AN APPRAISAL OF THE INCIDENCE OF CANDIDA ALBICANS AMONG PREGNANT AND NON-PREGNANT WOMEN
ABSTRACT
Vulvovaginal candidiasis (VVC) is a common genital tract infection that affects the quality of life in many women. It is more prevalent in pregnancy and may lead to complications. Aims and Objectives: The study aimed to determine the prevalence of VVC among pregnant women attending the antenatal clinic of a tertiary health institution in North-West Nigeria and to emphasize the need for accurate diagnosis and adequate treatment. Subjects and Methods: This is a 2-month cross-sectional study performed at the Department of Obstetrics and Gynaecology in association with the Department of Medical Microbiology of the Usmanu Danfodiyo University Teaching Hospital, Sokoto in North-Western Nigeria. It involved pregnant women at various periods of gestation presenting with vaginitis and selected by simple random sampling. A pair of high vaginal swabs was collected aseptically from the study subjects which was used for Gram’s staining and inoculation into Sabouraud’s dextrose agar (SDA). The samples were then cultured according to standard procedures on sterile SDA. Infection with Candida species was diagnosed by microscopy of a saline wet mount, Gram-stained smear and colony growth on SDA. Results: Of the 288 pregnant women sampled, 175 were positive for candidiasis giving a prevalence rate of 60.8%. The ages of the women ranged from 16 to 45 years with a mean of 26.8 (standard deviation ± 4.93). Pregnant women aged 26–30 years recorded the highest prevalence of 37.1% (65/175). The multigravidae were more affected 41.7% (120/288) than the primigravidae 19.1% (55/288). VVC showed a progressive increase with trimester of pregnancy. Candida albicans was the most prevalent species isolated in 73.7% of the women. Conclusion: There is a high prevalence of VVC among pregnant women in our institution. There is need to educate the women on genital hygiene and practice of regular screening for candidiasis in our antenatal program.
CHAPTER ONE INTRODUCTION
1.1 Background of the Study
The presence of any genital tract infection during pregnancy raises a lot of concerns because of the threat to the well-being of the mother and child. Early detection is thus important because maternal physiological alterations may hamper the diagnosis and management of the infection, and the presence of the fetus may limit treatment.[1] Vaginal discharge is a common symptom of genital tract infection in women. Identifying its source can be very challenging because a large number of pathogens may be responsible and several infections may co-exist. Vulvovaginal candidiasis (VVC) is an inflammation of the vagina and/or vulva in the presence of Candida species and in the absence of any other etiological agent.[1] It is a common infection affecting the quality of life of many women. It is estimated to be the second most common cause of vaginitis after bacterial vaginosis.[1],[2] It is estimated that around 75% of all women experience at least one episode of VVC during their childbearing years, of which about half have at least one recurrence.[3] Symptoms are thought to be caused by an overgrowth of yeast and its penetration of vulvovaginal epithelial cells.[4] The signs and symptoms of uncomplicated VVC include a thick cheese-like discharge associated with vaginal and vulvar pruritus, pain, burning, erythema, and/or edema. Dysuria and dyspareunia may also occur and may result in marital and sexual disharmony. The vaginal pH is usually normal and budding yeast cells, and pseudohyphae may be seen on wet mount. Asymptomatic prevalence has been reported in 10% of women.[5] VVC is most often caused by Candida albicans, however, other species of Candida such as Candida glabrata, Candida parapsilosis, and Candida tropicalis are emerging.[3],[4],[5] With the introduction of antifungal agents, the causes of Candida infections shifted from an almost complete predominance of C. albicans to the common involvement of non-albicans species listed above.[6],[7] These non-albicans Candida (NAC) species tend to be resistant to conventional anti-fungal drugs and are thus responsible for persistent infections.[3],[7],[8]
Risk factors for VVC include sexual activity, recent antibiotic use, pregnancy, and immune-suppression from such conditions as poorly controlled HIV infection or diabetes.[6] The main reservoir for Candida is thought to be the rectum, but vaginal colonization is also common.[9] The factors associated with evolution from colonization to symptomatic infection are multiple and involve a combination of host susceptibility, host inflammatory responses, and Candida virulence factors. VVC is not a reportable disease and is often diagnosed without confirmatory tests and most often treated empirically, and thus the exact incidence is unknown.[3]
The relationship between pregnancy and VVC indicates that increase in gestational hormones results in alteration of the pH of the vagina and increases a woman’s risk of developing VVC. The high estrogen levels result in higher glycogen content in vaginal secretions which acts as a nutrient for Candida organisms.[3] The vagina shows an increased susceptibility to infection by Candida species resulting in both a higher rate of vaginal colonization and a higher rate of symptomatic vaginitis. It is also said that estrogen enhances adherence of yeast cells to the vaginal mucosa.[10] Thus, in pregnancy, VVC can be prolonged and associated with more severe symptoms, and resolution of symptoms typically requires longer courses of therapy. Unfortunately, only topical azoles are recommended in pregnancy.[11] Oral fluconazole is usually avoided as it may increase the risk of tetralogy of Fallot in the fetus.[11] Complications of untreated VVC in pregnancy include chorioamnitis, abortion, preterm delivery and congenital infection in the neonate. Other complications in the nonpregnant woman include pelvic inflammatory disease, infertility, pelvic abscess, and menstrual disorders.[12]
A prevalent rate of 31.5%, 41%, and 56.3%, respectively among pregnant women with vaginal discharge has been reported from Northern Nigeria.[6],[13],[14] No previous studies to the best of our knowledge have been done on the prevalence of vaginal candidiasis among pregnant women in our institution. We undertook this study to determine the prevalence of VVC among pregnant women to underscore the importance of accurate diagnosis and prompt treatment of the condition.
