Lessons from history of socioeconomic improvements: a new approach to treating multi-drug-resistant tuberculosis

Dynamics of tuberculosis infection in various populations during the 19th and 20th century: The impact of conservative and pharmaceutical treatments

Humans and Mycobacterium tuberculosis have co-evolved together for thousands of years. Many individuals are infected with the bacterium, but few show signs and symptoms of tuberculosis (TB). Pharmacotherapy to treat those who develop disease is useful, but drug resistance and non-adherence significantly impact the efficacy of these treatments. Prior to the introduction of antibiotic therapies, public health strategies were used to reduce TB mortality. This work shows how these strategies were able to reduce TB mortality in 19th and 20th century populations, compared with antibiotic treatments. Previously published mortality data from historical records for several populations (Switzerland, Germany, England and Wales, Scotland, USA, Japan, Brazil and South Africa) were used. Curvilinear regression was used to examine the reduction in mortality before and after the introduction of antibiotic treatments (1946). A strong decline in TB mortality was already occurring in Switzerland, Germany, England and Wales, Scotland and the USA prior to the introduction of antibiotic treatment. This occurred following many public health interventions including improved sanitation, compulsory reporting of TB cases, diagnostic techniques and sanatoria treatments. Following the introduction of antibiotics, mortality rates declined further, however, this had a smaller effect than the previously employed strategies. In Japan, Brazil and South Africa, reductions in mortality rates were largely driven by antibiotic treatments that caused rapid decline of mortality, with a smaller contribution from public health strategies. For the development of active disease, immune status is important. Individuals infected with the bacterium are more likely to develop signs and symptoms if their immune function is reduced. Effective strategies against TB can therefore include enhancing immune function of the population by improving nutrition, as well as reducing transmission by improving living conditions and public health. This has been effective in the past. Improving immunity may be an important strategy against drug resistant TB.

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.

The technological imperative in tuberculosis care and prevention in Vietnam

A monocausal bacteriological understanding of infectious disease orients tuberculosis control efforts towards antimicrobial interventions. A bias towards technological solutions can leave multistranded public health and social interventions largely neglected. In the context of globalising biomedical approaches to infectious disease control, this ethnography-inspired review article reflects upon the implementation of rapid diagnostic technology in low- and middle-income countries. Fieldwork observations in Vietnam provided a stimulus for a critical review of the global rollout of tuberculosis diagnostic technology. To address local needs in tuberculosis control, health managers in resource-poor settings are readily cooperating with international donors to deploy novel diagnostic technologies throughout national tuberculosis programme facilities. Increasing investment in new diagnostic technologies is predicated on the supposition that these interventions will ameliorate disease outcomes. However, suboptimal treatment control persists even when accurate diagnostic technologies are available, suggesting that promotion of singular technological solutions can distract from addressing systemic change, without which disease susceptibility, propagation of infection, detection gaps, diagnostic delays, and treatment shortfalls persist.

Bi-logistic model for disease dynamics caused by Mycobacterium tuberculosis in Russia

In this work, we explore epidemiological dynamics by the example of tuberculosis in Russian Federation. It has been shown that the epidemiological dynamics correlates linearly with the virulence of Mycobacterium tuberculosis during the period 1987-2012. To construct an appropriate model, we have analysed (using LogLet decomposition method) epidemiological World Health Organization (WHO) data (period 1980-2014) and obtained, as result of their integration, a curve approximated by a bi-logistic function. This fact allows a subdivision of the whole population into parts, each of them satisfies the Verhulst-like models with different constant virulences introduced into each subsystem separately. Such a subdivision could be interconnected with the heterogeneous structure of mycobacterial population that has a high ability of adaptation to the host and strong mutability.

Tuberculosis Mortality and Living Conditions in Bern, Switzerland, 1856-1950

BACKGROUND

Tuberculosis (TB) is a poverty-related disease that is associated with poor living conditions. We studied TB mortality and living conditions in Bern between 1856 and 1950.

METHODS

We analysed cause-specific mortality based on mortality registers certified by autopsies, and public health reports 1856 to 1950 from the city council of Bern.

