Sexually Transmitted Diseases (STD)

Sexually transmitted diseases (STD), as the name suggests, refers to an illness that is acquired through sexual contact. These conditions are caused by infection with bacteria, virus or parasites. Often the presence of the infection may be asymptomatic, so it is now preferred to refer to STDs as sexually transmitted infections (STIs).

STIs are incredibly common with about 1 million infections acquired worldwide every day.

Types and Causes of STIs

Bacterial

Chlamydia: This is one of the most common STIs in the world and is often asymptomatic for a long period of time while still transmissible.
Gonorrhea: This is also a very common STI and can also affect the throat eyes and joints. There is a risk of spread to the rest of the body if untreated
Syphilis: this presents initially with a large painless ulcer in the genital region. It is effectively treated in the early stages but can progress to affect the skin, bones, liver, and brain at late stages.

Viruses

Herpes: this infection leads to small painful vesicles around the genitalia. Once infected, the virus resides in the nerves supplying that area of skin and cannot be eradicated. The lesions come and go episodically.
Human Immunodeficiency Virus (HIV): this is the virus, known to cause AIDS (Advanced Immunodeficiency syndrome), which currently has no cure. Drugs are available to control the progression of the illness. HIV can be transmitted through sharing infected needles during drug abuse and also from mother to child.
Human Papilloma Virus (HPV): this is the virus that causes warts and also has potential over a long period of time to manifest as cervical cancer in women and other forms of skin cancer in men.
Hepatitis A, B, and C: these viruses all lead to hepatitis (inflammation of the liver). Hepatitis A can also be transmitted through contaminated food and water, while Hepatitis B and C may also be transmitted through sharing needles and from mother to child. Hepatitis A resoles on its own with supportive care, while the other two types are harder to control. New medications are being developed for their management, but if left uncontrolled, result in liver cirrhosis, liver cancer failure of liver function and death.

Parasites

Trichomonas: this is a pear-shaped parasite with a flagella (tail), and causes a foul-smelling vaginal discharge. This is effectively treated using antibiotics.

Risk Factors for STIs

Multiple sexual partners
Unprotected sexual intercourse
Presence of another STI
Decreased Immunity
Men who have sex with men (MSM)
Injection drug abuse (HIV, Hepatitis B, and C)

Symptoms of STIs

Genital ulcers
Pain in the genital region
Discharge from the urethra or vagina which may be foul-smelling or bloody
Burning during the passage of urine
Swelling in the groin from swollen lymph nodes
Warts
Rash elsewhere on the body
Lower abdominal pain
Pain during sexual intercourse

Diagnosis of STIs

The diagnosis for most forms of STIs may be suspected based on the history of symptoms and clinical examination of the genitalia. Specific lab investigations may be performed to confirm the diagnosis as follows

Microscopic examination of ulcer scraping or discharge
Microscopic examination of discharge from urethra or vagina
Routine examination and culture of Urine
Blood investigations looking for evidence of infection (Syphilis, HIV, Hepatitis B)
DNA testing of discharge fluid for Chlamydia and Gonorrhea

Treatment of STIs

The treatment depends on the particular infection. Several STIs like Chlamydia, Gonorrhea, trichomoniasis and early-stage syphilis can be treated effectively with antibiotics. However, others do not have a cure.

In many cases, the sexual partner(s) of the individual would also need to be treated.

Options are available for controlling symptoms and delaying progression, which should be addressed along with a specialist in Infectious Diseases.

Complications of STIs

Spread of infection to reproductive organs leading to orchitis (inflammation of testes) in men and pelvic inflammatory disease (PID – inflammation of the female reproductive tract).
Infertility
Systemic spread of infection with risk of sepsis
HIV, Hepatitis B, and untreated syphilis are severe chronic illnesses with no cure and high risk of death
Increased risk of acquiring other STIs
Risk of miscarriage in pregnant women

Prevention of STIs

Usage of barrier contraception such as condoms
Avoid having multiple sexual partners
Improved identification and treatment of those with existing STIs, to control the spread

References

Centers for Disease Control and Prevention, et al. Sexually Transmitted Diseases Treatment Guidelines, 2015. MMWR. 2015;64:1. Accessed May 26, 2019.
Sexually transmitted infections (STIs). World Health Organization. https://www.who.int/news-room/fact-sheets/detail/sexually-transmitted-infections-(stis) Accessed May 26, 2019.
Ghanem KG, et al. Screening for sexually transmitted infections. http://www.uptodate.com/home. Accessed May 26. 2019.