Friendly Print preview

CHOLERA

The Disease: - An infection of the small intestine caused by the bacterium Vibrio cholera.
Cholera is an acute illness characterised by watery diarrhoea. The toxin released by the bacteria  can produce massive diarrhoea. Death can result from the severe dehydration brought on by the diarrhoea. Cholera occurs in epidemics when conditions of poor sanitation, crowding, war, and famine are present. Endemic areas include India, Asia, Africa, the Mediterranean, and more recently, South and Central America, Mexico, and the U.S.. The infection is acquired by ingesting contaminated food or water. A type of vibrio also has been associated with shellfish, especially raw oysters. 

Risk:  - Residence or travel in endemic areas and exposure to contaminated or untreated drinking water. Travellers should take precautions with food and drinking water, even if vaccinated because vaccination is not very effective. No vaccine covers the Bengal strain isolated in Bangladesh & India. However this organism is sensitive to tetracycline and ciprofloxacin. Other strains show varying resistance to antibiotics. A 3 days course of antibiotics (eg. tetracycline 500mg qid) will shorten the duration of cholera and fluid replacement needs. The risk of contracting Cholera is estimated at only 1 in 100,000 travellers.

Indications for current vaccination: Travellers to highly endemic areas who do not have ready access to medical attention and in those with impaired gastric defences.

Two new  oral vaccines 

• The WC/rBS vaccine  "Dukoral" (inactivated vaccine) and provides 85% efficacy, with 72% protection at 3 years in those over 5 years. 2 doses 1 - 6 weeks apart.
  (The vaccine also confers 52% protection against Entero-toxic E. Coli (ETEC) which causes about 40% of all cases of travellers diarrhoea.)

• CVD 103-HgR (live attenuated vaccine) - single dose. (Not available in Australia)

Current Cholera infected areas see CDC travel information (Outbreaks)
WHO year book www.who.int\ith\chapter05_02.html

Information mostly taken from: "International Travel and Health" (WHO year book - internet only)
Australian Immunisation Handbook, 8th Edition - 9/2003 - Part1 - Part 2 & Part 3 (large pdf files)
Centre for Disease Control, USA -  www.cdc.gov/travel Travel Health Seminar Oct 96, June 97,Feb 98, March 99, May 2000, August 2002 & March 2005 - Victorian Medical Postgraduate Foundation.
Manual of Travel Medicine, Melbourne, Oct 2004. Updated 18/09/2005.  Additional references & disclaimer.

  Last Update: 14-Sep-2005