RESULTS

TB mortality was higher in the Black Quarter (550 per 100,000) and in the city centre (327 per 100,000), compared to the outskirts (209 per 100,000 in 1911-1915). TB mortality correlated positively with the number of persons per room (r = 0.69, p = 0.026), the percentage of rooms without sunlight (r = 0.72, p = 0.020), and negatively with the number of windows per apartment (r = -0.79, p = 0.007). TB mortality decreased 10-fold from 330 per 100,000 in 1856 to 33 per 100,000 in 1950, as housing conditions improved, indoor crowding decreased, and open-air schools, sanatoria, systematic tuberculin skin testing of school children and chest radiography screening were introduced.

CONCLUSIONS

Improved living conditions and public health measures may have contributed to the massive decline of the TB epidemic in the city of Bern even before effective antibiotic treatment became finally available in the 1950s.

The Immune System and Responses to Cancer: Coordinated Evolution

This review explores the incessant evolutionary interaction and co-development between immune system evolution and somatic evolution, to put it into context with the short, over 60-year, detailed human study of this extraordinary protective system. Over millions of years, the evolutionary development of the immune system in most species has been continuously shaped by environmental interactions between microbes, and aberrant somatic cells, including malignant cells. Not only has evolution occurred in somatic cells to adapt to environmental pressures for survival purposes, but the immune system and its function has been successively shaped by those same evolving somatic cells and microorganisms through continuous adaptive symbiotic processes of progressive simultaneous immunological and somatic change to provide what we observe today. Indeed, the immune system as an environmental influence has also shaped somatic and microbial evolution. Although the immune system is tuned to primarily controlling microbiological challenges for combatting infection, it can also remove damaged and aberrant cells, including cancer cells to induce long-term cures. Our knowledge of how this occurs is just emerging. Here we consider the connections between immunity, infection and cancer, by searching back in time hundreds of millions of years to when multi-cellular organisms first began. We are gradually appreciating that the immune system has evolved into a truly brilliant and efficient protective mechanism, the importance of which we are just beginning to now comprehend. Understanding these aspects will likely lead to more effective cancer and other therapies.

The Immune System and Responses to Cancer: Coordinated Evolution

This review explores the incessant evolutionary interaction and co-development between immune system evolution and somatic evolution, to put it into context with the short, over 60-year, detailed human study of this extraordinary protective system. Over millions of years, the evolutionary development of the immune system in most species has been continuously shaped by environmental interactions between microbes, and aberrant somatic cells, including malignant cells. Not only has evolution occurred in somatic cells to adapt to environmental pressures for survival purposes, but the immune system and its function has been successively shaped by those same evolving somatic cells and microorganisms through continuous adaptive symbiotic processes of progressive simultaneous immunological and somatic change to provide what we observe today. Indeed, the immune system as an environmental influence has also shaped somatic and microbial evolution. Although the immune system is tuned to primarily controlling microbiological challenges for combatting infection, it can also remove damaged and aberrant cells, including cancer cells to induce long-term cures. Our knowledge of how this occurs is just emerging. Here we consider the connections between immunity, infection and cancer, by searching back in time hundreds of millions of years to when multi-cellular organisms first began. We are gradually appreciating that the immune system has evolved into a truly brilliant and efficient protective mechanism, the importance of which we are just beginning to now comprehend. Understanding these aspects will likely lead to more effective cancer and other therapies.

SOCIAL, HISTORICAL AND CULTURAL DIMENSIONS OF TUBERCULOSIS

Tuberculosis (TB) researchers and clinicians, by virtue of the social disease they study, are drawn into an engagement with ways of understanding illness that extend beyond the strictly biomedical model. Primers on social science concepts directly relevant to TB, however, are lacking. The particularities of TB disease mean that certain social science concepts are more relevant than others. Concepts such as structural violence can seem complicated and off-putting. Other concepts, such as gender, can seem so familiar that they are left relatively unexplored. An intimate familiarity with the social dimensions of disease is valuable, particularly for infectious diseases, because the social model is an important complement to the biomedical model. This review article offers an important introduction to a selection of concepts directly relevant to TB from health sociology, medical anthropology and social cognitive theory. The article has pedagogical utility and also serves as a useful refresher for those researchers already engaged in this genre of work. The conceptual tools of health sociology, medical anthropology and social cognitive theory offer insightful ways to examine the social, historical and cultural dimensions of public health. By recognizing cultural experience as a central force shaping human interactions with the world, TB researchers and clinicians develop a more nuanced consideration of how health, illness and medical treatment are understood, interpreted and confronted.