Overview: Sexually Transmitted Infections

Sexually transmitted infections (STIs) or sexually transmitted diseases (STDs) are infections that spread either by vaginal intercourse, anal sex, or oral sex. Symptoms and signs may include vaginal discharge, penile discharge, dysuria, skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin lesions (e.g., warts, ulcers) on or around the genitals, and pelvic pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain. Some infections can lead to infertility Infertility Infertility is the inability to conceive in the context of regular intercourse. The most common causes of infertility in women are related to ovulatory dysfunction or tubal obstruction, whereas, in men, abnormal sperm is a common cause. Infertility and chronic debilitating disease. And some STIs can affect infants by vertical transmission. Diagnosis of STIs includes a combination of comprehensive medical and sexual history, assessing risk factors, focused genitourinary physical exam, and disease-specific laboratory tests/cultures. Treatment and prevention include a combination of antibiotic/antiviral agents and patient education on safe sex practices.

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Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

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Epidemiology

  • 26 million new STIs diagnosed in the United States in 2018 
  • High-risk patient groups:
    • Adolescents and young adults ages 15–24 years (accounted for 50% of new STIs in 2018)
    • Men who have sex with men (MSM)
    • Racial and ethnic minorities 
  • HSV HSV Herpes simplex virus (HSV) is a double-stranded DNA virus belonging to the family Herpesviridae. Herpes simplex virus commonly causes recurrent infections involving the skin and mucosal surfaces, including the mouth, lips, eyes, and genitals. Herpes Simplex Virus 1 & 2-2 and syphilis Syphilis Syphilis is a bacterial infection caused by the spirochete Treponema pallidum pallidum (T. p. pallidum), which is usually spread through sexual contact. Syphilis has 4 clinical stages: primary, secondary, latent, and tertiary. Syphilis increase HIV infection HIV infection Human immunodeficiency virus (HIV), a single-stranded RNA virus belonging to the Retroviridae family, is the etiologic agent of acquired immunodeficiency syndrome (AIDS). The human immunodeficiency virus is a sexually transmitted or blood-borne infection that attacks CD4+ T lymphocyte cells, macrophages, and dendritic cells, leading to eventual immunodeficiency. HIV Infection and AIDS risk.
  • STIs can result in serious reproductive consequences and adverse long-term health effects.
  • STIs reportable to state health departments:
    • Syphilis 
    • Chancroid Chancroid Chancroid is a highly transmissible STD caused by Haemophilus ducreyi. The disease presents with painful ulcer(s) on the genital tract (termed chancroid or "soft chancre"). Up to 50% of patients will develop painful inguinal lymphadenopathy. Chancroid
    • HIV
    • Gonorrhea Gonorrhea Gonorrhea is a sexually transmitted infection (STI) caused by the gram-negative bacteria Neisseria gonorrhoeae (N. gonorrhoeae). Gonorrhea may be asymptomatic but commonly manifests as cervicitis or urethritis with less common presentations such as proctitis, conjunctivitis, or pharyngitis. Gonorrhea
    • Chlamydia Chlamydia Chlamydiae are obligate intracellular gram-negative bacteria. They lack a peptidoglycan layer and are best visualized using Giemsa stain. The family of Chlamydiaceae comprises 3 pathogens that can infect humans: Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae. Chlamydia

Etiology

Infections are mainly transmitted sexually, which can include unprotected vaginal, anal, or oral sex.

