LabSurv is an electronic notification system developed to support laboratories to directly notify the results of notifiable disease testing to public health services in New Zealand. A direct laboratory notification middleware framework was developed to manage the information flow between laboratories and public health services. The framework uses an HL7 messaging standard to receive the laboratory results and windows services to integrate the results with the cases of notifiable diseases within a national electronic surveillance system. This paper presents the system design and implementation details of direct laboratory notification system in LabSurv. It presents the HL7 messages structure implemented in the system. Finally, the performance of the system based on implemented framework is analysed and presented to evaluate the efficiency of our design.