1.2 Aims and objectives
The study aimed to determine the prevalence of VVC among pregnant women attending the antenatal clinic in a tertiary health institution in North-West Nigeria and emphasize the need for accurate diagnosis and adequate treatment.
This is a cross-sectional study that spanned over a period of 2 months. The study was performed in the Department of Obstetrics and Gynaecology in collaboration with the Department of Medical Microbiology of the Usmanu Danfodiyo University Teaching Hospital (UDUTH), Sokoto. It was conducted between June 1, 2012, and July 31, 2012; a period of 2-month. The hospital has 600-bed spaces and provides tertiary and secondary health care services to neighboring states and also runs a residency training program for doctors in the various subspecialists including Surgery, Obstetrics and Gynaecology, Internal Medicine, Paediatrics, Pathology among others. The study population consisted of pregnant women who were attending the antenatal clinic of UDUTH with of vaginitis and were recruited into the study by simple random sampling. A convenient sample size was generated using the formula N = Z2 (P (1 − P)/d2), where N is the minimum required sample size, Z = 1.96 at 95% confidence interval, P = estimated population proportion, which was 30% (from a previous work),[9]q = proportion of failure (=1 −P) and d = absolute precision required on either side of the proportions = 5%. This generated a convenient sample size of 288. Prior verbal and written consent was obtained from the women before sample collection, and the study was approved by the ethical committee of the hospital. The sociodemographic data of the patients were obtained and entered into a study proforma. A pair of high vaginal swabs was obtained from the posterior vaginal fornix of the subjects aseptically with the help of a vaginal speculum. One swab was used for Gram’s staining, and the other was inoculated on Sabouraud’s dextrose agar (SDA). The specimens were labeled, marked and were immediately transported to the microbiology laboratory for processing. The samples were then cultured according standard procedures on sterile SDA and chocolate agar and were incubated aerobically at 37°C for 18–48 h. Infection with Candida species was diagnosed by microscopy of a saline wet mount (which showed multiple pseudohyphae), Gram-stained smear of material from the vagina and colony growth on SDA and chocolate agar. Yeasts are identified in Gram-stained smears as Gram-positive cells. Isolates on the SDA plates were identified and speciated using conventional methods, i.e. germ tube test, sugar assimilation test among others. Statistical analysis of the collected data was performed using the SPSS IBM version 20 (IBM Corp., Armouk, NY, USA). The results were expressed in frequencies, means, percentages, tables, figures and charts. The Chi-square test was used for association at P = 0.05 at 95% confidence interval. The hospital’s ethical and research committee approved the study.
Of the 288 pregnant women sampled, 175 were found to be positive for candidiasis while 113 were negative thus giving a prevalence rate of 60.76% in the study population. The ages of the women ranged from 16 to 45 years with a mean of 26.8 (standard deviation [SD] ±4.93). VVC was most prevalent within the age group of 21–30 years 43.1% (124/288) and declined after the age of 35 years as shown in [Table 1]. Pregnant women aged 26–30 years recorded the highest prevalence 37.1% (65/175). The parity distribution showed that 86 (29.9%) were primigravidae while 202 (70.1%) were multigravidae. There was no significant relationship between the parity of the study subjects and the prevalence of VVC as shown in [Table 2] even though. The multigravidae were more affected 41.7% (120/288) than the primigravidae 19.1% (55/288), χ2 = 0.523, df = 1, P = 0.469.
