Classification and pathogenesis of vulvovaginal candidiasis

Antibiotic-associated vulvovaginal candidiasis

Vulvovaginal candidiasis (VVC) is one of the most common causes of vaginitis, and its incidence has increased markedly during the past three decades. The widespread overuse of antibiotics has been suggested as one of the major factors contributing to the increasing incidence of VVC. However, evidence supporting this association has been limited because few studies with rigorous scientific methodology have been conducted. Moreover, existing data regarding the risk for developing VVC after antibiotic use are conflicting. This review examines the available information in the literature regarding antibiotic-associated VVC, its incidence, and its potential mechanisms. Implications for clinical practice and research are also discussed.

Understanding the bacterial flora of the female genital tract

The microbiological flora of the lower female genital tract provides a dynamic, complex example of microbial colonization, the regulation of which is not fully understood. When an exogenous bacterial species, with its array of virulence factors, is introduced into the host, disease does not always occur. Conversely, under selected conditions, commensal endogenous bacteria-for example, Gardnerella vaginalis and group B streptococci-can participate in disease processes. Disease caused by both exogenous and endogenous bacteria correlates positively with a markedly increased level of bacterial replication. The key question is what determines the quantity of a given bacterium at any given time. For disease to occur, exogenous or endogenous bacteria that possess pathogenic prerequisites must attain replicative dominance. Their ability to do so is potentially governed by inhibitory or synergistic interrelationships with other microbes.

Infectious vaginitis. An accurate diagnosis is essential and attainable

Infectious vaginitis is a common clinical problem. Unfortunately, treatment, including self-medication, is often instituted before an adequate evaluation has been performed. An accurate diagnosis can usually be made in the office setting, and effective pharmacologic treatments are readily available.

Increased severity of Candida vaginitis in BALB/c nu/nu mice versus the parent strain is not abrogated by adoptive transfer of T cell enriched lymphocytes

The role of the host immune system in combating candidal infections in the vagina is poorly understood. A murine model of Candida vaginitis was used to elucidate the role of T cells in a candidal infection. Athymic BALB/c nu/nu mice or normal BALB/c mice were induced into estrus and then infected with 1 x 10(6) Candida albicans intravaginally. The infection was monitored over 1 week. Samples from blood, small intestine, tongue, kidney, spleen, liver, uterus and vagina were tested for recoverable C. albicans. Histology of the vagina was assessed for both inflammation and extent of infection. Results indicated that the BALB/c nu/nu mice had similar levels of vaginal yeast load to the normal BALB/c mice. In 25-30% of nude mice Candida was also recovered from extra vaginal sites (kidney, liver, small intestine), however, extra vaginal dissemination was not observed in any normal BALB/c animals. Histologically, both the nu/nu and control BALB/c had similar levels of vaginal inflammation; however, the nu/nu mice had more florid fungal growth in the vaginal epithelium. Adoptive transfer of either immune or non-immune BALB/c T cells into nude mice had no affect on either infection or vaginal inflammation. Immunohistochemical staining of vaginal tissues from normal BALB/c mice or nude mice adoptively transferred with either immune or non-immune T cells with anti-CD3 monoclonal antibody revealed no significant difference between groups in the numbers of CD3+ vaginal T cells. However, in mice receiving either immune or non-immune T cells no yeast was recovered from any tissues except the vagina. These data show that T cells have a limited role in protecting the vagina from C. albicans infection.

Evaluation and management of vaginitis

OBJECTIVE

To evaluate recent advances in our understanding of the clinical relevance, diagnosis, and treatment of vaginal infections, and to determine an efficient and effective method of evaluating this clinical problem in the outpatient setting.

DATA SOURCES

Relevant papers on vaginitis limited to the English language obtained through a MEDLINE search for the years 1985 to 1997 were reviewed.

DATA SYNTHESIS

Techniques that enable the identification of the various strains of candida have helped lead to a better understanding of the mechanisms of recurrent candida infection. From this information a rationale for the treatment of recurrent disease can be developed. Bacterial vaginosis has been associated with complications, including upper genital tract infection, preterm delivery, and wound infection. Women undergoing pelvic surgery, procedures in pregnancy, or pregnant women at risk of preterm delivery should be evaluated for bacterial vaginosis to decrease the rate of complications associated with this condition. New, more standardized criteria for the diagnosis of bacterial vaginosis may improve diagnostic consistency among clinicians and comparability of study results. Use of topical therapies in the treatment of bacterial vaginosis are effective and associated with fewer side effects than systemic medication. Trichomonas vaginalis, although decreasing in incidence, has been associated with upper genital tract infection. Therapy of T. vaginalis infection has been complicated by an increasing incidence of resistance to metronidazole.

