The general population places great importance on the avoidance of bad breath, illustrated by the annual $1 billion that consumers in the United States spend on deodorant-type mouth (oral) rinses, mints, and related over-the-counter products. Many of these practices are merely short term attempts at masking the odour. Some authors have suggested that there is an evolutionary basis to concern over bad breath. An instinctive aversion to unpleasant odours may function to detect spoiled food sources and other potentially invective or harmful substances. Body odours in general are thought to play an important role in mate selection in humans, and unpleasant odour may signal disease, and hence a potentially unwise choice of mate. Although reports of bad breath are found in the earliest medical writings known, the social stigma has likely changed over time, possibly partly due to sociocultural factors involving advertising pressures. As a result, the negative psychosocial aspects of halitosis may have worsened, and psychiatric conditions such as halitophobia are probably more common than historically. There have been rare reports of people committing suicide because of halitosis, whether there is genuine halitosis or not. Etymology
The word halitosis is derived from the Latin word halitus, meaning breath, and the Greek suffix -osis meaning diseased or a condition of. With modern consumerism, there has been a complex interplay of advertising pressures and the existing evolutionary aversion to malodour.
A trichrome stain of preserved stool is another method used to detect Giardia. Microscopic examination of the stool can be performed for diagnosis. This method is not preferred, however, due to inconsistent shedding of trophozoites and cysts in infected hosts. Multiple samples over a period of time, typically one week, must be examined. The Entero-Test uses a gelatin capsule with an attached thread. One end is attached to the inner aspect of the hosts cheek, and the capsule is swallowed. Later, the thread is withdrawn and shaken in saline to release trophozoites which can be detected with a microscope. The sensitivity of this test is low, however, and is not routinely used for diagnosis. Immunologic enzyme-linked immunosorbent assay (ELISA) testing may be used for diagnosis. These tests are capable of a 90% detection rate or more.Although hydrogen breath tests indicate poorer rates of carbohydrate absorption in those asymptomatically infected, such tests are not diagnostic of infection. Serological tests are not helpful in diagnosis. Prevention
The CDC recommends hand-washing and avoiding potentially contaminated food and untreated water.Boiling water contaminated with Giardia effectively kills infectious cysts. Chemical disinfectants or filters may be used. Iodine-based disinfectants are preferred over chlorination as the latter is ineffective at destroying cysts.Although the evidence linking the drinking of water in the North American wilderness and giardiasis has been questioned, a number of studies raise concern. Most if not all CDC verified backcountry giardiasis outbreaks have been attributed to water.