-mm range unless the vaccinee has been exposed to TB.
3. A large increase in skin test response for a BCG recipient indicates recent exposure to Mycobacterium tuberculosis.
4. Most children who have received BCG, particularly when received at birth, become skin-test-negative after 1 year if they have not been exposed to TB.
I would offer the following as suggestions for the private grade school in Moscow, Russia:
1. Skin test all children annually, and carefully record the response as measured by a healthcare professional.
2. Treat children with isoniazid if a skin test response increases significantly (usually 10 mm or greater but individual judgment must be used) and the chest x-ray is normal.
3. For children who have not received BCG vaccine or became skin-test-negative after BCG, a 10-mm response warrants investigation and treatment. A 5-mm response if there is a household contact for TB, particularly in a child younger than 4 years, should be investigated and treated.