CONCLUSIONS

Vaginitis is a common medical problem in women that is associated with significant morbidity and previously unrecognized complications. Research in recent years has improved diagnostic tools as well as treatment modalities for all forms of vaginitis.

Acute neutropenia decreases inflammation associated with murine vaginal candidiasis but has no effect on the course of infection

We have used a mouse model of vaginal candidiasis to determine the effect of neutrophil depletion on (a) the clearance of Candida albicans and (b) the degree of inflammation associated with infection. No differences in recoverable yeast number or rate of clearance were observed between normal and neutrophil-depleted mice; however, vaginal inflammation was significantly decreased in neutrophil-depleted animals.

Prevalence and susceptibility of vaginal yeast isolates in Jordan

The prevalence of vaginal yeast species has been studied in 140 women (41 pregnant, 66 infertile and 33 healthy controls) attending a gynaecological private clinic in Amman, Jordan. Yeast species were isolated from pregnant (68.2%), infertile (51.5%) and healthy control (48.4%) women. Patients manifesting one, two or three symptoms of vulvovaginitis were 22.1%, 26.8% or 24.2% respectively. Asymptomatic cases and cases with more than three symptoms were 22.4% and 4.5% respectively. Candida albicans was the dominant species (in 51.3% of the patients) followed by C. glabrata (17.9%). The percentage occurrence as well as the pattern of Candida species differed among the different groups of patients. Candida kefyr was found to be significantly higher in the infertile women. In vitro sensitivity tests using amphotericin B, nystatin, miconazole nitrate and chlorhexidine were carried out; amphotericin B was the most effective and miconazole nitrate the least.

Vaginal yeast flora of pregnant women in the Cusco region of Peru

A study of the vaginal yeast flora in pregnant women living in Cusco and in its region (Peru), located approximately 3000 m above sea level, is reported. We observed 300 pregnant, healthy and non-diabetic women who attended a gynaecological clinic in the Lorena, Regional or IPSS (Instituto Peruano de Seguridad Social) hospitals in Cusco. A comprehensive clinical history was obtained from each patient. It included age, work, parity, time of pregnancy, use of contraceptives or antibiotics, type of vaginal symptoms, type and amount of vaginal secretion. The yeasts were isolated from 44.3% of the cases. The positive cases were more frequently found in the following categories: 20-30 year-old patients (69.2%), ninth month of pregnancy (49.6%), first pregnancy (41.4%), no delivery (58.7%) and no abortion (66.9%). Most women complained of leukorrhea (75.9%) with mucus, scarce without odour (18.8%) or lumpy, regular, without odour (15.8%) secretion. The yeasts isolated were Candida albicans (66.2%), other Candida species (12.8%), Torulopsis glabrata (8.3%) or other Torulopsis species (2.2%), Saccharomyces cerevisiae (7.5%), Rhodotorula sp. (1.5%) and Trichosporon cutaneum (1.5%).

Chronic recurrent vaginal candidosis: easy to treat, difficult to cure. Results of intermittent treatment with a new oral antifungant

Research into the pathogenesis and treatment of chronic recurrent candidosis vaginalis did not come up with a clear answer of curing this phenomenon. In this investigation, data are presented of a therapy with a new antifungal agent, itraconazole. After a therapeutic treatment course, 17 patients received a prophylaxis for CRCV over 6 months. The treatment schedule for prophylaxis consisted of 4 capsules of 50 mg itraconazole on day 5 and 6 of the menstrual cycle. Eleven remained symptom-free in this period. Although there is no explanation for recurrence in most cases of CRCV, intermittent treatment schedules can be used to treat but not to cure these patients. Data of this investigation and data mentioned in the literature prove the necessity to discriminate between a sympatomtic and a mycological cure.

Candida albicans: cellular immune system interactions during different stages of the menstrual cycle

Candidal vaginitis most often recurs during pregnancy and in the late luteal phase just before menstruation. We examined the influence of the stage of the menstrual cycle on the cellular immune response to Candida albicans, the efficiency of C. albicans germination in sera, and the ability of products from activated lymphoid cells to inhibit germination. C. albicans germination was maximal in sera obtained during the luteal phase. During this period the cellular immune response to Candida was reduced as was the inhibition of Candida germination by products of activated peripheral blood mononuclear cells. Variations in immune response to Candida were of much lesser magnitude in women who took oral contraceptives, which suggests that it was the marked fluctuation in progesterone or estradiol levels during the menstrual cycle that influenced the changes in the immune response to C. albicans. Thus the hormonal status of women may influence the pathogenicity of C. albicans by modulation of immune system activity. These results explain the clinical observation that candidal vaginitis infections most frequently reappear before menstruation.