For health professionals: Cholera

Find detailed information on cholera for health professionals.

On this page

• What health professionals need to know about cholera
• Clinical manifestations
• Diagnosis
• Treatment
• Prevention and control
• Cholera surveillance in Canada
• For more information

What health professionals need to know about cholera

The bacteria primarily responsible for cholera outbreaks are Vibrio cholerae serogroups:

• O1 (classical and El Tor biotypes)
• O139

The pathogenic serogroups produce the cholera toxin, while the non-pathogenic serogroup strains may or may not produce this toxin.

Clinical manifestations

Vibrio cholerae can cause syndromes ranging from asymptomatic to cholera gravis.

The incubation period can range from 12 hours to 5 days after infection.

Most people infected with cholera are asymptomatic or experience mild diarrhea. Asymptomatic people can shed the bacteria in their feces between 7 and 14 days. Symptomatic people usually only shed for a few days after recovery.

In endemic areas:

• 75% of cases are asymptomatic
• 20% of cases are mild to moderate
• 2% to 5% of cases are severe, such as cholera gravis

Symptoms of cholera include:

• abrupt onset of watery diarrhea
• occasional vomiting
• abdominal cramps

In severe cases, rapid dehydration ensues and, if untreated, can cause death within a few hours to several days. In cases of cholera gravis with severe dehydration, up to 60% of patients can die. However, less than 1% of cases treated with rehydration therapy are fatal.

The disease is also dangerous for pregnant women and their fetuses during late pregnancy. A spontaneous abortion, premature labour or fetal death may occur.

Diagnosis

Cholera can be diagnosed by:

• polymerase chain reaction (PCR)
• enzyme-linked immunosorbent assay (ELISA)
• dark field microscopy of a wet mount of fresh stool

Treatment

Recommended treatments for cholera include:

• oral rehydration solution (most important)
• intravenous fluids (severe cases)

Administering an antimicrobial can reduce fluid replacement requirements and the duration of the illness in moderate or severe cases. Clinicians should consider the antimicrobial susceptibility of local strains to guide the choice of antimicrobial.

Prevention and control

There is a cholera vaccine available in Canada:

Dukoral^®

• see Part 4 of the Canadian Immunization Guide for detailed information on the cholera vaccine

The best prophylactic measures in endemic areas are:

• frequent hand washing
• safe food and water precautions

Cholera surveillance in Canada

Health professionals in Canada play a critical role in identifying and reporting cases of cholera. See the surveillance of cholera section for more information about surveillance in Canada.

For more information

• Canadian Immunization Guide
  • Cholera and enterotoxigenic Escherichia coli (ETEC) travellers' diarrhea vaccine
• Committee to Advise on Tropical Medicine and Travel (CATMAT)
  • Statement on Travellers' Diarrhea
• National case definition: Cholera
• Vibrio cholerae: Pathogen safety data sheet - Infectious substances