May 28, 2002
Individuals born outside the United States accounted for 46 percent of the 16,377 US cases of TB reported in 2000. To eliminate TB in the United States, the Institute of Medicine and others have identified screening for the disease as a priority among individuals applying for permanent US residence.
In 1995, 578,000 persons applied for US residency; 760,000 applied in 1997. Applicants age 2 or older are given a Mantoux tuberculin skin test (TST). If a reaction of 5 mm or more is observed, a chest x-ray is required. If the x-ray suggests TB, the applicant must be referred to the local health department for evaluation. The guidelines also recommend referring applicants with a TST induration of 10 mm or more and a chest x-ray not suggestive of TB to the health department for consideration of preventive therapy. Immigration and Naturalization Service (INS) district directors appoint physicians (known as civil surgeons) to perform screening examinations. The physicians must be licensed, have at least four years experience, and be provided with "Technical Instruction for Medical Examination of Aliens in the United States," developed by the CDC's Division of Quarantine.
In the current study, the researchers evaluated adherence to the CDC's technical instructions in five INS jurisdictions with large numbers of applicants for permanent US residence: San Diego County, San Francisco County, New York City, New York state and Massachusetts. The records of 5,739 applicants were analyzed.
San Diego had the highest percentage (11 percent) of applicants who were not screened at all, but most applicants with a TST reaction of 5 mm or more had the recommended chest x-ray. TSTs were administered to only 48 percent of San Francisco applicants, but 52 percent were given a chest x-ray rather than a TST. New York City had the best record of adherence: 91 percent of applicants underwent a TST; followed by Massachusetts (87 percent), New York state (75 percent) and San Diego (74 percent).
No active cases of TB were newly diagnosed as a result of screening. Ten applicants had a history of current or past TB noted on INS forms. When TST positivity was defined as an induration of 10 mm or more, TST positivity rates ranged from 10 percent among Massachusetts applicants to 24 percent among New York state applicants.
"As a result of this study's findings, efforts at both the national and state levels are being made to develop training materials that reflect established guidelines and recommendations for physicians who screen immigrants for TB infection and disease," the authors concluded. "These physicians need to be targeted to adopt appropriate screening practices so as to reduce the prevalence of TB among foreign-born Americans."