The prevalence of Candida species causing vaginitis is pregnant women vary from one population to another. In our study, 39% of participating women were infected by Candida species. NCAC were more frequently isolated (58%) than C.albicans (42%). NCAC were also shown to increase in non vaginal clinical samples isolated from Lebanon; that was observed in a previous retrospective study published where the authors have shown that among all Candida strains isolated, C.albicans rates had decreased from 86% in 2005 to around 60% in 2014. However, the NCAC rates increased from 14% in 2005 to around 40% in 2014, comprising mainly of C.tropicalis, C.glabrata, and C.parapsilosis [21]. Recent emergence of NCAC, such as C.glabrata and C. krusei has been seen in the post FCZ era and in settings with azole selection pressure [22]. Worldwide, there is a variation in the distribution of Candida spp. identified from vaginal swabs and depends largely on the location as well as the population studied. Figure 1 summarizes the distribution of Candida species isolated from vaginal swabs from population-based studies conducted in different countries. China, Brazil, Tunis, Kuwait, India and Turkey have reported that C.albicans remains the most commonly isolated yeast (60%-80%) in women diagnosed with VVC [23-28]. On the other hand, an increasing trend in the occurrence of NCAC (58%-60%) over time has also been observed in Pakistan and Burkina Faso [29, 30] (Figure 1).
Treatment of vaginal candidiasis is successfully achieved by use of azoles [31]. NCAC related disease is less likely to respond to azole therapy, alternative treatment with AMB suppositories with or without topical azole is recommended. In the current study, isolates showed high susceptibility to AMB (97.5%) and this observation has been corroborated by studies done in various other countries including Lebanon [21, 32-34]. Resistance rates of C.albicans to VCZ, FCZ, and ICZ and in this study were 2.5%, 10%, and 12.5%, respectively, which are in contrast to earlier data from Lebanon reporting susceptibility to FCZ (94-100%), VCZ (94-97%) and ICZ (62%) [21]. However, despite high susceptibility rates against FCZ and VCZ in the previous study, their MIC90 showed an elevated trend over 10 year of study period [21]. The increase in azole resistance in our study can be attributed to the frequent empiric prescription of FCZ for sporadic VVC, which may result in FCZ-resistant C.albicans causing recurrent VVC infection to emerge [35]. Identification of the most common molecular mechanism of resistance among our clinical isolates would help in understanding if there is any spread of resistance gene between C.albicans and NCAC. Since through vertical or horizontal transmission, 5-30% of all colonized preterm neonates may develop invasive Candida infection [13-15], prophylaxis with antifungal agents in this group of patients has proven effective in preventing such an infection. However, an increase in MIC against antifungal agents may have major consequences resulting in poor outcomes and higher mortality rate among neonates with ICI.
Although treatment of asymptomatic pregnant women with Candida colonization in the genital tract is not yet recommended, some countries such as Germany have started to implement the process of screening and treatment of women found to be colonized vaginally by Candida spp. or those who present with VVC in the third trimester [36]. In Lebanon, unlike group B streptococcus (GBS), routine screening for the presence of Candida spp. in pregnant women in the third week of gestation is not considered as part of a routine surveillance by the obstetricians. Since Invasive candidiasis in neonates is becoming a serious and common cause of late onset sepsis, with mortality rates reaching as high as 25-35% [10] , screening simultaneously for both GBS and Candida spp. in pregnant women would reduce the rate of sepsis, meningitis, oral thrush and diaper dermatitis in newborns with these organisms acquired during vaginal delivery.
It is reported that vaginitis in pregnancy is related to adverse perinatal outcome [37]. In the current study, we aimed to correlate between the presence of candidiasis and pregnancy outcome. Our results showed that height decreased with the presence of Candida species. This reduction was statistically significant in the presence of C.kreusi or C.glabrata. However no effect was observed on the weight of the baby. This finding was consistent with a study done previously in Iran where they found no association between vaginal Candida colonization and low birth weight [38]. The current study has also shown that Candida species cause gestational complications which is also in agreement with a previous study done in China [39]
Among the different studied variables which may be affected by Candida, such as gestational complications, gestational diabetes, vaginal discharge, induced labor and recurrent UTI, the present study confirmed that the presence of C.albicans had the most significant effects on women with gestational diabetes and both C.kreusi and C.glabrata on women with gestational complications. Future case control studies should be performed to compare the clinical outcome of pregnant women infected with any microorganism versus non infected women.
In conclusion, increasing rates of NCAC strains among pregnant women in Lebanon should be looked at as both novel and alarming. Extensive surveillance studies should be done on all clinical specimens yielding significant growth of Candida spp. and the effect of resistance pattern on invasive Candida infection. As a consequence of selective pressure, emergence of drug resistance is inevitable. Therefore future studies should focus on the emergence of drug-resistant Candida strains and their frequencies. The susceptibility pattern of C.albicans to antifungal agents varies with region and would require constant monitoring of any unusual increase in resistance.