TEST DEVICE AND METHOD FOR TESTING FOR VAGINAL INFECTIONS

Field of the Invention

This invention relates to a test device for testing for vaginal infections and, more particularly, to a device and a method of using the device for making a presumptive diagnosis for three different types of vaginal infections.

Background to the Invention

Bacterial vaginal infections or bacterial vaginosis can be diagnosed using the Amsel test which involves the evaluation of four criteria of a vaginal fluid sample, namely: an elevated pH (over 4.7), a positive whiff test (caused by alkaline volatilisation of amines), vaginal fluid homogeneity, and the presence of clue cells.

The inspection of vaginal fluid homogeneity and clue cell identification requires evaluation of a sample of vaginal fluid under a microscope by a skilled microscopist.

Tests using only two of the abovementioned criteria, namely pH and the whiff test, have been developed as these do not require laboratory evaluation and are therefore convenient and inexpensive. Such tests rely on a pH elevated to above 4.7 as well as a positive whiff test to arrive at a positive diagnosis of bacterial vaginosis.

Bacterial vaginosis is however only one of three common vaginal infections, the other two being protozoal infections (e.g. Trichomonas Vaginalis) and fungal infections (e.g. Candida Albicans). In rural areas in South Africa as well as in other developing areas, laboratory equipment and skilled medical practitioners

are not readily available to test for vaginal infections so that many infections go undiagnosed and untreated.

The inventor believes that a need exists for providing a device and a method for allowing a presumptive diagnosis for three different types of vaginal infections to be made, which device and method do not involve laboratory examination of samples and which do not rely on a skilled medical practitioner for evaluation.

Summary of the Invention

According to the invention, there is provided a device for making a presumptive diagnosis for three or more different types of vaginal infections, the device including three or more test areas for receiving a sample of vaginal fluid thereon, the test areas including:- - a pH indicator area for indicating the pH of the vaginal fluid sample, the indicator covering a pH range of from 3.5 to 8;

- a leucocyte count indicator area for indicating the leucocyte count of the vaginal fluid sample, the indicator covering a leucocyte count range from zero to three; and - an amine test area impregnated with a ten percent potassium hydroxide solution.

The vaginal infections may be selected from the group including: a bacterial infection, a protozoal infection, and a fungal infection.

The device may be in the form of a card with the test areas arranged thereon. The card may be elongate in shape.

The pH indicator area may include a conventional pH indicator covering a pH range of from 3.5 to 8. The colour of the pH indicator area after application of the vaginal fluid sample thereto may indicate a particular pH or pH range. A pH

colour chart may be provided together with the device to assist in establishing the pH of the vaginal fluid sample.

In particular, the pH indicator applied to the area may be an EMD colorpHast® indicator (catalogue number 9582-3) covering a pH range of from 4 to 7. Colour changes are visible every 0.2 to 0.3 pH units.

The leucocyte count indicator area may include a conventional leucocyte count indicator covering a leucocyte count range of from 0 to 3. The colour of the leucocyte count indicator area after application of the vaginal fluid sample thereto may indicate a particular leucocyte count. A leucocyte count colour chart may be provided together with the device to assist in establishing the leucocyte count of the vaginal fluid sample.

In particular, the leucocyte indicator applied to the area may be a Teco Urine reagent strip, a Multistix ® 10 SG reagent strip by Bayer, a Combur ⁹ -Test reagent strip by Roche, or a Uristix ® reagent strip by Bayer.

The amine test area may be any suitable absorbent material impregnated with a ten percent potassium hydroxide solution. After application of the vaginal fluid sample to the amine test area, this area may immediately be subjected to an olfactory test to determine the presence of volatilised amines.

The vaginal fluid sample may be applied to the test areas of the device using a conventional swab. Alternatively, the device may be inserted directly into the vagina of the patient to be tested to achieve application of a sample of vaginal fluid to the test areas of the device.

The device may include more than three test areas to permit testing of additional parameters for making presumptive diagnoses for various vaginal infections.

According to a further aspect of the invention, there is provided a method of making a presumptive diagnosis for three or more different types of vaginal infections using a device as described above, the method including at least the steps of:- - applying a vaginal fluid sample to test areas of the device, the test areas including a pH test area, a leucocyte count test area, and an amine test area; - subjecting the amine test area to an olfactory test immediately after the sample has been applied to said area; and - visually establishing the colour of the pH and leucocyte count test areas to establish the pH and leucocyte count of the vaginal fluid sample.

Should the olfactory test of the amine test area be positive by virtue of the detection of a fishy amine odour, the diagnosis is most likely a bacterial infection. The diagnosis may be confirmed by a sample pH 4.7 or higher (typically between 5 and 6) and a sample leucocyte count of between one and two or more.

