Three most common infection encountered, which cause abnormal discharge per vagina with or without itching are Trichomoniasis, Candida infections and Bacterial vaginosis.
Trichomoniasis of vagina
Trichomonas vaginalis (TV) is a flagellated protozoon which is predominantly sexually transmitted. It is able to attach to squamous epithelium and can infect the vagina and urethra. Trichomonas may be acquired perinatally in babies born to infected mothers.
Infected women may, unusually, be asymptomatic. Commonly the major complaints are of vaginal discharge which is offensive and of local irritation. Men usually present as the asymptomatic sexual partners of infected women, although they may complain of urethral discharge, irritation or urinary frequency.
Examination often reveals a frothy yellowish vaginal discharge and erythematous (reddish) vaginal walls. The cervix may have multiple small haemorrhagic areas which lead to the description 'strawberry cervix'.
Trichomonas infection in pregnancy has been asso ciated with preterm delivery and low birth-weight babies.
Diagnosis of Trichomoniasis
Phase-contrast, dark -ground microscopy of a drop of vaginal discharge shows TV swimming with a charac teristic motion in 40-80% of female patients. Similar preparations from the male urethra will only be positive in about 30% of cases. Many polymorphonuclear leucocytes are also seen. Culture techniques are good and confirm the diagnosis. Trichomonas is sometimes observed on cervical cytology with a 60-80% accuracy in diagnosis. New, highly sensitive and specific tests based on polymerase chain reactions are in development.
Treatment of Trichomoniasis
Metronidazole is the treatment of choice, either 2 g orally as a single dose or 400 mg twice -daily for 7 days. There is some evidence of metronidazole resistance and nimorazole may be effective in these cases. Topical therapy with intravaginal tinidazole can be effective, but if extravaginal infection exists this may not be eradicated and vaginal infection reoccurs. Male partners should be treated, especially as they are likely to be asymptomatic and more difficult to detect.
Candidiasis of vagina
Vulvovaginal infection with Candida albicans is extremely common. The organism is also responsible for balanitis( infection in the glans penis) in men. Candida can be isolated from the vagina in a high proportion of women of childbearing age, many of whom will have no symptoms.
The role of Candida as pathogen or commensal is difficult to disentangle and it may be changes in host environment which allow the organism to produce pathological effects. Predisposing factors include pregnancy, diabetes, and the use of broad -spectrum antibiotics and corticosteroids. Immuno suppression can result in more florid infection.
Symptoms of Candidiasis
In women, pruritus vulvae (itching in the vulva or, private parts) is the dominant symptom. Vaginal discharge is present in varying degree. Many women have only one or occasional isolated episodes. Recurrent candidiasis (four or more symptomatic episodes annually) occurs in up to 5% of healthy women of reproductive age. Examination reveals erythema (redness) and swelling of the vulva with broken skin in severe cases. The vagina may contain adherent curdy discharge.
Men may have a florid balanoposthitis (infection of the glans penis). More commonly, self limiting burning penile irritation immediately after sexual intercourse with an infected partner is described . Diabetes must be excluded in men with balanoposthitis.
Diagnosis of candidiasis
Microscopic examination of a smear from the vaginal wall reveals the presence of spores and mycelia. Culture of swabs should be undertaken but may be positive in women with no symptoms. Trichomonas and bacterial vaginosis must be considered in women with itch and discharge.
Treatment of candidiasis
Topical. Pessari es or creams containing one of the imidazole antifungals such as clotrimazole 500 mg single dose used intravaginally are usually effective. Nystatin is also useful.
Oral. The triazole drugs such as fluconazole 150 mg as a single dose or itraconazole 200 mg twice in 1 day are used systemically where topical therapy has failed or is inappropriate. Recurrent candidiasis may be treated with fluconazole 100 mg weekly for 6 months, or clotrimazole pessary 500 mg weekly for 6 months.
The evidence for sexual transmission of Candida is slight and there is no evidence that treatment of male partners reduces recurrences in women.
Bacterial vaginosis
Bacterial vaginosis (Bacterial Vaginosis) is a disorder characterized by an offensive vaginal discharge. The cause and methodology are unclear but a mixed flora of Gardnerella vaginalis, anaerobes including Bacteroides, Mobiluncus spp. and Mycoplasma hominis, replaces the normal lactobacilli of the vagina. Amines and their breakdown products from the abnormal vaginal flora are thought to be responsible for the characteristic odour associated with the condition. As vaginal inflammation is not part of the syndrome the term vaginosis is used rather than vaginitis. The condition has been shown to more common in black women than in white. It is not regarded as a sexually transmitted disease.
Symptoms of Bacterial Vaginosis
Vaginal discharge and odour are the most common complaint s although a proportion of women are asymptomatic. A homogeneous, greyish white, adherent discharge is present in the vagina, the pH of which is raised (greater than 5).
Associated complications are ill defined but may include chorioamnionitis and an increased incidence of premature labour in pregnant women.
Diagnosis of Bacterial Vaginosis
In general it is accepted that three of the following should be present for the diagnosis to be made:
#characteristic vaginal discharge
# the amine test: raised vaginal pH using narrow-range indicator paper (> 4.7)
# a fishy odour on mixing a drop of discharge with 10% potassium hydroxide
# the presence of clue cells on microscopic examination of the vaginal fluid.
Clue cells are squamous epithelial cells from the vagina which have bacteria adherent to their surface, giving a granular appearance to the cell. A Gram stain gives a typical reaction of partial stain uptake.
Treatment of Bacterial Vaginosis
Metronidazole given orally in doses of 400 mg twice daily for 5-7 days is usually recommended. A single dose of 2 g metronidazole is less effective. Topical 2% clindamycin cream 5 g intravaginally once daily for 7 days is effective.
Recurrence is high, with some studies giving a rate of 80% within 9 months of completing metronidazole therapy. There is debate over the treatment of asymptomatic women who fulfil the diagnostic criteria for Bacterial Vaginosis.The diagnosis should be fully discussed and treatment offered if the woman wishes. Until the relevance of Bacterial Vaginosis to other pelvic infections is elucidated, the treatment of asymptomatic women with Bacterial Vaginosis is not to be recommended. There is no convincing evidence that simultaneous treatment of the male partner influences the rate of recurrence of Bacterial Vaginosis, and routine treatment of male partners is not indicated.
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