Download STD`s

Unit Four
Reproductive System
“STD’s”
General Information about STD’s
• STD’s are caused by bacteria, viruses, or
microscopic insects
• Physical contact is required to pass an
STD from one infected person to another
(except Pubic Lice)
• Some STD’s are curable with prompt
treatment, but many are not, like Genital
Herpes and HIV
General Information about STD’s
• Just as Abstinence is 100% effective at
preventing unwanted pregnancies, it is
also 100% effective at preventing the
passage of STD’s
• Other than abstinence, a condom (male or
female) is the only other fairly reliable
method that protects against the passage
of STD’s
STD’s of Bacterial Origin
• Bacteria are Prokaryotes (single-cell
organisms)
• Within the single cell that comprises a
bacterium, there is DNA, a cytoplasm that
contains enzymes and ribosomes, and finally, a
plasma membrane that surrounds all its contents
• Whether a person acquires a bacterial infection
through sexual intercourse or eating improperly
prepared food, the infection can be treated with
antibiotics
STD’s of Bacterial Origin
• It is always important to take all the
antibiotics prescribed in order to totally
eradicate the bacteria from one’s body
• If a person does not take all the antibiotics
prescribed, the bacteria may not be
eradicated/killed, and additionally may
become resistant to those same antibiotics
• The above can translate into a very
difficult to kill bacterial infection
STD’s of Bacterial Origin
• Chlamydia
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Caused by bacterium: Chlamydia trachomatis
Infects and grows within the cells of the body
Leading STD in the USA
It is often asymptomatic
Symptoms:
• Men – burning sensation when urinating and mucoid
discharge
• Women – vaginal discharge and UTI symptoms; left
untreated can cause sterility – PID (Pelvic Inflammatory
Disease)
Chlamydia
• Chlamydia can cause inflammation of the eye in
adults and newborns
Erythromycin eye drops are used to prevent
newborns from contracting the eye infection
STD’s of Bacterial Origin
• Gonorrhea
– Caused by bacterium: Neisseria gonorrhoeae
– Rates of infection have increased in recent years
– Persons with gonorrhea often get infected with
chlamydia and/or HIV
– Can be asymptomatic
– Symptoms
• Men: pain during urination and milky discharge 3 to 5 days
after contact with pathogen
• Women: most women are asymptomatic until the bacteria
settles in the uterus/fallopian tubes – onset of PID
Gonorrhea
• Example of PID caused by Gonorrhea;
can lead to female infertility, ectopic
pregnancy, and chronic pelvic pain
STD’s of Bacterial Origin
• Syphilis
– Caused by bacterium: Treponema pallidum
– It is a corkscrew-like organism
– It has three stages:
• Primary – ulcer indicates site of infection
• Secondary – rash on hands and feet
• Tertiary – lasts until the patient dies; bacteria infect
the central nervous system and the heart, large
ulcers develop on the skin
Syphilis
STD’s of Viral Origin
• Viruses are not capable of independent
reproduction, and therefore require a host cell to
enable them to reproduce
• Viruses are referred to as Obligate Intracellular
Parasites
• Viruses are very specific as to the type of cells
they will infect; they are smaller than bacteria
and are not considered cellular organisms
• They always have two main parts: an outer
capsid (wall/barrier), and DNA/RNA on the
inside of the capsid
STD’s of Viral Origin
• Once a virus infects a cell, it begins to
make numerous copies of itself and hence
leave the host cell through the process
known as Budding
• Some viruses can become Latent: period
of inactivity
• While latent, the viral genes are integrated
into the host DNA, and are subsequently
copied whenever the host cell divides
STD’s of Viral Origin
• Viral diseases are controlled by preventing
transmission, administering vaccines, and
recently by administering antiviral drugs
(interferes with entry of virus into host cell,
replication of its DNA/RNA, or exit of the
virus from the host cell)
STD’s of Viral Origin
• Herpes Simplex Viruses
– HSV-1: causes cold sores and fever blisters
– HSV-2: results in genital herpes
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Tingling/itching sensation
Blisters that rupture into ulcers
Fever, pain on urination, ample vaginal discharge
Can cause blindness, neurological disorders, and
death of infants that encounter the infection in the
vaginal canal during birth
****No cure for Genital Herpes
Genital Herpes
STD’s of Viral Origin
• Genital Warts
– Human papillomaviruses (HPV’s) cause all warts,
including genital warts, which are sexually transmitted
– Many have genital warts but do not get treatment;
either is asymptomatic or symptoms are not severe
– Symptoms
• Warts develop on the penis and foreskin of men and near the
vaginal opening of women
• Women who have genital warts can develop cervical cancer
