Paleopathological study on infectious diseases in Japan • 135 



Table 6. Population number from earliest Jomon (prehistoric) to Kofun 

 (protohistoric) period (Koyama 1984) 



Period 



Jomon Yawi Kofun 



earliest early middle late latest 



Population 20100 105500 261300 160300 75800 594900 5399800 

 number 

 Density/km^ 0.07 0.36 0.89 0.55 0.26 2.02 18.37 



Table 7. Reported palaeopathological cases of bone tuberculosis 



Designation 



Period Sex Age 



Location 



Reporter 



Shiroyama-No. 3 Kofun 



Unoki-No. 3 Kofun 



Asahidai - No. 9 Kofun 



Ainu - A - 1336 Ainu 



M Adult Spine (lumbar-sacrum) Ogata 1972 



F Mature -senile Spine (thoracic-lumbar) Suzuki 1978 



M Mature - senile Spine (thoracic-lumbar) Tashiro 1982 



Ribs 



F Adult Sacrum Suzuki 1985a 



Koyama's (1984:10-39) estimation of the population from 

 the earliest Jomon to the protohistoric period is shown in 

 Table 6. The average population density calculated in the 

 Jomon period (0.43/km-) is about one-fifth of the Yayoi 

 period (2.02) and one-fortieth of the Kofun period (18.37). 

 Furthermore, Kobayashi (1967) stated that the average age at 

 the time of death for the individual over 1 5 years of age was 

 3 1 . 1 for males and 3 1 .3 for females. It is quite probable that 

 the Jomon people had rather short lives, probably caused by 

 some environmental factors such as unstable food supply, 

 hard labor in hunting-gathering-fishing activities, and un- 

 sanitary living conditions. These environmental factors also 

 may have influenced the inflammatory process in the bone. 

 The following tendencies can be suspected among the Jomon 

 people; infection may extend rather easily to the bone, and 

 individuals involved in such an infectious process tend to die 

 before periostitis becomes chronic and develops into more 

 advanced osteomyelitis. 



On the other hand, during the historic periods, probably 

 due to the development of agriculture and gradual improve- 

 ment of hygienic conditions, individual resistance against 

 infectious diseases may change to produce more severely 

 infected conditions of the bone as well as lengthen the aver- 

 age span of life at the social level. However, at the same time 

 it should be noted that other new epidemic diseases had been 

 introduced and prevailed widely in this country at that time, 

 accompanied by an increase in population density and 

 domiciliation. These epidemic diseases consisted of the two 

 specific infections, tuberculosis and syphilis. 



Zagreb Paleopathology Symp, 19H8 



ORIGIN AND PREVALENCE OF SPECIFIC 

 DISEASES IN JAPAN 



It is remarkable that there have been neither typical nor sus- 

 pected cases showing specific inflammatory bone changes 

 among a huge number of Jomon skeletal remains excavated 

 from various archeological sites in the Japanese archipelago. 

 In the present study also, except for the Jomon skeletal series, 

 typical/demonstrable cases of tuberculosis and syphilis were 

 limited to the Edo and Meiji Japanese skeletons as well as the 

 Ainu skeletal series. 



Four typical cases of spinal tuberculosis have been re- 

 ported to date in Japan (Ogata 1972; Suzuki 1978; Tashiro 

 1982; Suzuki 1985a) as shown in Table 7. None of them 

 belonged to the prehistoric ( Jomon) population from which a 

 great deal of well-preserved skeletons have been studied. 

 The three oldest cases (Figure 7) belong to the protohistoric 

 (Kofun) population in which there are considerably fewer 

 skeletons than in the Jomon population. There seem to be two 

 alternative possibilities why no case of bone tuberculosis has 

 been found among so many Jomon skeletal remains. The first 

 hypothesis attributes it to the lower population density of the 

 Jomon period. Tuberculosis is a density-dependent disease 

 and may have become established in human populations as 

 the result of the appearance of such population aggregates 

 (Cook 1984). In this sense tuberculosis might have existed in 

 a very limited area as a local endemic form. Tuberculosis 

 reached epidemic proportions after the Yayoi or Kofun period 



