Severity is variable.
Likewise, a less than four-fold fall may be important in these circumstances. Illnesses due to strains of V. Cholerae other than toxigenic V. Cholerae 01 or 0139 should not be reported as cases of cholera. The etiologic agent of a case of cholera should be reported as either V. Cholerae 01 or V. Cholerae 0139.