Cholera: Information for Clinicians
December 1, 2010
On November 26, 2010, the Ministère de la Sante Publique et de
la Population (MSPP) in Haiti reported 72,017 cases of cholera
and 1,648 deaths since mid October 2010.
extended to all of the country’s ten health departments and the
capital city of Port-au-Prince. No cholera outbreaks have been
reported in Haiti in the last century.1 The outbreak has
food-borne organism that can cause acute watery diarrhea,
vomiting, severe dehydration and death.
strain of cholera is confirmed as
serotype Ogawa, biotype El Tor., the causative agent of cholera, is a water- and2 The Haitian outbreakVibrio cholerae serogroup O1,3 All isolates of Vibrio cholerae
from the Haiti outbreak that have been typed demonstrate a common pulsed field gel electrophoresis pattern.
There have been two cases of cholera imported from Haiti confirmed to date; one in Florida and the second
in the Dominican Republic.
in returning travelers, to provide clinical guidance on diagnosis, management and infection control practices
of cholera, and to present information for travelers to areas with cholera disease.1, 4 The purpose of this document is to highlight the potential for cholera disease
In 2009, The World Health Organization reported a
worldwide, including 4,946 deaths.
limitations in reporting, surveillance and diagnostic capacity in the most vulnerable countries affected.total of 221,226 cholera cases from 45 countries5 This is known to be an underestimate of cholera infections due to6
Since the early 2000s the majority of cases have been reported from the African continent, with a lesser
incidence reported in Asia. Endemic cholera has not been reported in North America or Europe since the
middle of the 19
Lack of access to clean water and sanitation are the primary risk factors for cholera disease.
without immunity, cholera affects people of all ages. In cholera endemic regions, children less than 4 years
old are at highest risk of cholera. The incubation period of cholera is usually 2-3 days, with a range of a
few hours to 5 days.th century.Helicobacterinfection and O blood group are associated with increased risk of severe disease.2 In populations
Regions with known cholera activity in 2009 are listed World Health Organization Cholera annual report
cases from Haiti have been identified in Ontario as of November 26http://www.who.int/wer/2010/wer8531.pdf). 5 The current cholera outbreak in Haiti began in OctoberIn Ontario, there has been one laboratory confirmed case per year from 2005-2009. No importedth, 2010.
returning from endemic areas with
symptoms of acute watery diarrhea with
onset <5 days after return.Cholera should be suspected in travelers
aggressive rehydration and good hygiene.
Adjunctive antibiotics are recommended
for severe cases.Management of cholera includes
“cholera” and should be submitted in usual
(Cary Blair) transport media for stool
C&S.Stool specimens must specifically request
cholera to your public health department.
Cholera: Information for Clinicians
December 1, 2010Report all suspect and confirmed cases of
Cholera infection can be either symptomatic or asymptomatic. Asymptomatic persons infected with cholera
within 5 days of exposure: symptoms include watery diarrhea or “rice water” stools (up to 0.5-1 liter per
hour), vomiting, and dehydration. Fever is rare (less than 5 %). Mild to moderate cases may be
indistinguishable from other infectious forms of diarrhea. Severe cases of cholera may present with
electrolyte abnormalities, hypotension, and renal failure.Vibrio cholerae in stools for 7-14 days after infection. Those who will develop symptoms do so2
Microbiological Diagnosis ofVibrio cholerae in Ontario
Who to test
region with known cholera.Individuals who have profuse watery diarrhea < 5 days after returning from a
Specimen containerStool culture containers with usual (Cary-Blair) transport media
Requisition requirementsMust specify “Cholera” or “Vibrio cholerae” on requisition
Stool specimens will be forwarded from these laboratories to the OAHPP
Public Health Laboratories (PHL) for testing.Submit specimen to local hospital/ private laboratory
submitting specimen.Must be communicated directly to the OAHPP PHL at 416 526-5441, prior to
Tests not availableSerology, rapid stool tests
considered. Testing should be performed as per routine practice.Other bacterial, viral and parasitic causes of acute diarrhea should be
Management ofVibrio cholerae infection
to medical evaluation if they have onset of watery diarrhea <5 days after their
return.Travelers returning from regions with known cholera should present immediately
Fluid and electrolyte
Mortality from cholera can be reduced from 10-50% to less than 1% with
appropriate fluid and electrolyte replacement.
