Sexually Transmitted Infections
Sexually transmitted infections (STIs) are significant causes of illness and infertility. Notice that we use the term "infection" because not all infections progress to a disease state.
Sexually transmitted infections are primarily transmitted during sexual activity, though not exclusively.
Causative agents include parasites, bacteria, and viruses that travel in body fluids; many are transmitted via semen or vaginal fluids, and some are also transmitted via the blood.
Some pathogens may also be spread through non-sexual activity, for example, via infected needles, blood transfusions, or during childbirth.
Many people with sexually transmitted infections are asymptomatic or have only mild symptoms.
Because of this, individuals may be unaware of their infected status, and can unknowingly spread infection to their partners.
Prevention includes the use of barrier methods, such as condoms and dental dams, during sexual activity.
Screening programs can identify infections in asymptomatic individuals, and treatment programs can cure certain infections, thus preventing their spread.
Diagnosis involves blood, urine, and discharge testing.
Pelvic Inflammatory Disease
Some untreated sexually transmitted infections can lead to pelvic inflammatory disease (PID), which occurs when infection spreads from the vagina to the uterus, uterine tubes, or ovaries.
The two most common causes of pelvic inflammatory disease are Chlamydia trachomatis and Neisseria gonorrhoeae.
PID Symptoms worsen over time: Longer, heavier periods, abdominal and pelvic pain, pain during intercourse, vaginal discharge, fever, chills, and fatigue.
Permanent damage to the organs and peritoneum can lead to ectopic pregnancy, infertility, and chronic pelvic pain.
Common STI symptoms & complications:
- Vaginal or penile discharge.
- Urethral burning and pain during urination.
- Ulcers in the genital, anal, or oral areas.
- Itching.
- Abdominal and pelvic pain.
- Tender or swollen testicles.
- Bleeding between periods.
- Pelvic Inflammatory Disease
As mentioned previously, some infections, particularly chlamydia and gonorrhea, can lead to infertility and/or pelvic inflammatory disease if untreated.
- Many infections increase the risk of Human Immunodeficiency Virus infection; some infections break down physical or chemical barriers to HIV virion entry.
- Human papillomavirus (HPV) is associated with cervical cancer.
- Several sexually transmitted infections can produce congenital infections when passed to the fetus or neonate. Particularly syphilis, chlamydia, gonorrhea, hepatitis B, herpes simplex virus, and human immunodeficiency virus.
Trichomoniasis is caused by the parasite
Trichomonas vaginalis.
This is the most common non-viral curable sexually transmitted infection.
Women are more often symptomatic than men, and experience vaginal itching and a foul-smelling, sometimes frothy discharge.
Cervical irritation can lead to microscopic hemorrhaging and produce colpitis macularis, aka, "strawberry cervix".
Infections during pregnancy have been associated with low birth weight, premature membrane rupturing, and other complications.
Treatment typically involves metronidazole or tinidazole.
Although trichomoniasis has historically been thought of as relatively benign, infection increase a person's risk of acquiring other sexually transmitted infections, including HIV.
Chlamydia is caused by the bacterium
Chlamydia trachomatis, serovars D-K.
Chlamydia is one of the most common STIs in the United States.
In addition to the genitals and anus, it can also infect the throat and eyes, and it is associated with reactive arthritis.
This primarily affects the lower extremities, though the eyes and urethra may also be inflamed (reactive arthritis is historically known as Reiter's syndrome).
Treatment includes Azithromycin; Early treatment is important because of chlamydia's association with pelvic inflammatory disease.
Gonorrhea is the result of infection by the bacterium
Neisseria gonorrhoeae.
It is also a major cause of pelvic inflammatory disease; it can infect the throat and eyes.
Dual treatment with ceftriaxone and azithromycin recommended.
Syphilis is caused by the bacterium
Treponema pallidum.
Syphilis progresses thorough four stages:
During the early stages, a person is highly contagious, though symptoms may be mild or even go unnoticed.
Primary syphilis is characterized by painless lesions, called chancres, at the site of infection; nearby lymph nodes may also swell.
Secondary syphilis occurs when the infection disseminates. This leads to the following symptoms: rash, which may appear on the palms of the hands and soles of the feet; mucous membrane lesions; headache; malaise; lymphadenopathy; and others.
Even without treatment, these symptoms will subside on their own, and the latent period will begin. This asymptomatic phase can last for years.
Tertiary phase is characterized by aortitis and gummas that form in the skin, bone, viscera, and other tissues.
Neurosyphilis is an important complication of untreated syphilis; infection can affect the both the meninges and CNS parenchyma.
Early treatment is important; penicillin can cure syphilis by eradicating the bacteria, but cannot reverse organ damage.
Includes four viruses that cause incurable sexually transmitted diseases, including two that are preventable by vaccines.
Hepatitis B is transmitted in the blood in addition to semen and vaginal fluids; thus, infection can also be acquired via non-sexual activity.
Hepatitis B causes liver infection and inflammation; acute infections can progress to chronic infection, cirrhosis, or even liver cancer.
Infants, who can acquire infection from their mothers, are especially at risk for chronic hepatitis and serious complications.
Hepatitis B is preventable via vaccine.
Treatment for chronic hepatitis includes antivirals and interferons.
Human Herpes Viruses 1 & 2 can cause genital herpes.
Although Human Herpes Virus 1 is primarily responsible for oral lesions, the virus can also cause genital lesions when transmitted via oral-genital contact.
Genital herpes is common in the United States, and, when symptomatic, it produces painful blisters or ulcers in the genital or perianal regions.
Acyclovir is used to treat herpes infections.
Human Papillomavirus (HPV)
Very common; the CDC reports that most sexually active people will be infected with HPV at some point in their lives.
In addition to the genitals and anus, the mouth, throat, and eyes can also be infected.
HPV types 6 and 11 are associated with the formation of genital and anal warts; these growths can be flat or raised with a cauliflower-like appearance, and are generally harmless. When needed, warts can be removed.
HPV types 16 and 18 (and others), are associated with cervical, oropharyngeal, and other cancers.
HPV vaccines target several of the strains responsible for genital warts and cancer.
Human Immunodeficiency Virus travels in the blood as well as in semen and vaginal fluids.
HIV infection destroys
T-cells of the immune system and weakens the immune response.
Thus, infected people are vulnerable to recurrent and opportunistic infections.
If untreated, HIV can progress to AIDS (acquired immune deficiency syndrome).
Anti-retroviral therapy is used to treat patients with HIV and prevent the development of AIDS.
Pre-exposure prophylaxis (PrEP) can help prevent HIV acquisition in those who are at high risk of contracting the virus.
