Australian doctors and scientists are troubled by the sharp increase in cases of infectious skin disease Buruli ulcer. In the state of Victoria, 275 cases were registered last year, up 51 percent from a year earlier, the BBC reported. In addition, the disease occurs in new areas and is more serious than before, the BBC quoted the physician Daniel O’Brien. This is surprising inasmuch as the disease so far occurs mainly in tropical regions, but Victoria has a temperate climate. Type of transmission unclear The causative agent of skin disease is a mycobacterium, which has similarities with the agents of tuberculosis and leprosy. At the infected site, skin cells, adipose tissue and small blood vessels are attacked. The initial swelling can form large ulcers. How the transmission is done is not yet fully understood. The treatment of patients also needs a lot of research, according to the medical profession. “A mystery” This is exactly what O’Brien calls for with colleagues in an article in The Medical Journal of Australia. “We do not have time to sit around and philosophize about it,” O’Brien told the BBC, but the spread was already too large. “No one understands what’s actually going on there”, says the physician: “We can only offer hints”, the spread of the infections is a “mystery”.