20 • Don R. Brothwell 



gatherer peoples, there is serological evidence of tox- 

 oplasmosis in 6% to 27% of the groups studied (Nurse and 

 Jenkins 1977). 



Was it also in the Pleistocene that tuberculosis expanded its 

 horizons and became established in human groups? If so, was 

 it a mutant o\' Mycobacteria hovis as generally believed, or 

 could it have been derived from M. avium? What further 

 questions should we be asking of these species in relation to 

 M. tuberculosis to answer more satisfactorily the ancestral 

 relationships of one with the other? In terms of posing a 

 human threat, the development of dairying in association 

 with some early urban societies would have greatly increased 

 the chances of spreading bovine tuberculosis, of course, but 

 this time span of five or six thousand years is surely too short 

 to allow for the distinctive separation of the human tuber- 

 culosis variety — or was it? 



It has to be kept in mind that in the past, as more recently, 

 tuberculosis could be passed on from farm to farm by more 

 mobile domesticates. Dogs are certainly capable of carrying 

 the infection. They can also be a health threat in various other 

 ways, of course, from rabies to the nematode Toxocara 

 canis. Zoonoses can occur which are known to be established 

 only in domesticates. Louping ill, of the central nervous 

 system, is such a condition, and the virus can be transmitted 

 to humans. 



It has been pointed out (Fiennes 1967) that, as a result of 

 agricultural developments and urbanism, another possible 

 change afl'ecting zoonoses was the exploitation and adapta- 

 tion of various rodent species to crops and settlements. Evi- 

 dence of the infestation of habitations is provided early in 

 Egypt, as well as the actual evidence of mice from Catal 

 Huyuk in Turkey (Brothwell 1981). Perhaps the most in- 

 famous of the rodent-carried diseases is typhus, which even 

 in this century has been highly destructive of human life. 

 There seems little doubt that murine typhus was the early 

 established primary disease and that by the increasingly close 

 proximity of rodents to people (and the adopted parasite- 

 transmitting role of human lice from rodent fleas), the classic 

 human form of typhus evolved. So here we may well have a 

 relatively new disease of only six thousand years or so. 



If on epidemiological grounds, Fenner(1971) is correct in 

 stating that the viability of measles in a community depends 

 on about 3000 cases a year in a population of 300,000, then 

 this disease also was dependent on the emergence of larger 

 neolithic groups and urbanism. We need to look then for an 

 ancestor, and Fiennes (1978) suggests that of the pseudo- 

 myxoviruses of the measles-distemper-Rinderpest triad, dis- 

 temper could well have the greatest antiquity, extending back 

 from domestic dogs to the wolf ancestor. However, measles 

 could be relatively recent in this sequence of parasite micro- 

 evolution, so should we again be viewing the human disease 

 as only a few millennia old? 



Finally, as regards the impact of mammalian domesticates 



on human population health, it should be noted that accord- 

 ing to the World Health Organization (1962), milk has per- 

 mitted the transmission of over thirty distinct diseases, in- 

 cluding a number mentioned here. The advent of dairying 

 and its eventual wide distribution must then have made a 

 further significant contribution to the spread of evolving zoo- 

 noses. 



Zoonoses and the organic remains of humans 



So far, I have been discussing in general terms the impor- 

 tance of considering zoonoses in relation to changing human 

 disease patterns, societies and environments in the past. This 

 may seem to be a somewhat theoretical matter to consider at a 

 meeting specifically concerned with paleopathology. But of 

 course ancient pathology is a step toward the reconstruction 

 of changing disease ecologies through time, of paleoepide- 

 miology. Also, the whole question of accurate diagnosis of 

 pathology rests on a good knowledge of the disease alterna- 

 tives which may have occurred within a particular environ- 

 ment. As yet, there is a tendency to consider evidence of 

 pathology somewhat in a vacuum, neglecting if not ignoring 

 some disease ecology and the probability of microevolution 

 in specific parasites (and consequent changes in disease ex- 

 pression). 



To what extent, for instance, has histoplasmosis been con- 

 sidered in the differential diagnosis of bone pathology? It 

 may be considered uncommon enough today to escape atten- 

 tion, but has it always been so? It can result in considerable 

 skeletal pathology, especially the African form, caused by 

 Histoplasma duboisii (Cockshott 1 96 1 ; Cockshott and Lucas 

 1964), simulating to some extent metastatic deposits. New 

 World morbidity evidence suggests that it can still be picked 

 up from visiting caves, where the lloor may have bat feces 

 containing histoplasma; indeed it is sometimes called "cave 

 disease." As well as eventual bone changes, histoplasmosis 

 more commonly produces lesions of the lung, and these may 

 calcify (and could be confused with tubercular calcifica- 

 tions). How often have the burials of cave dwellers been 

 considered for this environmental problem? The answer is 

 probably never, and the likelihood of the interior of the rib 

 cages being carefully excavated for calcified masses is even 

 more remote! 



Ortner and Putschar (1981) have rightly pointed out that 

 glanders, primarily a disease of horses, can occasionally 

 today cause human skeletal lesions. These could be confused 

 with treponemal disease and to some extent leprosy (in skull 

 and long bones), although the exact nature of the dry-bone 

 pathology is not really known. There may also be infectious 

 arthropathies, especially at the knee, elbow and ankle, a fact 

 which on present knowledge is likely to be missed for what it 

 is by rheumatologists concerned with arthropathies in the 

 past. 



ZuRivh PiileopiUhology Symp. 1988 