• Men and women who have genital warts can develop tumors
of the anus and mouth
*** No cure for Genital Warts
Genital Warts
STD’s of Viral Origin
• Hepatitis
– Several types of Hepatitis: A, B, C, and E
• Hepatitis A – contracted through sewage
contaminated drinking water or oral and anal
contact; symptoms include tiredness, fever, sore
muscles, headache, nausea, yellow skin
• Hepatitis C – contracted through blood
transfusions and can lead to chronic hepatitis, liver
cancer, and death
STD’s of Viral Origin
• Hepatitis continued
• Hepatitis E – occurs in developing countries and then is
brought back to USA by travelers who visited developing
countries; usually mild disease and symptoms can include
abdominal pain, nausea, fatigue, poor appetite, and dark
urine
• Hepatitis B – is a DNA virus spread in the same way as HIV
through sharing needles and unprotected sex; it is common
for an AIDS patient to also have Hepatitis B; symptoms are
similar to those of the flu, and can lead to the need for a liver
transplant if symptoms are chronic
**** No cure for Hepatitis viruses
Hepatitis B
Diseased liver of a person with chronic
Hepatitis B
Other Infections
• Vaginal Infections
– Bacterial Vaginosis (BV)
• Males pass excess amounts of a bacterium called,
Gardnerella vaginalis to the female during
intercourse
• Excess amounts of this bacterium causes a
decline in lactobacilli, and hence, a change in the
pH of the vagina
• Symptoms include foul odor coming from vagina
after sex and a thin gray discharge
• BV can increase the risk of PID and HIV infections
Bacterial Vaginosis (BV)
Other Infections
• Vaginal Infections continued
– Trichomoniasis
• Caused by protozoan Trichomonas vaginalis
• 5 million new cases each year in the USA
• Usually acquired by females through sexually
intercourse with an asymptomatic male
• Symptoms include heavy frothy, white foulsmelling vaginal discharge from the vagina, and
severe itching
• Can lead to cervical cancer if left untreated
Trichomoniasis
Trichomonas vaginalis
Other Infections
• Pubic Lice aka “Crabs”
– Parasitic crab louse Phthirus pubis, resembles a
small crab and inhabits the pubic hair of humans
– Can be contracted through direct physical contact or
contact with infected person’s clothes or bedding
– Females of the species lay many eggs near the base
of each hair and hatching occurs in a few days
– Main symptom is severe itching around pubic area
due to removal of blood from the host human by each
crab louse
– Can self treat with topical cream
Pubic Lice aka “Crabs”
HIV/AIDS
• History
– First documented in January of 1981 by the
Center for Disease Control
– Thought to have spread to the USA by a gay
flight attendant who traveled abroad
– Originally called the “Gay Cancer” and/or
“Gay Plague” because the initial outbreak was
mainly confined to homosexual males
HIV/AIDS
• History continued
– Less than a year later the list of at risk
individuals expanded to include intravenous
drug users, recent Haitian immigrants, and
Hemophiliacs regardless of sexual orientation
– The virus that causes AIDS was first
discovered by a French scientist in 1983
– Circa 1987, Rock Hudson announced he had
AIDS and died shortly after
HIV/AIDS
• History continued
– In the 1990’s heterosexual celebrities and
professional athletes announced they too had
acquired HIV: Magic Johnson and Arthur Ashe
– The 1990’s saw large amounts of research dedicated
to treatment drugs and finding a cure
– Currently there are some very effective drugs to treat
HIV and keep it from developing into AIDS
– Majority of new cases are in Sub-Saharan Africa, and
unfortunately those people lack the finances to pay
for those drugs to treat HIV
HIV/AIDS
• Three phases of the disease
– Acute Phase
• Virus infects person (host) and replicates ferociously
• Replication process causes death of lymphocytes in the
person’s blood
• Person may be asymptomatic for several weeks; if person
does have symptoms they include fever, chills, aches,
swollen lymph nodes, and an itchy rash
• After many weeks the person’s body reacts to the foreign
invader by producing numerous immune cells to fight the
virus
HIV/AIDS
– Chronic Phase
• Several months to several years an untreated
individual will most likely progress to this phase
• Number of HIV viruses increases causing
reemergence of symptoms like fatigue, persistent
fever, night sweats, persistent cough, and
persistent diarrhea
• These symptoms are a signal that full blown AIDS
will develop soon
HIV/AIDS
– AIDS
• Lymphocyte count has dropped drastically; viruses
have taken over the blood
• Person is extremely weak and thin due to
persistent diarrhea and coughing
• Person eventually dies due to the presence of
another infection
• People do not die from AIDS, but rather, Acquired
Immune Deficiency Syndrome weakens their
bodies ability to fight other common infections
*** There is currently no cure for HIV/AIDS