Bacterial

  • Chancroid Chancroid Chancroid is a highly transmissible STD caused by Haemophilus ducreyi. The disease presents with painful ulcer(s) on the genital tract (termed chancroid or "soft chancre"). Up to 50% of patients will develop painful inguinal lymphadenopathy. Chancroid ( Haemophilus Haemophilus Haemophilus is a genus of Gram-negative coccobacilli, all of whose strains require at least 1 of 2 factors for growth (factor V [NAD] and factor X [heme]); therefore, it is most often isolated on chocolate agar, which can supply both factors. The pathogenic species are H. influenzae and H. ducreyi. Haemophilus ducreyi)
  • Chlamydia Chlamydia Chlamydiae are obligate intracellular gram-negative bacteria. They lack a peptidoglycan layer and are best visualized using Giemsa stain. The family of Chlamydiaceae comprises 3 pathogens that can infect humans: Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae. Chlamydia and lymphogranuloma venereum ( Chlamydia Chlamydia Chlamydiae are obligate intracellular gram-negative bacteria. They lack a peptidoglycan layer and are best visualized using Giemsa stain. The family of Chlamydiaceae comprises 3 pathogens that can infect humans: Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae. Chlamydia trachomatis)
  • Gonorrhea Gonorrhea Gonorrhea is a sexually transmitted infection (STI) caused by the gram-negative bacteria Neisseria gonorrhoeae (N. gonorrhoeae). Gonorrhea may be asymptomatic but commonly manifests as cervicitis or urethritis with less common presentations such as proctitis, conjunctivitis, or pharyngitis. Gonorrhea ( Neisseria Neisseria Neisseria is a genus of bacteria commonly present on mucosal surfaces. Several species exist, but only 2 are pathogenic to humans: N. gonorrhoeae and N. meningitidis. Neisseria species are non-motile, gram-negative diplococci most commonly isolated on modified Thayer-Martin (MTM) agar. Neisseria gonorrhoeae)
  • Granuloma inguinale or donovanosis Donovanosis Donovanosis (also known as granuloma inguinale) is an STD caused by Klebsiella granulomatis and is mainly seen in tropical regions. The condition is characterized by chronic, progressive, ulcerating disease mostly affecting the genital region. Donovanosis ( Klebsiella Klebsiella Klebsiella are encapsulated gram-negative, lactose-fermenting bacilli. They form pink colonies on MacConkey agar due to lactose fermentation. The main virulence factor is a polysaccharide capsule. Klebsiella pneumoniae is the most important pathogenic species. Klebsiella granulomatis)
  • Mycoplasma Mycoplasma Mycoplasma is a species of pleomorphic bacteria that lack a cell wall, which makes them difficult to target with conventional antibiotics and causes them to not gram stain well. Mycoplasma bacteria commonly target the respiratory and urogenital epithelium. Mycoplasma pneumoniae (M. pneumoniae), the causative agent of atypical or "walking" pneumonia. Mycoplasma genitalium
  • Syphilis ( Treponema Treponema Treponema is a gram-negative, microaerophilic spirochete. Owing to its very thin structure, it is not easily seen on Gram stain, but can be visualized using dark-field microscopy. This spirochete contains endoflagella, which allow for a characteristic corkscrew movement. Treponema pallidum)

Viral

  • Herpes simplex (herpes simplex virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology: Overview, HSV HSV Herpes simplex virus (HSV) is a double-stranded DNA virus belonging to the family Herpesviridae. Herpes simplex virus commonly causes recurrent infections involving the skin and mucosal surfaces, including the mouth, lips, eyes, and genitals. Herpes Simplex Virus 1 & 2 types 1 and 2)
  • Hepatitis B virus Hepatitis B Virus Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Hepatitis B virus is transmitted by exposure to infectious blood or body fluids. Examples of types of exposure include sexual intercourse, IV drug use, and childbirth. Hepatitis B Virus
    • Sexual transmission
    • Other modes of transmission: blood/blood product exposure, mother-to-child
  • HIV
    • Sexual transmission
    • Other modes of transmission: blood/blood product exposure, breastfeeding Breastfeeding Breastfeeding is often the primary source of nutrition for the newborn. During pregnancy, hormonal stimulation causes the number and size of mammary glands in the breast to significantly increase. After delivery, prolactin stimulates milk production, while oxytocin stimulates milk expulsion through the lactiferous ducts, where it is sucked out through the nipple by the infant. Breastfeeding
  • HPV HPV Human papillomavirus (HPV) is a nonenveloped, circular, double-stranded DNA virus belonging to the Papillomaviridae family. Humans are the only reservoir, and transmission occurs through close skin-to-skin or sexual contact. Human papillomaviruses infect basal epithelial cells and can affect cell-regulatory proteins to result in cell proliferation. Papillomaviridae: HPV
    • Most common STI worldwide
    • Genital warts Genital Warts Condylomata acuminata are a clinical manifestation of genital HPV infection. Condylomata acuminata are described as raised, pearly, flesh-colored, papular, cauliflower-like lesions seen in the anogenital region that may cause itching, pain, or bleeding. Condylomata Acuminata (Genital Warts): HPV HPV Human papillomavirus (HPV) is a nonenveloped, circular, double-stranded DNA virus belonging to the Papillomaviridae family. Humans are the only reservoir, and transmission occurs through close skin-to-skin or sexual contact. Human papillomaviruses infect basal epithelial cells and can affect cell-regulatory proteins to result in cell proliferation. Papillomaviridae: HPV-6 and 11
    • Anogenital squamous intraepithelial lesions: associated with 15 types, with HPV HPV Human papillomavirus (HPV) is a nonenveloped, circular, double-stranded DNA virus belonging to the Papillomaviridae family. Humans are the only reservoir, and transmission occurs through close skin-to-skin or sexual contact. Human papillomaviruses infect basal epithelial cells and can affect cell-regulatory proteins to result in cell proliferation. Papillomaviridae: HPV-16 as the most common

Parasites

  • Pediculosis pubis or crab louse (Phthirus pubis)
  • Trichomoniasis (Trichomonas vaginalis)

