Tuberculosis and leprosy: Evidence for interaction of disease • 31 



the figures is correct, and documented foundation dates are. 

 in many cases, probably true foundation dates. However, 

 there remains the possibility that the first literary mention of a 

 lazar house may. erroneously, be construed as its foundation 

 date, which may. in reality, have been many years previous. 

 Neither should it be assumed that an observed rate of increase 

 in lazar house foundations in unit time represents a similar 

 arithmetic increase in the number of leprosy sufferers. No 

 account is taken in these gross figures of lazar house founda- 

 tions of the actual size of individual houses. To use a modem 

 analogy, no account is taken of "bed state," no assessment of 

 potential occupancy by leprosy sufferers is made. During the 

 post-Norman Conquest years a religious fervor was develop- 

 ing, one outlet of which was the demonstration of personal 

 conscience, piety, and wealth, outwardly manifest as the 

 foundation and endowment of hospitals in the medieval 

 period. It is noted, therefore, that not only is there an increase 

 in lazar house foundations, but there is a similar increase in 

 nonlazar house establishments (Roberts 1986). 



Notwithstanding these constraints of interpretation, the 

 increase in leprosaria and the legal enactments, royal dic- 

 tates, and comments all indicate that leprosy as an endemic 

 disease did increase in prevalence during the first three cen- 

 turies after the Norman Conquest. 



The rate of increase of lazar house foundations, or literary 

 mentions, seems to have been maximal during the 12th and 

 early 13th centuries, reaching a peak during the 13th century. 

 Thereafter, foundations, although continuing, declined 

 markedly. In the 16th century only four new houses were 

 founded, three in the southwest of England and one in East 

 Anglia (Richards 1977:83). As with the increase in founda- 

 tions, so with the decline; this cannot be taken, in isolation, 

 as a direct arithmetic indication of a declining incidence of 

 leprosy. There is a decline in foundations of nonlazar hospi- 

 tals, although this phenomenon postdates the lazar house 

 decline by a century or so. This event for both may represent 

 changing attitudes toward endowment, social changes conse- 

 quent upon the decline of feudalism, or maybe a preoccupa- 

 tion with the ravages of the Hundred Years War and the Wars 

 of the Roses. Additional documentary evidence does, how- 

 ever, indicate that the disease declined by the 15th century. 

 The house of Sherbum was so reduced from an establishment 

 of 65 leprosy sufferers at foundation in 1181 to two by 1434. 

 By the mid !6th century Sherburn housed no lepers at all. 

 Similar circumstances were recorded in this period at Ripon, 

 Shrewsbury, and Ilford. It is unfortunate that there is, as yet, 

 no osteoarcheological evidence to support this phenomenon 

 of decline. The sole reason for this absence of evidence is 

 that, hitherto, no significant excavation and postexcavation 

 analysis of lazar houses and their cemeteries has been under- 

 taken in Britain. The stratigraphic demonstration, by archeo- 

 logical excavation, of a declining number, through time, of 

 leprosy skeletons in lazar house cemeteries would indeed be 

 noteworthy. 



Zagreb Paleopathology Symp. 1988 



Thus, it is reasonable to conclude that leprosy, as an en- 

 demic disease in Britain, was present at least by the late 

 Roman period, increased steadily in incidence during the 

 Anglo-Saxon and post-Norman Conquest period, reaching 

 its zenith during the 1 3th century or so. Thereafter the disease 

 declined and, except for pockets of isolation to a later century 

 in southwest England and in northern Scotland, virtually 

 disappeared by the 16th century. 



What is not known, and would be so interesting epi- 

 demiologically, is whether there was any shift in the immu- 

 nologically determined type of leprosy during its period as an 

 endemic disease in Britain. Browne has suggested that lep- 

 romatous leprosy was the only type of leprosy of significance 

 in antiquity. In this endemic infectious disease, one may 

 theorize that the decline in prevalence may have been associ- 

 ated, post hoc propter hoc. with an increasing immunity and 

 shift to the tuberculoid end of the spectrum. Although the 

 presence of rhinomaxillary change in a skeleton is unequivo- 

 cal evidence of lepromatous leprosy, the absence of this 

 change is not a contraindication to this diagnosis. It may be 

 that the individual of antiquity died before the develop- 

 ment of the specific skull changes. In Professor M0ller- 

 Christensen 's researches at Njestved ( 1 96 1 ), nasal inflamma- 

 tory change was found in 100%^ of skeletons with peripheral 

 osseous stigmata of leprosy. Anterior nasal spine change was 

 found in 76.2%, and alveolar process of maxilla change in 

 66%. This high proportion of rhinomaxillary change, per- 

 haps as high as 100% of leprous skeletons, indicated the 

 overwhelming prevalence of lepromatous disease in the lep- 

 rosy sufferers of Nsstved. There was no stratigraphic. and 

 therefore no chronological , differentiation of the skeletons at 

 Nasstved. The prevalence of lepromatous disease is assumed 

 to be constantly high throughout the period 1 250- 1 550 when 

 Nasstved leprosarium was active. However, this does not 

 affirm that the immunological pattern of the disease was 

 universally constant throughout this period. Bone change 

 pathognomonic of leprosy was found in 70% of the excavated 

 skeletons at Naestved. This is much higher than the rate of 

 involvement of bone in modem leprosy studies. The implica- 

 tion of this finding is threefold: the rate of bone involvement 

 may have been higher in leprosy in antiquity than it is today; 

 the modem figures may be clouded by therapy relatively 

 early in the clinical course of disease, and such therapy was 

 clearly not a feature of antiquity; that only the most severely 

 affected leprosy sufferers, those with mutilating osseous 

 change, were segregated in antiquity. There is no evidence, 

 as yet, for the first two propositions. There is, however, 

 evidence for the last proposition. M0ller-Christensen discov- 

 ered a leprous skeleton from his excavations at /Ebelholt 

 (1953:13-14), and Manchester and Roberts (1987), and 

 Henderson (1985) have discovered leprous skeletons from 

 Norton Priory and Guildford Friary. These sites are not asso- 

 ciated with established medieval leprosaria. It is enigmatic 

 however that these "extramural" skeletons exhibit advanced 

 rhinomaxillary features of lepromatous disease. If the last 



