Sexually Transmitted Diseases: Causes, symptoms & treatments

Sexually Transmitted Diseases (STD), also known as Sexually Transmitted Infection (STI) or Venereal Disease (VD) is transmitted between human through sexual contacts, which includes vaginal intercourse, oral sex and anal sex.

In the recent years, public health officials have started using the term sexually transmitted infection instead of sexually transmitted disease as the former has a broader range of meaning. The difference between the two terms being that STI simply means that the person being infected with the virus, bacteria or parasite would necessarily show symptoms of feeling sick whereas an STD would mean that the person shows signs of being sick.


Chancroid (Haemophilus ducreyi)

Chancroid is a sexually transmitted bacterial infection caused by Haemophilus ducreyi, fastidious gram-negative Coccobacillus and is characterised by painful sores on the genitalia. It is also a risk factor for contracting Human Immunodeficiency Virus (HIV).


The symptoms are usually visible within one day to two weeks of the incubation period, which begins with a small bump and turns into an ulcer within a day of its appearance. The size of the ulcers varies dramatically from 3 to 50 mm across and has sharp defined, undermined ragged borders. The ulcers are very painful and are covered with a gray or yellowish-gray material that bleeds easily if traumatised.

There is only a single ulcer in most infected men and appears in coronal sulcus of the uncircumcised glans penis, whereas women frequently have four or more ulcers, characterized by dysuria (pain with urination) and dyspareunia (pain with intercourse).The common location in women is the labia majora.


The Centers for Disease Control and Prevention recommend a single oral dose (1 gram) of Azithromycin or oral Erythromycin or a single IM dose of Ceftriaxone for seven days.

Chlamydia (Chlamydia trachomatis)

This infection is caused by bacterium Chlamydia trachomatis and is one of the most common sexually transmitted infections worldwide. Chlamydia is a major cause of genital and eye disease among humans.


Chlamydial infection of cervicitis is asymptomatic in about half and three-quarters of all infected women. The infection which is transmitted through vaginal, anal or oral sex, if not detected timely, can cause pelvic inflammatory disease (PID), a generic term for infection of the uterus, fallopian tubes, and/or ovaries. PID can cause scarring inside the reproductive organs, which can later cause serious complications during pregnancy and chronic pelvic pain.

Symptoms that may occur include

• Pain in the abdomen
• Vaginal bleeding or discharge
• Dyspareunia (painful sexual intercourse)
• Fever
• Urinary urgency (painful urination or the urge to urinate more frequently than usual)
In 50% of cases among men, Chlamydia shows symptoms of infectious urethritis (inflammation of the urethra) characterised by
• Painful or burning sensation when urinating
• Unusual discharge from the penis
• Swollen or tender testicles
• Fever
• It can spread to the testicles causing epididymitis, which in rare cases, can cause sterility if left untreated

Chlamydia can also cause Chlamydia conjunctivitis or trachoma, reactive arthritis (Reiter`s Syndrome), urethritis (inflammation of the urethra) - especially in young men, perinatal infections, lymphogranuloma venereum, an infection of the lymph nodes and lymphatics.

Chlamydial infections can be diagnosed through Nucleic Acid Amplification Tests (NAAT), such as Polymerase Chain Reaction (PCR), Transcription Mediated Amplification (TMA), and the DNA Strand Displacement Amplification (SDA).


Chlamydia trachomatis infection can be effectively cured with antibiotics once it is detected. The Centers for Disease Control and Prevention recommend Azithromycin 1 gram oral as a single dose or doxycycline 100 milligrams twice daily for seven to fourteen days or tetracycline or erythromycin.

Granuloma inguinale or (Klebsiella granulomatis)

Granuloma inguinale is a bacterial disease that spreads from one host to another through contact with the open sores and is characterized by ulcerative genital lesions.
It is also known as donovanosis, lupoid form of groin ulceration, granuloma genitoinguinale, granuloma inguinale tropicum, serpiginous ulceration of the groin, granuloma venereum, granuloma venereum genitoinguinale, ulcerating granuloma of the pudendum and ulcerating sclerosing granuloma.