Clinical Presentation

Bacterial STIs

Table: Clinical presentation of bacterial STIs
Type of STI Organism Signs and symptoms
Chancroid Chancroid Chancroid is a highly transmissible STD caused by Haemophilus ducreyi. The disease presents with painful ulcer(s) on the genital tract (termed chancroid or "soft chancre"). Up to 50% of patients will develop painful inguinal lymphadenopathy. Chancroid Haemophilus Haemophilus Haemophilus is a genus of Gram-negative coccobacilli, all of whose strains require at least 1 of 2 factors for growth (factor V [NAD] and factor X [heme]); therefore, it is most often isolated on chocolate agar, which can supply both factors. The pathogenic species are H. influenzae and H. ducreyi. Haemophilus ducreyi
  • Erythematous papule at the site of inoculation
  • Papules become ulcers.
  • Inguinal lymphadenopathy Lymphadenopathy Lymphadenopathy is lymph node enlargement (> 1 cm) and is benign and self-limited in most patients. Etiologies include malignancy, infection, and autoimmune disorders, as well as iatrogenic causes such as the use of certain medications. Generalized lymphadenopathy often indicates underlying systemic disease. Lymphadenopathy/buboes
Chlamydia Chlamydia Chlamydiae are obligate intracellular gram-negative bacteria. They lack a peptidoglycan layer and are best visualized using Giemsa stain. The family of Chlamydiaceae comprises 3 pathogens that can infect humans: Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae. Chlamydia Chlamydia Chlamydia Chlamydiae are obligate intracellular gram-negative bacteria. They lack a peptidoglycan layer and are best visualized using Giemsa stain. The family of Chlamydiaceae comprises 3 pathogens that can infect humans: Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae. Chlamydia trachomatis
  • Abnormal vaginal/penile discharge
  • Burning during urination
  • Bleeding in between periods
  • Proctitis in receptive anal intercourse
  • Epididymitis Epididymitis Epididymitis and orchitis are characterized by acute inflammation of the epididymis and the testicle, respectively, due to viral or bacterial infections. Patients typically present with gradually worsening testicular pain and scrotal swelling along with systemic symptoms such as fever, depending on severity. Epididymitis and Orchitis, prostatitis Prostatitis Prostatitis is inflammation or an irritative condition of the prostate that presents as different syndromes: acute bacterial, chronic bacterial, chronic prostatitis/chronic pelvic pain, and asymptomatic. Bacterial prostatitis is easier to identify clinically and the management (antibiotics) is better established. Prostatitis in men
Gonorrhea Gonorrhea Gonorrhea is a sexually transmitted infection (STI) caused by the gram-negative bacteria Neisseria gonorrhoeae (N. gonorrhoeae). Gonorrhea may be asymptomatic but commonly manifests as cervicitis or urethritis with less common presentations such as proctitis, conjunctivitis, or pharyngitis. Gonorrhea Neisseria Neisseria Neisseria is a genus of bacteria commonly present on mucosal surfaces. Several species exist, but only 2 are pathogenic to humans: N. gonorrhoeae and N. meningitidis. Neisseria species are non-motile, gram-negative diplococci most commonly isolated on modified Thayer-Martin (MTM) agar. Neisseria gonorrhoeae
  • Dysuria, urinary frequency
  • Discharge from the penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis/ vagina Vagina The vagina is the female genital canal, extending from the vulva externally to the cervix uteri internally. The structures have sexual, reproductive, and urinary functions and a rich blood supply, mainly arising from the internal iliac artery. Vagina, Vulva, and Pelvic Floor
  • Red or swollen urethra
  • Swollen or tender testicles Testicles The testicles, also known as the testes or the male gonads, are a pair of egg-shaped glands suspended within the scrotum. The testicles have multiple layers: an outer tunica vaginalis, an intermediate tunica albuginea, and an innermost tunica vasculosa. The testicles are composed of testicular lobules and seminiferous tubules. Testicles
  • Sore throat
  • Proctitis
Granuloma inguinale or donovanosis Donovanosis Donovanosis (also known as granuloma inguinale) is an STD caused by Klebsiella granulomatis and is mainly seen in tropical regions. The condition is characterized by chronic, progressive, ulcerating disease mostly affecting the genital region. Donovanosis Klebsiella Klebsiella Klebsiella are encapsulated gram-negative, lactose-fermenting bacilli. They form pink colonies on MacConkey agar due to lactose fermentation. The main virulence factor is a polysaccharide capsule. Klebsiella pneumoniae is the most important pathogenic species. Klebsiella granulomatis
  • Chronic progressive ulcerating disease (genital region)
  • Painless nodular lesions that ulcerate, commonly with a beefy-red base
Lymphogranuloma venereum (LGV) L1, L2, and L3 serovars of Chlamydia Chlamydia Chlamydiae are obligate intracellular gram-negative bacteria. They lack a peptidoglycan layer and are best visualized using Giemsa stain. The family of Chlamydiaceae comprises 3 pathogens that can infect humans: Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae. Chlamydia trachomatis
  • Genital ulcer
  • Inguinal lymphadenopathy Lymphadenopathy Lymphadenopathy is lymph node enlargement (> 1 cm) and is benign and self-limited in most patients. Etiologies include malignancy, infection, and autoimmune disorders, as well as iatrogenic causes such as the use of certain medications. Generalized lymphadenopathy often indicates underlying systemic disease. Lymphadenopathy/buboes
  • Vaginitis (discharge)
  • Proctocolitis
Mycoplasma Mycoplasma Mycoplasma is a species of pleomorphic bacteria that lack a cell wall, which makes them difficult to target with conventional antibiotics and causes them to not gram stain well. Mycoplasma bacteria commonly target the respiratory and urogenital epithelium. Mycoplasma pneumoniae (M. pneumoniae), the causative agent of atypical or "walking" pneumonia. Mycoplasma genitalium infection Mycoplasma Mycoplasma Mycoplasma is a species of pleomorphic bacteria that lack a cell wall, which makes them difficult to target with conventional antibiotics and causes them to not gram stain well. Mycoplasma bacteria commonly target the respiratory and urogenital epithelium. Mycoplasma pneumoniae (M. pneumoniae), the causative agent of atypical or "walking" pneumonia. Mycoplasma genitalium
  • Nongonococcal urethritis
  • Pelvic inflammatory disease Pelvic inflammatory disease Pelvic inflammatory disease (PID) is defined as a polymicrobial infection of the upper female reproductive system. The disease can affect the uterus, fallopian tubes, ovaries, and adjacent structures. Pelvic inflammatory disease is closely linked with sexually transmitted diseases, most commonly caused by Chlamydia trachomatis, Neisseria gonorrhoeae, and Gardnerella vaginalis. Pelvic Inflammatory Disease
  • Proctitis
Syphilis Treponema Treponema Treponema is a gram-negative, microaerophilic spirochete. Owing to its very thin structure, it is not easily seen on Gram stain, but can be visualized using dark-field microscopy. This spirochete contains endoflagella, which allow for a characteristic corkscrew movement. Treponema pallidum
  • Ulceration of the urogenital tract (chancre)
  • Secondary and late syphilis Syphilis Syphilis is a bacterial infection caused by the spirochete Treponema pallidum pallidum (T. p. pallidum), which is usually spread through sexual contact. Syphilis has 4 clinical stages: primary, secondary, latent, and tertiary. Syphilis symptoms will vary.

