Sexually Transmitted Infections Overview

STIs are spread through intimate contact, including vaginal, anal, and oral sex, as well as skin-to-skin contact for some infections.

Most STIs do not provide immunity after infection. This means you can get re-infected with the same STI even if you've had it before.

The term "sexually transmitted infections" is preferred over "diseases" because many people with STIs have no symptoms and can still spread the infection.

The bacterium Neisseria gonorrhoeae causes gonorrhea.

Males with gonorrhea often experience painful urination and a pus discharge from the urethra.

Females with gonorrhea may have a mucus, pus, or bloody vaginal discharge, and sometimes painful urination.

Gonorrhea is typically treated with antibiotics. In the USA, a combination of two antibiotics is usually prescribed.

Untreated gonorrhea can cause serious complications like infertility and pelvic inflammatory disease.

Neisseria gonorrhoeae (the bacteria that causes gonorrhea) is resistant to all but one class of antibiotics.

Untreated gonorrhea in males can cause scarring of the urethra, leading to partial blockage and potential infertility. It can also infect the testes or vas deferens.

Untreated gonorrhea in females can lead to inflammation and Pelvic Inflammatory Disease (PID), potentially scarring the fallopian tubes and causing infertility.

Untreated gonorrhea can spread throughout the body, leading to infections of the heart, meninges (surrounding the brain and spinal cord), eyes, and joints, causing arthritis.

N. gonorrhoeae bacteria can be transmitted to a newborn during birth, potentially causing blindness.

Chlamydia often presents with no symptoms, especially in females (80%). When symptoms do occur, they include painful urination and watery discharge.

Females under 30 are at a high risk for chlamydia, with teenagers being at the highest risk due to the bacteria's preference for cells found on the adolescent cervix.

Untreated chlamydia in males can lead to infection and inflammation throughout the reproductive tract, potentially causing infertility.

Untreated chlamydia in females can lead to inflammation and PID, potentially scarring the fallopian tubes and causing infertility.

C. trachomatis bacteria can be transmitted to a newborn during birth, causing blindness or chlamydial pneumonia.

A sexually transmitted infection caused by the Herpes simplex virus (HSV), typically HSV-2, though HSV-1 can also cause it. Symptoms include painful blisters in the genital area and sometimes flu-like symptoms during the initial infection. Many infected individuals have no symptoms. Transmission occurs through direct contact with the blisters or through skin-to-skin contact even when no blisters are present.

After the initial infection, HSV travels to the nerve cells in the spine and becomes dormant, or latent. This means it remains in the body without causing symptoms. However, HSV can reactivate and travel back to the skin, causing new blisters.

There is no cure for HSV infection. However, antiviral drugs can help keep the virus latent, reduce viral transmission, and alleviate symptoms. Antivirals help manage outbreaks and reduce the risk of spreading the virus to partners.

If a pregnant woman experiences her initial infection with HSV early in pregnancy, the virus can cross the placenta and infect the developing fetus. This can lead to miscarriage, developmental disabilities, birth defects, and even death of the newborn.

Reactivated HSV during pregnancy generally does not enter the bloodstream and does not pose a direct risk to the fetus. However, if reactivation occurs close to birth, the virus can be transmitted to the newborn during delivery from skin-to-skin contact.

To prevent neonatal HSV infection, pregnant women are tested for HSV. If positive, they are monitored for reactivation during the last four weeks of pregnancy. If reactivation occurs, the baby will be delivered via C-section to avoid transmission during vaginal delivery.

An infection of the mucous membranes caused by the Human Papillomavirus (HPV), primarily affecting the genitals. Certain strains of HPV cause no symptoms, while others cause genital warts or even cancer. The immune system can sometimes destroy HPV before disease develops.

HPV types 16 and 18 are most associated with cervical cancer in women. Pap smears detect abnormal cell changes indicating potential cancer development. Specific tests for HPV 16 and 18 are recommended for women over 30. HPV 16 is also linked to throat cancer. Other HPV types are linked to other cancers in both genders' genital areas.

There is no cure for HPV infection. Warts can be removed using various methods like topical treatments, lasers, or freezing. Abnormal cells detected by pap smears can be removed from the cervix to prevent invasive cervical cancer. Early detection of abnormal cells usually leads to a better prognosis.

A vaccine containing proteins from 9 HPV types that provides protection against genital warts and cervical, vulvar, vaginal, and anal cancers. Recommended for both girls and boys aged 11-12, and can be given from ages 9 to 45. 2 doses for ages 9-14, and 3 doses for ages 15-45.

Studies have shown that Gardasil® vaccination significantly reduced the prevalence of HPV types 6, 11, 16, and 18, indicating its effectiveness in preventing HPV-related infections. This reduction was observed in both vaccinated individuals and within communities as a result of herd immunity.

Infection with the Human Immunodeficiency Virus (HIV), a retrovirus that targets and destroys cells crucial for immune system function, specifically helper T cells and macrophages, leading to a weakened immune system.

Acquired Immunodeficiency Syndrome (AIDS) is a disease caused by HIV. It develops when the damaged immune system can no longer effectively fight off infections, making individuals vulnerable to opportunistic infections and diseases.