Tests for sexually transmitted diseases and how to read the medical report

According to the WHO estimates, around 1 million new cases of sexually transmitted diseases (STDs) occur worldwide every day. In most cases, the symptoms of these diseases are very mild in the beginning and often go unnoticed. You may pass on an infection to your partner without knowing it. Getting tested for sexually transmitted diseases can ensure timely detection and prevent you from infecting your partner. What are the tests for sexually transmitted diseases? There is a host of STDs and various kinds of tests to diagnose them. For most people, STD is synonymous with HIV/AIDS. But there are a significant number of diseases that you can get from having sex with an infected person that can damage your sexual health and general wellbeing. Depending upon the disease, your blood, saliva, vaginal/penile discharge or urine sample may be collected and used for detecting the organisms or the antibodies against them. Blood tests for STDs most commonly include testing for chlamydia, gonorrhea, hepatitis B, herpes, HIV/AIDS, syphilis, and trichomoniasis. 1. Chlamydia Chlamydia infection causing bacteria is detected either in a urine sample or a vaginal/penile swab. 2. Gonorrhea Vaginal/penile swabs are checked to detect gonorrhea. Sometimes, a throat or anus culture may be done. 3. Hepatitis B

• Hepatitis B surface antigen test determines recovery from or vaccination for hepatitis B infection.
• Hepatitis B core antigen test determines past or recent infection.

4. Herpes Swabs from the sores or open ulcers are checked in the lab for the presence of the virus. Blood may be examined for antibodies. Recommended lab tests are:

• Viral culture
• DNA or PCR test
• Antibody test

5. HIV/AIDS HIV/AIDS tests detect HIV antigen or antibodies against HIV. There are separate tests for detecting HIV type1 and HIV type 2. The more recent tests may detect both forms with equal sensitivity. HIV antigen tests can detect the virus in newly infected persons. The RNA test directly detects the HIV organism within 11 days of exposure. HIV antibodies can be detected in blood drawn three to six months after possible exposure Tests that detect the HIV antigen

• Antigen p24 test
• PCR for plasma HIV RNA test

Tests that detect antibodies against HIV

• ELISA test
• Western blot test
• Antibody differentiation test

6. Syphilis VDRL and Rapid plasma reagin (RPR) tests done after possible exposure to the bacteria can detect antibodies in the blood. Treponemal antibody tests are blood tests that detect antibodies specific to the T. pallidum bacteria. 7. Trichomoniasis A lab test of swab samples taken from the genitals of men and women may be necessary to detect the presence of the one-celled parasite trichomonas vaginalis. When are the tests recommended? Testing for STDs is recommended as a part of preventive healthcare. The tests are also a part of routine prenatal care as the diseases can be transmitted from mother to child. Get yourself tested for sexually transmitted diseases is advised if you

• are 40 and have an active sex life
• have unprotected sex
• have a sexual relationship that is not mutually monogamous
• share syringes and needles with others

Once infected, you will have to live with some STDs all your life. So getting tested before tying the knot would be wise. There are some tests you need to take before marriage! Get tested for hepatitis today!Testing the blood for the presence of hepatitis C started in India only after 2002. Hence, it is advisable to get tested for if you have had a blood transfusion before 2002. Reading your test report The test report may be negative or positive. A negative test result means no STD-causing bacteria/viruses or antibodies to them were found at the time of the test. Some bacteria that cause STDs can be identified by looking through a microscope. Detection of the causative organism or antibodies to it indicates an infection. If your Hepatitis B surface antigen test report says positive or ‘reactive’, it may mean you are actively infected with hepatitis B virus. It also signifies that you are immune to the infection in the future. A negative or ‘nonreactive’ test results means no hepatitis B surface antigen was found. A positive test combined with positive results for the Hepatitis B core antigen indicates a long-standing infection. A positive p24 antigen test means the viral protein called p24 is detected. High levels of p24 antigen are seen in persons who are newly infected with HIV. The test is not reliable to detect HIV once it has progressed beyond the early stage. The gold standard for detecting HIV is an ELISA test followed by Western blot. ELISA is the screening test for HIV. Western blot test is performed to confirm the results of two positive ELISA tests. Positive ELISA and Western Blot test results mean that antibodies to HIV have been detected. The test result is negative during the time between HIV infection and the appearance of antibodies in the blood (window period). The anti-HIV antibodies may also be undetectable in the terminal stage of AIDS. Image source: Shutterstock (Image for representational purpose only)

---