Middle East DVEP - Armed Forces Pest Management Board

period immediately following it (1917 to 1923), an estimated 30 million cases ofepidemic typhus occurred in Russia and Europe, with over 300,000 deaths. DuringWorld War II, there were severe epidemics of typhus in some endemic areas. In 1942there were 77,000 cases in French North Africa. Despite this incidence, US Armypersonnel experienced only 30 cases of typhus with no typhus deaths in the NorthAfrican-Middle East-Mediterranean zone during the years 1942 to 1945. In the MiddleEast, the British Army experienced annual hospital admissions due to typhus of 5 to 6 per10,000 troops during World War II. These rates may seem low, but their significancewas magnified by an estimated hospitalization of 14 days per case, for a loss of 78 mandaysper 10,000 British troops. When Allied forces landed in Italy in 1943, a typhusepidemic in Naples was ravaging the city of one million. Death rates reached 80%. Aneffective delousing campaign, chiefly using DDT, was waged. This marked the first timein history that an epidemic of typhus did not exhaust itself but instead was terminated byhuman action.The development of modern antibiotics and insecticides has reduced the threat of thisdisease to military forces. However, the short incubation period and severe clinicalsymptoms of epidemic typhus should be of concern to medical personnel when dealingwith large concentrations of refugees and prisoners of war.Disease Distribution. Epidemic typhus is more common in temperate regions and in thecooler tropics above 1,600 m. It is absent from lowland tropics. It usually occurs inmountainous regions where heavy clothing is worn continuously, such as the Himalayanregion, Pakistan and Afghanistan, and the highlands of Ethiopia. The incidence ofepidemic typhus has been steadily declining in the last two decades. The majority ofrecent cases have occurred in Africa, primarily in Ethiopia, with most of the remainderoccurring in Peru and Ecuador. Historically, epidemic typhus has been recordedthroughout the Middle East. The only recent outbreaks in the Middle East have occurredin Lebanon and Tel Aviv, Israel.Transmission cycle(s). The head louse, Pediculus humanus capitis, and the crab louse,Pthirus pubis, can transmit R. prowazekii experimentally, but epidemics have alwaysbeen associated with the body louse, P. h. humanus. Humans are reservoirs of thepathogen and the only hosts for the lice. Transmission of the disease occurs whenindividuals wear the same clothes continuously under crowded, unsanitary conditions.Major epidemics have been associated with war, poverty and natural disasters. Personsin cold climates are more likely to acquire epidemic typhus when they are unable to batheor change clothes for long periods of time.Lice become infective after a blood meal from an infected human. During subsequentblood meals, the louse defecates and rickettsiae are excreted in the feces. Louse bites areirritating, and scratching by the host produces minor skin abrasions, which allow entry ofthe pathogen from feces or crushed body lice. Rickettsia prowazekii can survivedesiccation for several weeks. Infection may also occur by inhalation of infective lousefeces.79