SEXUALLY TRANSMITTED DISEASES AND HIV SCREENING

If you are sexually active, getting tested for STDs is one of the most important things you can do to protect your health. Make sure you have an open and honest conversation about your sexual history and STD testing with your doctor and ask whether you should be tested for STDs. If you are not comfortable talking with your regular health care provider about STDs, there are many clinics that provide confidential and free or low-cost testing.

Below is a brief overview of STD testing recommendations. In depth STD screening information for healthcare providers can be found here.

All adults and adolescents from ages 13 to 64 should be tested at least once for HIV.

Annual chlamydia screening of all sexually active women younger than 25 years, as well as older women with risk factors such as new or multiple sex partners, or a sex partner who has a sexually transmitted infection

Annual gonorrhea screening for all sexually active women younger than 25 years, as well as older women with risk factors such as new or multiple sex partners, or a sex partner who has a sexually transmitted infection.

Syphilis, HIV, and hepatitis B screening for all pregnant women, and chlamydia and gonorrhea screening for at-risk pregnant women starting early in pregnancy, with repeat testing as needed, to protect the health of mothers and their infants.
Screening at least once a year for syphilis, chlamydia, and gonorrhea for all sexually active gay, bisexual, and other men who have sex with men (MSM).

MSM who have multiple or anonymous partners should be screened more frequently for STDs (e.g., at 3-to-6 month intervals).

Sexually active gay and bisexual men may benefit from more frequent HIV testing (e.g., every 3 to 6 months).

Anyone who has unsafe sex or shares injection drug equipment should get tested for HIV at least once a year.
[CDC, Centers for Disease Control]

[Everything About Chlamydia and Chlamydia Testing July 31, 2015 By McKinzie Brocail

How do you test for chlamydia?

Nucleic Acid Amplification (NAA)
The three NAA tests described below, urine, swab, and DFA, work by finding the DNA of chlamydia bacteria. Because NAA tests search for the bacteria’s genetic material, it is very unlikely that a false-positive test result will occur. The incubation period for chlamydia is 1-5 days so wait five days after potential chlamydia exposure before getting tested to ensure the most accurate results possible.

Urine samples (recommended test method)
Testing via urine samples need to consist of first-catch urine (approximately 20-30mL of the initial urine stream). Patients should notinclude more than the first-catch in the collection cup to avoid diluting the sample.
Patients should not urinate for at least one hour prior to providing a sample.
Female patients should not cleanse the labial area prior to providing the specimen.
Swab cultures
Endocervical swab
Male urethral swab
Vaginal swab
Rectal swab
Pharyngeal swab (throat swab) if the throat is infected

Direct Fluorescent Antibody (DFA)
Swab cultures
Endocervical swab
Male urethral swab
Rectal swab
Neonates conjunctival swab
How do you test for gonorrhea?

Nucleic Acid Amplification (NAA)
These NAA tests find the DNA of gonorrhea bacteria. Because it searches for the bacteria’s genetic material, it is very unlikely that a false-positive test result will occur. Often, the gonorrhea NAA test is a urine test.

Urine samples (recommended test method)
Urine samples should consist of first-catch urine (approximately 20 to 30 mL of the initial urine stream). Typically, patients should not include more than the first-catch in the collection cup to avoid diluting the sample.
Patients should not urinate for at least one hour prior to providing a sample.
Female patients should not cleanse the labial area prior to providing the specimen.

Swab cultures
Endocervical swab (women)
Male urethral swab
Vaginal swab
Rectal swab
Pharyngeal swab

Gram Stain
Swab cultures from eye; used to detect Neisseria gonorrhoeae infection of the eye.

