Vulvo-vaginal candidiasis is a fungal or yeast infection of the female lower genital tract (Sobel, 2007) and is characterized by curd-like vaginal discharge, itching, and erythema, (Achkar and Fries, 2010). It can be referred to as candidiasis  or  moniliasis.  About  70-75%  of  healthy women will at least either experience one episode of vulvo-vaginal candidiasis during their lifetime or during their reproductive life (Ferris et al., 2002). It can be recurrent or relapsing when a woman presents with four or  more  episodes  per  year and  this condition has been reported among less than 5% of healthy women (Rex et al., 2000).

Also, half of college women by age of 25 years would have had one episode of vulvo-vaginal candidiasis diagnosed by a physician (Sobel, 1997). Candida species are part of the lower genital tract flora in 20-50% of healthy asymptomatic women (Akah et al., 2010) and in most cases prevalence of vaginal colonization and symptomatic vaginitis is higher in pregnant women than in those who are not pregnant. This is due to high concentration of reproductive hormones that increase the glycogen content in the vaginal tissue thereby providing a carbon source for candida organisms (Dennerstein and Ellis, 2001). Increasing Candida infection colonization had been found among women who douche (Rathod et al., 2012). Infectious Disesse Of Obsterics and Gynecology, and women using certain types of contraceptives, (Tarry et al., 2005) although this is not found in a study among some college students (Demirezen et al., 2005).

Vulvo-vaginal candidiasis has been associated with considerable direct and indirect economic costs (Foxman et al., 2000), enhanced susceptibility to HIV infection (Røttingen et al., 2001) and is being investigated for a potential relationship with preterm birth (Roberts et al., 2011). Carrier rates are higher in women treated with broad spectrum antibiotics (Singh, 2003) pregnant women, diabetic women (Donders et al., 2002; Reed et al., 2003) and women with HIV/AIDS (Nelson et al., 2013). Treatment of vulvo-vaginal candidiasis is warranted when a woman presents with a complaint of symptoms of this condition and laboratory confirmation of the presence of candida from a vaginal specimen.  

A study conducted in Ghana, West Africa reported that among a cohort of apparently healthy women, 30% had confirmed cases of diagnosed vulvo-vaginal candidiasis (Maccato and Kaufman, 1991). Also, in a study conducted by Okonofua et al. (1995) reported a prevalence of 36.0% VVC among pregnant women in south-western, Nigeria. Okonkwo (2010) in Nigerian study found no significant difference among patients who were positive with vulvo-vaginal candidiasis and their socioeconomic status. C. albicans is the most frequent colonizer, and is incriminated in most cases of vulvo-vaginal candidiasis (Ugwa, 2015). Nelson et al. (2013), showed C. albicans as the most common Candida species followed by Candida glabrata causing vaginal candidiasis among pregnant women. Okonofua et al. (1995), a high prevalence of C. albicans among infertile women compared with controls.  Over the last 10 years, research evidence has revealed an increase in frequency of  cases caused by non - albicans species, with C. glabrata consistently being the leading species (Cheesbrough, 2000). Candida species that rarely cause candidiasis include Candida parapsilosis, Candida pseudotropicalis, Candida krusei, Candida guilliermondi and Candida stellatoidea.

Vulvo-vaginal candidiasis remains a common problem worldwide affecting all strata of society. They are much more so in the developing country context because of various health care delivery related constraints such as work force shortages and regulatory inadequacies. The absence of rapid, simple, and inexpensive diagnostic tests continues to result in either over-diagnosis, under diagnosis or misdiagnosis, leading to inappropriate treatment (Mohamadi et al., 2015). Although commonly caused by C. albicans, non-albicans species immunosuppression has led to the development of recurrent diseases some of which are nonresponsive to conventional antifungal regimes (Mohamadi et al., 2015).

This study aimed to determine, the prevalence of vulvo-vaginal candidiasis and the pattern of Candida species in women who attend some selected hospitals in Ibadan, Oyo state, Nigeria. The findings of the study will inform the need for a well sustained health education and awareness programme targeted at women of reproductive age on need for routine and periodic Candida specie diagnosis. The findings will also re-affirm the orthodoxy of physicians’ basic and mandatory requirement for empirical laboratory diagnosis as a gold-standard for management of vulvo vaginal candidiasis. 

where n = z² p q/d²

(n = Sample size, z = Standard normal deviation = 1.96 at 95% confidence limit, p = Prevalence rate = 14.0%, q = 1 = 1–14.0% =0.86, d = Error margin = 5%).

This study was conducted, in principle with the Helsinki Declaration, and the protocol was approved by the Human Research Ethical Committee of the University College Hospital, Ibadan. All subjects gave written informed consent prior to being included in the study. All data were analyzed anonymously throughout the study. A pro-forma was used to obtain basic information such as age, clinical diagnosis and test result. Data were analyzed using the SPSS version 21. Descriptive statistics were presented as proportions in tables and charts. Inferential statistics were limited to bivariate analysis conducted between Candida species test outcome and clinical symptoms at p=0.05.

