Various workers, including T. D. Stewart, claim that the aboriginal Americas were relatively disease-free because of the bering Strait cold-screen, eliminating many pathogens, and the paucity of zoonotic infections because of few domestic animals. Evidence of varying validity suggests that precontact Americns had their own strains of treponemic infections, bacillary and amoebic dysenteries, influenza and viral penumonia and other respiratory diseases, salmonellosis and perhaps other food poisoning, various arthritides, some endoparasites such as the ascarids, and several geographically circumscribed diseases such as the rickettsial verruca (Carrion's disease) and New World leishmaniasis and trypanosomiasis. Questionably aboriginal are tuberculosis and typhus. Accordingly, virtually all the "crowd-type" ecopathogenic diseases such as smallpox, yellow fever, typhoid, malaria, measles, pertussis, polio, etc., appear to have been absent from the New World, and were only brought in by White conquerors and their Black slaves. My hypothesis is that native American medical care systems--especially in the more culturally advanced areas--were sufficiently sophisticated to deal with native disease entities with reasonable competence. But native medical systems could not cope with the "crowd-type" disease imports that struck Indian and Eskimos as "virgin-field" populations. Reanalysis of native population losses through a genocidal combination of diease, war, slavery and attendant cultural disruption by Dobyns, Cook and others strongly suggest that traditiona estimates underplayed the death toll by a factor of the general order of ten. This would make for an immediately pre-contact Indian population of some 90-111 million instead of the tradition 8-11 million. Evidence is growing that Indians may have been no more susceptible to new pathogens that are other "virgin soil" populations, and thus their immune systems need not be considered less effective than those in other people. Present-day high mortality rates in Indians of both continents from infectious disease imports may be more socioeconomic than anything else.
A discharge register maintained by the National Research and Development Center for Welfare and Health was employed to study the use of hospital services, attributable to chronic obstructive pulmonary disease (COPD), in Finland. From a total population of 5 million COPD caused 113,016 hospital treatment periods during 1983-92 of persons aged 35 years or over. In men the need of hospital treatment for COPD started to rise sharply after the age of 50. Men aged 73 had the highest amount of admissions (3962 admissions per 10-year period). Women aged 68 had the highest amount of admissions (802 admissions per 10-year period). The highest admission rate per 1000 inhabitants was found for men at the age of 82 (37.0 admissions per 1000 population/ year) and for women at the age of 77 (3.8 admissions per 1000 population/year). During the 10-year period a total of 27,008 new COPD patients aged 35 or over received hospital care. The highest number of new admissions occurred among both sexes at the age of 71 (750 admissions per 10-year period in men and 233 admissions per 10-year period in women). This means that most of admissions are due to elderly COPD patients seeking treatment repeatedly. As the populations in the developed countries are ageing, the significance of COPD for the health care system is growing.
The rate at which children are maltreated is one of the most sensitive measures of demographic, social, and economic conditions. Although the consequences of maltreatment and the effectiveness of treatment programs in reducing the incidence have been extensively studied, little attention has been given to identifying spatial variations in maltreatment in terms of characteristics of areas, especially demographic, social or economical. Maltreatment may differ markedly in terms of an area's socio-demographic and economic makeup and this phenomenon needs to be studied in a structural context. This study employs an ecological perspective to predict variations in the rate of maltreatment (including neglect and abuse) among children aged 0 to 19 years in Alberta, Canada in 1986. Several hypotheses are tested in a multivariate framework and the implications of the findings in assessing the effectiveness of intervention strategies are briefly discussed.
The mortality rates from anencephalus from 1950-1969 in Canadian cities are shown to be strongly correlated with city growth rate and with horizontal geomagnetic flux, which is directly related to the intensity of cosmic radiation. They are also shown to have some association with the magnesium content of drinking water. Prior work with these data which showed associations with magnesium in drinking water, mean income, latitude and longitude was found to be inadequate because it dismissed the observed geographic associations as having little biological meaning, and because the important variables of geomagnetism and city growth rate were overlooked.
Mast seeding, the intermittent, synchronous production of large seed crops by a population of plants, is a well-known example of resource pulses that create lagged responses in successive trophic levels of ecological communities. These lags arise because seed predators are thought capable of increasing reproduction and population size only after the resource pulse is available for consumption. The resulting satiation of predators is a widely cited explanation for the evolution of masting. Our study shows that both American and Eurasian tree squirrels anticipate resource pulses and increase reproductive output before a masting event, thereby increasing population size in synchrony with the resource pulse and eliminating the population lag thought to be universal in resource pulse systems.
This study was conducted to explain a more than threefold increase in anticipated patient visits associated with the opening of a separate pediatric emergency department (PED) 2 miles from the nearest general emergency department. Population demographics and data pertaining to visits to other emergency departments were obtained. Parents visiting the new PED were surveyed using a standardized questionnaire. Over the study period (1984-1989), the city population increased by 7%; school population increased by 17%, with no increase in birth rate. Total patient visits to the other city hospitals increased by less than 10%, while the number of visits to the PED increased 250% over anticipated visits. Of children visiting the PED, 48% were less than 5 years old, 30% had lived at their current address less than 2 years, and 80% came from the geographic area close to the PED. Parental decision to bring the child to the PED was as follows: a service perceived to be "for kids" (47%), previous visit (42%), closest facility (33%), better service (20%), referred (12%), and pediatrician availability (10%). The PED is staffed by licensed pediatricians, whereas the general emergency departments are staffed by emergency physicians. We conclude that the increase in visits cannot be accounted for by increases in regional population base only. Anticipated patient volume to a new health care facility should not be based on population demographics only, but on other factors such as user perception of facility. Patient or parent preference should also be considered.