Testing for Syphilis
Testing for syphilis is a two-step identification and confirmation process that either requires a sample of blood, tissue, or fluid from a syphilis sore. Blood tests check for the antibodies to the infection, whereas fluid and tissue tests can detect the T pallidum bacteria itself. Tissue and fluid from a sore can only be obtained during the stages of syphilis that include sores or rashes, limiting the ability to test for the infection in its later stages. Antibodies can linger in blood even after treatment, making it possible to test positive after being cured.
Screening for syphilis is done using a venereal disease research laboratory (VDRL) test or a rapid plasma reagin (RPR) test. The VDRL test checks blood or spinal fluid for antibodies that produced by people with a syphilis infection, but those antibodies aren’t specific to the T pallidum infection and can, therefore, result in a false-positive. The RPR test also searches for non-specific antibodies that are produced by the body due to damage done to cells by the T pallidum bacteria. Because the antibodies detected can be caused by infections other than syphilis, the second step in diagnosing syphilis is to conduct a test to confirm the presence T pallidum.

One of the simplest testing methods for confirming syphilis is called dark-field microscopy, which identifies the T pallidum germ in fluid or tissue from an open syphilitic sore. The test can only be performed when sores are present, limiting the time frame for testing, and even if the presence of the T pallidumbacteria isn’t confirmed using this method, a syphilis infection could still be possible. There are many factors that affect the success of the test, such as the need for experienced microscopists to perform the test and the early time frame. This test is recommended any time a sore or ulcer is present.

The most specific test for confirming syphilis is the Fluorescent Treponemal antibody absorption (FTA-ABS) test, which uses a fluorescent marker to identify T pallidum antibodies in a blood or spinal fluid sample. However, this method doesn’t differentiate between T pallidum and other strains of bacteria that can cause other diseases and can only be conducted successfully during the first 3 to 4 weeks after exposure to syphilis.

The enzyme immunoassay (EIA) test checks blood using antibodies specific to syphilis infection to locate syphilis antigens. This is a second step in the testing process, used in conjunction with a VDRL or RPR test to confirm a suspected syphilis infection.

Microhemagglutination assay (MHA-TP) and Treponema pallidum particle agglutination assay (TPPA) tests are performed as a confirmation after a screening test has come back positive.

With blood testing, syphilis can be detected as early as 1 to 2 weeks after exposure. The highest accuracy can be expected within about three months, with false positive results possible any time within the initial 90 days after infection. People who have suffered from a syphilis infection in the past could also have a false positive result due to syphilis antibodies lingering in the bloodstream. If a reliable testing method returns a negative result 90 days or later after exposure, it is considered a negative diagnosis.

Herpes Simplex 1 and 2 Testing
Antigens are foreign substances such as a viruses or bacteria that cause your immune system to respond. Thus, HSV-1 and HSV-2 viruses are antigens and the body’s immune system creates antibodies in response to these antigens to fight or neutralize them. Antibodies are also called immunoglobulins (Ig). Antibodies are always present, whether you are having an active outbreak or not. You can have the test anytime.

The testing methods for HSV-1 and HSV-2 include:

Direct fluorescent antibody (DFA)
Direct microscopic examination (nonculture) of virus-infected cells: Impression smears of tissues, lesion/ulcer scrapings and swabs, or upper respiratory tract swabs.
Used to distinguish HSV-1 from HSV-2.
Generally, this test is not as sensitive as a cell culture.

Immunoblot (IgG)
Blood test
Also known as a Western Blot (WB)
Qualitative assay that uses an immunoblot format for the differentiation of herpes types 1 and 2 IgG antibodies. IgG antibodies are the most abundant type of antibody; they are found in all body fluids and protect against bacterial and viral infections.
Most accurate form of HSV-1 and HSV-2 testing.

Accurate 99 percent of the time because once infected, antibodies are always present, whether you are having an active outbreak or not, so this test can be done at anytime.

Culture and Typing (ELVIS®)
Enzyme-linked virus-inducible system (ELVIS®) — Cultures positive by ELVIS® are confirmed by immunofluorescent staining.
Specimens include: Vesicular fluid, ulcerated lesions, pharyngeal and throat swabs, urine, cerebrospinal fluid (CSF), autopsy and biopsy material, eye exudates, or vaginal swabs.