the cornerstone of cholera therapy, and will save lives if given rapidly and in
adequate volume to replace and maintain losses.Fluid and electrolyte therapy is
For full details of appropriate fluid and electrolyte replacement therapy for
cholera, including 1) using oral rehydration therapy in mild to moderate cases,
and 2) intravenous replacement in severe dehydration preferentially with Ringer’s
lactate, please see the CDC guidelines,
Cholera: Information for Clinicians
December 1, 2010, accessed November 27,
Antimicrobial therapy is of secondary priority to ongoing fluid and electrolyte
replacement, and is indicated for severe cholera disease only. Antibiotics should
not be prescribed for asymptomatic cholera infections.
In severe cholera, antimicrobial treatment is associated with decreases in the
following: 1) duration of diarrhea (from 4 to 2 days on average), 2) stool volume,
3) intravenous fluid requirements, and 4) clinical relapses.8
The initial strains of
2010 are susceptible to tetracycline (a proxy for doxycycline) and azithromycin,
resistant to sulfisoxazole and nalidixic acid, and show reduced susceptibility to
ciprofloxacin.Vibrio cholerae identified in Haiti in October and November7
Recommended empiric therapy for individuals for suspected severe cholera
returning from Haiti as of November 27, 2010 is:
Patient population Recommended antimicrobials
Non pregnant adults Doxycycline 300 mg PO x 1 dose
Pregnant women Azithromycin 1gm PO x 1 dose
(oral suspension recommended
for children less than 12 months/
children unable to swallow pills)
Azithromycin: 20 mg/kg X 1 dose
Erythromycin: 12.5 mg/kg QID x 3 days
accessed November 28, 2010.
Antimicrobial therapy must be chosen in accordance with individual clinical
treatment of cholera
Zinc supplementation has been associated with decreased duration and severity
of diarrhea in children infected with cholera in a randomized controlled trial in
mg per day for 5-7 days may be considered.Antimotility agents, analgesics and antiemetics are not recommended in the9 If severe cholera is suspected, zinc supplementation with 10-30
Infection control recommendations
sanitation systems mitigate ongoing transmission of cholera infections in Ontario.is spread primarily by contaminated water and food sources. Access to clean water and modern
While it is very rare for cholera to spread directly from person to person, patients hospitalized with severe
cholera should be cared for in isolation using contact precautions until the diarrhea has resolved.10,11
When possible, hospitalized individuals with diarrhea possibly due to cholera should not share toilet facilities
with other patients.
Public health reporting
All suspected and confirmed cases of cholera must be reported to the local health unit under the Ontario
Health Protection and promotion act.
Cholera: Information for Clinicians
December 1, 2010
Information for travelers to regions with cholera activity
Measures to reduce illness from
Health Agency of Canada and the US CDC websites (
These recommendations include ensuring safe water and food, and frequent hand washing. Additional
considerations include bringing a prescription antibiotic to take in case of travelers’ diarrhea, water
purification tablets, and oral rehydration salts.