Viral STIs

Table: Clinical presentation of viral STIs
Type of STI Organism Signs and symptoms
Herpes HSV HSV Herpes simplex virus (HSV) is a double-stranded DNA virus belonging to the family Herpesviridae. Herpes simplex virus commonly causes recurrent infections involving the skin and mucosal surfaces, including the mouth, lips, eyes, and genitals. Herpes Simplex Virus 1 & 2-1 or 2 If symptomatic, patients manifest:
  • Small fluid-filled blisters
  • Itching/tingling in the genital or anal area
  • Dysuria
  • Flu-like symptoms (e.g., fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever)
Hepatitis B Hepatitis B Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Most individuals with acute HBV infection are asymptomatic or have mild, self-limiting symptoms. Chronic infection can be asymptomatic or create hepatic inflammation, leading to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B Virus Hepatitis B virus Hepatitis B Virus Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Hepatitis B virus is transmitted by exposure to infectious blood or body fluids. Examples of types of exposure include sexual intercourse, IV drug use, and childbirth. Hepatitis B Virus ( HBV HBV Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Hepatitis B virus is transmitted by exposure to infectious blood or body fluids. Examples of types of exposure include sexual intercourse, IV drug use, and childbirth. Hepatitis B Virus) Acute:
  • Abdominal pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain, vomiting
  • Malaise
  • Jaundice Jaundice Jaundice is the abnormal yellowing of the skin and/or sclera caused by the accumulation of bilirubin. Hyperbilirubinemia is caused by either an increase in bilirubin production or a decrease in the hepatic uptake, conjugation, or excretion of bilirubin. Jaundice
  • Dark urine
Chronic:
  • Asymptomatic
  • Chronic liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver disease/ cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic parenchymal necrosis and scarring (fibrosis) most commonly due to hepatitis C infection and alcoholic liver disease. Patients may present with jaundice, ascites, and hepatosplenomegaly. Cirrhosis can also cause complications such as hepatic encephalopathy, portal hypertension, portal vein thrombosis, and hepatorenal syndrome. Cirrhosis
HIV Two species of Lentivirus Different disease stages include:
  • Primary infection
  • Asymptomatic infection
  • Symptomatic infection
  • AIDS
HPV HPV Human papillomavirus (HPV) is a nonenveloped, circular, double-stranded DNA virus belonging to the Papillomaviridae family. Humans are the only reservoir, and transmission occurs through close skin-to-skin or sexual contact. Human papillomaviruses infect basal epithelial cells and can affect cell-regulatory proteins to result in cell proliferation. Papillomaviridae: HPV Different types (6, 11, 16, and 18) of HPV HPV Human papillomavirus (HPV) is a nonenveloped, circular, double-stranded DNA virus belonging to the Papillomaviridae family. Humans are the only reservoir, and transmission occurs through close skin-to-skin or sexual contact. Human papillomaviruses infect basal epithelial cells and can affect cell-regulatory proteins to result in cell proliferation. Papillomaviridae: HPV
  • Genital warts Genital Warts Condylomata acuminata are a clinical manifestation of genital HPV infection. Condylomata acuminata are described as raised, pearly, flesh-colored, papular, cauliflower-like lesions seen in the anogenital region that may cause itching, pain, or bleeding. Condylomata Acuminata (Genital Warts) around the anogenital area
  • Cervical cancer Cervical cancer Cervical cancer, or invasive cervical carcinoma (ICC), is the 3rd most common cancer in women in the world, with > 50% of the cases being fatal. In the United States, ICC is the 13th most common cancer and the cause of < 3% of all cancer deaths due to the slow progression of precursor lesions and, more importantly, effective cancer screening. Cervical Cancer

