CNN's Jacqueline Howard reviews the safe foods that can be eaten during the cyclospora outbreak and how to prepare them before consumption. Cyclospora is a parasitic infection transmitted through contaminated water or food, causing watery diarrhea.

Health officials in the US state of Michigan are focusing on lettuce or leafy greens in salads as potential sources of this outbreak, but they have not completely ruled out other food sources.

It is advisable to buy whole heads of lettuce, as you can remove the outer leaves that may have been exposed to germs, then wash the inner leaves and use them for eating.

When washing fresh vegetables and fruits, rinsing them with water alone is not enough; they should be rubbed thoroughly by hand or with a brush, as the friction from rubbing can help remove potential germs.

Attention should also be paid to some foods that are difficult to wash, such as raspberries and basil, which have been linked to previous outbreaks.

This step is useful, but it does not guarantee 100% elimination of the cyclospora parasite. To achieve that, heat must be used, and care should be taken to cook food at a temperature of at least 70 degrees Celsius.