found on the Foreign Affairs and International Trade Canada website at
Cholera vaccination is recommended for travelers to endemic regions with a high risk of exposure such as
humanitarian relief workers, and travelers visiting areas of high risk with limited access to clean water and
sold as MutacolVibrio cholerae for travelers to endemic regions are detailed on Publichttp://www.phac-aspc.gc.ca/tmp-pmv/info/choleraeng., http://wwwnc.cdc.gov/travel/yellowbook/2010/chapter-5/cholera.aspx, accessed Nov. 27, 2010).3 Travel advisories for Canadians travelling abroad can behttp://www.voyage.gc.ca/indexeng.(Accessed November 29, 2010).12 Two oral cholera vaccines targeted to V. cholerae O1 serogroup are available in Canada: 1) killedV. cholerae O1 with purified recombinant B-subunit of cholera toxoid (WC/rBS) sold asTM and 2) an attenuated live oral genetically modified V. cholerae O1 vaccine (CVD 103-HgR)®. Studies of WC/rBS have demonstrated overall efficacy of 64-90% against infection with
administered 1-6 weeks apart, and in children aged 2 to 6 years 3 doses must be administered 1-6 weeks
apart. Full immunity is not attained until 10-14 days after completing the vaccination series, and protection
against cholera is estimated to be 6 months to 2 years. This vaccine is not protective againstO1 El Tor. In adults, the WC/rBS vaccine (Dukoral TM) requires 2 doses of vaccineV. cholerae
O139, and is not approved for children less than 2 years old.
If travelling to a cholera endemic area, consultation with a clinician experienced in travel medicine is advised.
1. Pan American Health Organization (PAHO).
accessed November 26, 2010.
2. Sack DA, Sack RB, Nair GB, Siddique AK. Cholera.
3. CDC Outbreak notice: Cholera in Haiti.
4. Goddard J. New York Times online Nov 17, 2010.
accessed Nov 26, 2010.
5. World Health Organization Cholera annual report 2009.http://new.paho.org/disasters/index.php?option=com_content&task=view&id=1423&Itemid=1 ,Lancet. 2004 Jan 17;363(9404):223-33.http://wwwnc.cdc.gov/travel/content/outbreak-notice/haiti-cholera.aspx, accessed November 27, 2010.http://www.nytimes.com/2010/11/18/us/18florida.html?scp=7&sq=haiti%20cholera&st=cse,Weekly Epidemiological Record, 2010, 85(31):293-308.
6. Zuckerman JN, Rombo L, Fisch A. The true burden and risk of Cholera: implications for prevention and control.
7. Centers for Disease Control and Prevention. Update: Cholera Outbreak — Haiti, 2010.
8. Lindenbaum J, Greenough WB and Islam MR. Antibiotic therapy of cholera,
9. Roy SK, Hossain MJ, Khatun W, Chakraborty B, Chowdhury S, Begum A, Mah-e-Muneer S, Shafique S, Khanam M, Chowdhury R. Zinc
supplementation in children with cholera in Bangladesh: Randomized controlled trial.
10. Centers for Disease Control and Prevention. CDC Health Information for International Travel 2010. Atlanta: U.S. Department of Health and Human
Services, Public Health Service, 2009. Online Edition., accessed November 26, 2010.Lancet Infect Dis. 2007MMWR Weekly: Vol. 59, No. 45.November 19, 2010Bull World Health Organ 36 (1967), pp. 871–883.BMJ 2008; 336:266-268.
11. Swaddiwudhipong W, Peanumlom P. A Case of Nosocomial Cholera during a Community Outbreak in a Thai-Myanmar Border Area.
12. Committee to Advise on Tropical Medicine and Travel. Statement on New Oral Cholera and Travellers' Diarrhea Vaccination. CCDR Volume 31 •
ACS-7 1 July 2005., accessed Nov. 27, 2010.J Med Assoc2010; 93 (9): 1112-4.http://www.phac-aspc.gc.ca/publicat/ccdr-rmtc/05vol31/asc-dcc-7/index-eng.php, accessed Nov 27, 2010.
This document was developed by the Ontario Agency for Health Protection and Promotion (OAHPP). OAHPP provides scientific and technical advice to
Ontario’s government, public health organizations and health care providers. OAHPP’s work is guided by the best available evidence. This best practice
document has been peer reviewed and reflects the consensus of experts advising OAHPP.
This document is intended to assist physicians in clinical decision-making by describing a range of generally acceptable approaches for diagnosis and
management. This document should not be considered inclusive of all proper methods of care or exclusive of other methods of care reasonably directed at
obtaining the same results. The ultimate judgment regarding care of a particular patient must be made by the physician in light of the individualcircumstances presented by the patient. OAHPP is not responsible for the results of the use by anyone of this document.