The 44-year-old mother of three may have been infected with HIV along with three other patients, one of whom was an 11 month-old baby - through blood tainted with the virus the Daniel Carrion hospital in the port city of Callao near Lima in April.

National review

Peruvian officials have been inspecting the country's 240 blood banks after at least four people were infected with HIV, the virus that causes Aids, during blood tranfusions.

Carlos Vallejos, Peru's health minister, said that all the blood banks would be inspected by a commission that includes officials from the World Health Organisation.

Rivera was infected with the virus after receiving blood transfusions during an operation for a tumour in her uterus in April.

"This situation cannot continue," he said late on Thursday. "All of Peru's blood banks are being reviewed."

The situation created widespread panic and brought extensive criticism in the country's media.

'Worrying'

Vallejos appealled to the public to trust the country's public health services and said Peru fulfilled international standards for blood donation screening.

But Jose Cruz, an adviser on blood and laboratory safety for the Washington-based Pan-american Health Organisation, told the Associated Press news agency that Peru's blood banks were "worrying".

He said that Peru, along with Bolivia, Colombia and Mexico, is on the organisations list of countries that fail to perform preliminary disease screening on all blood collected in blood banks.

The organisation's most recent figures show almost a quarter of the blood Peru's banks receive is not properly screened, Cruz said.

This is not the first time patients have been infected at state facilities. In 2004, five newborn babies were infected with HIV at Lima's maternity hospital.

About 30 people were recently shown to have  been infected with hepatitis C at a state-run dialysis center.