Modeling the impact of changes in day-care contact patterns on the dynamics of varicella transmission in France between 1991 and 2015.

Annual incidence rates of varicella infection in the general population in France have been rather stable since 1991 when clinical surveillance started. Rates however show a statistically significant increase over time in children aged 0-3 years, and a decline in older individuals. A significant increase in day-care enrolment and structures' capacity in France was also observed in the last decade. In this work we investigate the potential interplay between an increase of contacts of young children possibly caused by earlier socialization in the community and varicella transmission dynamics. To this aim, we develop an age-structured mathematical model, informed with historical demographic data and contact matrix estimates in the country, accounting for longitudinal linear increase of early childhood contacts. While the reported overall varicella incidence is well reproduced independently of mixing variations, age-specific empirical trends are better captured by accounting for an increase in contacts among pre-school children in the last decades. We found that the varicella data are consistent with a 30% increase in the number of contacts at day-care facilities, which would imply a 50% growth in the contribution of 0-3y old children to overall yearly infections in 1991-2015. Our findings suggest that an earlier exposure to pathogens due to changes in day-care contact patterns, represents a plausible explanation for the epidemiological patterns observed in France. Obtained results suggest that considering temporal changes in social factors in addition to demographic ones is critical to correctly interpret varicella transmission dynamics.

Patterns of Infection and Patterns of Evolution: How a Malaria Parasite Brought "Monkeys and Man" Closer Together in the 1960s.

In 1960, American parasitologist Don Eyles was unexpectedly infected with a malariaparasite isolated from a macaque. He and his supervisor, G. Robert Coatney of the National Institutes of Health, had started this series of experiments with the assumption that humans were not susceptible to "monkey malaria." The revelation that a mosquito carrying a macaque parasite could infect a human raised a whole range of public health and biological questions. This paper follows Coatney's team of parasitologists and their subjects: from the human to the nonhuman; from the American laboratory to the forests of Malaysia; and between the domains of medical research and natural history. In the course of this research, Coatney and his colleagues inverted Koch's postulate, by which animal subjects are used to identify and understand human parasites. In contrast, Coatney's experimental protocol used human subjects to identify and understand monkey parasites. In so doing, the team repeatedly followed malaria parasites across the purported boundary separating monkeys and humans, a practical experience that created a sense of biological symmetry between these separate species. Ultimately, this led Coatney and his colleagues make evolutionary inferences, concluding "that monkeys and man are more closely related than some of us wish to admit." In following monkeys, men, and malaria across biological, geographical, and disciplinary boundaries, this paper offers a new historical narrative, demonstrating that the pursuit of public health agendas can fuel the expansion of evolutionary knowledge.

Ross, macdonald, and a theory for the dynamics and control of mosquito-transmitted pathogens.

Ronald Ross and George Macdonald are credited with developing a mathematical model of mosquito-borne pathogen transmission. A systematic historical review suggests that several mathematicians and scientists contributed to development of the Ross-Macdonald model over a period of 70 years. Ross developed two different mathematical models, Macdonald a third, and various "Ross-Macdonald" mathematical models exist. Ross-Macdonald models are best defined by a consensus set of assumptions. The mathematical model is just one part of a theory for the dynamics and control of mosquito-transmitted pathogens that also includes epidemiological and entomological concepts and metrics for measuring transmission. All the basic elements of the theory had fallen into place by the end of the Global Malaria Eradication Programme (GMEP, 1955-1969) with the concept of vectorial capacity, methods for measuring key components of transmission by mosquitoes, and a quantitative theory of vector control. The Ross-Macdonald theory has since played a central role in development of research on mosquito-borne pathogen transmission and the development of strategies for mosquito-borne disease prevention.

Environmentalist thinking and the question of disease causation in late Spanish Philippines.

The scientific understanding of disease causation was crucial to the ways in which the Spanish colonial state addressed epidemic diseases which periodically struck nineteenth-century Philippines. Scholars have often described Spanish colonial responses in terms of ineptitude and failure, and have often glossed over the multiple and competing scientific theories that preoccupied Spanish and Filipino physicians. This article examines the work and ideas of nineteenth-century Spanish colonial and patriotic Filipino physicians regarding disease causation in the tropical environment of the Philippines. It will focus on two key developments-Spanish environmentalist thinking and the emerging fields of microscopy and bacteriology. Much like the British and French colonialists, Spaniards viewed tropical climates as insalubrious and conducive to disease, perceiving themselves as constitutionally at risk in hot places, ill-suited, exposed, and vulnerable to so-called native diseases. By the 1880s, however, young Filipino researchers, some of whom had trained in Spain and France, were undertaking new research on polluted water, malaria, and cells. Influenced by the revolutionary new discoveries being made in bacteriology, these researchers questioned prevailing environmentalist explanations and focused, for the first time, on the nature of pathogens and microbial pathogenesis in disease development and transmission. But germ theory remained an idea among many. This article argues that although late nineteenth-century studies in microscopy by Filipinos slowly began to challenge Spanish colonial ideas, different streams of thinking overlapped and no single scientific explanation came to predominate.

