The strain H5N1, was believed to have infected four brothers, two of whom have died. The main concern, is that only one of the two brothers that died worked at the farm where the disease was found. The details are confusing with conflicting reports, but so far the fatal cases of bird flu, as far as doctors are aware, have been caught directly from birds. They are still on the alert for a case of human to human transmission. If such a variant happens to arise, the transmission will increase, and it will need to be identified quickly and specifically to develop an effective vaccine or treatment.