Cost for control and management

Public Health Significance of Urban Pests 161 In North America, plague has been reported primarily in the West, ranging from south- western Canada to Mexico. Human cases average fewer than 10 a year in North America, a rate that has remained relatively constant since plague was introduced into the Americas in 1899 WHO, 2004. Worldwide, the number of murine typhus cases is low, but because symptoms are non- specific and frequently misdiagnosed, infection is presumed to be much more common than reported Gratz, 2004. In Europe, murine typhus has been reported from Bosnia and H erzegovina, Croatia, the Czech Republic, France, Greece, Italy, Montenegro, Portugal, the Russian Federation, Serbia, Slovakia, Slovenia and Spain, and it is consi- dered likely to be present in most other countries, as well Gratz, 2004.

5.5. Economic burden of flea infestations

As urbanization increases and pets become more important to their owners, fleas have become more and more economically significant. Few other single species of urban pests cost consumers more than the cat flea, not only in terms of costs of over-the-counter control products and pest control services, but also in terms of the costs of veterinary bills both for flea control and for treatment of flea-caused conditions, such as FAD and tape- worm infestations.

5.5.1. Cost for control and management

In North America, costs of domiciliary flea control are borne typically by the homeow- ner or property owner. The average pet owner in the United States spends an estimated US 38 on over-the-counter non-veterinary flea control products annually Hinkle, 1997. Also, in the United States, over US 175 million is spent every year for flea control services provided by pest control firms G. Curl, private pest management consultant, Mendham, NJ, personal communication, 2005. In a survey of ten pest control compa- nies in southern states and areas along the coast where environmental conditions are conducive and fleas thrive, the so-called United States flea belt, charges for a single flea control treatment averaged US 196 range: 85–314 N.C. Hinkle, unpublished data, 2006. With new on-host veterinary products available for flea suppression, annual cat flea control costs typically average about US 90. Luechtefeld 2005 indicated that 63 of pet owners purchase flea control products annually. The number of households that own pets is increasing in both Europe and North America, with 30 cats and 25 dogs per 100 Americans APPMA, 2006, compared with about 13 cats and 9 dogs per 100 Europeans Statistics Belgium, 2003. As more homes acquire pets, the incidence of fleas is likely to increase, exposing more people to cat fleas and increasing the market for flea control pro- ducts. In plague outbreaks, public health personnel are mobilized and taxes fund rodent- and Fleas 160 primarily a disease of domestic rats and mice, but is transmitted to people when the crus- hed bodies of infected fleas or their faeces are rubbed into an open sore or onto mucous membranes. The disease occurs worldwide, particularly in warm climates with large reservoir populations such as rats or opossums and flea vectors Traub, Wisseman Farhang Azad, 1978. Dramatic declines in reported cases of murine typhus began in the 1940s, and the current prevalence of the disease globally is estimated at fewer than 100 cases a year Boostrom et al., 2002, although cases may be considerably underestimated due to its nonspecific symptomatology Jensenius, Fournier Raoult, 2004. Murine typhus often goes unrecognized and is perceived as a clinically mild disease, with a case fatality rate less than 1. Texas and regions of Southern California have the highest pre- valence in the United States, but epidemiological studies Azad, 1990; Boostrom et al., 2002 have stimulated concern that typhus reservoirs and vectors are spreading. Although most patients are adults, children constitute up to 75 of infections in some outbreaks. Systemic involvement is evident from the frequent occurrence of abnormal laboratory findings that involve multiple organ systems, including the liver, kidney, blood and cen- tral nervous system. In the future, ecotourism and increased international travel are likely to result in more imported cases of rickettsioses in Europe and elsewhere Jensenius, Fournier Raoult, 2004, indicating that medical communities in nonendemic regions must expand their differential diagnoses to include these importations. The cat flea is also the recognized vector of Bartonella henselae, Bartonella clarridgeiae and Rickettsia felis Shaw et al., 2004. Many of the infections related to these bacteria are sub- clinical in both pets and humans, but the increasing immunocompromised population puts more individuals at risk of clinical illness. In addition, Bartonella quintana and Bartonella koehlerae have been detected in cat fleas, indicating that there may be emerging unknown diseases caused by as yet unidentified microbes in cat fleas Kelly, 2004; Lappin et al., 2006. In addition to transmitting pathogens, fleabites produce pruritic lesions in both humans and animals. Flea allergy dermatitis FAD is a serious atopic hypersensitivity reaction to flea salivary secretions that commonly afflicts cats and, more prevalently, dogs. The itching and discomfort produced by fleabites are the main reason cat fleas are considered human and pet pests Hinkle, 2003.

5.4. Notification and reporting