ROANOKE, Va. -

We now know the official cause of death of the Snowville mother and daughter who mysteriously died in April.

Dr. Jennifer Bowers, with the Office of the Chief Medical Examiner in Roanoke tells WDBJ7 Julie Simpkins died from septic shock due to Group A Streptococcus and Influenza B co-infection.  Septic shock is when an overwhelming infection leads to low blood pressure and the body's organs shut down.

Her daughter Ginger Simpkins died from Acute Lobar Pneumonia also due to Group A Streptococcus and Influenza B, a co-infection, according to Dr. Bowers.   Acute Lobar Pneumonia is a form of pneumonia that affects a large lobe of the lung.

Both septic shock and acute lobar pneumonia are complications from co-infection.

The head of infectious disease at Carilion Roanoke Memorial, Dr. Thomas Kerkering, told WDBJ's Jean Jadhon during an interview in May that co-infection cases are extremely rare and because of that the Centers for Disease Control and Prevention is also investigating this case.

It was late April that Julie and Ginger Simpkins became ill after working to clean out a trailer on the family property in Snowville, a community in Pulaski County.  The  two were taken to Carilion Roanoke Memorial Hospital where both died just a few days later.

Ginger Simpkins attended Dublin Middle School.  Julie Simpkins was a longtime member of Snowville Baptist Church. 

Three other family members including two younger children and a family friend were also treated at Carilion Roanoke Memorial during that time.