FDA initiated a ban on fresh cilantro originating from the state of Puebla, Mexico this week after an investigators looking into illnesses caused by the herb observed human waste and toilet paper in the plants growing fields.

CDC and state public health officials identified annual recurring outbreaks of cyclosporiasis in the US from 2012 through 2014 which they traced back to the cilantro. Officials in Texas and Wisconsin suspect fresh cilantro from this region is responsible for additional illnesses this year. The partial ban will impact particular shipments of cilantro from the Mexican state of Puebla from April through August.

According to FDA, Cyclospora cayetanensis is a human specific parasite that causes prolonged and severe diarrheal illness known as cyclosporiasis. Illnesses are seasonal though the parasite is not known to be native to the US as it prefers warmer, tropical regions.

Because of the recurrence of these outbreaks, FDA says it does not believe these illnesses are due to isolated contamination events. FDA worked with state officials to recognize a connection between the illnesses and consumption of cilantro from Mexico.

In a joint investigation with Mexican regulatory authorities, FDA inspected 11 farms and packing houses that produce cilantro in Puebla. Five of these facilities were linked to the illnesses in the US and objectionable conditions were observed at eight. In addition to human feces and toilet paper found in the growing fields, FDA discovered some farms had no running water, toilets or hand washing facilities. At one farm, water in a holding tank used by employees to wash their hands tested positive for the parasite.

“Based on those joint investigations, FDA considers that the most likely routes of contamination of fresh cilantro are contact with the parasite shed from the intestinal tract of humans affecting the growing fields, harvesting, processing or packing activities or contamination with the parasite through contaminated irrigation water, contaminated crop protectant sprays, or contaminated wash waters,” FDA announced.

 More information can be found here.