After 10-40 days of contact with the bacteria, small, painless nodules appear on the shaft of the penis, the labia, or the perineum which later bursts, creating open lesions mutilating the infected tissue, with extensive leakage of mucus and blood from the highly vascular lesions

The infection can be diagnosed through tissue biopsy and Wright-Giemsa stain.


Streptomycin, erythromycin or tetracycline treatment for 3 weeks or 12 weeks of treatment with ampicillin can help cure of the infection effectively.

Gonorrhea (Neisseria gonorrhoeae)

Caused by the bacterium Neisseria gonorrhoeae, Gonorrhea is a sexually transmitted disease which, if left untreated, may spread throughout the body, affecting joints and heart valves or cause epididymitis or pelvic inflammatory disease (PID).


Though Gonorrhea infection in half of the women is asymptomatic, it is usually characterised by vaginal discharge, pain during intercourse and lower abdominal pain. Burning with urination and discharge from the penis are common signs of infection among men. The symptoms occur within 4-6 days after being infected.

Gonorrhea was traditionally diagnosed with gram stain; however, newer polymerase chain reaction (PCR) based testing methods are becoming common these days.


Gonorrhea is commonly treated with ceftriaxone.

Syphilis (Treponema pallidum)

Syphilis disease is caused by the spirochetal bacteria Treponema pallidum subspecies pallidum. Though it`s a sexually transmitted disease, it can also spread from an infected mother to her newborn causing congenital syphilis.


Signs and symptoms of syphilis vary depending on which of the four stages it presents in:

1. Primary: A chancre (painless ulceration) appears within 3-90 days after initial exposure.

2. Secondary: It occurs approximately 4 to 10 weeks after the primary infection. An infected person at this stage can have a symmetrical reddish-pink non-itchy rash on the trunk and extremities including the palms and soles or form condyloma latum (flat, broad, whitish, wart-like lesions). Other symptoms include malaise, weight and hair loss, fever, sore throat, and headache. Rare symptoms include periostitis, hepatitis, kidney disease, uveitis, arthritis, optic neuritis, and interstitial keratitis.

3. Latent: it shows little or no symptoms

4. Tertiary: It occurs approximately 3 to 15 years after the initial infection and may be divided into three: late neurosyphilis, cardiovascular syphilis and gummatous syphilis.

Blood tests or direct visualisation using microscopy can be used to diagnose syphilis.

For early infections, a single dose of intramuscular penicillin G can be very effective. Doxycycline and tetracycline can also be used as an alternative choice but is not recommended for pregnant women. Ceftriaxone can also be an effective treatment.

For later stage of infection or neurosyphilis, heavy doses of intravenous penicillin are given for a minimum of 10 days. In case the infected person is allergic, ceftriaxone may be used. Intramuscular penicillin G once weekly for three weeks can also be used in later stages. Doxycycline or tetracycline may be used for a longer duration in case a person is allergic.


Tinea cruris

Tinea cruris is a dermatophyte fungal infection of the groin region which may be sexually transmitted.

Also called jock itch, crotch itch, eczema marginatum, gym itch, crotch rot and ringworm of the groin is caused by a fungus called Trichophyton rubrum.


It causes itching or a burning sensation in the groin area, thigh skin folds, or anus.
Affected areas may appear red, tan or brown, with flaking, or cracking skin and the borders may exhibit tiny pimples or even pustules. The rashes usually advance down the thigh and can extend back to the perineum and perianal areas.


It is usually treated with antifungal drugs applied topically. Usually creams containing terbinafine, econazole nitrate, tolnaftate, miconazole, Ciclopirox, naftifine, oxiconazole or clotrimazole are used.

In case of itching, glucocorticoid steroids may be combined with the anti-fungal drug to help prevent further irritation.

In order to avoid a fungal infection, it`s best advised to wear loose inner wear and sleepwear, exposing the area to wind and sun and thoroughly cleaning the area with water and soap.

Candidiasis (yeast infection)

Candidiasis or thrush is a fungal infection, which is also referred to as a yeast infection, candidosis, moniliasis, and oidiomycosis.

