Of the over 4000 described species of cockroach, less than a dozen cockroach species are pests. The most difficult cockroach pests to control are the German cockroach and brown banded cockroach. These cockroaches rapidly reproduce and can build large populations in a short time under suitable conditions. Suitable conditions for cockroaches are simple: a source of water and access to food. Water is readily found where there is leaky plumbing, under refrigerators in the drip pan or as condensate on the sides of toilets and access to food. Food for cockroaches is any table scrap left in an open garbage can, food left in the sink, on the table or floor or food that is not stored in a tightly sealed container. In urban areas, one dysfunctional (when it comes to cleaning) tenant can produce enough cockroaches to over run an entire apartment building.
Many people think of cockroaches as unhealthy and transmitters of disease, but cockroaches are not a major source of disease transmission. The major medical concern for those who live with large populations of cockroaches is allergy and asthma. Cockroaches secrete proteins on their cuticle and eliminate proteins in their droppings that can be allergenic. Cockroach allergies are especially high in urban areas. Recently, an Inner-City Asthma Study found that between 59% and 81 percent of asthmatic children test positive for allergy to cockroaches.
An important medical concern is that cockroach allergens can be inhaled and cause inflammation of the air passages and lungs, or asthma. Allergy to cockroaches is the leading cause of hospitalization of children with asthma attacks. Not only is cockroach allergy a serious medical problem, it can be an educational problem as children with asthma are often too sick to attend school and learn.
It is important for children with cockroach allergies to live in an environment with little to no cockroaches. In dense urban housing this requires a concerted effort on the part of all the residents, which may be difficult to achieve, but it is possible. Good sanitation plus modern cockroach control techniques can greatly reduce and eliminate cockroach populations. Once living cockroaches have been eliminated, more work and deep cleaning may be needed to remove the allergenic proteins from the environment.
Exposure to cockroaches and cockroach allergens may increase allergy to arthropod foods. Many people with allergy to cockroaches are also allergic to shrimp. Cockroaches can be controlled, and the most important component is good sanitation. Sanitation may require investments by landlords to fix leaky plumbing. Sanitation most often requires changes in behavior of the residents to clean often and effectively and to keep food stored so that cockroaches will not have ready access. These behavioral changes, which are the most important, are often the most difficult part of cockroach control.