Objectives The citywide emergency test is widely used to identify all the infected persons, and thus contributes to realize "dynamic zero" during the public health emergency. Citywide emergency test is usually implemented by assigning nurses and material resources to the service areas. However, citywide emergency test is often characterized by the extremely heavy task covering millions of residents, the very limited time such as within one day or even 6 hours, and the shortage of nurses, laboratory professionals and equipment. It is also a possible risk factor that causes infectious disease. Therefore, the design of the service areas is crucial for successful citywide emergency test.

Methods This paper proposes the equal districting model to design the equal, compact and contiguous areas as service areas for emergency test. The proposed model is tested in two urban areas in different scales, which are Fengqing road subdistrict and Jinshui district in Zhengzhou, Henan Province, China.

Results The results show that the service areas can be effectively delineated, and are much better than the existing planning models in terms of the equality of responsibility districts and the spatial accessibility of service.

Conclusions Since the delineation of service areas does not depend on the candidate locations that used in classical location models, the proposed equal districting approach has application potentials in some scenarios of emergency planning.