What are Common sexually transmitted infection?

Overview of Sexually Transmitted Infections

Sexually transmitted infections (STIs), also termed sexually transmitted diseases or STDs, can be caused by a number of microorganisms that vary widely in size, life cycle, the diseases and symptoms caused, and susceptibility to available treatments.

 

Bacterial STIs include

·         Syphilis

·         Gonorrhea

·         Chancroid

·         Lymphogranuloma venereum

·         Granuloma inguinale

·         Chlamydial, mycoplasmal, and ureaplasmal infections

Viral STIs include

·         Genital and anorectal warts

·         Genital herpes

·         Molluscum contagiosum

·         HIV infection

Parasitic infections that can be sexually transmitted include

·         Trichomoniasis (caused by protozoa)

·         Scabies (caused by mites)

·         Pediculosis pubis (caused by lice)

Many other infections not considered primarily to be STIs—including salmonellosis, shigellosis, campylobacteriosis, amebiasis, giardiasis, hepatitis (A, B, and C), Zika virus infection, and cytomegalovirus infection—can be transmitted sexually.

 

Because sexual activity includes close contact with skin and mucous membranes of the genitals, mouth, and rectum, many organisms are efficiently spread between people. Some STIs cause inflammation (eg, in gonorrhea or chlamydial infection) or ulceration (eg, in herpes simplex, syphilis, or chancroid), which predispose to transmission of other infections (eg, HIV).

 

STI prevalence rates remain high in most of the world, despite diagnostic and therapeutic advances that can rapidly render patients with many STIs noninfectious. In the US, an estimated 20 million new cases of STIs occur each year; about half occur in people aged 15 to 24 years (see also Centers for Disease Control and Prevention [CDC]: Sexually Transmitted Disease Surveillance 2018).

 

Factors impeding control of STIs include

 

·         Unprotected sexual activity with multiple partners

·         Difficulty talking about sexual issues for both physicians and patients

·         Inadequate funding for implementing existing diagnostic tests and treatments and for developing new tests and treatments

·         Susceptibility to reinfection if both partners are not treated simultaneously

·         Incomplete treatment, which can lead to development of drug-resistant organisms

·         International travel, which facilitates rapid global dissemination of STIs

Symptoms and Signs of STIs

Symptoms and signs of STIs vary depending on the infection. Many STIs cause genital lesions (see table Differentiating Common Sexually Transmitted Genital Lesions).

Differentiating Common Sexually Transmitted Genital Lesions  

Diagnosis of STIs

Often clinical evaluation

Gram staining and culture

Laboratory tests

STIs are diagnosed and treated in a variety of settings; for many, diagnostic tests are limited or unavailable or patient follow-up is uncertain. Thus, identification of the causative organism is often not pursued. Often, diagnosis is based only on clinical findings.

 

Diagnostic testing may include Gram staining and culture or laboratory tests such as nucleic acid amplification tests (NAATs). Diagnostic testing is done more often in the following situations:

 

The diagnosis is unclear.

The infection is severe.

Initial treatment is ineffective.

Other reasons (eg, public health surveillance, psychosocial reasons, including extreme mental distress and depression) are compelling.

Treatment of STIs

Syndromic treatment

Sometimes antimicrobials

Simultaneous treatment of sex partners

Because diagnostic tests are often limited or unavailable and/or patient follow-up is uncertain, initial treatment is often syndromic—ie, directed at the organisms most likely to cause the presenting syndrome (eg, urethritis, cervicitis, genital ulcers, pelvic inflammatory disease).

 

Most STIs can be effectively treated with drugs. However, drug resistance is an increasing problem.

 

Patients who are being treated for a bacterial STI should abstain from sexual intercourse until the infection has been eliminated from them and their sex partners. Sex partners should be evaluated and treated simultaneously.

 

Viral STIs, especially herpes and HIV infection, usually persist for life. Antiviral drugs can control but not yet cure all of these infections.

 

Prevention of STIs

STI control depends on

 

·         Adequate facilities and trained personnel for diagnosis and treatment

·         Public health programs for locating and treating recent sex partners of patients

·         Follow-up for treated patients to ensure that they have been cured

·         Education of health care practitioners and the public

·         Avoidance of high-risk behaviors by patients

·         Condoms and vaginal dams, if used correctly, greatly decrease risk of some STIs.

 

Vaccines are unavailable for most STIs, except for hepatitis A, hepatitis B, and humanpapillomavirus infection.