Biggest risk of outbreak is incoming HORROR diseases like cholera, typhoid, diphtheria and tuberculosis may have been eliminated from our shores, but they are only a plane flight away. Each year potential killers are brought in by passengers visiting or migrating, or travellers returning to Australia. In 2012, 10 cases of cholera were identified and the patients were quarantined. There were 123 cases of typhoid fever, 43 cases in NSW alone. There were also 1323 cases of tuberculosis, four cases of leprosy and one case of Japanese encephalitis. Four cases of diphtheria have been picked up over a five-year period, according to the nation's notifiable diseases surveillance system. Even polio, which was eradicated from Australia decades ago after mass immunisation programs, returned to Australia in 2007 in a 19-year-old student who picked it up in Pakistan. There are no effective screening programs for many of these diseases, which is why vigilant immunisation programs are still encouraged, said Professor Peter McIntyre from the National Centre for Immunisation Research and Surveillance. We can't screen for polio, it's one of the many diseases we are concerned about and we may never get to the point where we don't have to vaccinate because a lot of people who get polio don't get symptoms, so it makes it harder and yes, polio has flown in. The only screening program in place was for tuberculosis, Professor McIntyre said: "There is full screening for TB, if you are coming in from countries with high rates of TB you have to have a chest X-ray." He added the screening program was not perfect as people may not show symptoms for up to a year. Amuthan Annamalai, a 23-year-old medical student from James Cook University died in January from typhoid after picking it up in the Middle East and an unimmunised young Queensland woman died of diphtheria in 2011 after her boyfriend brought the disease back from Asia. The AMA has been concerned about low rates of vaccination in children because measles enters the country and finds pockets of low immunisation as it did in southwest Sydney last year when over 100 children fell ill. "We will have a measles death in coming years," AMA president Dr Steve Hambleton said, adding travellers needed to heed immunisation advice.