Sample collection and laboratory analysis

Paired high vaginal swab and endocervical swab samples were collected from each of the 200 participating subjects and analyzed in medical microbiology laboratory of the hospital for the isolation and identification of both C. albicans and non-C. albicans species.

The specimens were routinely cultured for Candida species using sabouraud’s dextrose agar, incubated in paired sets, one set at 25^ºC for 3 to 7 days and the other at 37ºC for 24 h.

The culture revealed whitish soft cream colonies. Direct gram staining was done with standard procedures to differentiate positive slides of large purple oval yeast cells. Microscopic examination also showed bacteria which are normal cocci and bacilli forms of floral of the body. Wet preparation processes were done and showed budding yeasts and hyphae with buds at points of constriction. C. albicans was identified by the production of germ tubes. Other candida isolates were speciated with a battery of biochemical tests using sugar fermentation such as glucose, sucrose, lactose, maltose, urease tests. CHROMagar (CAC, Becton Dickinson, Heidelberg, Germany) was also used in the speciation of C. albicans, C. tropicalis, C. krusei, C. glabrata by colony, color and morphology.

Of the 200 subjects recruited, 80 respondents had Candida-positive cultures from both High Vaginal Swab and Endocervical Swab samples, giving a prevalence of vulvo-vaginal candidiasis as 40.0%.

Candida-positive cultures were observed mostly among those aged 20–30 years, at 36 (45.0%) and lowest among those less than 20 years, 2 (1%) (Figure1). There was no significant statistical relationship between the prevalence of vulvo-vaginal candidiasis and age (P>0.05).

With respect to speciation of cultures, C. albicans had the highest prevalence 67 (83.8%) (Figure 2) and was diagnosed mostly among patients aged 20-30 years (47.8%) followed by  those aged 31-40, 32 (37.30%). The laboratory investigations yield low prevalence of the remaining Candida species; C. tropicalis 10 (12.5%); C. glabrata 2 (2.5%) and C. krusei 1 (1.25%). The Bar-chart representation of Candida-positive cultures among  those with vulvo-vaginal discomfort of itching and those with no vulvo-vaginal discomfort (Figure 3).

There were unequal Candida-positive cultures between women  who  presented with clinical symptoms of vaginal discharge and those who were without discharge. Of the 79 test subjects who are presented with vaginal discharge 28 (35.0%) had candidiasis while those without discharge accounted for 52 (65.0%). High prevalence of C. albicans (64.2 %) and C. tropicalis (60.0%) were diagnosed in women without vaginal discharge symptoms. Table 1 shows the age distribution of Candida species speciation in the study of the work.

This pattern was also observed for pelvic inflammatory disease. Positive cultures of individuals without PID (88.8%) were higher than those with symptoms of PID (11.2%). Also C. albicans and C. tropicalis had the highest prevalence of 89.6% and 90.0% among those without PID symptoms compared to 10.4% and 10.0% among those with the symptoms respectively (Table 2). A higher prevalence of 34.5% positive cultures of Candidiasis was reported among those without clinical diagnosis of vaginal itching compared with those who had symptoms (5.5%).

Vulvo-vaginal candidiasis is a common fungal infection among women worldwide. The infection occurs  commonly  at  the  lower  female  genitalia and is reported in 35% - 80% of cases without any symptoms (Mohamadi et al., 2015). Symptomatic vulvo-vaginal candidiasis has been found in up to 70% of the sexually active women (Lisiak et al., 2000). Chronic vulvo-vaginal candidiasis severely affects the quality of life for millions of women in the world and is frequently refractory to antifungal treatments (Sobel, 2007).

The prevalences of vaginal candidiasis reported by different studies were 14, 16.5, 21.31, and 19% (Emeribe et al., 2015; Yadav et al., 2016; Mahadani et al., 1998; Nandan et al., 2011). In this study, the prevalence was found to be 40%. This relatively high prevalence of vaginal candidiasis among women in this study may be due to a combination of habits such as poor personal hygiene, the use of contraceptives, and drug abuse (Lisiak et al., 2000; Mahadani et al., 1998). The disparity in prevalence in studies of vulvo-vaginal candidiasis might be due to the fact that vulvo-vaginal candidiasis shows different frequency of occurrence from region to region and some studies have disclosed that the incidence differs in various areas. It can be related to geographical conditions, social and cultural factors, hygiene practices, and diagnostic techniques (Salvi, 2019).

Candida-positive cultures were observed mostly among  women  aged  20–30  years (45.0 %). The high prevalence is consistent with Emeribe et al. (2015) which reported a prevalence of 60.0% among the specified age-group.

