Sexually Transmitted Diseases

Sexually transmitted infections (STIs) or sexually transmitted diseases (STDs) are infections that are spread from one person to another during sexual activity. These infections are passed through the exchange of blood or other bodily fluids, such as semen or vaginal fluids. In addition to intercourse, the infections can also be passed through anal or oral sex, and skin-to-skin contact.

In some cases, these types of infections can be transmitted without sexual contact, such as from a mother to her infant during pregnancy or childbirth, shared needles, or blood transfusions.

STIs can be caused by bacteria, parasites, or viruses. Some of the most common STIs and their etiologic agents are the following:

  • Chlamydia is caused by Chlamydia trachomatis. This usually presents with vaginal discharge in women and penile discharge in men. This can cause painful urination and itching or burning sensation around the genital area.
  • Syphilis is caused by Treponema pallidum. This is characterized by painless ulcers on the genital area or on the mouth that usually heal spontaneously.
  • Gonorrhea is caused by Neisseria gonorrhea. This presents with whitish to yellowish vaginal discharge in women and penile discharge in men. This can cause sore throat among those who engage in oral sex.
  • Trichomoniasis is caused by the parasite Trichomonas vaginalis. Similar to Chlamydia, this also presents with genital discharge that is yellowish to greenish in color, associated with painful urination and burning or itching around the genital area.
  • Genital Herpes is caused by Herpes Simplex Virus (HSV). It is typically characterized by blisters or ulcers on the genital area or mouth.
  • Genital Warts is caused by Human Papilloma Virus (HPV) and is characterized by small, flesh, cauliflower-like lesions on the genital area. HPVs can also cause cervical and penile cancers.
  • Hepatitis B and C are caused by Hepatitis Virus. Hepatitis affects the liver and presents with flu-like symptoms, jaundice (yellowing of skin), and abdominal pain.
  • HIV is caused by Human Immunodeficiency Virus, the virus that causes Acquired Immunodeficiency Syndrome (AIDS), which makes an individual vulnerable to many other infections.


As mentioned, STIs can exist without symptoms especially in women; therefore, it is recommended that men and women undergo screening even if they do not feel any signs and symptoms of infection. Screening can help catch a disease in its early stages so that treatment can be started immediately. In addition, by detecting infection in apparently well individuals, screening can help prevent the spread of STIs.

The following are the recommendations for screening for STIs:

  • All adults and adolescents ages 13 to 64 be tested at least once for HIV.
  • Sexually active women younger than 25 years old should be screened routinely for chlamydia and gonorrhea annually and for HIV at least once. Screening for cervical cancer should also begin in this age group.
  • Sexually active women who are 25 years and older should be screened for chlamydia, gonorrhea, syphilis, trichomoniasis and hepatitis if they have risk factors for STIs. These risk factors are new or multiple sex partners, sex partners with multiple concurrent partners, recent STI diagnosis, and sexual activity in exchange for money or drugs. Screening for cervical cancer should be continued in this age group. HIV screening should be done at least once if not yet done previously.
  • Cervical cancer screening every 3 years for all sexually active women or women aged 21-29. Women aged 30 to 65 should have a combination pap test and HPV test every 3 years.
  • Pregnant women are routinely screened in the first trimester for syphilis, chlamydia, gonorrhea, hepatitis, and HIV.
  • Heterosexual men (or those who have sex only with women) are screened at least once for HIV.
  • Yearly HIV testing for anyone who shares injection drug equipment.
  • Men who have sex with men (MSMs) should be routinely screened for chlamydia, gonorrhea, syphilis, and HIV at least annually. Hepatitis screening should be done at least once.
  • HIV-infected men and women should be screened for chlamydia, gonorrhea, syphilis, and trichomoniasis (for women only) at least annually. Hepatitis screening should be done at least once.

Screening for STIs usually involves tests on blood and/or other specimens like urine, vaginal swab, urethral swab, rectal swab, and oropharyngeal swab. Screening for syphilis, hepatitis and HIV involve blood tests whereas screening for gonorrhea, chlamydia, and trichomoniasis involve urine tests and other swabs.

Screening tests can be done in clinics or in other certified laboratories under the guidance of a doctor or a nurse. Some laboratories will allow anonymous screening to protect the reputation of the patient in case the test comes out positive. Other self-test screening kits are available which allow the patient to do the test at home. However, the accuracy and reliability of these tests are not guaranteed and should be used with caution.

Management of STIs

If a screening test comes out positive, then prompt treatment should be given. Treatment varies depending on the type of STI. In general, STIs caused by bacteria are treated with antibiotics whereas STIs caused by viruses are treated with anti-virals (or anti-retrovirals for HIV). These treatments aim to prevent the progression of the infection and prevent its spread to other people.

As soon as a person is diagnosed with STI, his or her partner/s should be informed. The local health department should be notified as well to facilitate contact tracing or screening of those whom the patient could have possibly infected. Sexual activity should be avoided until the patient is cleared by the doctor to resume sex.


There is no foolproof way of preventing STIs other than abstinence from sex. However, there are ways that can decrease an individual’s risk of acquiring STIs:

  • The use of latex condom during sex is proven to decrease the risk of STI transmission. However, if lubricant is to be used, make sure that it is water-based so as not to compromise the integrity of the condom.
  • Limiting the number of sexual partners limits the risk of STI transmission. If possible, practice monogamy, that is, have sex with only one partner and that partner should have sex only with you.
  • Know the signs and symptoms of STIs and look for them in you or in your partner. Avoid having sex with persons whom you suspect to have STI. Similarly, avoid having sex if you suspect that you have STI.
  • Ask your doctor about vaccines that can protect you from STIs. At present, vaccines are available for HPV and hepatitis infection. Get these vaccines and encourage your partner to do likewise.