Middle East DVEP - Armed Forces Pest Management Board

similar to Ae. aegypti but is more commonly found breeding in natural containers, such astree holes, leaf axils, and fallen fruit husks. It is a slightly stronger flier than Ae. aegypti.Aedes albopictus is strongly anthropophilic but has a broader host range than Ae. aegypti.Vector Surveillance and Suppression. Landing rate counts provide a quick relativeindex of adult abundance. The number of mosquitoes that land on an individual within ashort period of time, usually one minute, is recorded. Several indices (container, house,Breteau indices) have been devised to provide a relative measure of the larval populationsof Ae. aegypti. Adult egg-laying activity can be monitored by using black ovipositioncups.Control of dengue fever is contingent upon reducing or eliminating vector populations.Ground or aerial applications of insecticidal aerosols have been relied upon to reduceadult populations during epidemics of dengue. Many vector control specialists havequestioned the efficacy of ULV adulticiding. In some outbreaks of dengue fever, ULVdispersal of insecticides has had only modest impact on adult mosquito populations.Aedes aegypti is a domestic mosquito that frequently rests and feeds indoors andtherefore is not readily exposed to aerosols. The sides of large storage containers shouldbe scrubbed to remove eggs when water levels are low. Water should be stored incontainers with tight-fitting lids to prevent access by mosquitoes. A layer of oil willprevent mosquito eggs from hatching and will kill the larvae. The elimination ofbreeding sources, such as old tires, flowerpots, and other artificial containers, is the mosteffective way to reduce mosquito populations and prevent dengue outbreaks. InSingapore, passage of sanitation laws and their strict enforcement to eliminate breedingsites reduced the house index for Ae. aegypti larvae from 25% to 1%. Proper disposal oftrash, bottles and cans at military cantonments must be rigidly enforced. The individualsoldier can best prevent infection by using personal protective measures during the daywhen the vector mosquitoes are active. Wear permethrin-impregnated BDUs and useextended-duration DEET repellent on exposed skin surfaces (TIM 36).D. Epidemic typhus.Epidemic typhus is a severe disease transmitted by the human body louse, Pediculushumanus humanus. The infectious agent is the bacterium Rickettsia prowazekii. Itcauses high mortality, particularly in populations weakened by malnutrition. Casefatality rates normally vary from 10 to 40% in the absence of specific therapy. Onset isusually sudden and marked by fever, headache, and general pains followed by a rash thatspreads from the trunk to the entire body. Untreated cases of epidemic typhus may lastup to 3 weeks.Military Impact and Historical Perspective. Epidemics of typhus have changed thecourse of history. One author has stated that the louse has killed more soldiers than allthe bullets fired during conflict. In one of the worst disasters in military history, over halfof Napoleon’s army perished from epidemic typhus during the invasion of Russia in1812. During the first year of World War I, typhus started as an epidemic in the SerbianArmy. In six months, 150,000 people had died of the disease, including 50,000 prisonersof war and one-third of the Serbian physicians. At the end of the war, and during the78