Culture Without Typing
Does not distinguish between HSV-1 and HSV-2.
Submit one specimen per test requested. Specify the exact specimen source/origin (eg, genital lesion).

Specimens include: Vesicular fluid, ulcerated lesions, pharyngeal and throat swabs, urine, cerebrospinal fluid (CSF), autopsy and biopsy material, eye exudates, or vaginal swabs.

Specimen is best collected within the first three days following the appearance of a lesion, but no more than seven days.

Enzyme-linked Immunosorbent Assay (ELISA) IgM and Type-Specific IgG
Blood test for herpes; The blood sample will be sent to a laboratory for analysis via Enzyme-linked Immunosorbent Assay (ELISA). In the lab, a technician adds the sample to a petri dish containing the specific antigen related HSV-1 or HSV-2. If your blood contains antibodies to the antigen, the two will bind together. The technician will check this by adding an enzyme to the petri dish and observing how your blood and the antigen react. If the contents of the dish change color, you may have the condition. How much change the enzyme causes allows the technician to determine the presence and amount of antibody.

IgM antibodies are found mainly in the blood and lymph fluid; they are the first antibody to be made by the body to fight a new infection.

Most helpful in determining brand new/primary cases of HSV, but if confirmation is received additional testing (IgG) is necessary to confirm results, because IgM testing can be faulty.

IgM testing is most helpful in determining HSV cases in newborns, not adults.
An indirect fluorescent antibody (IFA) test is performed at an additional cost if IgM antibodies are confirmed. In the indirect fluorescent antibody method, the specific antibody is allowed to react with the antigen. The nonantibody globulin is then washed off. This is then treated with a labeled antibody to the specific antibody, which results in a combination of this labeled antibody with the immunoglobulin already attached to the antigen.

The IFA procedure for measuring IgM antibodies to HSV-1 and HSV-2 will detect both type-common and type-specific HSV antibodies. Thus, detection of antibodies to both HSV 1 and HSV 2 may represent cross-reactive HSV antibodies rather than exposure to both HSV-1 and HSV-2.

The presence of IgM HSV antibodies indicates acute infection with either HSV type 1 or 2. The IgG antibody assay detects IgG-class antibodies to type-specific HSV glycoprotein G (gG), and may allow for the differentiation of infection caused by HSV types 1 and 2. The presence of IgG-class antibodies to HSV types 1 or 2 indicated previous exposure, and does not necessarily indicate that HSV is the causative agent of an acute illness.

Chemiluminescent immunoassay (CLIA)
Blood test; detect IgG antibodies specific to HSV types 1 and/or 2 infection
There is a considerable homology between HSV-1 and HSV-2 antigens, so that antibodies formed against either virus are highly cross-reactive. These assays are based on purified recombinant glycoprotein G-1 (HSV-1) or G-2 (HSV-2) antigens.

DNA Polymerase Chain Reaction (PCR)
A single test that both detects the presence of HSV DNA and determines which type is present in the positive samples. There is no mechanism, therefore, for testing for HSV-1 without simultaneously testing for HSV-2.
Specimens include: Cerebrospinal fluid (CSF), swab of lesions, whole blood, serum, plasma, or vitreous fluid.

This test is intended for use as an aid in the diagnosis of herpes simplex virus (HSV) infections; it also differentiates HSV-1 from HSV-2. PCR testing of blood, serum, or plasma samples is clinically useful only in potential cases of disseminated HSV infection (neonates, immunosuppressed individuals) and not as an aid in the diagnosis of either mucosal or CNS disease.

The testing methods for hepatitis B include:
Core Antibody Immunoassay (IgM) Blood Test
Hepatitis B core-specific IgM class antibodies have been detected in most acute infections and is a reliable marker for acute disease.

This is a blood test; IgM antibodies are found mainly in the blood and lymph fluid; they are the first antibody to be made by the body to fight a new infection. Hepatitis B core-specific IgM class antibody has been detected in most acute infections and is a reliable marker for acute disease.

