Larimer County Department of Health and Environment (LCDHE) and CDPHE are investigating an outbreak of Campylobacter infections that are probably associated with consumption of raw milk obtained through a cow-share program.

LCDHE noted an unusual number of Campylobacter cases reported during the first week of January 2006. Upon interview, four of five cases reported consuming unpasteurized milk from a Larimer County raw milk dairy. The fifth case's parent denied that the case drinks raw milk, although the family is listed as a shareholder at the dairy.

LCDHE and CDPHE are in the process of contacting all of the dairy's shareholders to identify additional cases and determine potential risk factors. CDPHE and LCHD visited the dairy on Friday, Jan. 13, 2006 and collected milk specimens for testing at the state laboratory.

Confirmed or probable cases have been identified among members of at least seven households to date, although interviewing is ongoing. This represents 26 percent of the 27 households with shares in the dairy. The five lab-confirmed cases range in age from 7 - 44 years; four are female. No cases have been hospitalized. Onset dates range from Dec. 23, 2005 to Jan. 4, 2006, although the case with the latest onset date was a household contact of another case and may be due to secondary transmission.

The sale of raw or unpasteurized milk is not permitted in Colorado, however, cow-share programs are legal. Shareholders purchase a share in a dairy herd and in exchange receive unpasteurized milk. The dairy must register with CPDHE, however, CDPHE does not inspect or regulate these facilities.