Diagnosis of Cholera
Cholera can be diagnosed with the help of detailed patient history and stool examination.
A patient history of watery stools especially during an epidemic should raise the suspicion of cholera.
Stool examination-
- Macroscopic / Gross Examination-
Stools resembles ‘rice water’ and contain mucus
- Microscopic Examination-
Dark field microscopic examination of stool sample shows rapidly motile V.cholerae bacteria. Epithelial cells are also present in the stool sample.
- Culture-
A stool culture may be done to confirm the presence of V. cholerae. Enrichment is done in alkaline peptone water at pH 8.7 for 6-8 hours incubation.
Typical yellow color colonies appear in thiosulfate-citrate-bile salts-sucrose (TCBS) agar after 18 hours of incubation. Organisms can be confirmed from culture by staining and examining under microscope.
Specific Tests-
Vibrio cholerae are further identified by slide agglutination tests using anti-O group 1 antiserum and by biochemical reactions.
