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Sexually transmitted infections (STIs)
- • Infections transmitted from one person to another during coitus or other genital contact
- • Also referred to as sexually transmitted diseases (STDs)
- • In past these infections were commonly referred to as venereal diseases, after Venus, the Goddess of Love
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Sexually transmitted infections (STIs) STATISTICS
• 25% of Americans between the ages of 15 and 55 will acquire some form of STI
• Over 15 million Americans acquire an STI each year
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Transition Zones for Organisms causing STI's
• Organisms causing STIs typically require moist membranes of transition zones
- Transition zones occur at the openings between external and internal body surfaces:
- • Female: vulva, vagina, urethra
- • Male: penis and urethra
- • Both sexes: mouth, oral cavity, throat,eyes, and anus
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Vaginal Environment
• Different bacteria, fungi, and protozoa are part of the normal vaginal microbial ecology and contribute to maintaining a healthy normal vaginal microbial environment
- • Under the influence of estrogen, cells of the vaginal epithelium accumulate large amounts of
- glycogen
- • As these glycogen-rich cells slough off into the vaginal cavity, certain commensal bacteria
- metabolize the glycogen to lactic acid, which makes the vaginal environment acidic
• The acidic environment retards Candida yeast fungal overgrowth
- • Certain antibiotics kill these beneficial bacteria which results in the vaginal environment
- becoming basic which supports the development of Candida yeast vaginitis infections
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There is 6 Types of Sexually Transmitted Infections:
- • Viral
- • Bacterial
- • Fungal
- • Protozoan
- • Lice
- • Scabies
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viral
• Human papilloma virus (genital warts)
• Herpes simplex virus Type 2 (herpes
genitalis)
• Human immunodeficiency virus (HIV)
• Hepatitis B virus
• Hepatitis C virus
• Molluscum contagiosum
bacterial
• Chlamydia trachomatis
• Neisseria gonorrhoeae
• Treponema pallidum (syphilis)
• Ureaplasma urealyticum (urethritis)
• Haemophilus ducreyi (chancroid)
• Haemophilus vaginalis (vaginitis & urethritis)
• Calymmatobacterium granulomatous (granuloma inguinale)
- • Fungal:
- Candidal albicans (monilia vaginitis)
- • Protozoan:
- Trichomonas vaginalis (vaginitis) see Fig 18-3
- • Crab lice:
- Phthirus pubis (Pediculosis pubis) (Fig 18-4)
- • Scabies:
- Sarcoptes scabiei
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Trichomonas vaginalis
- • Flagellate protozoan transmitted during coitus
- • Vaginitis with frothy, odorous discharge that develops 4 - 28 days post exposure
- • Vulva, cervix, urethra, and bladder may also become inflamed
- • Most men are asymptomatic, but may develop urethritis or cystitis
- • Diagnosis by microscope (Fig 18-3)
- • Treatment with single dose of metronidazole
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What is Chlamydia? STATS
- Chlamydia trachomatis is a group of small bacteria transmitted by coitus
- • Incubation period is 7 - 28 days
- • 50% of infected men are asymptomatic
- • 75% of infected women are asymptomatic
- • Nearly half of Chlamydia cases in women in the USA occur in adolescents ages 15-19
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Chlamydia can.....
• Can cause urethritis in both men and women resulting in yellow discharge from the urethra
• Can be transmitted to eyes of a newborn if present in vaginal canal during delivery
• The infection can lead to conjunctivitis and pneumonia in the newborn infant
• Newborns’ eyes are routinely treated with topical antibiotic e.g., erythromycin or silver nitrate
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Chlamydia in women
- • Cervix is main site of infection in females which can cause yellow vaginal discharge
- • The cervix, vagina, urethra, and vulva can become reddened and irritated
- • Salpingitis (oviduct inflammation) can lead to scarring and blockage of the oviducts which can cause infertility in women
- • Pelvic inflammatory disease can also occur in women
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Chlamydia diagnosis & treatment Diagnosis
- • Urine (first stream) is collected and PCR evaluation detects genetic material from Chlamydia
- • Culture of purulent material
- Treatment:
- • Azithromycin by mouth
- • Doxycycline by mouth
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Gonorrhea
- • Neisseria gonorrhoea is the gram negative, diplococcus bacteria that causes this STI
- • Transmitted during homosexual and heterosexual coitus
- • Thrive in moist membranes of the urogenital tract, mouth, oral cavity, anus, and eyes
- • In USA most new cases are in 15-29 year old group
- Incidence is especially high in two groups:
- • Sexually active individuals under age 24
- • Men who have sex with men (MSM)
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Gonorrhea in MEN
- • 70-90% of men infected with gonorrhea develop symptoms
- • Purulent discharge from the urethra
- • Redness of glans and penis
- • Urethritis: urethral inflammation
- • Prostatitis: prostate inflammation
- • Epididymiditis: epididymides inflammation
- • Orchitis: testes inflammation
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Gonorrhea in females
and Complications
• 75% are asymptomatic Symptomatic females develop whitish, yellowish, or greenish
