Week 11 common diseases by route of
exposure Learning objectives – STI-diseases
1. Explain the difference in the terminology between sexually transmitted infections (STIs) and
sexually transmitted diseases (STDs)
2. Describe gonorrhea, syphilis, and chlamydia, and their incidence, symptoms, and treatment
3. Describe the less common bacterial STIs, including nongonococcal urethritis, chancroid,
and donovanosis
4. Discuss the cause, prevention, and treatment of human immunodeficiency virus and
acquired immunodeficiency syndrome
5. Discuss the cause, prevention, and treatment of hepatitis B, C, and D
6. Describe the cause, prevention, and treatment of genital herpes and human
papillomavirus infections
Sexually transmitted infections/disease
1. Affect same organs as the organs of the reproductive system
o Difference mode of transmission
2. Sexually transmitted infection: presence of pathogenic organisms in a host
3. Sexually transmitted diseases: appearance of symptoms and damaging effects because of
an infection
4. Although reproductive organs are the primary targets, STIs may affect other organ systems and
cause systemic problems.
5. One of the likely reasons that sexual activity can lead to a high probability of STI transmission is the
fact that most areas of the reproductive system are lined with mucous membranes, which are
more susceptible to the penetration of pathogens than the skin
Organs affected by STIs
• Females: ovaries, fallopian tubes, uterus, vagina, external genitalia
• Males: testes, prostate gland, urethra, penis
Bacterial STIs
• Gonorrhea – most reported STI in US, transmitted through vaginal, anal, oral sexual activity, can
be transmitted by asymptomatic individuals
• Female symptoms: vaginal discharge, painful burning urination, painful intercourse,
bleeding between periods
• Male symptoms: white, yellow, or green discharge from the penis, painful burning urination,
swelling of testicles
• Increase risk of other infection (HIV, Chlamydia), can lead to pelvic inflammatory disease, can
be passed from mother to baby during movement through birth canal
o Newborn – infections of joints, bacteremia, blindness
• No vaccine for this STI
• Syphilis – cause Treponema pallidum, reservoir and transmission is humans, can be passed
from pregnant woman to child
• Three stages – primary and secondary most infectious
o Stage 1: 3-90 days after exposure/ sore
o Stage 2: 4-10 weeks after initial infection/ body rash
o Stage 3: 3-15 years after initial infection/ affects internal organs
,• Incubation time: 10 to 90 days after initial infection
• Although the bacterium can be passed on through body fluids such as saliva, the primary means
of transmission is through any sexual activity: Vaginal, anal, or oral.
• Primary syphilis represents itself as small, red sores (chancres) that appear on the body.
• During secondary syphilis, the organism enters the bloodstream and travels to other organ
systems, causing a wide variety of symptoms.
• Primary syphilis
● Small red sores (chancres)
● Will disappear, leaving a scar on skin
• Secondary syphilis
● 2 to 10 weeks after primary stage
● Wide variety of symptoms
• Tertiary syphilis
● Characterized by gummas in vital organs
• At least two blood tests are done to determine and confirm an infection (do to the possibility of
a false-negative reading)
Chlamydial infections
• Cause: chlamydia trachomatis, most prevalent STIs in Canada, females are often asymptomatic,
can be transmitted from mother to infant, untreated infection can cause serious health problems
• Transmission through exchange of semen or vaginal fluid during vaginal, oral, or anal sex
• Women are more likely to experience serious problems associated with a chlamydial infection in
the form of pelvic inflammatory disease (PID).
• Lymphogranuloma venereum (LGV) chlamydial infections are 20 times more common in men than
in women.
• Current treatment for all types of chlamydial infections consists of a course of antibiotics
including tetracycline, azithromycin, and erythromycin.
Mycoplasmal and Ureaplasmal Nongonococcal Urethritis (NGU)
• Causes: Mycoplasma hominis and Ureaplasma urealyticum
• Transmission is primarily through vaginal sexual activity
• M. hominis can cause PID in women and urethritis in men
• Diagnosis is done by culturing the organism from the placenta or in urethral and vaginal discharge
• U. urealyticum is a major cause of fetal and neonatal death, premature births, miscarriages, and
low birth weight.
o Treatment for these infections is typically tetracycline; however,
erythromycin, spectinomycin, and clindamycin have also proven to be
effective
Chancroid
• Rare in the US – incidence worldwide is greater than gonorrhea or syphilis
• Cause is Haemophilus ducreyi
• Affects both men and women
• Primary symptom: Soft, painful lesions or chancres, highly infective
• Diagnosis involves identifying the presence of the organism in scrapings from a lesion or from
fluids from a bubo
• Incubation time between initial infection and the appearance of symptoms is about 3 to 7 days
,• Treatment will heal the lesions, but deep tissue scarring may remain.
