Johns Hopkins Gazette: September 23, 1996

In Brief

DNA test sensitivity can fool doctors

Hopkins scientists report that a new urine test for chlamydia infection is so sensitive it can detect the genetic footprints of the germs that cause it up to two weeks after successful treatment with antibiotics.

"This means that doctors should wait no less than two weeks after patients finish antibiotic treatment before using this test to verify treatment success," said Charlotte Gaydos, assistant professor of medicine. It takes that long, she said, for the chlamydia DNA to clear completely from cells that had been infected, and that accumulate in the urine.

Infecting an estimated 4 million young adults in the United States, chlamydia is the most common sexually transmitted disease. Gaydos said her study suggests that failure to wait long enough after therapy to retest urine by the DNA test may cause a positive result because of the DNA from dead cells, rather than from live organisms.

Simpler and more convenient than taking small scrapings of cells from a woman's cervix or a swab from a man's urethra, the tests use a technology called DNA amplification. Like a super-copying machine for genes, DNA amplification produces millions of copies of genetic material found in the Chlamydia trachomatis organism, making it more easily detectable in the laboratory.

"For two weeks after treatment, doctors should avoid using this technique to test urine samples to ensure they get accurate results," said Gaydos, who presented the findings of this study at the 36th annual meeting of the Interscience Conference on Antimicrobial Agents and Chemotherapy in New Orleans, on Sept. 17.

Hopkins authors taking part in first book festival

Hopkins authors Mark Strand and Mark Crispin Miller are among the participants in the Baltimore Book Festival, the inaugural celebration of the literary arts in Maryland taking place Sept. 28 and 29 at Mt. Vernon Place. Writing Seminars professor emeritus John Barth and department colleague Madison Smartt Bell are among the festival's honorary co-chairs.

The two-day festival is produced by the Baltimore Office of Promotion in cooperation with Baltimore Reads and the Maryland Department of Business and Economic Development.

There will be book sales, author signings, hands-on activities for kids, street theater, storytelling, cooking demonstrations, ethnic entertainment and continuous poetry readings with an eclectic group of more than 20 poets sharing their work in 30-minute intervals. Participants range from established writers such as Daniel Mark Epstein and Sharon Olds to familiar faces in the region's literary community, such as Maryland's poet laureate Roland Flint, Rosemary Klein and Richard Sober.

Also represented at the festival will be local presses-- including the Johns Hopkins University Press--writer's groups and bookstores.

TCI Communications of Baltimore and the History Channel are sponsoring the Great Book Hoof, a walking tour of dozens of literary and literary-related sites located in Mt. Vernon. The tour begins at the site of the Mount Vernon home where "The Star Spangled Banner" author Francis Scott Key died in 1843.

The event runs from 10 a.m. to 8 p.m. on Saturday, Sept. 28, and from noon to 6 p.m. on Sunday, Sept. 29. For more information, call (410)837-4636 or (800)282-6632. You also can find the festival on the World Wide Web by pointing your browser to

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