- discharge from:
- • vagina (vaginitis)
- • cervix (cervicitis)
- • urethra (urethritis)
- • bladder (cystitis)
- Complications in females include:
- • Endometritis: uterine infection
- • Salpingitis: inflammation and infection of oviducts which can cause scarring of tissue leading to infertility because of oviduct blockage
- • Pelvic inflammatory disease: general infection of pelvic tissues
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Gonorrhea and Oral Sex
• Oral sex can lead to infection of pharynx (throat) with gonococcus
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Gonorrhea in pregnancy
- • If transmitted across placenta to fetus in the first trimester, there is an increased risk of miss-carriage
- • When present in the birth canal, can infect newborns eyes on delivery
- • Newborns’ eyes are routinely treated with topical antibiotic e.g., erythromycin or silver nitrate
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Gonorrhea diagnosis & treatment
- Diagnosis
- • Urine (first stream) is collected and PCR evaluation detects genetic material from gonococcus
- • Culture of purulent material
- • Swab of throat or rectum
- Treatment:
- • Ceftriaxone injection
- • Doxycycline by mouth
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Syphilis
Has Primary,Secondary,Latent,Tertiary,and Congenital Stages
- • Treponema pallidum is spirocete bacterium
- • Thrives in moist regions of body
- • 90% of syphilis is transmitted by sex
- • Also can be transmitted into an open sore on the skin
- • Number of syphilis cases in USA population has increased each year between 1999-2006
- • In 2006, 60% of the new cases in the USA were in Gay men
- • In 1998, 5% of the new cases in the USA were in Gay men
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Syphilis: Primary stage
- • Chancre sore develops at site where syphilis entered the body
- • These painless chancres are 0.5-1.0 inches in diameter, with hard edge and soft center
- • In males occur on glans or corona of penis • In females occur on vulva, cervix, or vaginal wall • Oral coitus can result in sores on lips, tongue or throat • Chancres appear 10 - 90 days after entrance of microbe and lasts for 1 - 5 weeks• On resolution of chancre, primary stage is over
- • Person is contagious during primary stage
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Syphilis: Secondary stage
- • Develops 2-6 weeks after the primary stage
- • Rash develops on upper
body, upperextremities, and other areas of skin- • Rash is painless and
not itchy- • Other symptoms include hair loss, sorethroat, swollen lymph
nodes, painful joints,and poor appetite• Secondary stage goes away in - 2-6 weeks,but may recur over next two years
- • Person is contagious
during secondarystage
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Syphilis: latent stage
- • Can last for years and person will have no or few symptoms
- • Half of
the patients who enter the latent phase, never progress on to tertiary phase- • People in latent stage are not contagious, except for
pregnant women who can transmit to fetus
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Syphilis: tertiary stage
- • Tertiary phase develops as microbe invades tissues throughout the body and develop large tumor-like(gummas) in skin, muscle,
- intestines,liver, lungs, heart, and endocrineglands, eyes, brain, & spinal cord
- • People in tertiary stages are not contagious, except for pregnant women who can transmit to fetus
- • Tertiary cardiovascular syphilisdevelops 10 - 40 years after infectionresulting in infection of the heart andblood vessels which can be fatal
- • Tertiary neurosyphilis develops 10 -20 years after infection when thecentral nervous system (brain & spinalcord) are infected; these people candevelop blindness, paralysis,dementia, psychosis, and death
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Syphilis: congenital
- • Infected pregnant women in all stages of syphilis can pass syphilis on to their fetuses in the 3rd trimester of pregnancy
- • 30% of these fetuses miscarry
- • 70% are born with congenital syphilis andare contagious in 1st and 2nd years of life
- • If untreated, over 20% will go on to developtertiary syphilis in 10 - 20 years
- • Congenital syphilis includes blindness,deafness, flattening of the bridge of thenose, & notched central incisor teeth
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Syphilis: diagnosis & treatment
- Diagnosis:
- • VDRL and RPR blood tests
- Treatment
- :• Benzathine Penicillin G injected
- • Tetracycline
- • Erythromycin
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Human papilloma virus (HPV)
- • Of 100 types of HPV, over 40 types aresexually transmitted
- • Female tissues that may be infected: vulva,perineum, labia, cervix
- • Male tissues that may be infected: prepuce,glans, coronal ridge, urethra, and scrotum
- • 20 million Americans are infected with HPV
- • Half of these 20 million infections are among adolescents and young adults,ages 15-24 years
- • 20% of sexually active 14 - 18 year old females have this virus
- • Most sexually active adults becomeinfected with HPV at some time in life
- • Of the more than 40 types of HPV that infecthuman mucosal surfaces, most infections areasymptomatic and transient
- • Many people who get infected with HPV will nothave any symptoms and the infection clears on itsown
- • HOWEVER, certain oncogenic types can causecervical cancer, or less often, anogenital cancerincluding cancers of the anus, penis, and vulva