• As with most other STIs, preventive measures include abstinence from sexual activity, use
of condoms, and protection from contact with lesions (primarily for caregivers)
Donovanosis
• Uncommon in the United States
• Most cases among homosexual men
• Cause: Klebsiella granulomatis
• Epidemiology not fully established
• Symptoms: Appearance of irregular, painless ulcers on or near the genitals
o Within 9 to 50 days after infection
• Diagnosis is performed by staining of scrapings from the lesions and microscopic examination
• Whatever the method of transmission, the infection rate is relatively low, and even with
regular sexual contact the infection may not spread
o The ulcers may heal without treatment, but they do cause loss of skin pigment in the area
of the lesion
Viral STIs
• Human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS)
• Hepatitis
• Genital herpes
• HPV
• Unlike bacterial STIs, viral STIs are at the present time are incurable
• The antiviral drugs available can be used to manage the disease but not to cure the disease
HIV and AIDs
• HIV - causative agent of AIDS
• AIDS – not a disease but a syndrome, complex signs and symptoms, results in many
opportunistic infections due to compromised immune system, pandemic infection
• Transmitted from person-to-person
• Many methods for diagnosis
• There is no treatment that can cure HIV
• HIV, if left untreated, basically destroys the immune system, thus leaving the body open to
various infections that ultimately prove fatal
• The fluids typically involved in transmission of the virus include blood, semen, and vaginal
secretions
• OraSure is a home-type test using secretions from between the cheek and the gums to detect
the presence of HIV antibodies; this contrasts with the blood used in the three previous tests
• Common HIV-related infections – pneumocystis pneumonia PCP, Kaposi’s sarcoma, shingles, oral
candida
HIV
• Destroys the immune system
• Virus targets: helper T cells, macrophages, dendritic cells, and Langerhans cells
• Battle the virus in early stages of infection, late stage numbers diminish
• Decreases the bodies ability to make antibodies that fight infection
, HIV then eventually aids
STAGE TIME FRAME SYMPTOMS
1 1-12 months HIV antibodies appear; flu like symptoms
2 1-8 years Mild anemia, low WBC count, some decrease in T-cell count,
seborr dermatitis, shingles, hair leukoplakia
3 9-15 years Moderate anemia, low albumin, low cholesterol, decrease
helper cell count, severe dermatitis, thrush, weight loss, diarrh
recurrin fever, tuberculosis, various bacterial infections, recurr
shingle
4 Months - years Death – usually 2 years of diagnosis in men, 12-18 months in
wome opportunistic infections, lymphoma, and wasting syndrom
Kaposi’s sarcoma (KS)
• When blood vessels grow in tangled mass filled with blood and rupture easily
• Appearance: Pink or purple splotches on skin
• Can spread to organs: digestive tract, lungs, liver, spleen, lymph system
Hepatitis B, C, and D
• Infection of the liver
• The virus itself replicates in liver cells, lymph tissue, and hematopoietic tissue.
• What are some of the symptoms of HBV infection? (Symptoms include yellowing of the skin,
nausea, diarrhea, and lack of appetite.)
