An infective disease of worldwide distribution caused by the genus RICKETTSIA.
in which the infecting rickettsia is transmitted by the louse, includes epidemic typhus, Brill's disease – which is a recrudescent form of epidemic typhus – and TRENCH FEVER.
due to Rickettsia prowazeki and also known as exanthematic typhus, classical typhus, and louse-borne typhus, is an acute infection of abrupt onset which, in the absence of treatment, persists for 14 days. It is largely confined to parts of Africa. It is transmitted by the human louse, Pediculus humanus. The rickettsiae can survive in the dried faeces of lice for 60 days, and these infected faeces are probably the main source of human infection.
The incubation period is usually 10–14 days. The onset is preceded by headache, pain in the back and limbs and rigors. On the third day the temperature rises, the headache worsens, and the patient is drowsy or delirious. Subsequently a characteristic rash appears on the abdomen and inner aspect of the arms, to spread over the chest, back and trunk. Death may occur from SEPTICAEMIA, heart or kidney failure, or PNEUMONIA about the 14th day. In those who recover, the temperature falls by CRISIS at about this time. The death rate is variable, ranging from nearly 100 per cent in epidemics among debilitated refugees to about 10 per cent.
also known as flea typhus, is worldwide in its distribution and is found wherever individuals are crowded together in insanitary, rat-infested areas (hence the old names of jail-fever and ship typhus). The causative organism, Rickettsia mooseri, is transmitted to humans by the rat-flea, Xenopsyalla cheopis. Once humans are infected, the human louse may act as a transmitter of the rickettsia from person to person. This explains how the disease may become epidemic.
These are similar to those of louse-borne typhus, but the disease is usually milder, and the mortality rate is very low (about 1.5 per cent).
in which the infecting rickettsia is transmitted by ticks, occurs in various parts of the world. The three best-known conditions in this group are ROCKY MOUNTAIN SPOTTED FEVER, fièvre boutonneuse and tick-bite fever.
in which the infecting rickettsia is transmitted by mites, includes scrub typhus, or TSUTSUGAMUSHI FEVER, and rickettsialpox.
is a mild disease caused by Rickettsia akari, which is transmitted to humans from infected mice by the common mouse mite, Allodermanyssus sanguineus. It occurs in the United States, West and South Africa and the former Soviet Union.
The general principles of treatment are the same in all forms of typhus.
consists of either avoidance or destruction of the vector. In the case of louse typhus and flea typhus, the outlook has been revolutionised by the introduction of efficient insecticides. Efficient rat control reduces the risk of typhus very considerably.
was revolutionised by the introduction of CHLORAMPHENICOL and the TETRACYCLINES.