Parasitic STIs

Table: Clinical presentation of parasitic STIs
Type of STI Organism Signs and symptoms
Trichomoniasis Trichomonas vaginalis
  • Burning pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain or itching in the genital area
  • Urethritis
  • Vaginitis
Pediculosis pubis or crab louse Pthirus pubis Pruritus in genital and perianal area

Diagnosis

Diagnostic approach

Comprehensive sexual history:

  • Number of partners 
  • Types of sexual practices 
  • Types of protection used, if any 
  • Past history of STIs 
  • Prior history of pregnancy Pregnancy Pregnancy is the time period between fertilization of an oocyte and delivery of a fetus approximately 9 months later. The 1st sign of pregnancy is typically a missed menstrual period, after which, pregnancy should be confirmed clinically based on a positive β-hCG test (typically a qualitative urine test) and pelvic ultrasound. Pregnancy: Diagnosis, Maternal Physiology, and Routine Care 
  • Vaccination Vaccination Vaccination is the administration of a substance to induce the immune system to develop protection against a disease. Unlike passive immunization, which involves the administration of pre-performed antibodies, active immunization constitutes the administration of a vaccine to stimulate the body to produce its own antibodies. Vaccination history: 
    • Hepatitis A Hepatitis A Hepatitis A is caused by the hepatitis A virus (HAV), a nonenveloped virus of the Picornaviridae family with single-stranded RNA. HAV causes an acute, highly contagious hepatitis with unspecific prodromal symptoms such as fever and malaise followed by jaundice and elevated liver transaminases. Hepatitis A Virus/B
    • HPV HPV Human papillomavirus (HPV) is a nonenveloped, circular, double-stranded DNA virus belonging to the Papillomaviridae family. Humans are the only reservoir, and transmission occurs through close skin-to-skin or sexual contact. Human papillomaviruses infect basal epithelial cells and can affect cell-regulatory proteins to result in cell proliferation. Papillomaviridae: HPV 
  • Travel history

Focused physical exam:

  • Head, eyes, ears, nose Nose The nose is the human body's primary organ of smell and functions as part of the upper respiratory system. The nose may be best known for inhaling oxygen and exhaling carbon dioxide, but it also contributes to other important functions, such as tasting. The anatomy of the nose can be divided into the external nose and the nasal cavity. Anatomy of the Nose, throat (HEENT): Examine oral mucosa and lips Lips The lips are the soft and movable most external parts of the oral cavity. The blood supply of the lips originates from the external carotid artery, and the innervation is through cranial nerves. Oral Cavity: Lips and Tongue for rashes Rashes Rashes are a group of diseases that cause abnormal coloration and texture to the skin. The etiologies are numerous but can include irritation, allergens, infections, or inflammatory conditions. Rashes that present in only 1 area of the body are called localized rashes. Generalized rashes occur diffusely throughout the body. Generalized and Localized Rashes or ulcers.
  • Abdominopelvic exam: Assess for lower abdominal or pelvic tenderness. 
  • Genitourinary exam: 
    • Palpate inguinal lymph nodes for nodules.
    • Genital exam for rashes Rashes Rashes are a group of diseases that cause abnormal coloration and texture to the skin. The etiologies are numerous but can include irritation, allergens, infections, or inflammatory conditions. Rashes that present in only 1 area of the body are called localized rashes. Generalized rashes occur diffusely throughout the body. Generalized and Localized Rashes, ulcers, exudate, warts 
    • Male: testicular exam to assess for swelling, tenderness

Specific tests

Specimen for testing is obtained from the site(s) of infection/lesion, which may include anogenital, lymph nodes, and oral areas.

