Typhus is an acute febrile illness that is caused by bacteria in the Rickettsiaceae family. Rickettsia is a pleomorphic bacteria that may appear as cocci or bacilli and are intracellular parasites. They have the ability to multiply in arthropods such as lice, mites, and fleas and some warm-blooded animals, which include human, mice, rats, cats and squirrels. There are different types of Typhus. The following types are the more commonly occurring.
Epidemic Typhus fever caused by Rickettsia prowazekii, is the most notorious of Typhus disease. Infected humans are the primary reservoir. The human body louse is infected by feeding on the blood of an infected person. When the louse feeds on another person, it defecates and releases the bacteria on to that person's skin. Infection occurs when he/she rubs the feces of the louse into the bite or other nearby skin lesion. Infected lice die after 2-3 weeks of infection. Epidemics occur among people who live in unsanitary conditions and are louse infested. Enormous and explosive outbreaks have occurred worldwide during famine and war.
Murine Typhus is transmitted to humans by fleas. Rats and mice are the reservoir. Fleas living on these animals become infected when they feed on the blood of the infected animals. Similar to lice, fleas defecate when they feed. Humans become infected directly from the fleabite or when the fleas' feces containing Rickettsia typhi enters the fleabite or other open lesions. People may also become infected in locations heavily infested by mice or rats by breathing in air-borne infected flea feces particles. Unlike the louse, infected fleas do not die after being infected. They can remain infected for up to a year.
Flea-infested mice and rats spread Murine Typhus. Persons who acquire Typhus cannot spread it to others. Once infected, they develop antibodies and are immune to future disease.
Symptoms of Typhus include fever, headache, chills, and general pains followed by a rash. The rash spreads to the whole body except the face, palms and sole of the feet. Murine typhus (flea-borne) symptoms are similar but milder than Epidemic (louse-borne) typhus. Symptoms appear from 1-2 weeks after the fleabite.
Diagnosis and Treatment
Typhus infections are diagnosed by blood tests. The subject's blood is tested for the presence of Typhus antibodies. Antibiotics such as Tetracycline, Doxycycline and Chloramphenicol are the primary methods of treating Typhus infections.
Avoid contact with non-domesticated and potentially flea-infested mice and rats. Take precautions and control the mice and rats around your home. It is also important to control fleas that may depart trapped or dead rats or mice. Check the traps daily and remove dead rodents immediately by sealing the carcass in a plastic bag. The Hawaii State Department of Health's Epidemiology Branch can be contacted for more information at (808) 586-4586.