In some cases, hepatitis B core IgM antibodies may be the only specific marker for the diagnosis of acute infection with hepatitis B virus.

False-positives may be detected shortly after immunization to influenza and with patients with hypergammaglobulinemia, positive rheumatoid factor, and connective tissue disorders.

Immunochemiluminometric Assay (ICMA) Surface Antigen Test
Blood test

Used to test blood donors (HBsAg positive individuals are rejected).
Hepatitis B surface antigen is the earliest indicator of the presence of acute infection. Also indicative of chronic infection.

Test is useful in the differential diagnosis of hepatitis.

Patients who are negative for HBsAg may still have acute type B viral hepatitis.

There is sometimes a “core window” stage when HBsAg has become negative and the patient has not yet developed the antibody (anti-HBs). On such occasions, both tests for anti-HBc are usually positive and anti-HBc, IgM is the only specific marker for the diagnosis of acute infection with hepatitis B. In cases with strong clinical suspicion of viral hepatitis, serologic testing should not be limited to detecting HBsAg, but should include a battery of tests to evaluate different stages of acute and convalescent hepatitis.

DNA Polymerase Chain Reaction (PCR)
Blood test
Chronic carriers will persist in producing detectable HBV. Patients with chronic liver disease of unknown origin most commonly have HBV that is detected by viral

DNA testing.
Quantitative measurement of HBV viral DNA may be used to monitor progression of disease.

the testing methods for hepatitis C include:
Antibody Tests

1. Enzyme Immunoassay (EIA)
Blood test; The 3rd generation HCV EIA has a sensitivity of approximately 98%.
Tells whether a person has been infected with the hepatitis C virus at some point in their life.

A positive antibody test does not necessarily mean a person still has hepatitis C.

An additional test (RNA test) is needed to determine if a person is currently infected with hepatitis C.

Antibodies are also called immunoglobulins (Ig). Antibodies are always present, whether you are having an active infection or not.

2. Chemiluminescence Immunoassay (CIA)

Blood test; CIA has similar sensitivity and specificity as the 3rd generation EIA.

Tells whether a person has been infected with the hepatitis C virus at some point in their life.

A positive antibody test does not necessarily mean a person still has hepatitis C.
An additional test (RNA test) is needed to determine if a person is currently infected with hepatitis C.

Antibodies are also called immunoglobulins (Ig). Antibodies are always present, whether you are having an active infection or not.

3. Point-of-Care Rapid Immunoassays:
Blood sample

OraQuick® HCV Rapid Antibody Test was FDA-approved in 2010 as a point-of-care test for use with whole blood samples obtained either by venipuncture or fingerstick.

OraQuick® HCV Rapid Antibody Test is the only point-of-care rapid immunoassay test that is FDA-approved at this time.

Viral RNA Polymerase Chain Reaction (PCR) Test

Blood test; Detects the presence or absence of hepatitis C virus circulating in the blood and is among the most sensitive tests available.

HCV RNA appears in blood and can be detected as early as 2–3 weeks after infection.

Determines if an individual is currently living with an active case of hepatitis C.

Quantitative tests to detect amount (titer) of virus (HCV RNA PCR)

Quantitative HCV RNA tests are used to evaluate the effect of antiviral therapy. If HCV RNA is undetectable both at the end of a course of treatment and 6 months later, long-term cure is highly probable.

Following antiviral therapy, a repeatedly negative test indicates clearance of the virus and recovery from the infection.

Genotyping
Blood test

Genotype refers to the genetic structure or makeup of living organisms. The hepatitis C virus has seven different genotypes so far and are named 1 through 7. Each genotype has subtypes, which were lettered in the order that they were discovered. Genotype 1 is the most common strain in the United States.
It is important to know which hepatitis C genotype you have, because it determines both the type and length of treatment and helps to predict the likelihood of curing HCV

In May 2013, the CDC published a new recommended testing sequence for diagnosing current (active) hepatitis C infection. The new recommended sequence consists of initial testing for HCV antibody (using either a rapid or laboratory-conducted assay), followed by HCV RNA testing for all positive HCV antibody tests. Persons who have a negative screening HCV antibody test are considered not infected with HCV and do not need further diagnostic evaluation, unless they have a known risk factor for a false-negative test, such as suspected acute HCV infection, chronic hemodialysis, or an immunocompromising condition.

