What are the guidelines for lab testing for children from other countries?

Guidelines for Laboratory Testing for Children from Other Countries

Foreign-born children should receive targeted tuberculosis testing and appropriate laboratory workup based on their country of origin, age, and risk factors. 1

Tuberculosis Screening Guidelines

General Approach

• Foreign birth in a country with high TB prevalence is the greatest attributable risk factor for latent tuberculosis infection (LTBI), making targeted testing essential for these children 1
• Testing for LTBI among children with low risk for infection should be avoided 1
• A risk assessment questionnaire can identify children with risk factors for LTBI who should undergo tuberculin skin testing 1

Age-Specific Testing Recommendations

• For children under 5 years old:

  • Most guidelines recommend tuberculin skin test (TST) alone 1
  • Countries including WHO, ECDC, France, Brazil, Switzerland, and Slovakia recommend TST alone for young children 1
  • South Korea specifically recommends TST alone for children under 5 years 1

• For children 5-17 years old:

  • Many countries recommend a two-step approach: TST followed by Interferon-Gamma Release Assay (IGRA) if TST is positive 1
  • This approach is used by Canada, Japan, Ireland, and USA-AAP 1
  • The American Academy of Pediatrics allows IGRA to replace TST for children over 5 years 1

• Special considerations:

  • Some countries recommend both TST and IGRA for high-risk contacts (Canada, Czech Republic, Croatia) 1
  • Australia may consider IGRA as a supplementary test for children over 2 years 1
  • Portugal and UK recommend TST followed by IGRA if TST is negative for very young children 1

BCG Vaccination Considerations

• For BCG-vaccinated children, many guidelines recommend TST followed by IGRA if TST is positive to distinguish true infection from BCG cross-reactivity 1
• This approach is used in Germany, Italy, Spain, Saudi Arabia, the Netherlands, and Bulgaria 1

Additional Laboratory Testing Recommendations

General Screening

• Laboratory testing for foreign-born children should include screening for common conditions prevalent in their country of origin 1
• Guidelines for diagnostic workup of physical conditions in children from different countries show significant variation and are often incomplete 1

Blood Testing

• Complete blood count to identify anemia and other cytopenias that may be common in certain regions 2
• Inflammatory markers (ESR, CRP) may be useful for diagnosing acute or chronic inflammatory conditions 2
• Ferritin levels should be checked to identify iron deficiency anemia, which is common in many developing countries 2

Immunization Status

• Assessment of immunization status is critical as foreign-born children may have incomplete or different vaccination schedules 3
• Serologic testing for vaccine-preventable diseases may be necessary if documentation is unavailable 3

Implementation Considerations

Documentation and Surveillance

• Public health agencies should develop enhanced surveillance methods for TB among foreign-born persons 1
• Cases identified through targeted testing activities should be distinguished from those identified by symptoms 1
• Imported cases present at the time of entry should be distinguished from incident cases that arise during residence in the United States 1

Cultural Considerations

• Pretravel services for immigrants visiting friends and relatives in their home countries should be culturally competent and accessible 4
• Laboratory data collection systems should be simple and easy to use, even in resource-limited settings 5

Common Pitfalls to Avoid

• Failing to distinguish between screening tests and diagnostic tests 6
• Not considering the child's country of origin when determining which tests are appropriate 1
• Overlooking the need for age-appropriate testing protocols, especially for TB screening 1
• Neglecting to assess immunization status and the need for catch-up vaccinations 3
• Not accounting for BCG vaccination status when interpreting tuberculin skin test results 1