Serologic diagnosis may also be made by the presence of a changing titer of vibriocidal antibodies. Patients suspected of having cholera should be treated aggressively while awaiting culture results. In both adults and children, fluid and electrolyte losses should be replaced by rehydration therapy. Patients with mild to moderate vomiting will absorb ORS taken in small sips. If ORS is not available, rehydration therapy should begin with intravenous fluids.
Intravenous therapy is necessary for patients who are severely dehydrated or in hypovolemic shock.
Severely dehydrated adults may require several liters of fluid immediately to restore an adequate circulating volume. As soon as the patient is hemodynamically stable, oral therapy may be substituted. Patients with cholera have substantial on-going fluid losses that also need to be replaced. Antimicrobial drugs are a useful adjunctive therapy, decreasing the duration of both diarrhea and bacterial shedding and diminishing the volume of fluid replacement needed for treatment. Adults may be treated with a single 300-mg dose of doxycycline.