Cockroaches present a significant public health risk due to their ability to spread disease. They are a particular concern for food safety; they contaminate food and food-handling surfaces via their droppings or mechanical transfer from their bodies. 

This photo shows the path of cockroaches spreading disease. On the left are German cockroaches on a petri dish; on the right are colonies of E. coli transferred by the cockroaches.

Types of Diseases: What Cockroaches Can Carry

According to the Centers for Disease Control and Prevention, the German cockroach is a known vector for diseases including:

• Salmonellosis: Salmonella food poisoning causes diarrhea, fever and abdominal cramps within 12 to 72 hours. Symptoms are generally mild, but can be severe, especially for those with a compromised immune system.
• Staphylococcus infections: This gastrointestinal illness develops soon after food is eaten and usually last about a day. The toxins are heat resistant so are not destroyed by cooking.
• Escherichia coli (E. coli): Bacteria normally lives in the intestines of people and animals and some types can cause illness with diarrhea.
• Typhoid fever: This life-threatening illness is caused by Salmonella Typhi. When a contaminated food is consumed, the bacteria multiply and spread into the bloodstream.
• Gastroenteritis: Inflammation of the stomach and small and large intestines, generally leading to vomiting or diarrhea.

People may become infected with any of these diseases. Additionally, cockroach feces and other debris associated with an infestation can trigger respiratory allergies and asthma. This makes it especially important to know the signs of a cockroach infestation.