Transfer of Cholera via Ballast Water?

It is very difficult to predict when Cholera outbreaks may occur, with low levels of infection common in many countries with cases being confused with other diarrhoeal diseases.  It is an opportunistic pathogen taking advantage of poor sanitation which so often occurs as a result of disasters and conflict. What is clear is that Cholera is both widespread and increasing in frequency with the WHO estimating between 3 to 5 million cases last year. There are two strains of Vibrio cholerae, 01 which has been identified as the cause of the current epidemic in Haiti, and the South-East Asian strain 0139. It is thought that up to 75% of people infected with the bacterium may not develop symptoms but will excrete the bacterium with their faeces for up to 14 days. So the increase in air travel is often cited as the cause of smaller outbreaks.  There is also increasing concern that the bacterium can be transported via water and algae held in ballast tanks in ships which when discharged can contaminate surface waters and shellfish.