Should the olfactory test of the amine test area be negative, a protozoal or fungal infection may be present.

A sample leucocyte count of three or more and a pH of 4.7 or higher (typically between 6 and 7) may be indicative of a protozoal infection.

A sample leucocyte count of from zero to two or more and a pH of less than 4.5 may be indicative of a fungal infection.

The vaginal fluid sample may be applied to the test areas of the device using a conventional swab. Alternatively, the device may be inserted directly into the vagina of the patient to be tested to achieve application of a sample of vaginal fluid to the test areas of the device.

The method may be applied to patients complaining of symptoms of vaginal infections such as an abnormal vaginal discharge and/or itching.

Once a presumptive diagnosis has been made using the method described above, further tests may be used to definitively identify the type of vaginal infection present.

The diagnostic method describe above may find particular application in rural and/or developing areas where the method may be used by clinic staff, family practitioners, and medical practitioners requiring an immediate presumptive diagnosis without the use of laboratory equipment.

Detailed Description of the Invention

The invention will now be described by way of the following, non-limiting example with reference to the accompanying drawing.

Figure 1 shows a schematic plan view of a device for making a presumptive diagnosis for three or more different types of vaginal infections.

In the drawing, reference numeral 10 generally indicates an embodiment of a device in accordance with the present invention.

The device 10 includes three test areas 12, 14 and 16 for receiving a sample of vaginal fluid thereon.

Test area 12 is a pH indicator area for indicating the pH of the vaginal fluid sample, the indicator covering a pH range of from 3.5 to 8.

Test area 14 is a leucocyte count indicator area for indicating the leucocyte count of the vaginal fluid sample, the indicator typically covering a leucocyte count range from zero to three.

Test area 16 is an amine test area impregnated with a ten percent potassium hydroxide solution.

The vaginal infections that the device 10 can be used to test for are: a bacterial infection, a protozoal infection, and a fungal infection.

The device 10 is in the form of an elongate card 18 with the test areas 12, 14 and 16 arranged thereon.

The pH indicator area 12 includes a conventional pH indicator covering a pH range of from 3.5 to 8, typically from 4 to 7. The colour of the pH indicator area 12 after application of the vaginal fluid sample thereto indicates a particular pH or pH range. A pH colour chart (not shown) is provided together with the device 10 to assist in establishing the pH of the vaginal fluid sample.

The leucocyte count indicator area 14 includes a conventional leucocyte count indicator covering a leucocyte count range of from 0 to 3. The colour of the leucocyte count indicator area 14 after application of the vaginal fluid sample thereto indicates a particular leucocyte count. A leucocyte count colour chart is provided together with the device 10 to assist in establishing the leucocyte count of the vaginal fluid sample.

The colour charts for the pH and leucocyte count indicator areas typically form part of the packaging of the device 10.

The amine test area 16 is any suitable absorbent material impregnated with a ten percent potassium hydroxide solution. After application of the vaginal fluid

sample to the amine test area 16, this area 16 is immediately be subjected to an olfactory test to determine the presence of volatilised amines.

The vaginal fluid sample can be applied to the test areas of the device 10 using a conventional swab. Alternatively, the device 10 can be inserted directly into the vagina of the patient to be tested to achieve application of a sample of vaginal fluid to the test areas 12, 14 and 16 of the device 10.

In use, a sample of vaginal fluid is applied to the test areas 12, 14 and 16 of the device 10. The amine test area 16 is immediately subjected to an olfactory test after the sample has been applied to said area.

Should the olfactory test of the amine test area 16 be positive by virtue of the detection of a fishy amine odour, the diagnosis is most likely a bacterial infection. The diagnosis can be confirmed by a sample pH 4.7 or higher and a sample leucocyte count of between one and two or more.

Accordingly, the colour of the pH and leucocyte count test areas 12 and 14 is established visually to establish the pH and leucocyte count of the vaginal fluid sample.

Should the olfactory test of the amine test area 16 be negative, a protozoal or fungal infection could be present.

A sample leucocyte count of three and a pH of 4.7 or higher is indicative of a protozoal infection.

A sample leucocyte count of from zero to two and a pH of less than 4.5 is indicative of a fungal infection.

The method is applied to patients complaining of symptoms of vaginal infections such as an abnormal vaginal discharge and/or itching.

Once a presumptive diagnosis has been made using the method described above, further tests are used to definitively identify the type of vaginal infection present.

The device 10 can be developed further to include more than three test areas to permit testing of additional parameters for making presumptive diagnoses for various vaginal infections.

It is to be appreciated, that the invention is not limited to any particular embodiment or configuration as hereinbefore generally described or illustrated.