Diagnosis of mixed vaginitis
A vaginitis diagnosis is made according to the presence of symptoms, clinical findings and microscopy examination (Gram-staining and wet-mount smears)(30). The key points in diagnosing mixed vaginitis are as follows(1):①the simultaneous presence of at least two vaginal pathogens; ②an abnormal vaginal milieu due to the pathogens and, hence, symptoms and signs of vaginitis; and ③the requirement of specific therapies for both pathogens.
Since the diagnosis of mixed vaginitis is largely dependent on the diagnostic criteria for single vaginitis, the criteria to facilitate recognition of the coexistence of multiple pathogens are as follows.
TV: at least one of the following must be present: ①positivity on wet-mount smear, although the sensitivity has been reported to be as low as 45–60%(31); ②positivity on culture, which has a higher sensitivity than microscopy but is not widely available in clinical settings; or ③positivity on a nucleic acid amplification test (NAAT), which has the highest sensitivity for the detection of TV in comparison to both microscopy and culture. The Guidelines Group recommends that the most effective tests to diagnose TV in women are NAATs(32). However, examination of wet-mount preparations is still commonly used in clinical practice.
VVC: at least one of the following must be present: ①the presence of yeast or pseudohyphae in vaginal discharge on wet-mount microscopy with either saline or 10–20% KOH solution (40–60% sensitivity); ②the presence of yeasts or pseudohyphae on gram staining (up to 65% sensitivity) of vaginal discharge; or ③positivity on culture, which is helpful in diagnosing recurrent or complicated vulvovaginal candidiasis because species other than C. albicans (e.g., Candida glabrata ,Candida tropicalis ) may be present. Moreover, drug sensitivity testing should also be conducted. The Guidelines Group recommends that the current best test to diagnose Candida in women is microscopy(32) because positivity on microscopy indicates a large number of Candida, and hyphal formation is infrequently observed with only colonization.
BV: at least one of the following must be present: ①a Nugent score(33) >6; the Nugent score is considered the gold standard for studies and relies upon estimating the relative proportions of bacterial morphotypes on a Gram-stained vaginal smear to assign a score between 0 and 10. A score of <4 represents normal conditions, 4–6 represents intermediate infection, and >6 represents BV. ②The presence of three of four Amsel’s criteria, including homogeneous, thin, white discharge that smoothly coats the vaginal wall; clue-cells on microscopic examination (prerequisite); pH of vaginal fluid >4.5; or vaginal discharge with a fishy odor before or after the addition of 10% KOH (whiff test). Amsel’s criteria have a sensitivity of 60–72% for the diagnosis of BV compared to the Nugent score(32).
AV: The diagnosis of AV should be based on a combination of clinical features and microscopic findings(32). ①The clinical features are as follows: vulvar erythema; vulvar swelling; thinning of the vaginal mucosa; vaginal congestion; scattered bleeding points; and yellow-colored vaginal secretion, increased discharge or pruritus. ②The microscopic features are as follows: wet mount smears with a AV score ≥3(30). Accordingly, three main characteristics form the basis of an AV diagnosis: a variable amount of inflammation; thinning of the vaginal epithelium; and a disturbed bacterial community lacking the commonly observed high abundance of lactobacilli(34).
Amalgamative infection of the cervical and vagina should be recognized. Some cervical infections caused by pathogens, such as HSV-2, CT, NG, mycoplasma, and HPV(35), might occur concurrently with vaginitis, and symptoms of cervical cancer are generally obscured, increasing the complexity of diagnosis. Thus, coinfection with the pathogens mentioned above should be excluded in the diagnosis of mixed vaginitis.