Cockroaches can carry pathogenic bacteria, viruses, protozoa, fungi, and parasitic helminth eggs, and can be used as the intermediate host of many worms. Cockroaches have been shown to carry about 40 species of vertebrate pathogenic bacteria, including Mycobacterium leprae, as an important infectious leprosy epidemic of bubonic plague bacilli infectious diarrhea rats, Shigella dysenteriae and infantile diarrhea caused by Shigella dysenteriae, it is the side of Staphylococcus aureus and Pseudomonas aeruginosa causing urinary tract infections and the cause of the genitourinary tract and intestinal infection of Escherichia coli and spread of intestinal disease and gastritis of Salmonella, hepatitis such as Salmonella typhi, Salmonella typhi and so on. Cockroaches can carry many kinds of pathogenic bacteria that can cause food poisoning. Except for Pseudomonas aeruginosa and Escherichia coli, they are still Clostridium perfringens, fecal streptococci and so on. In addition, the cockroach can lead to artificial infection, pneumonia, diphtheria, Asiatic cholera, anthrax and glanders tuberculosis bacteria. A cockroach can carry a variety of worm eggs of Ascaris lumbricoides, Ancylostoma duodenale, beef tapeworm, insects, etc. around whipworm. They can also be used as intermediate host moniliformis moniliformis and Hymenolepis nana, tumor and other gongylonema nematodes. Cockroaches can also carry a variety of protozoa, 4 of which are pathogenic to humans or animals, such as dysentery, Amima, intestinal Jia Di worms and so on. Experimental studies have confirmed that cockroaches can carry, maintain and excrete viruses, including coxsackievirus, poliomyelitis virus, etc.. Cockroaches can also carry fungi. In China, in Jiangsu, Nanjing and Nantong, many species of fungi have been isolated from indoor cockroaches, including a large number of yellow mold pathogens. Although cockroaches carry a variety of pathogens, it is generally believed that pathogens can not reproduce in their bodies, which belong to the machinery of transmission media. However, because of their wide invasion and feeding habits, they can be eaten in the garbage, toilets, toilets and other places, and they can also be eaten on food. Therefore, they can cause the spread of intestinal diseases and parasitic eggs, which should not be neglected. In addition, cases of allergic reactions caused by cockroaches, body fluids and faeces are also reported. Moreover, factory products, shop products, and domestic food can cause economic losses due to cockroaches' bite and bite.