Virology

Blood Borne Virus Antibody/Antigen and Molecular Testing

HIV, Hepatitis B and Hepatitis C serology test results may be available, in an emergency, within two hours of receipt of the sample in the laboratory. During laboratory hours requests for urgent HIV Ab/Ag, Hepatitis B surface antigen (HBsAg) and Hepatitis C Antibody (HCV Ab) tests are to be made by telephone to Castle Hill Hospital, Virology Laboratory, by the requesting Medical Officer. Outside laboratory hours, unless the request is for urgent pre-dialysis screening, the consultant in charge of the case may discuss the investigation with the on-call Consultant Microbiologist who may be contacted through the Hull Royal Infirmary switchboard on 01482 875875.

Human Immunodeficiency Virus (HIV)

When clinical assessment indicates, treat as a “Danger of Infection” specimen and label accordingly all samples from this patient.

HIV Antibody/Antigen Testing

Patients for whom blood is submitted for this test should give informed consent, after pre-test discussions as to the implications of the test and the potential results and as to the means of preventing HIV infection.

Lorenzo item name: “HIV1 and 2 Ab and p24 Ag screen, blood”

HIV Molecular Testing

Note this investigation is generally only performed when the individual is known to be HIV positive.

HIV Viral Load

This test is performed in house. Plasma must be separated within 24hrs of collection from the patient, and stored at -80°C within 5 days.

HIV DNA PCR (also known as proviral DNA and/or HIV1 nucleic acid test)

This test is referred to a reference laboratory. It is available for neonates from birth to 18 months. A single maternal sample is required to test in parallel with the first neonatal blood.

HIV Genotypic Resistance

This test is referred to a reference laboratory. The reference laboratory requires a full drug treatment history to be sent with the specimen. Please include the required completed proforma, produced by the reference laboratory; with all resistance requests Unless instructed otherwise, all samples will have the HIV Viral Load tested in-house prior to sending for resistance testing, as the reference laboratory require 1ml of plasma with a viral load of >1000c/ml.

HIV Tropism Assay

This test is referred to a reference laboratory and is only performed to see whether Maraviroc will be effective against the patients HIV.

The specimen requirements are dependant on the patient’s current viral load status.

Please include the required completed proforma, produced by the reference laboratory, with all tropism requests.

Hepatitis B Virus

When clinical assessment indicates, treat as a “Danger of Infection” specimen and label accordingly all samples from this patient.

Hepatitis B Antibody/Antigen Testing

Note a full “marker” antibody and antigen serology repertoire is available.

Hepatitis B Surface Antigen (Australia Antigen / HBsAg)

This investigation is used as a screening test to determine infectivity with Hepatitis B.

This test is carried out on site.

Lorenzo item name: “Hepatitis B surface Ag screen, blood”

Hepatitis B Total Core Antibody

This test is used to determine “past infection” with Hepatitis B it is also used along with the HBSAg assay to determine “acute/current” Hepatitis B infection.

This test is carried out on site.

Lorenzo item name: “Hepatitis B core Ab screen, blood”

Hepatitis B Surface Antibody

This test is carried out on site. It is primarily used to determine immune status following a vaccination course, but can be used with the Hepatitis B Total core antibody to determine “natural” past infection with Hepatitis B.

Lorenzo item name: “Hepatitis B surface Ab level”

Hepatitis B Molecular Testing

Note this investigation is generally only performed when the individual is known to be Hepatitis B positive.

Hepatitis B DNA Viral Load Analysis

This test is carried out on site.

Plasma must be separated within 24hrs of collection from the patient, and stored at -80°C within 5 days.

Hepatitis C Virus

When clinical assessment indicates, treat as a “Danger of Infection” specimen and label accordingly all samples from this patient.

Hepatitis C Virus Antibody Testing

Hepatitis C Total Antibody Serology

This investigation is used as a screening test to determine current and a past infection with Hepatitis C. This test is carried out on site.

If the initial test for Hepatitis C Antibody is reactive a qualitative PCR test will be carried out (providing there is sufficient sample and it is less than 48 hrs old). A second specimen of blood will also be requested – it is important that the laboratory receives this second sample.

Lorenzo item name: “Hepatitis C Ab level, blood”

Hepatitis C Molecular Testing

Note this investigation is generally only performed when the individual is known to be Hepatitis C positive or as a follow up test after a high risk exposure incident.

Hepatitis C RNA Viral Load Analysis

This test is carried out on site.

Plasma must be separated within 24hrs of collection from the patient, and stored at -80°C within 5 days.

Hepatitis D (Delta) Virus

When clinical assessment indicates, treat as a “Danger of Infection” specimen and label accordingly all samples from this patient.

Hepatitis D Virus (Delta) Serology Testing

Note, Hepatitis D serology is only indicated in patients with active Hepatitis B infection.

This test is not carried out on site and is sent to a Referral Laboratory.

Hepatitis E Virus

When clinical assessment indicates, treat as a “Danger of Infection” specimen and label accordingly all samples from this patient.

Hepatitis E Virus Serology

Note, this test is only performed following a negative “Hepatitis Screen” (to include Hep B SAg, Hep C, Hep A IgM, EBV and CMV serology) and where there is a significantly high ALT biochemical marker.

This test is not carried out on site and is sent to a Referral Laboratory.