ppd skin test after BCG

[Marsha1992]

I recently have assumed the duties of the employee health nurse and when reviewing the TB exposure plan I read in the plan that "An applicant who has received BCG vaccinatin and has no history of tuberculosisi will receive a Mantoux skin test using 1TU strength. If this skin test is negative, then a second dose of PPD using 5TU strength will be given one week later.
Is this necessary or can the first PPD be given with 5TU strength?
Thanks

[National Jewish Health]

The following excerpt does not directly address the question, but given that there is no mention of a 2 stage approach, it is likely that the administration of 1 TU is unnecessary.  However the best way to address and especially to address the interpretation of positive skin tests would be to check with local public health authorities.

The following is from:  
Long: Principles and Practice of Pediatric Infectious Diseases, 3rd ed.  Copyright © 2008 Churchill Livingstone, An Imprint of Elsevier http://www.mdconsult.com/das/book/body/104962327-2/0/1679/138.html
CHAPTER 134 – Mycobacterium tuberculosis by Jeffrey R. Starke, and Richard F. Jacobs

A second cause of false-positive tuberculin reactions is prior receipt of BCG vaccine.  BCG vaccines vary in immunogenicity, cross-reactivity, and longevity of response.  Tuberculin reactions caused by BCG vaccination cannot be distinguished with certainty from infection with M. tuberculosis.  Countries using BCG vaccine frequently have high rates of endemic tuberculosis.  In most studies of newborn infants vaccinated with BCG, only about 50% have a positive tuberculin skin test result, and 80% to 90% lose such reactivity within 2 to 3 years.  Older children or adults have higher initial and longer responses to BCG, but most lose tuberculin reactivity within 10 years of vaccination.  Degree of reactivity is also affected by BCG product and nutritional status.  Skin test reactivity after BCG vaccination is expected to measure < 10 mm of induration at 48 to 72 hours (although reactions of 10 to 15 mm can occur); severe reactions are extremely rare and are likely due to tuberculosis infection.  Prior receipt of BCG vaccine is not a contraindication to tuberculin testing.  In general, in the United States, the tuberculin skin test result is interpreted similarly for persons with and without a history of vaccination.  Several studies have demonstrated that a positive tuberculin skin test in a previously BCG-vaccinated child who is a close contact of a current tuberculosis case is likely to represent tuberculosis infection, and the child should be evaluated and treated.

In the United States, it may be preferable to screen children for M. tuberculosis infection risk factors with a questionnaire; the tuberculin skin test should be applied when risk factors are discovered through the questionnaire.  Clinicians performing skin testing should be familiar with tuberculosis case rates and characteristics in the community.  Local public health authorities should help determine interpretation of skin test reactions for each community.  Age and intervals for skin testing are based on personal and risk factors.