Vaginitis is the most common gynecologic diagnosis in medical center, which is characterized by the symptoms of abnormal vaginal discharge, odor, irritation, itching or burning . Diagnosis with vaginitis is often made by using a combination of symptoms, physical examination findings and laboratory testing. And the Nugent score is one of the most common laboratory tests, which demands for sophisticated experience. In our study, all 1130 patients underwent vaginal discharge test from experienced technician and a 37.67% infection rate was observed, in which bacterial vaginitis was overwhelmingly dominant followed by VVC and TV groups. This distribution data is consistent with most previously published data, although prevalence rate varies in different geographic regions and ethnicities .
To further investigate the relationship between vaginitis and HPV infection, 447 patients with vaginitis were chosen for HPV genotyping results, showing that the total HPV infection rate was 39.60% in women with vaginitis. Previous studies have focused on the prevalence of HPV infection in different countries [16, 17] and within China, and the prevalence varies from 9.9 to 31.9% in different areas in China [18–20].In our study, the infection rate was 39.60%, indicating a higher frequency in women with vaginitis. Considering this high prevalence, it is indispensable to know the HPV genotype distribution for vaccine development in women with vaginitis. Because vaccination remains an important means of preventing cervical cancer, though there appears low vaccine acceptability in some countries recently .Among 23 HPV subtypes examined in our study, HPV58, 52, and 16 had the highest prevalence in overall, single-type and multiple-type infected participants, which is slightly different from some data for screening. The study also showed that the most common infection was with HPV58, which was detected in 10.34% of the women with vaginitis. HPV52 was found in 6.32% of the cases and the frequency of HPV16 was 6.11%.These results are all higher than data published by Liang et al .In our study, the single HPV infection rate was also higher than multiple infection, which is consistent with data from the general population .
In different age groups, the peak cases of infection was noted in the 31–40 years group, with age ≤ 20 years and age༞60 years having the lowest cases, which is significantly different from the bimodal phenomenon in different age groups of the HPV screening population.HPV can be sexually transmitted and most HPV infections can be cleared or suppressed within 1 or 2 years in 70–91% of cases .
Therefore, the higher frequency in 31–40 years group may be associated with active sexual behavior and late marriage. Besides, women in this group also have a higher prevalence of vaginitis. A consistent trend can be seen between vaginitis and HPV infection in women with vaginitis. This phenomenon may indicate that there is a possible relationship between vaginitis and HPV infection.
On account of this phenomenon, we then explored the prevalence of HPV infection in women with different vaginitis and did compare with normal vaginal flora. In our study, the HPV infection rate in different vaginitis groups were all higher than the normal group, and the HPV prevalence in IBV group together with BV group was 67.47%, which is higher than the other vaginitis. The healthy vaginal flora are usually populated by Lactobacillus spp which can ensure a low pH, providing the first-line of defense against pathogenic agents . Once this healthy state being disturbed, vaginal dysbiosis will come in and BV is one of the best studied vaginal dysbiosis. Furthermore, BV is associated with increased rate of sexual transmitted infections including HPV .Some immune mechanisms also play an important role in BV regarding the development of HPV infection. Several BV and BV associated bacteria effect immune parameters within vagina have been found, such as cytokines/chemokines, antimicrobial proteins, proinflammatory responses and immune cell populations [27, 28]. Some clinical studies have also demonstrated immunosuppressive effects with lower levels of interferon gamma-induced protein 10 and soluble leukocyte protease inhibitor in women with BV[29, 30]These data can explain the high HPV prevalence in women with vaginitis especially with BV. As shown in our study there was a correlation between HPV infection and vaginitis and patients with BV showed a higher correlation with HPV infection, when compared with other groups. Therefore, timely HPV screening should be performed in women with BV, and early BV-related treatment should be taken to reduce HPV infection.
However, HPV infection has an impact on the host’s immune defenses
and the mucosal metabolism with an adverse effect on the community structure of the vaginal microbiota, so it is difficult to define the cause-and-effect. Similarly, we only analyzed the relationship between HPV infection and vaginitis, the causality and detailed mechanisms still need to be studied between them. And our study was a single center, there need more samples to be detected.