CDC sets new guidelines for STD diagnosis

CAP Today

February 2011
Feature Story

On Dec. 17, 2010, the CDC released new guidelines for STD diagnosis that reflect the findings of the CDC’s multicenter study of nucleic acid amplification tests in children under evaluation for sexual abuse.

“The guidelines recommend NAATs as an alternative to culture for the detection of CT and GC, with some limitations,” says John R. Papp, PhD, senior service fellow in the Laboratory Reference and Research Branch, CDC Division of Sexually Transmitted Disease Prevention. “This will allow clinicians investigating such infections greater access to testing since culture, which was solely recommended in the past, is no longer offered by many labs.” However, he cautions that laboratories need to be fully aware of the legal implications of the test results, including chain-of-custody issues or false-positives from contamination.

Janice Matthews-Greer, PhD, professor of research in pediatrics and clinical pathology and director of the diagnostic virology and HPV Diagnostics Labs at LSUHSC in Shreveport, La., is pleased the CDC has released the new guidelines. “It means that for medical [non-legal] purposes we don’t have to try to determine if a specimen from a 12- or 13-year-old girl is from Labor and Delivery (‘adult’) or the Peds Clinic (‘child’). Our pre-adolescent and adolescent females will get their results from the same sensitive platform as our adult women with those results charted to their record.”

The guidelines say the following:

For detection of C. trachomatis: “NAATs can be used in vaginal specimens or urine from girls. ... No data are available regarding the use of NAATs in boys or for extragenital specimens (e.g., those obtained from the rectum) in boys and girls. Culture remains the preferred method for extragenital sites.”
For detection of N. gonorrhoeae: “Data on use of NAATs in children are limited, and performance is test dependent. Consultation with an expert is necessary before using NAATs in this context to minimize the possibility of cross-reaction with nongonococcal Neisseria species and other commensals (e.g., N. meningitidis, N. sicca, N. lactamica, N. cinerea, and Moraxella catarrhalis). NAATs can be used as an alternative to culture with vaginal specimens or urine from girls, whereas culture remains the preferred method for urethral specimens or urine from boys and for extragenital specimens (pharynx and rectum) from all children.”

Source: CDC. Sexually transmitted diseases treatment guidelines, 2010. MMWR 2010;59(No. RR-12).

�Anne Paxton