Cholera O1 Ag Rapid Test

Description

Intended Use

Cholera O1 Ag Rapid Test (Feces) is an in vitro immunoassay for the direct and qualitative detection of Vibrio cholerae O1 antigen from human feces. Cholera O1 Ag Rapid Test is intended to aid in the rapid diagnosis of V. cholerae serogroup O1 infections. Negative results should be confirmed via bacterial culture or molecular assay.

Introduction

Cholera is an acute diarrheal infection caused by ingestion of food or water contaminated with the bacterium Vibrio cholerae. Cholera remains a global threat to public health and an indicator of inequity and lack of social development. Researchers have estimated that every year, there are roughly 1.3 to 4.0 million cases, and 21,000 to 143,000 deaths worldwide due to cholera1.

Most people infected with V. cholerae do not develop any symptoms, although the bacteria are present in their feces for 1-10 days after infection and are shed back into the environment, potentially infecting other people. Among people who develop symptoms, the majority have mild or moderate symptoms, while a minority develop acute watery diarrhea with severe dehydration. The primary symptoms of cholera are profuse diarrhea and vomiting of clear fluid2. Cholera takes between 12 hours and 5 days for a person to show symptoms after ingesting contaminated food or water3. Cholera affects both children and adults and can kill within hours if untreated.

Two serogroups of V. cholerae, O1 and O139, cause outbreaks of cholera. O1 causes the majority of outbreaks, while O139 – first identified in Bangladesh in 1992 – is confined to Southeast Asia.

It is almost impossible to distinguish a single patient with cholera from a patient infected by another pathogen that causes acute watery diarrhea without testing a stool sample. A review of clinical features of multiple patients who are part of a suspected outbreak of acute watery diarrhea can be helpful in identifying cholera because of the rapid spread of the disease. Isolation and identification of V. cholerae by culture of a stool specimen remains the gold standard for the laboratory diagnosis of cholera. Commercially available rapid test kits are useful in epidemic setting of Cholera.

Test Procedure

Bring tests, specimens, buffer and/or controls to room temperature (15-30°C) before use.

1. Specimen collection and pre-treatment:

1) Use clean, dry specimen containers for specimen collection. Best results will be obtained if the assay is performed within 2 hours after collection.

Note: Specimens collected in the specimen container may be stored at 2~8oC for 3 days, or at -20°C for 6 months, if not tested within 2 hours after collection.

2) For solid specimens: Unscrew and remove the dilution tube applicator. Be careful not to spill or spatter solution from the tube. Collect specimens by inserting the applicator stick into at least 3 different sites of the feces to collect approximately 100 mg of feces.

For liquid specimens: Transfer 3 drops (approximately 100µL) of the liquid specimen into the sample dilution tube.

3) Place the applicator back into the tube and screw the cap tightly. Be careful not to break the tip of the dilution tube.

4) Shake the specimen collection tube to mix the specimen and the diluent buffer thoroughly.

2. Testing

1) Remove the test device from its sealed pouch, and place it on a clean, level surface. Label the test with patient or control identification. To obtain a best result, the assay should be performed within 2 hours.

2) Using a piece of tissue paper, break the tip of the dilution tube. Hold the tube vertically and dispense 2 drops of solution into the specimen well (S) of the test device.

Avoid trapping air bubbles in the specimen well (S), and do not drop any solution in observation window.

3. Wait for the colored band(s) to appear. The result should be read at 10 minutes.