Typhus, urban. of Malaya: Murine typhus, an acute infectious disease with fever, headache, and rash, all quite similar to, but milder than, epidemic typhus. It is caused by a related microorganism, Rickettsia typhi (mooseri), transmitted to humans by rat fleas (Xenopsylla cheopis). The animal reservoir includes rats, mice and other rodents. Murine typhus occurs sporadically worldwide but is more prevalent in congested rat-infested urban areas.