Tuberculosis Transmission from a Patient with Skin Lesions and a Negative Sputum Smear
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《新英格兰医药杂志》
To the Editor: As illustrated in Case 40-2003 (Dec. 25 issue),1 it is often difficult to find the source of infection in a child who has tuberculosis. In 2001, we cared for a five-month-old girl who presented with miliary tuberculosis and multiple intracranial tuberculomas. An initial investigation indicated that she had had no contact with persons with active tuberculosis.
In 2003, a 20-year-old man presented with skin lesions (Figure 1). The first of these lesions had appeared on his ankle more than two years earlier, and subsequently more lesions appeared on his chest, back, and one elbow. A skin test for tuberculosis with purified protein derivative was positive (diameter of induration, 10 mm). Examination of a biopsy specimen of the elbow lesion by the polymerase chain reaction revealed Mycobacterium tuberculosis. He had no respiratory or systemic symptoms, but a chest radiograph showed biapical scarring. Acid-fast smears of randomly collected sputum samples were negative, but a sputum culture grew M. tuberculosis.
Figure 1. Cutaneous Tuberculosis Lesions in the Source Patient.
Although contact tracing for the infant had not identified this man, he reported that his mother, with whom he lived, had cared for the infant in her home. Thus, he and the infant had been in the same house for several hours each day during the two months before the infant's diagnosis, and the man's skin lesions antedated the infant's illness. The infant had been born prematurely and had spent much of her life in the hospital before the two-month period during which she was in contact with the man. M. tuberculosis isolates from the man and the infant matched exactly on both IS6110 restriction-fragment–length polymorphism analysis and spacer oligonucleotide typing.
These findings, coupled with the rarity of transmission of tuberculosis from young children to adults,2 implicated the man as the source of the infant's tuberculosis. It has been estimated that patients with negative acid-fast smears cause 17 percent of new infections3 and present serious challenges to tuberculosis control.
Jason E. Stout, M.D.
John J. Engemann, M.D.
Carol D. Hamilton, M.D.
Duke University Medical Center
Durham, NC 27710
stout002@mc.duke.edu
References
Case Records of the Massachusetts General Hospital (Case 40-2003). N Engl J Med 2003;349:2541-2549.
Curtis AB, Ridzon R, Vogel R, et al. Extensive transmission of Mycobacterium tuberculosis from a child. N Engl J Med 1999;341:1491-1495.
Behr MA, Warren SA, Salamon H, et al. Transmission of Mycobacterium tuberculosis from patients smear-negative for acid-fast bacilli. Lancet 1999;353:444-449.
In 2003, a 20-year-old man presented with skin lesions (Figure 1). The first of these lesions had appeared on his ankle more than two years earlier, and subsequently more lesions appeared on his chest, back, and one elbow. A skin test for tuberculosis with purified protein derivative was positive (diameter of induration, 10 mm). Examination of a biopsy specimen of the elbow lesion by the polymerase chain reaction revealed Mycobacterium tuberculosis. He had no respiratory or systemic symptoms, but a chest radiograph showed biapical scarring. Acid-fast smears of randomly collected sputum samples were negative, but a sputum culture grew M. tuberculosis.
Figure 1. Cutaneous Tuberculosis Lesions in the Source Patient.
Although contact tracing for the infant had not identified this man, he reported that his mother, with whom he lived, had cared for the infant in her home. Thus, he and the infant had been in the same house for several hours each day during the two months before the infant's diagnosis, and the man's skin lesions antedated the infant's illness. The infant had been born prematurely and had spent much of her life in the hospital before the two-month period during which she was in contact with the man. M. tuberculosis isolates from the man and the infant matched exactly on both IS6110 restriction-fragment–length polymorphism analysis and spacer oligonucleotide typing.
These findings, coupled with the rarity of transmission of tuberculosis from young children to adults,2 implicated the man as the source of the infant's tuberculosis. It has been estimated that patients with negative acid-fast smears cause 17 percent of new infections3 and present serious challenges to tuberculosis control.
Jason E. Stout, M.D.
John J. Engemann, M.D.
Carol D. Hamilton, M.D.
Duke University Medical Center
Durham, NC 27710
stout002@mc.duke.edu
References
Case Records of the Massachusetts General Hospital (Case 40-2003). N Engl J Med 2003;349:2541-2549.
Curtis AB, Ridzon R, Vogel R, et al. Extensive transmission of Mycobacterium tuberculosis from a child. N Engl J Med 1999;341:1491-1495.
Behr MA, Warren SA, Salamon H, et al. Transmission of Mycobacterium tuberculosis from patients smear-negative for acid-fast bacilli. Lancet 1999;353:444-449.