US health officials confirmed of a positive third victim of the deadly Middle East Respiratory Syndrome Coronavirus (MERS CoV), but the infected person is surprisingly feeling well, without any report of getting sick or hospitalized, and didn't require or seek any medical care.

The third victim is a resident of Illinois who reportedly has come in close contact with an Indiana patient who is positive with MERS CoV, based on ongoing investigation by health officials in the US.

"It's possible that as the investigation continues others may also test positive for MERS-CoV infection but not get sick. Along with state and local health experts, CDC will investigate those initial cases and if new information is learned that requires us to change our prevention recommendations, we can do so," Dr. David Swerdlow, leading the MERS-CoV response of the Centers for Disease Control and Prevention (CDC), says in a statement.

The positive identification of the MERS CoV infection in people without any signs or symptoms at all was said to be interesting though not surprising, says Dr. Richard Besser, chief health and medical editor at ABC News.

"With most (if not all) infectious diseases, there is a spectrum of disease following infection, ranging from asymptomatic transmission to full-blown fatal disease," Dr. Besser says to ABC News. He notes that regardless of lack of complete information of the full extent of contact of these two infected individuals, it is now known that transmission is also possible even through casual contact.

Meanwhile, the Indiana patient is a health care worker and a resident of the US who came from a travel in Saudi Arabia. Said first MERS patient was admitted on April 28 to a hospital in Indiana and was confirmed to be positive of the deadly disease on May 2. The Indiana patient was released from the hospital since then.

A second case was reported in Florida on May 11 when the MERS-infected Saudi Arabian man visited the place.

Despite not having sought medical care, local health officials continue to monitor the Illinois patient's health on a daily basis since May 3. Preliminary laboratory test results showing the third infection were confirmed late night of May 16. First test results, however, were negative.

CDC officials, however, suggested that perhaps the Indiana patient transmitted the virus to the Illinois resident, but the latter developed antibodies that fight off the virus.

The Illinois patient has not travelled lately outside the US, but admitted having met with the MERS-infected Indiana patient two times in a business meeting shortly before being diagnosed with MERS CoV.

Public health officials have reached out to healthcare providers, family members and others who came in close contact with MERS CoV patients to offer guidance on monitoring their personal health as well as recommendations on when to finally see a healthcare professional for evaluation. These officials have also been working with all airlines to identify and advise the US travelers who may have come in contact with the patient while on flight.