Individuals who have a positive HCV antibody test and a positive HCV RNA are considered to have current (active) HCV infection. If an individual has a positive HCV antibody test and a negative HCV RNA assay, they are considered to have no evidence of current HCV infection; in this situation, further testing with a different HCV antibody assay can usually help to differentiate past (resolved) infection from a biologic false positive result. The 2013 HCV diagnostic testing sequence recommended by the CDC is not intended for diagnosing acute HCV infection.

HIV Test Types:

Blood tests for HIV include antibody screening tests (known as immunoassays), DNA tests, RNA tests, and oral fluid Rapid Tests.

HIV Antibody Blood Tests
Antibody tests measure the antibodies created by the immune system to fight off the HIV infection and, when taken up to 3 months after exposure, provide very reliable results. Antibody testing uses either blood, urine, or cells found in the oral fluid taken from along the cheeks and gums. The first FDA-approved HIV antibody test, the ELISA test, is still in use today, though it has undergone updates to incorporate the latest advances in HIV research. The ELISA (or EIA) antibody and antigen tests are the most common type of HIV test administered in developing countries and are currently in the 2nd, and 3rd generation of testing. The “generation” is determined by what is used as an antigen for identification.
The 1st Generation ELISA tests detected infected viral cell lysate as an antigen and are no longer used.

ELISA (EIA) Test Generations currently in use:

2nd Generation uses glycopeptides or recombinant antigens

3rd Generation uses synthetic peptides

4th generation antibody/antigen tests detect both the p24 (HIV-1) antigen and the HIV-1/HIV-2Ab antibody. (HIV p24 antigens are viral proteins that make up most of the core of the virus. Blood serum concentrations of p24 antigens are high in the first few weeks after infection; therefore tests sensitive to p24 antigens are useful for diagnosing very early HIV infections when antibody levels are still low.)

The 4th Generation ELISA test, which is used as an Early Detection HIV test, typically 2-4 weeks after exposure. Most people develop these antibodies (proteins that fight the HIV virus) within 18-25 days, but in rare cases it may take up to three months for them to develop. accurate results in the early stage of HIV infection. If any immunoassay result comes back positive, a second round of testing called an HIV antibody confirmation test, is used to confirm the diagnosis.

Second round tests include antibody differentiation testing, which detects the virus itself, or the Western blot test or indirect fluorescent assay (IFA), which detect HIV antibodies specifically.

RNA/DNA Blood Tests

DNA and RNA tests are used as Early Detection HIV tests because they measure actual HIV genetic material, eliminating much of the window period necessary for antibodies to build up for an immunoassay test. DNA and RNA tests can be taken as quickly as 1-2 weeks after infection

DNA tests measure the amount of genetic material belonging to HIV in the body, and include:
Polymerase chain reaction (PCR) tests, which can detect trace elements of HIV DNA in the bloodstream

Branched DNA (bDNA) tests, which use a substance that emits light to bind with HIV

Nucleic acid sequence based amplification (NASBA) tests, which amplify viral proteins to measure

RNA tests identify the genetic material that belongs to HIV rather than antibodies and can be given 9-11 days after HIV exposure, and include:
Nucleic acid amplification testing (NAAT)

Polymerase Chain Reaction (PCR), which measures the amount of HIV RNA in the bloodstream

Rapid Tests

Rapid HIV tests are an immunoassay typically offered in on-the-spot HIV testing sites and clinics, used to detect the presence of HIV antibodies with results in approximately 30 minutes. If the test is taken during the window period while antibodies aren’t at high enough levels for detection, it will return a false negative result. All immunoassays, including the ELISA tests, require follow-up testing to confirm the result. Rapid tests use:

