Chapter041

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins

Chapter 41

Sexually Transmitted Infections

Chapter 41

Sexually Transmitted Infections


External InfectionsExternal Infections

• Condylomata

• Herpes

• Chancroid

• Granuloma


Condylomata (Genital Warts)Condylomata (Genital Warts)

• Human papillomavirus (HPV)

• Transient or persistent

• May be asymptomatic

• Associated with genital cancers

• Vaccine recently developed


Question Question

Tell whether the following statement is true or false:

The HPV vaccine is currently available for both males and females.


Answer Answer

False

The FDA has approved the vaccine for girls (optimal age is 9 to 12 years old). The vaccine is a series of three shots/injections. Clinical trials are currently underway evaluating the efficacy of the vaccine in males, but the vaccine won’t be available for males until the trials are complete and the FDA approves it.


Genital HerpesGenital Herpes

• Herpes simplex virus 2 (related to chickenpox and cold sores)

• Causes genital ulcers

• Grows in neurons

• Can remain dormant in neurons for years

• Can reactivate and spread back down neuron


Bacterial Diseases of External GenitaliaBacterial Diseases of External Genitalia

• Chancroid

– Haemophilus ducreyi

• Granuloma inguinale (genital ulcers)

– Calymmatobacterium


Vaginal InfectionsVaginal Infections

• Candidiasis

• Trichomoniasis

• Bacterial vaginitis


Normal Bacterial FloraNormal Bacterial Flora

• Many species of bacteria normally live in the vagina

• Lactic-acid-producing bacteria dominate

– Acid helps control growth of other bacteria

• Species composition of flora varies

– Between individuals

– Between ethnic groups

(Zhou, et al., [2004]. Characterization of vaginal microbial communities in adult healthy women using cultivation-independent methods. Microbiology,150, 2565-2573. Retrieved September 22, 2005, from http://mic. sgmjournals.org/cgi/content/full/150/8/2565.0)


CandidiasisCandidiasis

• “Yeast infection” or “thrush”

• Causes include:

– Decreased normal bacterial flora (antibiotics)

– Increased estrogen/progesterone levels

– Decreased immune system activity

• Results in:

– Inflammation

– Thick odorless discharge


TrichomoniasisTrichomoniasis

• Inflammation

• Frothy, malodorous, green or yellow discharge

• Associated with tubular infertility or pelvic inflammatory disease


Bacterial VaginosisBacterial Vaginosis

• Nonspecific: may be caused by many different bacteria

• Imbalance of normal vaginal bacterial flora

• Thin discharge with fishy odor

• Usually treated only if symptomatic or associated with other risk conditions (pregnancy, hysterectomy)


Question Question

Which vaginal infection is associated with suppressed immune function?

a. Candidiasis

b. Trichomoniasis

c. Bacterial vaginitis

d. Chancroid


Answer Answer

a. Candidiasis

Candidiasis (yeast infection/thrush) is associated with diminished immune function. When the normal flora is decreased, Candida albicans has room to thrive.


Urogenital-Systemic InfectionsUrogenital-Systemic Infections

• Chlamydia

• Gonorrhea

• Syphilis


ChlamydiaChlamydia

• Intracellular parasites

– Signs at site of infection: hypertrophy, drainage

– Signs of urinary tract infection: urinary frequency, dysuria, discharge, postcoital bleeding

– Signs of upper genital tract infection: irregular uterine bleeding, abdominal/pelvic discomfort

• Complications include infertility and ectopic pregnancy

• May cause conjunctivitis


GonorrheaGonorrhea

• Bacterium Neisseria gonorrhoeae

• May be asymptomatic

• May cause pain and discharge

• May cause conjunctivitis


SyphilisSyphilis

• Spirochete Treponema pallidum

• Primary syphilis

– Chancre at site of exposure


Syphilis (cont.)Syphilis (cont.)

• Secondary syphilis

– Disseminates to other organs

– Skin rash

– Mucosal lesions

• Tertiary syphilis

– Gumma lesions develop in organs

– CNS and heart often affected



Question Question

Which of the following STDs may cause conjunctivitis?

a. Chlamydia

b. Gonorrhea

c. Syphilis

d. a and b

e. All of the above


Answer Answer

d. a and b

Certain STDs affect other body systems - chlamydia (caused by an intracellular parasite/virus) and gonorrhea (caused by a bacteria) may both result in conjunctivitis.

Syphilis is affects the skin, organs, and CNS.

Chapter041

Documents

normal flora

genital cancers vaccine

bacterial vaginitisd

site of infection

hpv vaccine

cause conjunctivitis

secondary syphilis

species of bacteria