The Chattanooga-Hamilton County Health Department still has not been able to determine the source of mystery illness which struck at least ten construction workers last week at the BlueCross BlueShield construction site on Cameron Hill.

The health department began the investigation on Thursday, August 7 (2008).

Today a spokesperson tells NewsChannel9.com, "We are continuing to investigate to determine, if possible, the cause or causes of these illnesses and if these illnesses are related. All of the ill persons that we were notified of on Thursday and Friday have reported recovery from their symptoms."

A typical investigation consists of the following:

* Conduct interviews with ill individuals
* Collect specimens from ill individuals
* Send specimens for lab testing
* Perform an environmental inspection
* Recommend measures to stop transmission of illness
* Analyze data to determine a cause or source of the illness
Since August 7th, the Health Department has conducted patient interviews, acquired samples for lab testing, and conducted environmental health assessments. Symptoms of the ill workers include vomiting, diarrhea, nausea and dizziness.

"We are working with the Tennessee Department of Health to test for possible causes of the illnesses," said Becky Barnes, Administrator at the Chattanooga-Hamilton County Health Department. "Sometimes in situations like this a definitive cause is never determined."

All specimens have tested negative for norovirus, which frequently causes gastrointestinal illness. Currently, specimens are being further tested for several bacteria that also cause gastrointestinal illness. We anticipate having final lab results of bacterial testing by the end of this week.

Workers at the construction site and the contracting companies have been very cooperative during the on-going investigation.

The risk of contracting a gastrointestinal illness, like many other diseases, can be decreased by frequent and thorough hand washing. On Monday, the Health Department provided employee and employer educational materials and recommendations on hygiene and hand washing to reduce the potential for ongoing illness.

No conclusions regarding the source of the illness have been made and the investigation is ongoing.