Bacterial disease:

  • Chancroid Chancroid Chancroid is a highly transmissible STD caused by Haemophilus ducreyi. The disease presents with painful ulcer(s) on the genital tract (termed chancroid or "soft chancre"). Up to 50% of patients will develop painful inguinal lymphadenopathy. Chancroid
    • Culture from genital ulcers  
    • Rule out common etiologies of genital ulcer(s): herpes and syphilis Syphilis Syphilis is a bacterial infection caused by the spirochete Treponema pallidum pallidum (T. p. pallidum), which is usually spread through sexual contact. Syphilis has 4 clinical stages: primary, secondary, latent, and tertiary. Syphilis
  • Chlamydia Chlamydia Chlamydiae are obligate intracellular gram-negative bacteria. They lack a peptidoglycan layer and are best visualized using Giemsa stain. The family of Chlamydiaceae comprises 3 pathogens that can infect humans: Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae. Chlamydia
    • Test of choice: nuclear acid amplification testing (NAAT) (PCR is a common method.) 
    • Culture has limited use.
  • Gonorrhea Gonorrhea Gonorrhea is a sexually transmitted infection (STI) caused by the gram-negative bacteria Neisseria gonorrhoeae (N. gonorrhoeae). Gonorrhea may be asymptomatic but commonly manifests as cervicitis or urethritis with less common presentations such as proctitis, conjunctivitis, or pharyngitis. Gonorrhea:
    • Test of choice: NAAT
    • Gram stain (microscopy)
    • Cultures (urethral, vaginal, pharyngeal, rectal)
  • Granuloma inguinale ( donovanosis Donovanosis Donovanosis (also known as granuloma inguinale) is an STD caused by Klebsiella granulomatis and is mainly seen in tropical regions. The condition is characterized by chronic, progressive, ulcerating disease mostly affecting the genital region. Donovanosis): 
    • Tissue biopsy sample 
    • Pathology would show Donovan bodies (bipolar-staining cytoplasmic inclusion bodies) 
  • Lymphogranuloma venereum: NAAT 
  • Mycoplasma Mycoplasma Mycoplasma is a species of pleomorphic bacteria that lack a cell wall, which makes them difficult to target with conventional antibiotics and causes them to not gram stain well. Mycoplasma bacteria commonly target the respiratory and urogenital epithelium. Mycoplasma pneumoniae (M. pneumoniae), the causative agent of atypical or "walking" pneumonia. Mycoplasma genitalium: NAAT 
  • Syphilis: 
    • Nontreponemal tests: rapid plasma reagin and VDRL 
    • Confirmatory test: fluorescent treponemal antibody absorption (FTA-ABS)

Viral disease:

  • HSV HSV Herpes simplex virus (HSV) is a double-stranded DNA virus belonging to the family Herpesviridae. Herpes simplex virus commonly causes recurrent infections involving the skin and mucosal surfaces, including the mouth, lips, eyes, and genitals. Herpes Simplex Virus 1 & 2-1 and 2: 
    • Test of choice: PCR
    • Serology
    • Viral culture
    • Tzanck smear 
  • HIV:
    • Screening: immunoassay that detects HIV-1 and HIV-2 antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins and HIV-1 p24 antigen 
    • Confirmatory testing: specimens with reactive antigen/antibody immunoassay 
    • Acute infection: HIV RNA RNA Ribonucleic acid (RNA), like deoxyribonucleic acid (DNA), is a polymer of nucleotides that is essential to cellular protein synthesis. Unlike DNA, RNA is a single-stranded structure containing the sugar moiety ribose (instead of deoxyribose) and the base uracil (instead of thymine). RNA generally carries out the instructions encoded in the DNA but also executes diverse non-coding functions. RNA Types and Structure viral load 
  • HPV HPV Human papillomavirus (HPV) is a nonenveloped, circular, double-stranded DNA virus belonging to the Papillomaviridae family. Humans are the only reservoir, and transmission occurs through close skin-to-skin or sexual contact. Human papillomaviruses infect basal epithelial cells and can affect cell-regulatory proteins to result in cell proliferation. Papillomaviridae: HPV:
    • Detected in cervical specimen (as part of cervical cancer screening Cervical cancer screening Cervical cancer is the 3rd most common gynecologic cancer. More than 90% of cervical cancer cases are associated with high-risk human papillomavirus (hrHPV), which is transmitted by sexual contact. Cervical cancer can be prevented by early detection and treatment of precancerous lesions caused by hrHPV. Cervical Cancer Screening)
    • Also tested in oropharyngeal biopsy
  • Hepatitis B Hepatitis B Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Most individuals with acute HBV infection are asymptomatic or have mild, self-limiting symptoms. Chronic infection can be asymptomatic or create hepatic inflammation, leading to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B Virus
    • Serologic markers (e.g., hepatitis B surface antigen and antibody)
    • PCR ( HBV HBV Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Hepatitis B virus is transmitted by exposure to infectious blood or body fluids. Examples of types of exposure include sexual intercourse, IV drug use, and childbirth. Hepatitis B Virus DNA DNA The molecule DNA is the repository of heritable genetic information. In humans, DNA is contained in 23 chromosome pairs within the nucleus. The molecule provides the basic template for replication of genetic information, RNA transcription, and protein biosynthesis to promote cellular function and survival. DNA Types and Structure)

