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Source: Curtis AB, et al. Extensive transmission of Mycobacterium tuberculosis from a child. N Engl J Med 1999; 341:1491-1495.
A 36-year-old woman was found to have tuberculosis (TB) arthritis of one hip joint without pulmonary involvement or infectivity. She had had no known contact with anyone with TB, lived in a part of North Dakota where TB is rare, and had only left North Dakota for a trip to Montana. Evaluating contacts, her 9-year-old child (who had joined the family from the Marshall Islands 2 years earlier) was found to have cavitary pulmonary TB. In retrospect, it was noted that the child sometimes fell asleep
at school and had had a "dry cough" for a few months prior to diagnosis. After arriving in North Dakota two years earlier, a TB skin test had been placed but not read.
Careful evaluation suggested that the woman had probably contracted her infection in 1997. Thus, rigorous testing of the child’s other contacts was done. Three of four household contacts had positive skin tests (the guardian with TB in the hip and a twin brother with a positive sputum culture), as did 16 of 24 classroom contacts, 10 of 32 school bus riders, and nine of 61 day care contacts. Appropriate treatment was given.
Comment by Philip R. Fischer, MD, DTM&H
By conventional teaching, young children are not contagious for TB because they rarely generate a forceful enough cough to aerosolize and spread organisms. This child in North Dakota represents an alarming exception to conventional teaching. He not only had cavitary disease before being ill enough to prompt medical evaluation, but he had already spread active disease in his family and TB organisms to 20% of his contacts. Clearly, children in the first decade of life can spread TB.
Published recommendations can guide the evaluation of foreign-born children who are adopted into families in the United States. In particular, the history of having been vaccinated with BCG vaccine should not affect the decision about whether to place a TB skin test.1 The source patient in North Dakota had appropriately been subjected to TB skin testing, but the result of the skin test was never noted.
Policies vary for reading TB skin tests. Some health care providers require that results be read by medical personnel 48-72 hours after test placement, and others accept readings by presumably reliable patients or guardians. As sadly illustrated in North Dakota, providers should ensure that TB tests are not only placed but are also read and results documented. To facilitate this, medical offices should implement follow-up systems to confirm that tests are either read or repeated (and then read).
In addition to TB skin testing, what other evaluation should be done for adoptees and other children who are newly arrived in the United States? As reviewed in Travel Medicine Advisor Update in 1998, laboratory assessment could include tests for hepatitis B (both antigen and antibody testing), HIV, syphilis, and intestinal parasites.2 A blood count is also usually advised (with attention to anemia and to red cell indices). Increasingly, hepatitis C testing is also recommended because helpful treatment might be available. Assessments for normal, age-appropriate hearing, vision, dentition, development, and immunizations are also indicated. Though debatable, some experts recommend testing asymptomatic new arrivals for lead toxicity, thyroid dysfunction, and renal disease.
The source patient in North Dakota had his TB test placed "shortly after" arrival in the United States. When should TB testing be done in immigrants and foreign-born adoptees? Because some children coming into the United States could be in a "window" period between infection and conversion to a positive test, individuals testing negative initially could be retested six months later. Similarly, follow-up repeated testing for HIV and hepatitis C could be considered in children who tested negatively on arrival.3
The experience reported from North Dakota serves as a poignant reminder of the ability of M. tuberculosis to spread subtly through a community. Equally, the case demonstrates the public health implications of a missed screening opportunity. It also reminds us to screen new arrivals in the United States carefully. TB testing should be initiated and completed. Other testing, as adapted to the particular situation, should also be done. Follow-up is critical, and new arrivals must be integrated into the health care system.
(Philip R. Fischer, MD, is associate professor of pediatrics, department of pediatrics & adolescent medicine, Mayo Clinic, Rochester, MN.)
1. American Academy of Pediatrics. "Medical evaluation of internationally adopted children." In: Peter G, ed. 1997 Red Book: Report of the Committee on Infectious Diseases. 24th ed. Elk Grove Village, IL: American Academy of Pediatrics; 1997, 116-120.
2. Hill DR. The health of internationally adopted children. Trav Med Advisor Update 1998; 8:17-20.
3. Miller LC. Caring for internationally adopted children. N Engl J Med 1999; 341:1539-1540.
Source: Franchi A, Amicosante M, Rovatti E, et al. Evaluation of a Western blot test as a potential screening tool for occupational exposure to Mycobacterium tuberculosis in health care workers. J Occup Environ Med 2000; 42:64-68.
