A case of mass food poisoning hit Enka construction company's summer camp in the Moscow Region's Ruzsky district last week.
"At present, 319 people have been hospitalized, and only two of them have health insurance," the spokesperson said, adding that a total of 1,605 people resided in the camp at the time of the incident.
Olga Gavrilenko, head of Moscow Region's food safety watchdog, said all patients had been diagnosed with salmonella infection.
Anti-epidemic measures are currently being taken at the nearby Klin and Solnechnogorsk districts, to the northwest of the capital.
Russia's chief sanitary official, Gennady Onishchenko earlier said the majority of infected workers were nationals of Georgia, Uzbekistan and other CIS countries.
