The most common bacterial sexually transmitted disease (STD) in the US, Chlamydia is more common among people 15-25 years of age. An estimated 3 million Americans or more are infected with Chlamydia each year. Many people do not experience any symptoms, so cases often go undiagnosed and unreported but over 1 million new cases are reported each year. Diagnosis and treatment of Chlamydia is very important to prevent long-term complications and spread of the infection to others. Chlamydia is usually transmitted through sexual contact (oral, vaginal, or anal) with an infected partner. Risk factors include having co-infection or previous infection with another STD, multiple sex partners, and not using barrier contraception consistently. An infected mother may spread the disease to her baby during childbirth. These infants are in danger of developing conjunctivitis, an inflammation that can threaten eyesight, and pneumonia.
Gonorrhea is an easily treated STD, but left untreated can cause severe reproductive and health problems.
RPR, Qualitative - tests for the bacterium that causes syphilis, Treponema pallidum. Syphilis is an infectious disease most often spread by sexual contact, including direct contact with a syphilis sore (chancre). Syphilis is easily treated but left untreated can cause severe health problems. Infected mothers can also pass the disease to the fetus, with serious and potentially fatal consequences for the baby.
RPR, Quantitative - False-positive reactions for the RPR can occur due to pregnancy, drug addiction, collagen vascular disease, and advanced age. False-positive results have also been noted in the presence of many nonsyphilis infectious diseases and inflammatory states. False-positive RPR results have also been reported in patients vaccinated against influenza and hepatitis C.
Hepatitis B Surface Antigen (HBsAg) is a protein antigen that is produced by HBV. It is the earliest indicator of acute hepatitis B and often identifies infected people before symptoms appear. During the recovery period, HBsAg disappears from the blood. In certain people (particularly those infected as children or those with a weak immune system, such as those with AIDS), chronic infection with HBV may occur and HBsAg remains positive.
Human immunodeficiency virus (HIV 1/O/2), is the etiologic agent of the acquired immunodeficiency syndrome (AIDS) and a cytopathic retrovirus. This test uses recombinant antigen sources and detects antibodies by specific immune binding and the subsequent chemiluminescent reaction (ICMA technology). Sensitivity and specificity of this assay are respectively 100% and 99.9%. Sera which are found repeatedly reactive in two out of three tests are subject to confirmatory HIV-1 testing by the Western blot method. Certain individuals may be initially reactive by the preliminary test and negative or indeterminate by Western blot, which may be caused by other viral antibodies or autoantibodies which cross react with the viral antigens, although this is rare.
Hepatitis C Antibody - Following the development of specific and sensitive testing for hepatitis B, 90% of post-transfusion hepatitis is now hepatitis C. A gene product (c100) of hepatitis C virus (HCV) was isolated and an assay for anti-HCV was then developed. The assay detects antibody to a presumptive flavivirus or togavirus which may be an etiologic agent of non-A, non-B hepatitis (which may not be a unitary disease entity).
Hepatitis C serology will correlate with surrogate tests for non-A, non-B hepatitis (ALT and anti-HBc) for blood donors. Since hepatitis C serology identifies a broader group of infected individuals than surrogate testing does, it reduces risk of HCV during transfusion. Studies conducted in hemophiliacs indicate that antibody to HCV is a reliable marker of HCV.
Herpes Simplex Virus (HSV) I and II. Herpes simplex viruses which are more commonly known as herpes, are categorized into two types: herpes type 1 (HSV-1, or oral herpes) and herpes type 2 (HSV-2, or genital herpes). Herpes type 1 most commonly causes sores around the mouth and lips (sometimes called fever blisters or cold sores). HSV-1 may cause genital herpes, but most cases of genital herpes are caused by herpes type 2. In HSV-2, the infected person may have sores around the rectum or genitals. Although HSV-2 sores may occur in other locations, these sores generally are found below the waist.
