The Viapath Infection Sciences laboratories at GSTT are located on the 5th Floor of the North Wing at St. Thomas’ Hospital. The laboratories are UKAS accredited and perform over 800,000 routine and specialist investigations annually for GSTT, GPs and other Trusts and commissioners within the South East and Pan London. The wide-ranging portfolio of tests encompasses diagnostic virology, bacteriology, mycology and parasitology.
Nearly 60% of all the tests performed are carried out in the Virology section, which comprises serology and molecular laboratories, overseen by the three Consultants in Virology. It is recognised by the UK Clinical Virology Network as a Specialist Virology Centre.
The Serology laboratory performs approximately 250,000 tests per annum, providing an extensive screening, acute diagnostic and interpretive service for the management of infectious diseases in diverse clinical settings including GUM, HIV medicine, antenatal and fetal medicine, paediatrics, solid organ transplant and occupational health. The laboratory contains state of the art random-access analysers facilitating rapid high sample throughput.
The Molecular laboratory offers a comprehensive repertoire of nucleic acid amplification tests for the detection, quantification and genotyping of pathogenic viruses, using both commercial and validated in-house assays. This is an area of diagnostics that is evolving rapidly. Accordingly, the laboratory is proactive in developing and implementing assays which enhance the speed and sensitivity of diagnoses of healthcare-associated infections, blood borne viruses, respiratory tract infections, sexually transmitted and neurological diseases, amongst others.
The Trust serves the area with the highest prevalence of HIV and Hepatitis B in the UK and the department works closely with the HIV and Hepatitis services. HIV testing is offered as a routine to all patients undergoing venepuncture in the Emergency Department. In addition rapid HIV testing is available 24/7 in the lab using point of care testing technology. The laboratory repertoire includes genotyping for HIV predicted tropism and antiretroviral resistance testing using automated sequence analysis, as well as HIV, Hepatitis B and Hepatitis C viral load, antigen, and antibody testing and confirmation.
The molecular laboratory provides a broad range of tests for genitourinary (GU) infections, including nucleic acid amplification technology (NAT) testing for herpes simplex virus, syphilis, Trichomonas vaginalis, Neisseria gonorrhoea and Chlamydia trachomatis. The 2017 introduction of in house identification of lymphogranuloma venereum (LGV) chlamydial strains has replaced the need for reference lab referral. Molecular testing is complimented by type-specific herpes simplex virus serology and treponemal and non-treponemal tests for syphilis screening and confirmation.
GSTT is a major renal transplant centre for both adults and children, with the adult centre among the largest in Europe. CMV, EBV and BK viral load surveillance testing is a cornerstone of management. Cadaver donor testing is facilitated by the 7 day availability of urgent HIV, hepatitis C and B viral load testing.
St Thomas’ ICU is one of five designated regional centres for adult extra corporeal membrane oxygenation (ECMO) in the UK. The Evelina London Children’s Hospital, also on St Thomas’ site, is likewise a major referral centre for both specialist care and management of acute illness. The Paediatric Intensive care Unit retrieves severely ill children from centres all over the South East, some of whom require (ECMO).
Diagnosis of respiratory infections has thus been a major focus of the laboratory, to provide timely, in house identification of a broader range of respiratory pathogens. This has been achieved with the introduction of three new diagnostic assays in 2016-17, all giving a same day result and available every day:
- Respiratory Panel - Standard detects (and types) eight different respiratory viruses including Influenza, and bacterial pathogens Mycoplasma pneumoniae and Bordetella pertussis.
- Respiratory Panel – Lower Tract detects seven non-viral pathogens in the lower respiratory tract samples, including Legionella pneumophila, Mycoplasma pneumoniae, Chlamydophila psittaci and Pneumocystis jiroveci.
- Our respiratory repertoire has been further enhanced with the introduction of a rapid influenza and respiratory syncytial virus (‘flu/RSV’) test. This test is done in the Microbiology laboratory to allow 24/7 availability, and takes less than 2 hours. It is offered in the “Winter flu season”, to expedite diagnosis and side room management.