Seeing the unexpected increase in late-winter influenza cases, hospitals throughout some parts of the Southeastern United States have implemented strict visitor regulations.

The upswing in influenza cases has been seen in Illinois, Indiana and North Carolina. Public health officials said that the flu has turned more dangerous and deadlier in some areas.

As per the Illinois Department of Public Health, influenza cases in Chicago, Illinois have gone up from 49 in December 2015 to 326 by February 27 this year.

Public health department spokesperson Jennifer O'Malley said that in Indiana, 19 individuals have so far lost their lives because of the flu since October, 2015. Over 50% of the deaths of the current season were reported in the last two weeks.

The flu season in Indiana has kick-started mildly in comparison to last year, which had seen 789 cases. Presently, there are 127 positive influenza tests, and what made officials worried was the fact that 84 of the 127 cases were reported in February solely.

Epidemiologist Genessa Doolittle, said, “It appears that this flu season is picking up later than what we have seen in recent years, and it's too early to say if we've hit the peak or if it's yet to come”.

Similar scenario was seen in Chicago, where the flu season was on peak by the end of January, showing a deviation from past trends wherein the cases peaked in the beginning of January. Hospitals in both the states have noticed the change and have taken necessary measures.

Emergency rooms’ doctors of Advocate Christ Medical Center in Oak Lawn, Illinois, have seen more flu cases previous month and it is apparently increasing more and more every week.

Stephen Sokalski, the center's chief of infectious disease and epidemiology, said that couple of weeks ago, the emergency room was highly occupied and busy. Most of the cases reported in the hospital were of children.