Is there any risk of illness from eating summer squash?

Depending on how it is grown, harvested, and processed, summer squashes may harbor pathogenic bacteria such as E. coli and salmonella. Scientists continue to debate the most likely routes of produce contamination. In the field, fruits and vegetables can be contaminated by coming in contact with improperly composted animal manure or poultry litter. Bird, animal, and insect droppings can occasionally land on produce in the field and deposit pathogens on surfaces. Additionally, improper personal hygiene of workers who handle produce in the field and/or during processing can result in contamination. Contamination also can occur in retail settings or during preparation at home.
 
Summers squash also is subject to spoilage bacteria as a result of improper storage or proper storage over an extended period of time. It can develop mold under the same circumstances. Fortunately, proper storage, handling, and preparation of fresh summer squash eliminate most risk of illness.
 
Source(s):
University of Florida "Salmonella"