Aerobic vaginitis is an inflammatory vaginal microflora condition that is frequently confused with or appearing in conjunction with bacterial vaginosis (BV), and not diagnosed or treated properly. Aerobic vaginitis can occur with BV, yeast, trich, and/or cytolytic vaginosis (lactobacilli overgrowth syndrome). While BV is anaerobic, aerobic vaginitis is the aerobic counterpart.
The symptoms will provide clues, for example, BV does not cause inflammation or itching, whereas aerobic vaginitis (the ‘itis’ means inflammation), yeast infections and cytolytic vaginosis do. The most severe form of aerobic vaginitis is called desquamative inflammatory vaginitis.
It is estimated that between five and 10 per cent of women have aerobic vaginitis, with pregnant women also affected up to 11 per cent of the time. Asymptomatic women may have a prevalence of aerobic vaginitis up to 23 per cent.
Complications can include preterm labour, increased risk of contracting sexually transmitted infections, and abnormal Pap test results.
Symptoms of aerobic vaginitis
- Signs of inflammation of the vagina and/or vulva
- Possibly ulcers or erosions
- Painful sex (dyspareunia)
- Yellow discharge
- Thick discharge
- pH of 5 or more
- Changed vaginal odour
- Possibly long-lasting symptoms after multiple unsuccessful treatments
- Can be co-infected with BV, trich, yeast or lactobacilli overgrowth
Diagnosis of aerobic vaginitis
Diagnosing this condition will require a doctor who does a wet mount in his or her office at the time of your appointment. Your doctor can look under the microscope and see what microflora exists in your vagina, on the spot, including any overgrowth of lactobacilli and any existing pathogens.
The ideal diagnosis is done using a phase-contrast microscope with a magnification of 400x (high power field). Evaluations must include the relative numbers of leucocytes, percentage of toxic leucocytes, background flora and proportion of epitheliocytes, with lactobacillus grade evaluated, to get the score for diagnosis.
- Grade I – numerous lactobacilli, and no other bacteria
- Grade IIa – mixed flora, but mostly lactobacilli
- Grade IIb – mixed flora, but proportion of lactobacilli severely decreased due to an increase in other bacteria
- Grade III – lactobacilli severely depressed or absent due to an overgrowth of other bacteria
Aerobic vaginitis score of 0
- Lactobacillary grade I and IIa
- Leukocytes of <10/hpf
- Sporadic or no toxic leucocytes
- Unremarkable background flora or cytolytic vaginosis
- Parabasal epitheliocytes non or <1 per cent
Aerobic vaginitis score of 1
- Lactobacillary grade of IIb
- Leukocytes of >10/hpf and <10/epthithelial cell
- <50 per cent of toxic leukocytes
- Background flora of small coliform bacilli
- Parabasal epitheliocytes of 10 per cent or less
Aerobic vaginitis score of 2
- Lactobacillary grade III
- Leukocytes of >10/epithelial cell
- >50 per cent of toxic leukocytes
- Background flora of cocci or chains
- Parabasal epitheliliocytes of >10 per cent
The AV score is calculated thus:
- AV score <3: no signs of aerobic vaginitis
- AV score 3 or 4: light aerobic vaginitis
- AV score 5 or 6: moderate aerobic vaginitis
- AV score 6 or more: severe aerobic vaginitis
Clinical features of aerobic vaginitis for physicians
- Nugent scores – intermediate flora
- pH – increased (more alkaline)
- Sparsely populated with one or two enteric commensal flora like Streptococcus agalactiae, Staphylococcus aureus, or Escherichia coli
- Increased signs of inflammation/anti inflammatory response
- Increased leukocytes of >10
- Absence of lactobacilli and microbiologically isolated organisms E. coli, S. aureus, group B Strep, and enterococci
- Prominent signs of epithelial atrophy
- Negative amino odour test
- Red vaginal walls
Treatments for aerobic vaginitis
Medical treatments include antibiotics for the bacterial component, steroids for inflammation, and possibly oestrogen therapy for atrophy. If Candida is present (which it can be, as a mixed infection), treatment with antifungals may be appropriate.
Local antibiotics are most suitable, and should be broad spectrum to cover enteric gram-positive and gram-negative aerobes (like kanamycin). Oral treatments with amoxiclav or moxifloxacin may be used, particularly if group B strep or MRSA is present. Oral antibiotic use is discouraged in women with aerobic vaginitis, with topical treatments favoured.
The most common causes of aerobic vaginitis are E. coli and E. faecalis. Many women have both a Candida albicans yeast infection combined with aerobic vaginitis, or infection with Trichomonas vaginalis, or bacterial vaginosis (Gardnerella vaginalis). It’s possible to have a mixed infection.
A rinse with povidone iodine (also known as iodopovidone) can provide quick relief of symptoms, but bacteria will return. Clindamycin vaginal gel and hydrocortisone suppositories may be very effective in eradicating aerobic vaginitis.
Jahic M, Mulavdic M, Nurkic J, Jahic E, Nurkic M. Clinical Characteristics of Aerobic Vaginitis and Its Association to Vaginal Candidiasis, Trichomonas Vaginitis and Bacterial Vaginosis. Medical Archives. 2013;67(6):428-430. doi:10.5455/medarh.2013.67.428-430.
Curr Infect Dis Rep. 2015 May;17(5):477. doi: 10.1007/s11908-015-0477-6. Selecting anti-microbial treatment of aerobic vaginitis. Donders GG, Ruban K, Bellen G.