Economics of poor health

Public Health Significance of Urban Pests 409 Rats are known to cause damage to buildings and installations, with a significant risk of fire and electrocution as the result of damage to cables Colvin in Martindale, 2001; Hall Griggs, 1990. Burrowing rats can cause landslides on embankments; they can also cause the collapse of banks of canals and ditches, leading to flooding Meehan, 1984. The direct and indirect costs of structural damage caused by rats can be substantial DEFRA, 2006. The annual bill for rodent control in the United States in the early 1970s was estimated at US 100 million Brooks, 1973; at that time, commensal rodents in the United States caused between US 500 million and US 1 billion in damage annually Pratt, Bjornson Littig, 1977. The cost associated with damage and loss caused just by rats in the United States is now estimated at close to US 19 billion Pimentel et al., 2000. On farms in the United Kingdom, all sources of damage amounted to an estimated £10–20 million a year at 1989 prices Battersby, 2004. Richards 1989 reported fire as the most significant form of economic damage that occurred on farms, where roughly 50 of fires reported resulted from rats gnawing electrical cables. A model was constructed that estimated in the United Kingdom, the costs to the eco- nomy of damage to the infrastructure by rats could be between £61.9 million and £209.0 million. It was concluded that, based on the size of the rodent control industry, the higher figure was more likely Battersby, 2004. Moreover, the damage caused by rats in Budapest, Hungary, was estimated at between US 6.4 million and US 8.5 million annually between the years1978 and 1985 WHO Regional Office for Europe, 1998. In the agricultural sector, the International Rice Research Institute IRRI 2006 estima- tes that in rice-growing regions, rodents cause annual pre-harvest losses of between 5 and 17. A 6 loss in rice production amounts to approximately 36 tons, which would be enough rice to feed 215 million people roughly the population of Indonesia for one year IRRI, 2006. Brown Singleton 2002 reported that in a 1994–1995 house mouse plague more than 1000 mice per hectare, house mice caused an estimated US 60 million in damage to crops, livestock industries and rural communities in Australia.

12.7.2. Economics of poor health

Despite evidence that rats are infected with a range of zoonotic agents, little published data are available for assessing the costs to society of ill health due to commensal rodents. The paucity of data may be attributable to a lack of surveillance, diagnosis or awareness on the part of medical practitioners. One method of calculating the benefits of reducing or eliminating a disease is to estimate the current costs that will be averted by doing so. These costs include medical care, los- ses of current production, and the pain and discomfort caused by disease Mishan, 1994. In the context of current rat control activity, such a calculation appears to be impossible. The potential remains, however, for enumerating direct adverse effects on health that have a negative economic impact. These costs could include lost time at work, lost pro- duction or increasing demands on medical services. Regardless of such estimates, it can- not be denied that areas with substantial rodent infestations will be associated with ill Commensal rodents 408 States governments normally have in place some control, via building codes, over the design and construction of new buildings, particularly new dwellings. Although buil- ding codes may not be viewed as pest control laws, such codes, when properly enforced, can contribute to effective pest management by containing provisions for designing out potential deficiencies that can lead to future rodent problems. Municipal authorities will also have provisions available to address issues of repair and maintenance of existing hou- ses and other buildings, and they may apply somewhat different standards or criteria to justify interventions. These provisions should also take into account the need to exclude rodents. Provisions for hygiene, including refuse storage, should apply to existing buil- dings as well as new buildings. While public education is a necessary part of the control programme, there will be times when municipal authorities need to resort to the law. It is futile to deal with some infes- ted buildings and not others in an area. It is also futile to deal with part of a building and leave other parts infested. When there are clear legal requirements and obligations, it is also a form of education when municipal authorities advise building occupants of these obligations and responsibilities. Any legal framework must be appropriate for society’s needs, but it should recognize the need for an integrated approach to urban pest management. For this to be effective, however, requires properly trained enforcement personnel within the regulatory agen- cies. Such a legal framework should also address the need for adjoining urban munici- palities to operate similarly and cooperatively. Rodents do not recognize administrative boundaries, so there is little gained from one authority implementing a comprehensive strategy while the adjoining authority does little to manage urban commensal rodents. The foundation for assessing threats and emerging diseases from vectors is disease and pest surveillance. To strengthen this foundation, efforts should be made at the interna- tional level to establish and improve networks able to quickly gather and share infor- mation on the emergence or spread of communicable and novel diseases. Also, at natio- nal and regional levels, systems must be in place to ensure that diseases and conditions that can threaten public health and that occur within their jurisdiction are reportable to public health authorities by physicians, hospitals and laboratories.

12.7. Economic issues and the economic justification for effective control