Whooping cough, which has claimed the lives of ten people and left close to 18,000 infected so far, seems to have gained a stranglehold that is much bigger than the economic turbulences rocking the U.S.

The Centers for Disease Control and Prevention (CDC) has cited how data published early July reveal that more than twice the number has been affected in comparison to 2011.

Chicago Tribune report cites how the outbreak is set to become the worst in over a half century.

Though reports of whooping cough epidemic exposing vaccination problems were made available in the month of April, nothing seems to stop the epidemic from engulfing the healthy people.

Under normal circumstances, immunization against the disease commences two months after the baby is born. Many children are immunized with a DTaP five-dose series vaccine administered as a series of shots.

However, vaccination does not last forever. Adults require a booster shot every 10 years and failure to do so results in an outbreak. Even pregnant women are advised to get a booster shot as it a contagious illness.

The Chicago Tribune report also quotes statistics shared by Dr Anne Schuchat, director, CDC's National Center for Immunization and Respiratory Diseases, during a media briefing.

It's most dangerous for babies, Schuchat said, adding that the current outbreak at its existing pace could become the most severe since 1959, when 40,000 cases were reported. Preventing infant deaths from the disease is our primary national goal.

Whooping cough, better known as pertussis, causes severe, uncontrollable cough. Though it begins with cold-like symptoms such as fever, runny nose and sneezing, it is accompanied by cough that aggravates as days pass by. 

The initial vaccine for the disease used whole cell parts made of killed pertussis bacteria whereas the DTaP dose used a cellular bacteria pieces and not the whole bacteria cell, Washington State Health Department spokesman Donn Moyer told Reuters.

CDC officials might begin an investigation in Washington State in late July to analyze our data for cases among 13-to-14-year-olds to see what can be learned about disease rates and vaccination status, Moyer added.

The CDC plans to conduct a similar study in California where a 2010 epidemic identified more than 9,000 cases, including 10 infant deaths.