Poor housekeeping isn’t always the cause of a cockroach infestation. Some parts of the world are simply more susceptible to the problem than others. Sometimes larvae can piggy back into your home on infected items or they can come in through cracks in your homes foundation or through drainage or sewage pipes.
How they get into your home is important to know considering this is your first line of defense to keep them out. It is important to seal up any crevices with caulking or weather stripping. It is far easier to defend the perimeter of your home than it is to deal with a full fledge infestation. Limiting the food and water supply the cockroaches have access to. You can learn more about cockroaches here.
They can go long periods of time without sustenance but are much less likely to set up residence and start laying eggs where there is no food or water to sustain life. Poisons, traps, and professional services are the last line of defense once the bugs have been spotted in your home. The level of treatment that should be sought depend on the instance of reoccurrence, the part of the world you live in, and how difficult the infestation is to get under control.