• HBV infections can be prevented by vaccination, which is required for most healthcare providers or
other persons who may be exposed to blood products
• HCV RNA can be detected in the blood within 1 to 3 weeks of exposure
• At present, there is no vaccine available for hepatitis C, and the CDC recommendations for
prevention and control of HCV infections include screening and testing of blood donors, viral
inactivation of plasma-derived products, risk reduction counseling, screening of persons at risk
for HCV infection, and routine practice of infection control in healthcare setting
Hepatitis B (HBV)
• Sexually transmitted, sharing of needles, from infected mother during birth or breastfeeding
Hepatitis C (HCV)
• Mostly transmitted by blood-to-blood contact
• May be sexually transmitted
• Can be acute or chronic
exposure Learning objectives – STI-diseases
1. Explain the difference in the terminology between sexually transmitted infections (STIs) and
sexually transmitted diseases (STDs)
2. Describe gonorrhea, syphilis, and chlamydia, and their incidence, symptoms, and treatment
3. Describe the less common bacterial STIs, including nongonococcal urethritis, chancroid,
and donovanosis
4. Discuss the cause, prevention, and treatment of human immunodeficiency virus and
acquired immunodeficiency syndrome
5. Discuss the cause, prevention, and treatment of hepatitis B, C, and D
6. Describe the cause, prevention, and treatment of genital herpes and human
papillomavirus infections
Sexually transmitted infections/disease
1. Affect same organs as the organs of the reproductive system
o Difference mode of transmission
2. Sexually transmitted infection: presence of pathogenic organisms in a host
3. Sexually transmitted diseases: appearance of symptoms and damaging effects because of
an infection
4. Although reproductive organs are the primary targets, STIs may affect other organ systems and
cause systemic problems.
5. One of the likely reasons that sexual activity can lead to a high probability of STI transmission is the
fact that most areas of the reproductive system are lined with mucous membranes, which are
more susceptible to the penetration of pathogens than the skin
Organs affected by STIs
• Females: ovaries, fallopian tubes, uterus, vagina, external genitalia
• Males: testes, prostate gland, urethra, penis
Bacterial STIs
• Gonorrhea – most reported STI in US, transmitted through vaginal, anal, oral sexual activity, can
be transmitted by asymptomatic individuals
• Female symptoms: vaginal discharge, painful burning urination, painful intercourse,
bleeding between periods
• Male symptoms: white, yellow, or green discharge from the penis, painful burning urination,
swelling of testicles
• Increase risk of other infection (HIV, Chlamydia), can lead to pelvic inflammatory disease, can
be passed from mother to baby during movement through birth canal
o Newborn – infections of joints, bacteremia, blindness
• No vaccine for this STI
• Syphilis – cause Treponema pallidum, reservoir and transmission is humans, can be passed
from pregnant woman to child
• Three stages – primary and secondary most infectious
o Stage 1: 3-90 days after exposure/ sore
o Stage 2: 4-10 weeks after initial infection/ body rash
o Stage 3: 3-15 years after initial infection/ affects internal organs
,• Incubation time: 10 to 90 days after initial infection
• Although the bacterium can be passed on through body fluids such as saliva, the primary means
of transmission is through any sexual activity: Vaginal, anal, or oral.
• Primary syphilis represents itself as small, red sores (chancres) that appear on the body.
• During secondary syphilis, the organism enters the bloodstream and travels to other organ
systems, causing a wide variety of symptoms.
• Primary syphilis
● Small red sores (chancres)
● Will disappear, leaving a scar on skin
• Secondary syphilis
● 2 to 10 weeks after primary stage
● Wide variety of symptoms
• Tertiary syphilis
● Characterized by gummas in vital organs
• At least two blood tests are done to determine and confirm an infection (do to the possibility of
a false-negative reading)
Chlamydial infections
• Cause: chlamydia trachomatis, most prevalent STIs in Canada, females are often asymptomatic,
can be transmitted from mother to infant, untreated infection can cause serious health problems
• Transmission through exchange of semen or vaginal fluid during vaginal, oral, or anal sex
• Women are more likely to experience serious problems associated with a chlamydial infection in
the form of pelvic inflammatory disease (PID).
• Lymphogranuloma venereum (LGV) chlamydial infections are 20 times more common in men than
in women.
• Current treatment for all types of chlamydial infections consists of a course of antibiotics
including tetracycline, azithromycin, and erythromycin.
Mycoplasmal and Ureaplasmal Nongonococcal Urethritis (NGU)
• Causes: Mycoplasma hominis and Ureaplasma urealyticum
• Transmission is primarily through vaginal sexual activity
• M. hominis can cause PID in women and urethritis in men
• Diagnosis is done by culturing the organism from the placenta or in urethral and vaginal discharge
• U. urealyticum is a major cause of fetal and neonatal death, premature births, miscarriages, and
low birth weight.
o Treatment for these infections is typically tetracycline; however,
erythromycin, spectinomycin, and clindamycin have also proven to be
effective
Chancroid
• Rare in the US – incidence worldwide is greater than gonorrhea or syphilis
• Cause is Haemophilus ducreyi
• Affects both men and women
• Primary symptom: Soft, painful lesions or chancres, highly infective
• Diagnosis involves identifying the presence of the organism in scrapings from a lesion or from
fluids from a bubo
• Incubation time between initial infection and the appearance of symptoms is about 3 to 7 days
,• Treatment will heal the lesions, but deep tissue scarring may remain.
