Diphtheria is a bacterial disease spread mainly by exhaled water droplets and occasionally through infected skin lesions. It can be fatal if left untreated. Travelers are at risk when mixing closely with the local population in most developing countries. If they are likely to be at risk, travelers should ensure they have had a Diphtheria vaccine within the last 10 years.
The bacteria that causes Tetanus is present in soil worldwide and disease occurs when the bacteria gets into a wound or even small cut. The disease leads to uncontrollable muscle spasms and possibly death. Travelers should ensure they have had a Tetanus vaccine within the last 10 years before they travel.
Polio is a disease of the central nervous system usually spread through contaminated food and water. Many countries have eradicated Polio through vaccination although it still exists in some African and Asian countries and cases continue to occur worldwide.
For more information on Diptheria, Tetnus and Polio and vaccines required for specific countries please visit http://www.fitfortravel.nhs.uk/home