Blood

Oral fluid containing cells from the inner cheek/gums

Urine Tests
In the mid-1990s, the Calypte test became the first FDA-approved, urine-based HIV test. The Calypte test used the ELISA method to detect antibodies to the virus and provided an opportunity to take an HIV test in a setting where blood testing was inconvenient. The test could only be ordered by a physician and required follow-up testing using the more reliable blood testing methods. Currently, urine tests are less common but are often part of at-home HIV tests that are not FDA-approved.
At-Home Tests
OraQuick® In-Home HIV Test- the only FDA-approved kit for self-processed rapid result testing at home

Results in about 20 minutes. The oral swab method is used to collect a sample of cells from inside the cheek and gums, which is then used as part of a kit that is available for purchase online or at pharmacies like Walgreens or Walmart. The manufacturer provides a referral program and counseling for all positive results. Approximately 1 in 12 people using the OraQuick® In-Home HIV Test may receive false-negative results.

The Home Access HIV-1 Test System is an FDA-approved single-use, disposable at-home laboratory test kit that uses the fingertip prick method to collect a blood sample, which is then mailed into their laboratory for testing. The kit includes all necessary tools to collect blood dots and mail the sample to the lab, including a pre-paid envelope especially for the specimen, a booklet with information about HIV and AIDS, and a call center for receiving results and follow up counseling by phone using a confidential code. This method can take longer to receive results due to the time the sample spends in transit before being tested at the lab. The kit can be purchased online or over the counter at local pharmacies.

Aside from the OraQuick® In-Home HIV Test and the Home Access HIV-1 Test System, no other in-home test kits have been approved by the FDA. Kits claiming to offer at-home HIV or STD testing have not had their claims evaluated by the FDA and, therefore, can’t be guaranteed to provide reliable results.

Testing Methods For HPV

There currently is no test approved to test for HPV in men, and there is not currently a test for HPV of the throat or mouth.

Nucleic Acid Amplification (NAA)
Human Papillomavirus (HPV) High-Risk DNA Detection
Detection of high-risk type HPV DNA sequences in female exfoliated cells (swab) or tissue biopsies.
The test provides a qualitative molecular detection of 13 different human papillomavirus high-risk types: 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68 without differentiation of the individual type.

How to test for Trichomoniasis:

Without treatment, a trich infection can last for months or years, and it is impossible to diagnose a Trichomonas infection based on symptoms alone.
Diagnosing a trichomoniasis infection usually requires a sample of discharge, requiring a pelvic exam for women and a urethral swab or urine sample for men. However the least invasive way to test for trichomoniasis in men or women is simply via a urine sample. The most common testing method for women is a “wet mount” or “wet preparation,” which allows for evaluation of the discharge under a microscope to confirm the presence of the parasite. A Trichomonas vaginalis culture can also be used to confirm the infection after it is discovered during a woman’s Pap smear if the presence of the parasite can’t be confirmed using microscopy.

The least invasive way to test for trichomoniasis is via a first catch or first void urine sample– meaning that the urine sample is the first 20-30 milliliters of urine in the initial stream of urine. Individuals should not have urinated for at least one hour prior to specimen collection.

Rapid antigen and nucleic acid probe blood tests can be used for on-the-spot tests with results available in minutes, but do not offer the accuracy of a test conducted using a discharge sample.

Most STD screenings do not include trichomoniasis, so in most cases, patients must request a trichomoniasis test.

Trichomoniasis is easily treated with a single dose of the antibiotics metronidazole or tinidazole. Vaginally applied medications may relieve the symptoms of trich, such as itching or swelling, but will not kill the parasite that causes the infection. In cases where metronidazole doesn’t cure a trich infection, it is almost always because a sexual partner has not been cured and has caused reinfection. In fact, 1 in 5 people get reinfected with trichomoniasis within three months of treatment.
Pregnant women are approved to take antibiotics to treat and cure a trich infection, but it doesn’t reduce their risk of preterm labor.

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