HIV Testing

HIV – or human immunodeficiency virus is a member of the retrovirus family. Available data indicate that acquired immunodeficiency syndrome (AIDS) is caused by this virus which is transmitted by sexual contact, exposure to blood (including sharing contaminated needles and syringes) or certain blood products, or transmitted from a infected mother to her child during the prenatal period. People with AIDS and AIDS-related conditions demonstrate a high prevalence of antibody to HIV-1.

www.cdc.gov/std/hiv
www.dhss.mo.gov/CommunicableDisease/Reports

Enzyme immunoassay (EIA) and immunoblot (Western Blot) tests for the detection of antibody to HIV-1/2 are performed on serum/plasma samples on a daily basis (Monday through Friday) at the State Public Health Laboratory. Oral samples (accepted from pre-selected local public health agencies only) are processed daily by EIA, but the Western Blot is batched weekly and performed on Wednesdays. There is presently a ten dollar handling fee on specimens received from private sources. Acceptable specimens include: oral specimens, whole blood, serum, or plasma (derived from heparin, citrate, or EDTA). Not less than 2 ml of whole blood or 1 ml of serum/plasma should be submitted. The normal turn-around time from receipt of the specimen in the laboratory is same day for non-reactive and an additional 1 to 2 days for reactive specimens. Allowance should be considered for transit of the specimen to the laboratory and the mailing of the report back to the submitter.

Special instructions for submission of HIV specimens are as follows:

1. Specimens must be submitted in the shipping containers supplied by the State Public Health Laboratory.
2. Lab form 45 must be used to submit HIV specimens. Each form has a unique (patient ID) number that will not be duplicated. Please use this number to represent the specimen being submitted. Tear off copy #1 of the form and keep this copy for your record before submitting to the laboratory.
3. Use the pre-numbered peel off labels to properly identify the specimen being submitted. Do not put any other information on the specimen tube.
4. Containers for the collection of oral fluids are distributed exclusively to selected local public health agencies. This program is controlled by DHSS and is reserved only for high risk populations.

Submission of Specimens

Shipping containers are available from the SPHL upon request

SPECIMENS MUST BE SUBMITTED IN THE PROPER MAILING KIT SUPPLIED BY THE STATE PUBLIC HEALTH LABORATORY.

If specimens are not shipped the same day they are collected, please store in the refrigerator.

Western Blot Test Interpretation and Criteria for Reporting

1. A Non-reactive* blot is one that contains no bands.
2. A Reactiveblot must contain two of the three major bands of diagnostic significance with the exception of the minimal reactive:

gp 160 or 120    }
gp 41                }    two of three
p 24                  }

(i.e. p24 & gp41, p24 & gp160, p24 & gp120, gp41 & gp 160, gp41 & gp120)

3. A Minimal Reactive* blot is one with either of the following band patterns present p24 and gp 160 only or gp 41 and gp 160 only.  No other bands are present.
4. An Equivocal (Indeterminate)* blot is one that shows any band pattern that does not meet the reactive or minimal reactive criteria. 
5. A Nonspecific Binding blot is when a purple coloration appears over the entire Western Blot test strip, and can be caused by a serum specimen abnormality such as elevated gammaglobulins, anti-HLA antibodies or autoimmune disease.

*These specimens will be sent to CDC for additional testing and a separate report will follow. Submit a follow-up specimen 30 days after the initial draw date of the first specimen. All follow-up specimens need to indicate on the submission form that this is a follow-up specimen and write in the patient identification number(s) of previously submitted specimens.

The Western Blot assay for antibody to HIV is non-diagnostic of AIDS and AIDS-related diseases.  Non-Reactive test results do not exclude the possibility of exposure to or infection with the AIDS-associated virus.  Reactive test results do not indicate that an individual has or will develop AIDS.