Infections of the genital tract Flashcards
Describe the host defences in the vaginal area, which microorganisms are an exception?
Vaginal epithelium contains glycogen (due to the circulating estrogens) and when certain lactobacilli colonize the vagina they metabolize the glycogen to produce lactic acid - making the vaginal pH 4-5 which inhibits colonization for microbes other than lactobacilli, certain streptococci and diphtheroids
Name three ways lactobacilli colonize and protect the vagina from other microbes
It prevents other microorganisms from attaching to the epithelia by
- producing a defensive layer over the epithelia
- Producing lactic acid, lowering the pH
- 60% produce hydrogen peroxide which also inhibits bacterial growth
What is the gram and shape of lactobacilli and where are they found in the body?
Gram positive, rod shaped, part of normal vaginal flora
Name five symptoms and 3 signs of a vulvovaginal candidiasis infection?
Symptoms:
-pruritus (itchiness), dyspareunia, dysuria, vaginal soreness, abnormal vaginal discharge - becomes “cottage cheese like” (normally watery and clear)
Signs:
Vulvar edema, fissures, thick curdy discharge
How do other microorganisms colonize and invade the vagina?
- Must have specific mechanisms for attaching to vaginal or cervical mucosa OR 2. Take advantage of minute local injuries (warts, syphilis) or
- Impaired defences (tampons, estrogen imbalance)
What causes vulvovaginal candidiasis?
How common is this infection and how can it be spread?
Candida albicans and occasionally other candida species or yeasts (opportunistic bacteria)
70% will have one infection and 40-45% will have >1
Can be spread through sexual activity, childbirth and when there are alterations to the normal vaginal pH causing a more alkaline environment or changes in normal flora (i.e during antibiotic use)
How can vulvovaginal candidiasis be treated and what is a common symptom?
Antifungal agents in a cream, oral tablet or pessary
Vaginal itching/burning especially during urination.
Why are STIs so easily spreadable
Many only have mild symptoms or are asymptomatic
What five basic things should you think about when investigating someone you suspect has an STI?
5 Ps:
- Partners
- Practices
- Prevention of pregnancy
- Protection of STDs
- Past history of STDs
How are STIs spread?
Contact (penis, vagina, rectum, breaks in skin, mucous membranes)
And needle sharing, blood contacts, vertical transmission (mother-child)
Name four population groups that are particularly at risk of acquiring an STI
- Homosexual men
- Sex workers
- Older age groups
- Younger people; about half of STI diagnosis (especially chlamydia)
Name seven common symptoms experienced by those with an STI including three specific to the vagina
- Pain during urination
- Bumps/sores
- Bleeding between periods - vaginal
- Unusual discharge - vaginal
- Pain during intercourse
- Vulvar burning - vaginal
- Pruritus
Name three common bacteria, viral and parasitic STI pathogens
Bacterial: chlamydia, gonorrhoea, syphilis
Viral: herpes, HPV, Hep B
Parasitic: pubic lice, scabies, trichomoniasis
What are the treatment differences between a bacterial and viral STI
Bacterial infections are curable but meds don’t protect against future exposure (can have multiple infections)
Viral infections are mostly not curable but can be treated/managed with meds to reduce symptoms and outbreaks
What causes syphilis and how are they identified? How is the disease transmitted?
Caused by spirocytes (curved spiral bacteria), particularly treponema pallidum. The infection can’t be identified on gram staining as the organisms are too small, but can be seen by a silver stain or fluorescence techniques
Transmitted through contact (skin-skin, mucous membranes), vertical transmission
How is syphilis treated? Is syphilis completely curable?
With a single IM penicillin injection unless patient is in the tertiary stage
Although syphilis is curable the damage done to the body and/or internal organs is not reversible
Name three diseases characterized by vaginal discharge
Bacterial vaginosis (disease caused by excessive growth of bacteria, i.e during excessive antibiotic use), trichomoniasis, vulvovaginal candidiasis
What causes bacterial vaginosis? Name five general things that are commonly associated with acquiring this disease and the two major symptoms experienced with it
Replacement of the normal H202 producing lactobacillus with excessive growth of anaerobic gram + bacteria.
Malodour and a milky discharge
Associated with; multiple partners, new sex partners, lack of condom use, douching, and lack of vaginal lactobacillus (hormonal imbalance)
How would you treat bacterial vaginosis and what happens if it goes untreated?
With antibiotics (and douching can be prescribed)
If untreated the bacteria may spread to the uterus and Fallopian tubes which may progress to pelvic inflammatory disease, and transmission will continue between sex partners and newborns (increased risk of premature birth)
Name two diseases characteristic by urethritis and cervicitis?
Gonococcal infections, chlamydia
What happens to the cervix during cervicitis? Name three common symptoms and the major two organisms responsible. Are symptoms always experienced?
The cervix becomes edematous and hypertrophic
Symptoms: Vaginal mucopurulent discharge (yellowy, made of macrophages trying to fight the infection), deep dyspareunia, postcoital bleeding (bleeding unrelated to menstruation occurring during or after sexual intercourse). But many are asymptomatic!
C. Trachomatis (chlamydia) or N. gonorrhoea (gonorrhoea)
Is the bacterium chlamydia trachomatis gram -/+, and which cells does it infect?
The bacterium is said to have a biphasic life cycle, what is meant by this?
Gram -ve. Infects columnar epithelial cells
Can have two live forms 1st phase (intracellular): small Elementary Bodies (EB) enter the cell and can indicate a new infection. Once inside, they transform into a large body with multiple initial bodies called...
A Reticulate Body (RB), larger and once inside the cell can multiply in the cytoplasm via binary fusion. The reticulate bodies will then reorganize/convert themselves into the elementary bodies…
2nd phase (extracellular): once maturation is complete (after 2-3 days), the cell ruptures freeing elementary bodies to penetrate other cells. EBs are transmittable particles, surrounded by a rigid cell wall that allows them to divide outside the host cell.
Why is chlamydia an ‘obligatory intracellular bacteria’?
It can only replicate within a host cell (which results in the host cell’s death)
Name four symptoms experienced by men and four by women when infected with chlamydia
How common is it that men and women are asymptomatic when infected with C. trachomatis?
Men: epididymitis, urethritis, dysuria, penile discharge
Women: itching/burning in/around the vagina, abdominal pain with fever, painful periods, abnormal vaginal discharge (+ the 3 symptoms mentioned for cervicitis!)
50% of men have no symptoms and 80% of women
