Exhibit 15.1 December 23, 2004 To the Board of Directors and Stockholders of Calypte Biomedical Corporation LETTER RE: UNAUDITED INTERIM FINANCIAL STATEMENT INFORMATION Re: Registration Statement on Form SB-2: With respect to the subject registration statement, we acknowledge our awareness of the use therein of our report dated October 25, 2004, related to our review of interim financial information. Pursuant to Rule 436 under the Securities Act of 1933 (the "Act"), such report is not considered a part of a registration statement prepared or certified by an accountant within the meaning of Sections 7 and 11 of the Act. /s/ Odenberg Ullakko Muranishi & Co. LLP ODENBERG ULLAKKO MURANISHI & CO. LLP San Francisco, California