Use, location, and timeliness of clinical microbiology testing in Georgia for select infectious diseases

Although clinical microbiology testing facilitates both public health surveillance of infectious diseases and patient care, research on testing patterns is scant. We surveyed hospital laboratories in Georgia to assess their diagnostic testing practices.

Using e-mail, all directors of hospital laboratories in Georgia were invited to participate. The survey focused on timing and location of diagnostic testing in 2006 for 6 reportable diseases: giardiasis, legionellosis, meningococcal disease, pertussis, Rocky Mountain spotted fever, and West Nile virus disease.

Of 141 laboratories, 62 (44%) responded to the survey. Hospitals varied widely in their use of diagnostic testing in 2006, with 95.1% testing for meningococcal disease, but only 66.1% and 63.3% testing for legionellosis and West Nile virus disease, respectively. Most laboratories (91%) performed gram stain/culture to diagnose meningococcal disease in-house and 23% performed ova and parasite panels for giardiasis were conducted in-house. Fewer than 11% of laboratories performed in-house testing for the remaining diseases. Laboratories affiliated with small hospitals (≤100 beds) were more likely to send specimens for outside testing compared with laboratories associated with large hospitals (>250 beds). Median turnaround time for ova and parasite panel testing for giardiasis was significantly shorter for in-house testing (1.0 days) than within-system (2.25 days) or outside laboratory (3.0 days) testing (P = .0003). No laboratories reported in-house testing for meningococcal disease, pertussis, or Rocky Mountain spotted fever using polymerase chain reaction.

Many hospitals did not order diagnostic tests for important infectious diseases during 2006, even for relatively common diseases. In addition, hospital laboratories were unlikely to perform diagnostic testing in-house; sending specimens to an outside laboratory may result in substantial delays in receiving results. These unsettling findings have adverse implications for both patient care and public health surveillance; they indicate an immediate need to study nationally the use and timeliness of clinical microbiologic testing.