Some details below on health care associated infections from the WHO. Infection is the second leading cause for iatrogenic harm in medicine (right after medication error).
Reliable data is difficult to come by. People in health care settings by definition have a compromised immune system and without in depth investigation infections and their sources are easily missed.
Without knowing how many patients travelled to Mexico for surgery the number of infected patients is statistically irrelevant.
One of the worst (and best documented) cases of hospital acquired infections occurred in New Orleans and was responsible for the death of 5 children. And of course it was the parents who wanted answers and forced an investigation.