• As with most other STIs, preventive measures include abstinence from sexual activity, use
of condoms, and protection from contact with lesions (primarily for caregivers)
Donovanosis
• Uncommon in the United States
• Most cases among homosexual men
• Cause: Klebsiella granulomatis
• Epidemiology not fully established
• Symptoms: Appearance of irregular, painless ulcers on or near the genitals
o Within 9 to 50 days after infection
• Diagnosis is performed by staining of scrapings from the lesions and microscopic examination
• Whatever the method of transmission, the infection rate is relatively low, and even with
regular sexual contact the infection may not spread
o The ulcers may heal without treatment, but they do cause loss of skin pigment in the area
of the lesion
Viral STIs
• Human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS)
• Hepatitis
• Genital herpes
• HPV
• Unlike bacterial STIs, viral STIs are at the present time are incurable
• The antiviral drugs available can be used to manage the disease but not to cure the disease
HIV and AIDs
• HIV - causative agent of AIDS
• AIDS – not a disease but a syndrome, complex signs and symptoms, results in many
opportunistic infections due to compromised immune system, pandemic infection
• Transmitted from person-to-person
• Many methods for diagnosis
• There is no treatment that can cure HIV
• HIV, if left untreated, basically destroys the immune system, thus leaving the body open to
various infections that ultimately prove fatal
• The fluids typically involved in transmission of the virus include blood, semen, and vaginal
secretions
• OraSure is a home-type test using secretions from between the cheek and the gums to detect
the presence of HIV antibodies; this contrasts with the blood used in the three previous tests
• Common HIV-related infections – pneumocystis pneumonia PCP, Kaposi’s sarcoma, shingles, oral
candida
HIV
• Destroys the immune system
• Virus targets: helper T cells, macrophages, dendritic cells, and Langerhans cells
• Battle the virus in early stages of infection, late stage numbers diminish
• Decreases the bodies ability to make antibodies that fight infection
, HIV then eventually aids
STAGE TIME FRAME SYMPTOMS
1 1-12 months HIV antibodies appear; flu like symptoms
2 1-8 years Mild anemia, low WBC count, some decrease in T-cell count,
seborr dermatitis, shingles, hair leukoplakia
3 9-15 years Moderate anemia, low albumin, low cholesterol, decrease
helper cell count, severe dermatitis, thrush, weight loss, diarrh
recurrin fever, tuberculosis, various bacterial infections, recurr
shingle
4 Months - years Death – usually 2 years of diagnosis in men, 12-18 months in
wome opportunistic infections, lymphoma, and wasting syndrom
Kaposi’s sarcoma (KS)
• When blood vessels grow in tangled mass filled with blood and rupture easily
• Appearance: Pink or purple splotches on skin
• Can spread to organs: digestive tract, lungs, liver, spleen, lymph system
Hepatitis B, C, and D
• Infection of the liver
• The virus itself replicates in liver cells, lymph tissue, and hematopoietic tissue.
• What are some of the symptoms of HBV infection? (Symptoms include yellowing of the skin,
nausea, diarrhea, and lack of appetite.)
• HBV infections can be prevented by vaccination, which is required for most healthcare providers or
other persons who may be exposed to blood products
• HCV RNA can be detected in the blood within 1 to 3 weeks of exposure
• At present, there is no vaccine available for hepatitis C, and the CDC recommendations for
prevention and control of HCV infections include screening and testing of blood donors, viral
inactivation of plasma-derived products, risk reduction counseling, screening of persons at risk
for HCV infection, and routine practice of infection control in healthcare setting
Hepatitis B (HBV)
• Sexually transmitted, sharing of needles, from infected mother during birth or breastfeeding
Hepatitis C (HCV)
• Mostly transmitted by blood-to-blood contact
• May be sexually transmitted
• Can be acute or chronic
