The tainted baby formula that has been blamed for killing four infants and sickening 6,200 in China since the scandal broke last week.  About 1,300 babies, mostly newborns, are in hospitals and 158 of them are suffering from acute kidney failure.

Today, the U.S. Food and Drug Administration (FDA) stepped up with a word of assurance for Americans and a note of caution for Chinese-American communities.

The FDA said "there is no known threat of contamination in infant formula manufactured by companies that have met the requirements to sell such products in the United States.

But  FDA "also warned members of Chinese communities in the United States that infant formula manufactured in China, possibly available for purchase at Asian markets, could pose a risk to infants.

Since issuing a Health Alert on Sept. 12th, FDA said it had contacted the companies who manufacture infant formula for distribution in the United States and received information from the companies that they are not importing formula or source materials from China.

At the same time, the FDA—in conjunction with state and local officials—began a nation-wide investigation to check Asian markets for Chinese manufactured infant formula that may have been brought into the United States. In particular, this effort focused on areas of the country with large Chinese communities, such as Los Angeles, San Francisco, Seattle and New York.

To date, investigators have visited more than 1,000 retail markets and have not found Chinese infant formula present on shelves in these markets.

In addition, the FDA is advising consumers not to purchase infant formula manufactured in China from internet sites or from other sources.

For today’s statement from FDA, go here.