Historically, public health laboratories (PHLs) have focused activities on specified core functions. Considered broadly, these functions encompass activities in support of the three charges of all public health entities: (1) assessment, (2) policy development, and (3) assurance.3 PHLs perform functions directly associated with these objectives, as well as testing activities that are excluded for various reasons from the practices of commercial laboratory service vendors. Examples of PHL core functions include:11
- coordinating disease reporting activities among laboratories and providers in support of state disease tracking objectives
- responding to increased testing needs during times of disease outbreaks
- performing serological typing and other specialized tests useful for tracking disease and pathogen type across a population but insignificant to clinical therapy
- performing tests that are not commercially profitable
- performing environmental testing services
- performing quality assurance across all clinical laboratories
- conducting applied research in the areas of emerging infections
- verification of results from other laboratories
By performing these functions, PHLs provide state health officials with empirical information critical to assessing community health status, evaluating the success of existing public health initiatives (e.g., childhood lead abatement programs), and developing new policies related to disease prevention. Additionally, PHLs provide the specialized testing support needed in times of outbreaks or upon the occurrence of unusual diseases.
While the primary source of funding for state PHLs is state government, this varies by state. All states receive support from the CDC in the form of training and information, and some receive some outside funding from the CDC through grants. User fees (e.g., those associated with prenatal screening or other tests provided to the public) can be an important source of funding for some state labs.