Public health laboratories provide both routine and enhanced molecular diagnostic services to both their host and sister regional Trusts, as well as epidemiological surveillance services core public health and health protection purposes. In all cases, this involves a full 'sample to script' service offering, which includes routine phenotypical and genotypic laboratory analysis, expert results interpretation and treatment advice from a dedicated HPA consultant microbiologist, and retained 'surge capacity' to assist and complement existing NHS microbiology laboratories in the event of epidemic outbreak.

In summary, HPA PHLs provide the following functions:

• Specialist advice and support, particularly for the investigation of outbreaks and incidents
• Specialist referred tests: tests not performed in all laboratories, but which do not necessarily have to be sent to a Reference Laboratory (such as viral culture, other virology, mycology and serology tests, particularly if low volume)
• Molecular diagnostic tests that are not widely available in other laboratories, such as nucleic acid amplification tests for HIV and Hepatitis C
• Emergency response to bioterrorist incidents, natural outbreaks, and serious epidemics, such as SARS and H5N1 influenza
• Research and development: Our public health laboratories are at the forefront of research and development in medical microbiology and molecular diagnostics. This provides our service partners with direct ‘real-time’ access to technological improvements and advancements.
• Additional work (identification or typing) where not done by a reference laboratory

Some PHLs also provide food, water and environmental microbiology testing services, in direct support of their sister FW&E laboratories.

From the 1st April 2011 the HPA also has a number of collaborating centres (CCs), which futher support (and strengthen) existing PHL coverage and function.

If you are interested in hearing more about the tests and services available to the NHS Trusts and linked healthcare service providers in your region, please contact the PHL or CC for your region.