The Implications of Syphilis Electronic Laboratory Reporting on a Morbidity-based Disease Reporting System

Background:
Syphilis morbidity began being reported via the Michigan Disease Surveillance System (MDSS) in January 2005. The MDSS is Michigan's NEDSS solution and has been operational since the summer of 2004. Several Michigan laboratories electronically submit testing results into the system. However, for many diseases positive laboratory results do not always translate to new morbidity.

Objective:
To quantify the number of syphilis laboratory tests referred into the MDSS that were determined to be new morbidity as a model for worker and programmatic implications of non-disease determining labs.

Method:
Two data sets were developed, one with all syphilis electronic lab report referrals, and one with all syphilis morbidity from Jan 1, 2006 to December 31, 2006. These two data sets were merged by name to produce a third data set of those whose initial laboratory referral was electronic and were subsequently assigned as new morbidity.

Result:
There were 560 syphilis electronic laboratory results referred into the system during the investigational time frame. A total of 378 new cases were reported during this time frame, which included cases referred electronically and by traditional paper lab reports. 17% of the new cases resulted from electronic laboratory referrals, thus 88% of electronically referred syphilis laboratory tests were previous cases, false-positives, or administrative closures.

Conclusion:
A significant number of laboratory tests are being referred into a morbidity-based disease reporting system that are not associated with new morbidity. As electronic laboratory reporting continues to be pursued in Michigan, this percentage will almost certainly increase.

Implications:
This data certainly underestimates the impact of laboratory results especially compared to diseases involving on-going medical care (Hep C, TB, HIV) or those where a positive lab only translates to a reportable disease in certain situations (HSV for neonates). Those involved in surveillance system development and program management must collaborate to address these issues.