Parasitic disease:

  • Trichomonas vaginalis: 
    • Microscopy (wet mount) shows motile trichomonads.
    • PCR 
    • Vaginal culture 
    • Cervical cytology
  • Pthirus pubis:
    • Demonstration of lice or nits (louse eggs) by direct or microscopic examination of hair shafts

Management

Bacterial STIs

Table: Management of bacterial STIs
Type of STI Treatment
Chancroid Chancroid Chancroid is a highly transmissible STD caused by Haemophilus ducreyi. The disease presents with painful ulcer(s) on the genital tract (termed chancroid or "soft chancre"). Up to 50% of patients will develop painful inguinal lymphadenopathy. Chancroid Azithromycin or ceftriaxone
Chlamydia Chlamydia Chlamydiae are obligate intracellular gram-negative bacteria. They lack a peptidoglycan layer and are best visualized using Giemsa stain. The family of Chlamydiaceae comprises 3 pathogens that can infect humans: Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae. Chlamydia Azithromycin 1 g orally x 1 or doxycycline x 7 days (preferred in proctitis)
Gonorrhea Gonorrhea Gonorrhea is a sexually transmitted infection (STI) caused by the gram-negative bacteria Neisseria gonorrhoeae (N. gonorrhoeae). Gonorrhea may be asymptomatic but commonly manifests as cervicitis or urethritis with less common presentations such as proctitis, conjunctivitis, or pharyngitis. Gonorrhea Ceftriaxone 500 mg (with doxycycline if chlamydia has not been ruled out)
Granuloma inguinale or donovanosis Donovanosis Donovanosis (also known as granuloma inguinale) is an STD caused by Klebsiella granulomatis and is mainly seen in tropical regions. The condition is characterized by chronic, progressive, ulcerating disease mostly affecting the genital region. Donovanosis
  • Azithromycin
  • Doxycycline
Lymphogranuloma venereum (LGV) Doxycycline
Mycoplasma Mycoplasma Mycoplasma is a species of pleomorphic bacteria that lack a cell wall, which makes them difficult to target with conventional antibiotics and causes them to not gram stain well. Mycoplasma bacteria commonly target the respiratory and urogenital epithelium. Mycoplasma pneumoniae (M. pneumoniae), the causative agent of atypical or "walking" pneumonia. Mycoplasma genitalium infection Azithromycin
Syphilis Penicillin G (parenteral)

Viral STIs

Table: Management of viral STIs
Type of STI Treatment
Herpes Antivirals:
  • Acyclovir, famciclovir, valacyclovir
  • Regimens for episodic and suppressive therapy
HPV HPV Human papillomavirus (HPV) is a nonenveloped, circular, double-stranded DNA virus belonging to the Papillomaviridae family. Humans are the only reservoir, and transmission occurs through close skin-to-skin or sexual contact. Human papillomaviruses infect basal epithelial cells and can affect cell-regulatory proteins to result in cell proliferation. Papillomaviridae: HPV Cytodestructive therapy:
  • Podofilox 0.5% cream
  • Imiquimod 5% cream
Surgical therapy:
  • Cryotherapy
  • CO2 laser ablation
HIV Combination antiretroviral therapy Antiretroviral therapy Antiretroviral therapy (ART) targets the replication cycle of the human immunodeficiency virus (HIV) and is classified based on the viral enzyme or mechanism that is inhibited. The goal of therapy is to suppress viral replication to reach the outcome of undetected viral load. Anti-HIV Drugs with the following:
  • Nucleotide reverse transcriptase inhibitors
  • Nonnucleoside reverse transcriptase inhibitors
  • Integrase inhibitors
  • Protease inhibitors
Hepatitis B Hepatitis B Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Most individuals with acute HBV infection are asymptomatic or have mild, self-limiting symptoms. Chronic infection can be asymptomatic or create hepatic inflammation, leading to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B Virus
  • Regimen can include pegylated interferon, tenofovir, or entecavir
  • Agents used depend on clinical considerations (e.g., pregnancy Pregnancy Pregnancy is the time period between fertilization of an oocyte and delivery of a fetus approximately 9 months later. The 1st sign of pregnancy is typically a missed menstrual period, after which, pregnancy should be confirmed clinically based on a positive β-hCG test (typically a qualitative urine test) and pelvic ultrasound. Pregnancy: Diagnosis, Maternal Physiology, and Routine Care, cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic parenchymal necrosis and scarring (fibrosis) most commonly due to hepatitis C infection and alcoholic liver disease. Patients may present with jaundice, ascites, and hepatosplenomegaly. Cirrhosis can also cause complications such as hepatic encephalopathy, portal hypertension, portal vein thrombosis, and hepatorenal syndrome. Cirrhosis)

