Human major infections: Tuberculosis, treponematoses, leprosy-A paleopathological perspective of their evolution.

The key to evolution is reproduction. Pathogens can either kill the human host or can invade the host without causing death, thus ensuring their own survival, reproduction and spread. Tuberculosis, treponematoses and leprosy are widespread chronic infectious diseases whereby the host is not immediately killed. These diseases are examples of the co-evolution of host and pathogen. They can be well studied as the paleopathological record is extensive, spanning over 200 human generations. The paleopathology of each disease has been well documented in the form of published synthetic analyses recording each known case and case frequencies in the samples they were derived from. Here the data from these synthetic analyses were re-analysed to show changes in the prevalence of each disease over time. A total of 69,379 skeletons are included in this study. There was ultimately a decline in the prevalence of each disease over time, this decline was statistically significant (Chi-squared, p<0.001). A trend may start with the increase in the disease's prevalence before the prevalence declines, in tuberculosis the decline is monotonic. Increase in skeletal changes resulting from the respective diseases appears in the initial period of host-disease contact, followed by a decline resulting from co-adaptation that is mutually beneficial for the disease (spread and maintenance of pathogen) and host (less pathological reactions to the infection). Eventually either the host may become immune or tolerant, or the pathogen tends to be commensalic rather than parasitic.

What skeletons tell us. The story of human paleopathology.

Human skeletal paleopathology provides important insight regarding the antiquity of some diseases and their distribution in past human groups. The history of human skeletal paleopathology extends back more than 150 years. Rudolf Virchow published reports on the subject, and research on paleopathology has provided critical data on important topics such as the origin of syphilis. With the development of powerful new research tools, human paleopathology will continue to be a source of data on the development of disease and its effect on human biological and cultural development.

Skin and treponemal diseases among Asian domestic house-helpers in northern Saudi Arabia.

BACKGROUND: Asian domestic house-helpers in Saudi Arabia come from a different socioeconomic setting with a different disease pattern from that of their host country. This study reports the incidence of skin and treponemal diseases in this group seen at a referral hospital in northern Saudi Arabia. METHODS: The study was based on the analysis of the dermatologic and serologic examinations of 1520 domestic house-helpers during resident permit issue, and a retrospective study of clinical records of house-helpers with skin disorders. RESULTS: Routine examination revealed significant skin disease in 374 (24.6%) individuals, and the disease was transmissible in 126 (8.3%). Treponemal infection (5, 0.3%) and leprosy (1, 0.07%) were seen. Hand dermatitis and chicken pox were the most common causes of hospital attendance. Psychologic skin disorders included three cases of neurotic excoriations, two cases of delusion of parasitosis, and a case of dermatitis artefacta. CONCLUSIONS: The prevalence of transmissible skin diseases in Asian domestic house-helpers is low compared with that in their home countries. Excluding individuals with stigmata of atopic dermatitis from employment as house-helpers, adequate counselling will reduce the incidence of hand dermatitis and psychologic skin disorders. There is a need for continuous surveillance to prevent the introduction of skin diseases not normally seen in the native population.

A family study of leprosy: subcutaneous amyloid deposits and humoral immune responses.

One group of 11 aboriginal families, consisting of 27 persons with leprosy and 43 unaffected family members, and a second group of 26 patients with leprosy were studied in the Northern Territory of Australia. Amyloid deposits were sought in fine needle aspirates of subcutaneous fat and serological investigations relevant to amyloidosis and to the humoral immune response were done. The study showed unexpectedly high frequencies of amyloid deposits, evidence of persisting hepatitis B virus (HBV) infection, and antibodies to smooth muscle, to skin basement membrane, and to extractable nuclear antigens (ENA). Compared with unaffected family members, patients with leprosy had increased serum alpha-lipoprotein (alpha-LP) and were more often hepatitis B surface antigen (HBsAg) carriers but, contrary to expectations, the presence of amyloid, the alpha-LP level, serum amyloid associated (SAA) protein, and the HBsAg carrier state all appeared unrelated to the type of leprosy.

Human treponematosis and tuberculosis: evidence from the New World.

The purpose of this study has been first, to critically review the evidence for the presence of human treponematosis and tuberculosis in the skeletal remains of prehistoric natives in the New World, and second, to report on nine new cases dated to before contact and suggesting the presence of these two disease conditions. A review of the medical history and findings by human paleopathologists leaves little doubt that both diseases originated in the Old World. The findings of this study lend further support to the fact that, although rare, human treponematosis and tuberculosis were indeed endemic in the pre-Columbia New World before contact. There is no evidence that these two diseases could have arisen independently and de novo, especially during the relatively short time since man's arrival in the New World. Where a disease has been endemic for quite some time as appears to be the case with human treponematosis and tuberculosis, milder forms of the disease and improved host response could have developed in which only the most severe cases would be observable. This explains the rarity of skeletal lesions suggestive of these two human disease conditions in prehistoric human populations.