Paraguay asked international health authorities on Thursday to supply 600,000 doses of vaccine for yellow fever after the first cases were detected in the country in 34 years.
Antonio Barrios, a public health official, said the government had 100,000 vaccine doses but wanted to bolster stocks as a "reserve measure" after five cases of yellow fever were detected this week in a central farming region.
Barrios said the request was being made to the Pan American Health Organization. An expert on vaccination issues at the Washington-based offices was not immediately available for comment.
Barrios said the five cases of the mosquito-borne viral disease were found in and around a town in rural San Pedro department some 240 miles (400 kilometers) from the border with Brazil. In January, Brazil reported eight deaths after an outbreak in rural areas.
No deaths from yellow fever have been confirmed in Paraguay, but health officials said it was awaiting pathologists' reports on two people who died recently of unknown causes.
"Pathologists are working in the laboratory to determine whether they died as a result of yellow fever or as a result of some other ailment," public health minister Oscar Martinez said.
The government has announced vaccination plans in and around San Pedro of all those between 1 and 60 years of age. Others were also seeking vaccinations elsewhere at public hospitals.