My girlfriend has had a string of infections one after the other for at least 7 months now. First, she had MRSA on her ankle and leg. Then she had a few infections on her breast. Then she had an infection near her anus that had to be drained. Now she has another infection on her breast. Also, she has recently been noticing blood in her urine, which she says is coming from her vagina but is NOT part of her period. How likely is it that this is an immune-system problem ? Could it be an STD ?