Transcript Sexually Transmitted Disease

Sexually Transmitted
Diseases
Stavropol state medical academy
Department of asu
Sexually Transmitted Diseases
transmitted during coitus or genital
contact
 1 in 4 will contract STD between 15-55
yrs of age
 require moist environments (“transitional
zones”)
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STDs
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common areas of infection:
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vulva, vagina urethra in females
penis, urethra in males
mouth, oral cavity, eyes, anus in both sexes
if untreated, can pass from transitional
zone to other tissues
 person usually has >1 STD as a time
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Causes
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BACTERIA :
– single-celled, microscopic organisms
– cause disease by producing toxins
– can be prevented by vaccines; killed by
antibiotics
Examples of bacterial STDs: chlamydia,
gonorrhea, syphilis
Causes
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VIRUSES:
– tiny, noncellular particle
– has DNA or RNA core and a protein coat
– parasitic (reproduces in host cell)
– some can be prevented by vaccine
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Examples of viral STDs:
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Herpes genitalis, HPV, HIV
OTHERS: FUNGI, PROTOZOA,
INVERTEBRATES
Chlamydia (most prevalent bacterial
STD)
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caused by bacterium-like microorganism that
lives inside cells
symptoms:
– urinary tract infection in both males and
females
– yellowish vaginal discharge
– Infected tissues become red, irritated
– some may be asymptomatic (30% of males, 5070% of females)
Chlamydia Life Cycle
Chlamydia Cervicitis
Chlamydia
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if left untreated, PID can result in females
untreated males can develop infertility (due to
scarring of sex accessory tubes)
can be passed from pregnant woman to child
during delivery > lung and eye infections in
newborn
detected by tissue culture
treated with antibiotics (note: penicillin is
ineffective)
association exists between chlamydia and cervical
cancer
Gonorrhea
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Bacterial STD
Symptoms similar to those of chlamydia
Syphilis
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STD caused by bacterium
1st epidemic: 15th century, W. Europe
bacterium thrives in moist regions
9/10 cases due to transmission during coitus
Stages of Syphilis:
Primary stage
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involves single sore (chancre) where bacteria
1st entered the body
appears 10-90 days after entry
heals in 1-5 weeks
afterwards, travels in blood, lymph to other
parts of body
Sores
Primary Syphilis Chancre
12
Secondary stage of syphilis
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occurs 2 weeks - 6 months after primary stage
characterized by rash on upper body, arms, hands,
spreads to other skin
larger bumps develop, burst (release lots of bacteria!)
doesn’t itch; painless
can also cause hair loss, sore throat, headache, loss
of appetite, nausea, muscle / joint pain, low fever
sometimes symptoms are overlooked
goes away in 2-6 weeks
enters latent stage
Secondary Syphilis Rash
Latent stage of syphilis
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can last for years
has few or no symptoms
after 1 yr, bacteria can no longer be
transmitted (except to fetus)
1/2 never leave latent stage
1/2 enter tertiary stage if not already treated
with antibiotics
Tertiary stage of syphilis
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bacteria has invaded tissues throughout the body
causes large, tumor-like sores on skin, muscle, internal
organs
greatly damages heart, valves
ultimately affects central nervous system > paralysis,
blindness, psychotic behavior
4000 die per year in U.S. due to advanced syphilis
Congenital Syphilis
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can be passed from mother to fetus at any stage of
syphilis
placenta protects baby up to 6 mo.