Salvi (2019) and Ugwa (2015) in a similar study of prevalence of vulvo-vaginal candidiasis among reproductive age group of pregnant and non-pregnant women done separately in Dubai and North-west Nigeria reported of 39.1 and 53.0% of VVC among mid-upper interval of 26-30 years age group, respectively. While Yadav and Prakash (2016) found the highest of vulvo-vaginal candidiasis among 21-25 years age group (40.4%) followed by 26-30 years with 32.6%. These findings could essentially be attributed to exposure to risk of sexually transmitted diseases of the group because of their high sexual activity during this period for procreative purposes and possibly due to financial benefits that arise from prostitution.

Whereas, the lowest prevalence among those less than 20 years of age in this study corroborates the finding of (Ugwa, 2015) who reported that women above 40 years had the lowest rate of infection (14.0%). Except women of this age group are still using contraceptives (Tarry et al., 2005), their risk of candida infections are likely to be low due to the fact that they have entered menopausal period of their lives. The study also  revealed  the  isolation  of  C.  albicans and non-C.albicans organisms to be the causative fungal agents associated with vulvo-vaginal candidiasis among women in selected hospitals in Oyo-state. C. albicans showed the highest prevalence at 83.8% followed by C. tropicalis (12.5%) while C. glabrata (2.5%) and C. krusei (1.25%) recording the lowest.

C. albicans having the highest prevalence in this study corroborate different previous studies. For example, (Shekufe et al., (2017) in an Iranian study among women of reproductive age conducted traditional tests such as gram-staining, microscopic examination, and culture for species identification and reported C. albicans as the most prevalent species (83.5%), followed by Candida glabrata (16%). (Mucci et al., (2016) showed that the occurrence of vulvo-vaginal candidiasis was 25% among pregnant women and C. albicans with a prevalence of 80.7% was the predominant Candida species. Also, the study of Nnadi and Singh (2017) reported that out of 288 pregnant women, 212 were positive for c. albicans giving a prevalence rate of 73.7%. C. albicans can colonize on the mucous membrane of genitourinary tracts of healthy humans (Singh, 2003). In contrast to this study, (Emeribe et al., (2015) revealed a lower prevalence of C. albicans 13 (6.5%), than  that  of  non-albicans candidiasis 15 (7.5%). Their study reported that among the non-albicans species, C. glabrata was the commonest type (10.5%) and C. krusei the least among the Candida species (3.5%). The reasons for the increase in incidence of C. glabrata in their study were as a result of single-dose antifungal treatment, low-dosage azole-maintenance regimens, and the use of over-the-counter antimycotics (Alo et al., 2012). Therefore, for effective control of candidiasis, laboratory diagnosis must be a pre-requisite for candida infection management.

In this study, cultures from the patients who did not present with clinically diagnosed symptoms of vagina discharge and pelvic inflammatory disease had higher rate of VVC than those with symptoms. Of the 79 subjects who presented with vaginal discharge, 28 (35.0%) had candidiasis while those without discharge had 65.0% (n=52). Also, positive cultures of individuals without PID (88.8%) were higher than those with symptoms of PID (11.2%). The Subjects whose cultures were positive, for Candida species and were without symptoms of PID and vaginal discharge are likely to have built some level of resistance to the infection as a result of drug abuse of antifungal prescription and self-medication  (Mucci  et  al.,  2016).  Also,  those  who  had symptoms of discharge and PID but did not have Candida specie positive cultures could have other diseases causing infectious agents which could be from known or unknown origin (Hofs et al., 2016). Subjects with no vulvo-vaginal discomfort of itching had a higher percentage of Candida-positive cultures (34.5%) than those with no discomfort (5.5%). This report is in agreement with the findings of (Emeribe et al., 2015) Vaginal discomfort of itching irrespective of the fungal test outcome could be as a result of infections such as enterobiosis from poor personal hygiene and some deep socio-cultural beliefs that encourage poor hygiene (Burkhart et al., (2005). Itching could also be as a result of sexually transmitted diseases. According to (Aurora and Aurora (2014) approximately 10% of vulvo-vaginitis is due to infection of Trichomonas vaginalis (Hofs et al., 2016).

This is a cross-sectional study to assess the pattern and prevalence of candida spp to strengthen the need for careful diagnosis of VVC infection. This study did not assess life-style and behavioral information that could be associated with incidence of VVC.

The highest prevalence of candida infection was among respondents age 20-30 years. C albicans was the commonest pattern of species in the area. The findings also revealed the that majority of the respondents without symptoms of pelvic inflammatory disease, vaginal discharge tested positive for Candida infection.

The prevalence of vulvo-vaginal candidiasis among women has been a fast growing and serious burden in our environment which can result in a lot of future health challenges. Emergence of C. albicans and non-albicans species among clinical specimens are crucial concern in medical mycology. For better management of fungal infections like vulvo-vaginal candidiasis this study thus recommend that medical practitioners through their various channels of engagement such as workshop and conferences should  emphasis on laboratory diagnosis of Candida infection for precise identification of fungal isolates prior to commencement of treatment. Also, health education and awareness for routine screening are highly recommended for women of reproductive age to aid early Candida diagnosis and treatment.

The author has not declared any conflict of interests.