Cholera
Cholera, which results from ingesting water or food contaminated with Vibrio cholerae, can cause severe profuse diarrhea that leads rapidly to dehydration and death. Risk of cholera is extremely low in travelers with access to clean water and good sanitation. Three oral whole-cell cholera vaccines are currently manufactured. WC-rBS (Dukoral®, Crucell, The Netherlands) contains killed whole cells of both El Tor and classical biotypes and the Ogawa and Inaba serotypes of V. cholerae 01, with recombinant B subunit of cholera toxin. It is licensed as a two-dose series for persons ≥6 years old and a three-dose series for persons aged 2–5 years, available in Europe, Australia and Canada. Its protection lasts 2 years with efficacy of 65–85% in adults. WC-rBS has also shown limited protection against heat-labile toxin-producing enterotoxigenic Escherichia coli, although generally it is not recommended for this purpose. The other vaccines contain killed whole cells of 0139 in addition to 01, but do not contain the cholera toxin (mORC-Vax®, Company for Vaccine and Biological Production No. 1, Hanoi, Vietnam; Shanchol®, ShanthaBiotechnics Ltd, Hyderabad, India). A previously available live-attenuated oral cholera vaccine, CVD 103-HgR (Orochol®, Mutacol), is being considered for production again. Business travelers who will be working under austere conditions in regions with cholera epidemics should consider vaccination.