then, bacteria enters fetal bloodstream:
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30% miscarry
70% born with congenital syphilis and go through normal
progression of disease
can severely damage developing tissues of newborn;
many die
Diagnosis / treatment of syphilis
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Cultures; blood test for antibodies
several antibiotics are effective
curable, like gonorrhea
may cause permanent damage if tertiary stage
is reached
Herpes genitalis
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most common viral STD (1 million in U.S. contract
/ year)
incurable
caused by herpes simplex type 2 virus
other herpes viruses exist (cause fever blisters,
cold sores, chicken pox, infectious
mononucleosis)
type 2 invades areas below the waist; type 1
invades above the waist
20% of infections in genital region are due to type
1
Genital Herpes Simplex
Genital Herpes Simplex in Females
Herpes
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likewise, type 2 is sometimes found in mouth
sores
condoms not 100% effective in preventing
transmission
type 2 can be transmitted by nonsexual contact
Herpes: Symptoms
Burning sensation followed by
appearance of blisters
 Blisters rupture in 1-2 days; become
painful ulcers
 Possible flu-like symptoms
 in males > sores occur on penis
 in females > on labia, clitoris, cervix,
vagina, urethra, perineum
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Herpes Symptoms
in both sexes: painful urination and
coitus; sometimes fever and enlargement
of lymph nodes
 sores heal between 1-6 weeks
 if virus comes into contact with eye, can
cause blindness
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Herpes: Transmission
even with no sores, virus is harbored
within body in nerve cells near spinal
cord
 a person is most infectious when sores
are present; transmission at other
times?
 sores can reappear throughout a
persons lifetime
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Herpes: Transmission
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triggers for recurrence:
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sunlight
stress
menstruation
sex
sometimes, antibodies are developed
that alleviate or stop recurrences
Herpes: Treatment
no cure for herpes
 drugs can disrupt viral reproduction
 some forms resistant
 proper hygiene helps reduce spread
 vaccine is currently being developed
that decreases frequency of sore
recurrence
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Herpes
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vaginal deliveries can result in infection
of newborn:
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25% can develop blindness, brain damage
25% develop skin lesions
rarely, virus can cross placenta
Human papilloma virus
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Over 70 strains
Some cause “venereal warts” -moist, soft,
cauliflower-like bumps (within 3 weeks - 8
months)
appear on cervix, labia, vulva, perineum in
females
on penis in males, urethra, scrotum
treated topically with dry ice, liquid nitrogen >
warts dry up and fall off in a few days
warts may recur
Perianal Wart
HPV Penile Warts
Possible HPV on the Tongue
Human papilloma virus
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major cause of cervical cancer (95% of cases
associated with HPV)
also associated with cancer of the penis, vagina, anus
AIDS
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AIDS = acquired immune deficiency syndrome:
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condition is caught, not inherited
virus attacks immune system
certain infections, cancers occur in infected persons
caused by human immunodeficiency viruses
(HIV)
live and reproduce in helper T cells
host cells die as viruses depart to infect other
cells
consequence: decrease in helper T cells, which
are necessary for stimulating antibody
production by B cells and activity of killer T cells
AIDS
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between 4.2 and 15 years, HIV infection
leads to fullblown AIDs
stages:
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“window period” (incubation period):
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can be as long as six months
virus replicates slowly; no antibodies detected
“acute phase of HIV disease” (after
seroconversion):
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lasts 2-4 weeks
accompanied by flu-like illness (fever, swollen
glands, muscle aches, weight loss)
AIDS
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“asymptomatic phase”:
 little or no symptoms
 virus continues to replicate, destroy T cells
“symptomatic phase”:
 opportunistic infections begin
 examples: bacterial skin infections,
diarrhea, fever, tuberculosis
AIDS
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T cell count less than 200 cells per microliter
of blood (normal is 900-1200 cells)
accompanied by one or more opportunistic
infections:
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pneumonia
neurological problems (meningitis, seizures)
cancers of skin, cervix, lymph nodes
death follows in about 2 years
AIDS: Transmission of HIV
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virus is present in bodily fluids: blood, semen,
cervical and vaginal secretions
low levels also present in urine, saliva, tears (no
evidence that virus can be transmitted by these
fluids)
transmitted when contaminated fluid enters
another’s body
risk of contraction is greatest in receptive partner
during anal or vaginal intercourse
common modes of transmission: use of
contaminated needles, sexual contact, during
pregnancy
AIDS: Transmission of HIV
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virus does not live long outside of the body
cannot be contracted from classroom activities,
bathrooms, swimming pools, kissing, sharing
food, coughing, sneezing, sweating, sharing
utensils, giving blood
Pregnancy and HIV
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Use of protease inhibitors during pregnancy
can reduce risk of infecting fetus (25% to 8%)
HIV-positive women are advised not to
breastfeed