Nocturnal activity and nutritional behaviors are important to increase the potential of diseases transmission by them.
Some researchers have shown that the cockroaches can potentially carry pathogenic bacteria and play an important role in their spread in the hospitals and environments.
Fakoorziba et al showed that the bacteria carried by cockroaches are responsible for nosocomial infections, which is unfortunately paid less attention to this issue in the hospitals.
In addition, the researches carried out in Iran indicated the decrease of susceptibility level to pyrethroid insecticides in cockroaches that it reveales how hard is controlling of cockroaches.
So, considering the importance of cockroaches in mechanical and biological transmission of pathogenic bacteria in hospitals, the current investigation wascarried out in Hamedan hospitals, west of Iran, in order to study bacteria carried by cockroaches in relation to their distribution in different hospital wards.