Giardiasis Surveillance in Indiana, 2010-2012: An Evaluation of the Indiana National Electronic Disease Surveillance System

BACKGROUND:  Giardia spp. is the most commonly identified intestinal parasite in humans in the United States and the most commonly reported enteric parasite in Indiana. Positive lab specimens of Giardia are reportable to the Indiana State Department of Health. Statewide, local health departments interview identified cases with standardized case investigations and responses are entered into the Indiana National Electronic Disease Surveillance System (I-NEDSS). This surveillance system was evaluated in context of giardiasis reporting to assess the system’s ability to meet self-identified objectives and to make recommendations for improving enteric disease reporting.

METHODS:  This evaluation analyzed quality of data, and timeliness of giardiasis reporting and investigation in I-NEDSS. Results were compared to guidelines outlined in Indiana’s Communicable Disease Reporting (CDR) Rule and I-NEDSS objectives for an overall assessment of the surveillance system. Over 1,000 case investigations for giardiasis recorded from 2010-2012 were reviewed for quantitative data analyses. Stakeholder interviews and user surveys were conducted and analyzed providing qualitative data regarding willingness to participate in the surveillance system and ease of use. All analyses were done with SAS (Version 9.2) and Microsoft Excel (2007).

RESULTS:  Of the variables analyzed, key demographic variables were missing 18.1% of the time. Occupations of the individuals were missing for 75% of the investigations, and patients’ telephone numbers were not included for 20% of the investigations. Nearly 10% of investigations were missing specimen collection dates. The CDR Rule requires notifiable diseases to be reported within seven days of diagnosis, however nearly 50% of labs did not report within this time limit. This evaluation also found that nearly 40% of giardiasis cases were not reviewed by ISDH until a month after first notification. When compared to previous methods of reporting, the majority of users stated that I-NEDSS was easy to use and has improved speed, accuracy, accountability, security, and situational awareness of notifiable enteric diseases.

CONCLUSIONS:  Based on this evaluation, I-NEDSS has challenges with data entry omissions and timeliness. These issues highlight the need to reiterate the importance of timely reporting and form completion, which in turn would increase data quality and may also decrease recall-bias when interviewing cases. Since its implementation, I-NEDSS has met the objectives it was designed to complete and users are happy with the system’s interface. In addition, I-NEDSS staff works to constantly improve the system, and continuously accepts feedback from users.