Parasitic STIs

Table: Management of parasitic STIs
Type of STI Treatment
Trichomoniasis
  • Metronidazole or tinidazole
  • Treat sexual partners.
Pediculosis pubis Topical permethrin or topical pyrethrins with piperonyl butoxide

Prevention

  • STI screening
  • Counseling on safe sex practices:
    • Educate on behaviors that increase risks of STIs.
    • Preventive measures (e.g., use of condom)
    • Importance of treating partners
  • Vaccination Vaccination Vaccination is the administration of a substance to induce the immune system to develop protection against a disease. Unlike passive immunization, which involves the administration of pre-performed antibodies, active immunization constitutes the administration of a vaccine to stimulate the body to produce its own antibodies. Vaccination:
    • Hepatitis B Hepatitis B Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Most individuals with acute HBV infection are asymptomatic or have mild, self-limiting symptoms. Chronic infection can be asymptomatic or create hepatic inflammation, leading to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B Virus
    • HPV HPV Human papillomavirus (HPV) is a nonenveloped, circular, double-stranded DNA virus belonging to the Papillomaviridae family. Humans are the only reservoir, and transmission occurs through close skin-to-skin or sexual contact. Human papillomaviruses infect basal epithelial cells and can affect cell-regulatory proteins to result in cell proliferation. Papillomaviridae: HPV
  • Prophylaxis:
    • Preexposure antiretroviral prophylaxis against HIV (HIV PrEP)
    • Postexposure antiretroviral prophylaxis against HIV (given within 72 hours)
  • Suppressive therapy for HSV HSV Herpes simplex virus (HSV) is a double-stranded DNA virus belonging to the family Herpesviridae. Herpes simplex virus commonly causes recurrent infections involving the skin and mucosal surfaces, including the mouth, lips, eyes, and genitals. Herpes Simplex Virus 1 & 2 reduces transmission of infection to uninfected partner.

References

  1. Centers for Disease Control and Prevention. (2021). Sexually transmitted infections prevalence, incidence, and cost estimates in the United States. Retrieved April 21, 2021, from https://www.cdc.gov/std/statistics/prevalence-2020-at-a-glance.htm
  2. Ghanem, K. (2021) Clinical manifestations and diagnosis of Neisseria gonorrhoeae infection in adults and adolescents. UpToDate. Retrieved April 21, 2021, from https://www.uptodate.com/contents/clinical-manifestations-and-diagnosis-of-neisseria-gonorrhoeae-infection-in-adults-and-adolescents
  3. Ghanem, K. (2019). Screening for sexually transmitted infections. UpToDate. Retrieved April 17, 2021, from https://www.uptodate.com/contents/screening-for-sexually-transmitted-infections
  4. Goldstein, A., Goldstein, B. (2021) Pediculosis pubis and pediculosis ciliaris. UpToDate. Retrieved April 21, 2021, from https://www.uptodate.com/contents/pediculosis-pubis-and-pediculosis-ciliaris
  5. Hamill, M. (2021) Lymphogranuloma venereum. UpToDate. Retrieved April 21, 2021, from https://www.uptodate.com/contents/lymphogranuloma-venereum
  6. Hicks, C. (2021) Chancroid. UpToDate. Retrieved April 21, 2021, from https://www.uptodate.com/contents/chancroid
  7. Lok, A. (2021) Hepatitis B virus: overview of management. UpToDate. Retrieved April 21, 2021, from https://www.uptodate.com/contents/hepatitis-b-virus-overview-of-management
  8. Martin, D. (2021) Mycoplasma genitalium infection in men and women. UpToDate. Retrieved April 21, 2021, from https://www.uptodate.com/contents/mycoplasma-genitalium-infection-in-men-and-women
  9. Palefsky, J. (2021) Human papillomavirus infections: epidemiology and disease associations. UpToDate. Retrieved April 21, 2021, from https://www.uptodate.com/contents/human-papillomavirus-infections-epidemiology-and-disease-associations
  10. Simma-Chiang, V. (2021). Sexually Transmitted Infection. AUA Core Curriculum. Retrieved April 18, 2021, from https://auau.auanet.org/core 
  11. Sobel, J., Mitchell, C. (2021) Trichomoniasis. UpToDate. Retrieved April 21, 2021, from https://www.uptodate.com/contents/trichomoniasis
  12. Teo, E., Lok, A. (2021) Epidemiology, transmission and prevention of hepatitis B infection. UpToDate. Retrieved April 21, 2021, from https://www.uptodate.com/contents/epidemiology-transmission-and-prevention-of-hepatitis-b-virus-infection

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