- • Other, non-oncogenic HPV types can causegenital warts,
- • Certain types of human papilloma virus(HPV) causes genital warts =Condyloma acuminata
- • Soft cauliflower like warts appear 3weeks to 8 months after exposure tocertain types of HPV (e.g., HPV-6, 11,42, 43, & 44)
- • About 1% of sexually active men andwomen in the USA have genital warts at any given time
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Human papilloma virus (HPV) & cervical cancer
- • Strong association between infection with certaintypes of papilloma virus and development ofcervical cancer
- • Of 100 types of HPV, over 40 types are sexuallytransmitted and four of the types are known to beassociated with development of cervical cancer(HPV-16, 18, 31, 45)
- •95% of women with cervical cancer have one ormore types of HPV
- •Association of the HPV virus and anal cancer inmen who have sex with men
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Human papilloma virus (HPV)diagnosis, treatment, & prevention
- Prevention:
- • HPV vaccine recommended to be given as earlyas 9 years of age to prevent HPV, if the female is going to be a sexually active
- teen
- Diagnosis:
- • antibody tests for HPV types
- • Pap smear of cervix to rule out development of cancer
- Treatment:
- • Podophyllin: antimitotic agent
- • Imiquimod: immunosuppressant
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HPV vaccine
- • Quadrivalent HPV vaccine (Gardasil) for the prevention (and not treatment) of 4 different types of HPV• Protects against HPV 16 & 18, whichcause 70% of cervical cancers• Protects against HPV 6 & 11, whichcause 90% of genital warts
- • Three dose vaccine recommended for females 9 - 26 years
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Herpes simplex Type 2 virus
- • Infection results in retention of the virus innerve fibers for life
- •Mainly infects genital area, but can occur within oral cavity from oral sex
- • Typically is transmitted from a person who has an active lesion, however, can be transmitted form a person who has no obvious symptoms
- •Herpes viruses can survive on toilet seats for hours and a person could potentiallyacquire the virus from these surfaces• Through genital, anal, or oral contact, tinyblisters develop that change into painfulround sores in 4 - 7 days and may progressto ulcers
- • Males: prepuce, glans, urethra, shaft
- • Females: labia, prepuce, urethral orifice,vaginal introitus, and cervix
- • Lesions usually resolve in 1 - 2 weeks
- • Virus remains dormant in sensory nervefibers and intermittent
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HERPES diagnosis and Treatment
- Diagnosis:
- • PCR or culture of tissue
- Treatment:
- • Acyclovir by mouth can limit thefrequency and length of outbreaks
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Herpes 1 vs. Herpes 2
- • Herpes simplex 1 causes “cold sores”around the mouth and infects over 90% ofadults
- • Herpes 1 is very similar to Herpes 2 andHerpes 2 can infect humans around themouth while Herpes 1 can infect genitalia
- • Oral sex can result in Herpes 2 infectionaround the mouth and herpes 1 infection of the genitalia
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Congenital herpes simplex
- • If a Mom has active genital lesions at thetime of a vaginal delivery, the newborn canpotentially acquire herpes simplex and thiscan result in
- infant death
- • Women with active lesions at time of delivery are recommended to have acesarian section
- • Newborns with herpes simplex are treated with IV acyclovir
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Hepatitis B & Hepatitis C
- • Hepatitis B is small, circular DNA virusin the Hepadnavirus family
- •Hepatitis C is a linear, single-stranded,RNA virus in the Flaviviridae family
- • Both of these viruses are primarilytransmitted through blood, so they canbe sexually transmitted when there isexposure to blood
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Human immunodeficiency virus(HIV) transmission routes
• HIV is present in blood, semen,cervical & vaginal secretions,breast milk, saliva, and tears
- Blood inoculation
- Perinatal
- • Across placenta
- • During birth
- • Breastfeeding
- Sex
- • Sores on genital or anal area from another infection
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Circumcision and HIV transmission
- • Studies have demonstrated that circumcised men are 50% less likely to acquire HIV through sex
- • Studies have demonstrated that circumcised men are less likely to acquire other sexually transmitted diseases as well
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HIV DIAGNOSIS
- Diagnosis
- • Detection of HIV antibodies in blood orsaliva
- • Nearly all persons infected with HIV havedetectable antibodies (seroconversion)within 6 months of infection
- • Viral RNA test can detect virus beforeantibodies emerge
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HIV PREVENTION
- Prevention
- • Condoms both for men and women
- • Circumcised men have a 50% reductionin likelihood of acquiring HIV
- • HIV positive women who are pregnantreceive AZT during pregnancy, labor,and delivery and the newborn receives AZT at birth
- • Breast milk can be heated to a low temperature to eliminate the HIV
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HIV TREATMENT
- Treatment
- • Nucleoside reverse transcriptase inhibitors(NRTIs) e.g., AZT (zidovudine)
- • Nonnucleoside reverse transcriptaseinhibitors (NNRTIs)
- • Protease inhibitors
- • Fusion inhibitors
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