Health officials were investigating the death of a middle school student in Nashville after preliminary tests suggested the pupil had a potent virus that has infected hundreds of children nationwide.

Specific testing to confirm or rule out the student had Enterovirus D68 (EV-D68) was pending, according to an email sent to middle school parents on Friday by the Metropolitan Nashville Public Schools and the Metro Public Health Department.

School spokesman Joe Bass said on Saturday that there was no further information about the student, who attended Haynes Middle School.

The virus strain has infected nearly 700 people, most of them children, in 46 states and the District of Columbia since mid-August, according to the U.S. Centers for Disease Control and Prevention.

Two deaths in the United States have been directly linked to the strain of the virus, CDC officials said. At least four others who have died were infected with the enterovirus, but it is unclear what role it played in their deaths.

Health officials say the virus is transmitted through sneezes, coughs and contact with surfaces that have been touched by an infected person.

The letter to Nashville parents, a hard copy of which will be sent home on Monday, said the virus that has been circulating throughout the country had not yet been confirmed in middle Tennessee.