The Cholera Rapid Antigen Test is a quick stool test designed to detect antigens (specific proteins) from the bacterium Vibrio cholerae, the organism that causes cholera. It is often used when cholera is suspected—especially in settings where fast answers matter, such as a possible outbreak, emergency department visits for severe watery diarrhea, travel-related illness, or areas with unsafe water and sanitation.

This is a rapid antigen test, meaning it looks for parts of the bacteria rather than trying to grow the organism in a lab (culture) or detect genetic material (PCR). Results are typically available quickly, which can help clinicians and public health teams start treatment and infection-control measures sooner.

What the test measures: the presence of Vibrio cholerae antigens in a stool sample (or sometimes rectal swab, depending on the test kit and local protocol).

What results can mean:

• Positive: Vibrio cholerae antigens were detected. This supports a diagnosis of cholera infection, particularly in someone with compatible symptoms (profuse watery diarrhea). A positive rapid test may be followed by confirmatory testing (such as stool culture or PCR), especially during outbreak investigations or for reporting.
• Negative: Vibrio cholerae antigens were not detected. Cholera is less likely, but it is not completely ruled out—especially if the sample was collected very early/late in illness, the stool was diluted, or there are test limitations. Other causes of infectious diarrhea or foodborne illness may be considered.

Because cholera can cause rapid dehydration, clinicians may begin rehydration treatment based on symptoms and risk—even while waiting for or confirming test results.

This test is usually ordered when a person has symptoms and/or exposures that raise concern for cholera or when health officials need rapid screening during suspected outbreaks. It is most useful when immediate decisions are needed for treatment and public health response.

Common symptoms that may prompt testing include:

• Sudden onset of profuse watery diarrhea (often described as “rice-water” stools)
• Frequent vomiting
• Signs of dehydration: intense thirst, dry mouth, dizziness, weakness, decreased urination, muscle cramps
• Rapid heart rate, low blood pressure, or confusion (more severe dehydration)

Risk factors and situations where testing is commonly considered:

• Living in or recent travel to areas with known cholera activity or poor water/sanitation
• Exposure to unsafe drinking water, untreated water, or contaminated ice
• Eating high-risk foods (for example, undercooked seafood or foods handled with unsafe water)
• Close contact with someone suspected or confirmed to have cholera
• Community clusters of acute watery diarrhea suggesting an outbreak
• Humanitarian crises, natural disasters, or displacement settings where waterborne infection risk is higher

Why the test matters: Cholera can progress quickly and lead to dangerous dehydration, especially in children, older adults, and people with limited access to fluids and care. A rapid stool test helps guide timely treatment (rehydration and, when appropriate, antibiotics) and supports outbreak control measures such as water safety interventions, hygiene guidance, and case tracking.

• Cholera (infection caused by Vibrio cholerae)
• Acute infectious gastroenteritis (acute infectious diarrhea)
• Waterborne illness related to contaminated drinking water
• Foodborne illness with severe watery diarrhea (differential diagnosis)
• Traveler’s diarrhea (when cholera is a concern based on destination and symptoms)
• Dehydration secondary to severe diarrhea and vomiting

• Getting a fast, accurate diagnosis for severe watery diarrhea to guide immediate care
• Supporting prompt rehydration and preventing complications from dehydration
• Reducing spread of infection through early identification and isolation/hygiene measures
• Improving decision-making during a suspected cholera outbreak (community and clinic settings)
• Helping public health teams track cases and respond with water and sanitation interventions
• Clarifying whether symptoms may be due to cholera versus other causes of infectious or foodborne diarrhea