Candidiasis includes infections ranging from superficial, such as oral thrush and vaginitis, to systemic and potentially life-threatening diseases. Types of Candidiasis:

• Oral candidiasis (Thrush)
• Perlèche (Angular cheilitis)
• Candidid
• Antibiotic candidiasis (Iatrogenic candidiasis)
• Candidal vulvovaginitis
• Candidal intertrigo
• Diaper candidiasis
• Candidal paronychia
• Erosio interdigitalis blastomycetica
• Congenital cutaneous candidiasis
• Perianal candidiasis
• Chronic mucocutaneous candidiasis
• Systemic candidiasis


Candidiasis symptoms vary depending on the area affected.

Infection of the vagina or vulva can cause severe itching, burning, soreness, and a whitish or whitish-gray cottage cheese-like discharge.

Infection of the male genitalia includes red patchy sores near the head of the penis or on the foreskin, severe itching, or a burning sensation.

Microscopic examination or culturing is used to diagnosis Candidiasis.


Candidiasis is commonly treated with antimycotics, antifungal drugs like topical clotrimazole, topical nystatin, fluconazole, and topical ketoconazole.


Viral hepatitis

Hepatitis A and Hepatitis E are transmitted via the faecal-oral route and Hepatitis B virus can be transmitted through blood transfusion, tattoos, sexual intercourse or via mother to child by breast feeding.

Herpes simplex

Herpes simplex (Ancient Greek: ??p?? - herpes, lit. "creeping") is a viral disease caused by both herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2).

HSV1 primarily causes mouth, throat, face, eye, and central nervous system infections, while HSV2 primarily causes anogenital infections.


HSV infection causes different medical disorders. Common infection of the skin or mucosa may affect
• Face and mouth (orofacial herpes)
• Genitalia (genital herpes)
• Hands (herpes whitlow)

The virus also infects and damages the eye (herpes keratitis), damages the brain (herpes encephalitis) causing more serious disorders.

Primary orofacial herpes is readily identified by clinical examination of persons. Genital herpes laboratory tests include: Polymerase Chain Reaction (PCR), culture of the virus, Skin biopsy and Direct Fluorescent Antibody (DFA).


Vaccines for HSV are still undergoing trials and no method has been discovered yet to eradicate this virus. Analgesics such as ibuprofen and acetaminophen can be helpful in reducing pain and fever and topical anaesthetic treatments such as lidocaine, benzocaine, prilocaine, or tetracaine can help relieve pain and irritation.

HIV (Human Immunodeficiency Virus)

Human Immunodeficiency Virus (HIV) is a life threatening virus that causes Acquired Immunodeficiency syndrome (AIDS) in humans leading to failure of the immune system.

The Four major routes of transmission are
• Unsafe sex
• Contaminated needles
• Breast milk
• Perinatal transmission (transmission from an infected mother to her baby at birth)


The count of helper T cells, specifically CD4+ T cells decreases drastically and viral load increases in an infected person.

The four basic stages of infection include

Incubation period: This period usually lasts between two and four weeks and is asymptomatic.
Acute infection: This period lasts an average of 28 days and the infected person at this stage shows symptoms like fever, lymphadenopathy, sore throat, muscle pain, rash, malaise, and mouth and esophageal sores.
Latency stage: This stage can last anywhere from two weeks to twenty years and beyond and shows few or no symptoms.
AIDS: The CD4+ T cell count of a person at this stage drops below a critical level of 200 cells per µL, shows symptoms of various opportunistic infections and loses cell-mediated immunity.

Diagnosis of HIV is difficult as the person infected may be unaware of the presence of the virus. Initially, the virus is detected with an Enzyme-Linked Immunosorbent Assay (ELISA). The specimens with a reactive ELISA result are re-tested in duplicate. In case the specimen is repeatedly reactive, it undergoes confirmatory testing like Western blot or an Immunofluorescence Assay (IFA).


Currently there is no available vaccine or cure for HIV or AIDS.

Compilation by: Liji Varghese