Biogenic Amine Detection as a Low Cost Point-of-Service Test for Bacterial Vaginosis
What is BV?
- BV is the name of a condition in women where the normal balance of bacteria in the vagina is disrupted and replaced by an overgrowth of certain bacteria. It is sometime accompanied by discharge, odor, pain, itching or burning.
How common is bacterial vaginosis?
- It is the most common vaginal infection in women of childbearing age. BV is common in pregnant women (CDC publishes a number>1,000,000 pregnant women with BV annually).
- 50-75% of women get it and have no symptoms.
- > 47% of women entering the military have it at time of initial physical
- National Health and Nutrition Examination Survey, which included results from self-collected vaginal swabs from over 3700 women, estimated the prevalence of BV was 29 percent in the general population of women aged 14 to 49 years and 50 percent in African-American women.
- > 50% of women treated for BV relapse within the first 12 months
- Low birth weight (under 5.5lbs)
- Spontaneous miscarriage
- Premature birth
- Increased likelihood of infection post delivery, after C-section, and other surgical procedures
- Increased probability of contracting STD/HIV
- Infections of the uterus and fallopian tubes leading to ectopic pregnancy and infertility
Bacterial Vaginosis –Current diagnostic methods
How is BV diagnosed?
To make a diagnosis of bacterial vaginosis, a swab from inside the vagina should be obtained. These swabs should be tested for:
- A health care provider must examine the vagina for signs of BV and perform laboratory tests on a sample of vaginal fluid to look for bacteria associated with BV.
- Gram Stain
- Laboratory send out
- Chemical enhancement
- A characteristic "fishy" odor on wet mount . This test, called the whiff test , is performed by adding a small amount of potassium hydroxide to a microscopic slide containing the vaginal discharge. A characteristic fishy odor is considered a positive whiff test and is suggestive of bacterial vaginosis .
- Loss of acidity . To control bacterial growth,the vagina is normally slightly acidic with a pH of 3.8–4.2. A swab of the discharge is put onto litmus paper to check its acidity. A pH greater than 4.5 is considered alkaline and is suggestive of bacterial vaginosis .
- The presence of clue cells on wet mount. Similar to the whiff test, the test for clue cells is performed by placing a drop of sodium chloride solution on a slide containing vaginal discharge. If present, clue cells can be visualized under a microscope.They are so-named because they give a clue to the reason behind the discharge.These are epithelial cells that are coated with bacteria.
- Two positive results in addition tothe discharge itself are enough to diagnose BV. If there is no discharge, then all three criteria are needed.
In clinical practice BV is diagnosed using the Amsel criteria:
- Thin, white, yellow, homogeneous discharge
- Clue cells on microscopy
- pH of vaginal fluid >4.5
- Release of a fishy odor on adding alkali —10% potassium hydroxide (KOH) solution .
- At least three of the four criteria should be present for a confirmed diagnosis .
- Detect the biogenic amines associated with the BV bacteria.
- Utilize exactly the same detection solution used for food spoilage adjusted for dosing as there are hundreds of times higher concentrations of both putresine and cadavarine in vaginal fluids of women with BV
- Product will be a self contained test where any swab can be used to gather the sample with dosing controlled in the design of the package.
- Provide green light – red light test results in minutes.
- No training or external machines.
- Test can be done at a fraction of the cost of existing methods.
- Definitive in home test can be sold reducing unnecessary use of medications that are ineffective and potentially harmful
- Provides a test that can be more widely used in primary care as well as specialists practices