"BASIC ROACH INFORMATION Disease Transmission. Cockroaches can carry organisms that cause human diseases, including food poisoning, dysentery and diarrhea. However, roaches have not been associated with serious disease outbreaks in the United States. Repulsive Odor. Most cockroaches produce a secretion or chemical that has a repulsive odor. This characteristic odor can be detected in infested areas. Allergy. Roaches can cause allergic reactions in some people. The response is caused by roach "allergen" that is ingested with contaminated food or inhaled when dried fecal particles and fragments of roaches are mixed with house dust." Scared me, I thought for a minute I stumbled onto the drug forum or the NORML site!