Is there a better way to test health care workers for occupational exposure to TB? Researchers at the University of Modena in Italy say there is: Using a Western blot test to detect an antibody as a marker of exposure to TB.
Currently, skin tests measure the reaction to tuberculin purified protein derivative (PPD) to screen health care workers for risk of TB infection. The researchers developed an M. bovis serological Western blot test as an earlier marker of TB contact.
The antibody test could not be used with BCG-vaccinated workers due to their high reactivity. But among non-vaccinated health care workers, the Western blot test did, in fact, detect exposure earlier than the PPD skin test and with greater sensitivity. For example, the Western blot test identified 95% of workers in the TB and respiratory diseases division as being sensitized to Mycobacterium tuberculosis, as compared to 73% identified by PPD. In the infectious disease division, Western blot identified 59% of workers as sensitized, compared to 41% identified by PPD.
On the downside, the authors noted that the Western blot methodology "would give more limited information about the level or intensity of MTB-exposure than the PPD skin test.
"Overall, this study suggests that the WB test antibody market, as a sensitive indicator of MTB contact among exposed HCWs, might provide, in association with the PPD skin testing, new tools to assess the TB risk in health care facilities with higher accuracy, thus allowing a more timely and appropriate implementation of the environmental and health surveillance measures for the primary prevention and control of TB infection in the workplace," the authors stated.
Source: Bratcher DF, Stover BH, Lane NE, and Paul RI. Compliance with national recommendations for tuberculosis screening and immunization of healthcare workers in a children’s hospital. Infect Control Hosp Epidemiol 2000; 21: 338-340.
Hospital-based, non-employee physicians should be included in mandatory immunizations and tuberculosis screening, researchers at Kosair Children’s Hospital in Louisville, KY, concluded.
A survey of 55 physicians and 351 hospital employees found different patterns of compliance with national immunization and TB guidelines. Only 40% of physicians reported having an annual TB screening compared to 93% of employees.
"Many states require annual TB screening for health care facility employees, and there are published recommendations and guidelines for TB screening programs to include all health care personnel," the authors note. "Despite these recommendations, physicians have not been included in many hospitals’ employee-health programs, and they fail to have annual TB screening."
The disparity was not as great for immunizations, but lack of compliance was still significant. Eighteen percent of physicians and 14% of employees indicated they had incomplete hepatitis B virus status. "One half (5 of 10) of physicians reporting an incomplete HBV vaccine series were specialists who regularly performed invasive procedures," the authors noted.
Most physicians indicated they were aware of the national immunization recommendations for health care workers. Why are there gaps in immunization and screening for TB? A moderate to high factor, according to 94% of physicians, is the lack of mandatory participation in an employee health program. Lack of availability of an employee health program was cited as of moderate to high importance by 74% of the physicians.
"We recommend that mandatory immunization and TB screening policies encompass all HCWs, including physicians," the authors concluded. "Compliance with these policies may require enforcement through the credentialing process or through other innovative strategies that circumvent time-constraint issues."
Interestingly, the study found one area in which physicians had a significantly higher rate of immunization than hospital staff: influenza. Some 57% of physicians reported having an influenza immunization, compared to 31% of employees. The authors noted that both rates are "alarmingly low," and speculated that the higher rate among physicians may be due to greater awareness of recommendations or less concern about potential side effects or complications from the vaccine.
Source: Latini JM, et al. J Urol 2000; 163:1870.
An unfortunate elderly man with transitional cell carcinoma of the bladder developed progressive dorsal penile nodules and a coronal abscess two weeks after completion of a six-week course of weekly intravesicular bacillus Calmette-Guerin (BCG) (a live attenuated strain of Mycobacterium bovis).
The BCG treatment had been uneventful except for transient dysuria following the final installation. The coronal abscess did not respond to incision and drainage or antibiotics. An excisional biopsy was performed, which revealed non-caseating granulomata and fibrous tissue. Cultures for HSV, bacteria, and fungi were negative and AFB smears were negative. Eventually, M. bovis grew from culture, and the lesions quickly responded to antituberculous therapy.
Interestingly, the man had contracted pulmonary tuberculosis in 1955 in Korea, requiring segmental lobe resection and nine months of treatment with isoniazid and p-aminosalicylic acid.
Urethral and penile complications from intravesicular BCG are rare but should be suspected in patients with evidence of penile induration or infection in whom routine cultures are negative, irrespective of the results of AFB smears. Current recommendations support the use of PCR in such cases, which may have resulted in a speedier diagnosis.