PULASKI CO., Va. -

Influenza B and Group A streptococcus were present in the mother and daughter who died last week from a mysterious illness in Pulaski County.

The official cause of death for Julie and Ginger Simpkins has not been determined. Health officials say co-infections are very rare, but there is no threat to the public.

“This type of co-infection is so rare, that it doesn't appear to be a community threat. But as you all know, flu and strep are circulating,” said Dr. Molly O'Dell New River Health District.

O'Dell said both types of infections have been circulating in the New River Health District. On their own, both Influenza B and Strep A are treatable.  People suffering from a cough, fever, or illness are asked to contact their doctor. Unlike strep commonly found in the throat, this type of strep were found in Ginger and Julie's lungs.

Officials say it is not too late to get a flu shot. No one who was sickened last week in Pulaski County had a flu vaccine. Doctors say the vaccine may have provided some benefit, but it's not always 100 percent effective.

A doctor from Carilion Clinic says this is the first co-infection case of Influenza B and Strep A that he has seen in 35 years. Dr. Tom Kerkering is the Chief of Infectious Diseases and gave the latest news to the family today. He says this co-infection has only been documented around ten times in all medical literature and has never been formally studied.

Hantavirus, which is spread through rodents, was previously suspected by Pulaski County officials.