Some lots of the two brands were found to be contaminated with the pathogen Enterobacter sakazakii. The brands are produced in Vermont of the United States by Wyeth Nutritionals Inc, a unit of global pharmaceutical giant Wyeth.

State quarantine authorities took a further pre-emptive move Wednesday to suspend clearance and quarantine procedures for the two brands.

This puts a temporary lid on imports of the two products from the United States, the State Administration of Quality Supervision, Inspection and Quarantine (AQSIQ) said in a circular.

Products that have already arrived in Shanghai and Shenzhen, two major import gateways, are required to be destroyed under the close scrutiny of local quarantine officials, the circular said.

In addition, tourists are prohibited from carrying these two brands of infant formula into China. Mailed packets are banned as well, the notice said.

The move came on the heels of the US Food and Drug Administration's (FDA's) announcement on November 1 of a voluntary recall of powdered infant formula by Wyeth Nutritionals of Georgia, Vermont.

Certain lots of S-26Mama and Nursoy manufactured between July 12 and September 25, 2002 may be contaminated with Enterobacter sakazakii, the FDA said.

E. sakazakii is a food borne pathogen that can in rare cases cause sepsis (bacteria in the blood), meningitis (inflammation of the lining of the brain), or necrotizing enterocolitis (severe intestinal infection) in newborn infants, according to the FDA. It said no illnesses have been reported to date in connection with this contamination.

The products can be identified by a six-digit character embossed on the bottom of the cans. The first four characters include: K12N through K19N; L07N through L30N; and N03N through N25N.

"We have tracked the distribution of all related lot numbers and at the same time reported and communicated with AQSIQ," said Yang Bin, a spokeswoman for Wyeth-Ayerst (China) Ltd.

"It is confirmed that none of the affected products entered the China market," Yang told China Daily yesterday.

She noted the affected products were confined to those produced between July 12 and September 25. Any product made before and after this period is not tainted.

(China Daily November 28, 2002)