An outbreak of life-threatening bacteria has prompted the shutdown of shellfish harvesting in Virginia after at least five people have fallen ill. 

State health officials closed the Little Wicomico River in Northumberland County, a rural region in northern Virginia, after they traced an outbreak of salmonella in Pennsylvania back to shellfish harvested from those waters. 

The closure to harvesting began October 9, just eight days into Virginia's oyster season. It will be in effect through November 7.

The outbreak in Pennsylvania has sickened at least five people so far.   

The Virginia Department of Health (VDH) said: 'Effective October 9, out of an abundance of caution... VDH announced that the waters in the Little Wicomico River in Northumberland County are closed to the harvesting of oysters and clams due to a link to a Salmonella outbreak in Pennsylvania.

'VDH was recently notified of a Salmonella outbreak in Pennsylvania that has been epidemiologically linked to shellfish harvested from this area. VDH is currently conducting testing of shellfish in the implicated area.'

The harvesting shutdown applies to bivalve mollusks, including oysters and clams, but not crabs or finfish. 

The river closure, which is being made also in conformance with recommendations from the Food and Drug Administration (FDA), has no impact on drinking water, the VDH added. 

This is not the only closure in the area, according to notices from VDH. 

The department also issued a second emergency shellfish closure on October 9 temporarily barring harvesting in portions of Lower Machodoc Creek in nearby Westmoreland County, a coastal county in northern Virginia, through October 29.

While in effect, it is illegal to harvest, store or transport shellfish from the areas without a special permit from the Marine Resources Commission.

Foods contaminated with salmonella bacteria can smell, taste and look fine, but still pose a health risk. 

Salmonella can cause diarrhea, fever, stomach cramps and dehydration – symptoms that require medical attention, particularly for children under five, adults over 65 and those with weakened immune systems.

The bacteria can also spread into the bloodstream and cause the life-threatening complication sepsis, when the immune system overreacts to an infection.

Many salmonella cases resolve with just supportive care, primarily hydration and rest, and healthy adults should recover from the infection within a week.

For more severe cases, doctors can also use antibiotics to help clear infections.

Children under five years old, older adults and those who are immunocompromised are at higher risk of a severe infection or complications.

Salmonella is one of the leading causes of foodborne illness in the US, triggering about 1.35 million infections, 23,000 hospitalizations and 450 deaths every year.