A historical perspective: infection from cadaveric dissection from the 18th to 20th centuries.

Today, the study of human anatomy utilizing the ultimate study guide, the cadaver, is relatively safe. In the past, however, human dissection was dangerous. Prior to the germ theory, antibiotics, and the use of gloves, cadavers were often life threatening to dissectors including both the teacher and the student. Medical students who graduated in the United States before 1880 were unlikely to practice antisepsis in the dissecting room. In the present article, we review human cadaveric dissection in Europe and the United States primarily from the 1700s to the early 1900s in regard to its potential for transmission of infection to the dissector. A brief account of the infectious hazards of human cadavers in general and those of cadavers used for dissection in particular is given.

Precarious employment, ill health, and lessons from history: the case of casual (temporary) dockworkers 1880-1945.

An international body of scientific research indicates that growth of job insecurity and precarious forms of employment over the past 35 years have had significant negative consequences for health and safety. Commonly overlooked in debates over the changing world of work is that widespread use of insecure and short-term work is not new, but represents a return to something resembling labor market arrangements found in rich countries in the 19th and early 20th centuries. Moreover, the adverse health effects of precarious employment were extensively documented in government inquiries and in health and medical journals. This article examines the case of a large group of casual dockworkers in Britain. It identifies the mechanisms by which precarious employment was seen to undermine workers and families' health and safety. The article also shows the British dockworker experience was not unique and there are important lessons to be drawn from history. First, historical evidence reinforces just how health-damaging precarious employment is and how these effects extend to the community, strengthening the case for social and economic policies that minimize precarious employment. Second, there are striking parallels between historical evidence and contemporary research that can inform future research on the health effects of precarious employment.

The ancient history of kissing.

Sources from Mesopotamia contextualize the emergence of kissing and its role in disease transmission.

Development and dissemination of infectious disease dynamic transmission models during the COVID-19 pandemic: what can we learn from other pathogens and how can we move forward?

The current COVID-19 pandemic has resulted in the unprecedented development and integration of infectious disease dynamic transmission models into policy making and public health practice. Models offer a systematic way to investigate transmission dynamics and produce short-term and long-term predictions that explicitly integrate assumptions about biological, behavioural, and epidemiological processes that affect disease transmission, burden, and surveillance. Models have been valuable tools during the COVID-19 pandemic and other infectious disease outbreaks, able to generate possible trajectories of disease burden, evaluate the effectiveness of intervention strategies, and estimate key transmission variables. Particularly given the rapid pace of model development, evaluation, and integration with decision making in emergency situations, it is necessary to understand the benefits and pitfalls of transmission models. We review and highlight key aspects of the history of infectious disease dynamic models, the role of rigorous testing and evaluation, the integration with data, and the successful application of models to guide public health. Rather than being an expansive history of infectious disease models, this Review focuses on how the integration of modelling can continue to be advanced through policy and practice in appropriate and conscientious ways to support the current pandemic response.

The history of ultraviolet germicidal irradiation for air disinfection.

Public health concerns such as multi- and extensive drug-resistant tuberculosis, bioterrorism, pandemic influenza, and severe acute respiratory syndrome have intensified efforts to prevent transmission of infections that are completely or partially airborne using environmental controls. One such control, ultraviolet germicidal irradiation (UVGI), has received renewed interest after decades of underutilization and neglect. With renewed interest, however, come renewed questions, especially regarding efficacy and safety. There is a long history of investigations concluding that, if used properly, UVGI can be safe and highly effective in disinfecting the air, thereby preventing transmission of a variety of airborne infections. Despite this long history, many infection control professionals are not familiar with the history of UVGI and how it has, and has not, been used safely and effectively. This article reviews that history of UVGI for air disinfection, starting with its biological basis, moving to its application in the real world, and ending with its current status.

Changes in historical typhoid transmission across 16 U.S. cities, 1889-1931: Quantifying the impact of investments in water and sewer infrastructures.

Investments in water and sanitation systems are believed to have led to the decline in typhoid fever in developed countries, such that most cases now occur in regions lacking adequate clean water and sanitation. Exploring seasonal and long-term patterns in historical typhoid mortality in the United States can offer deeper understanding of disease drivers. We fit modified Time-series Susceptible-Infectious-Recovered models to city-level weekly mortality counts to estimate seasonal and long-term typhoid transmission. We examined seasonal transmission separately by city and aggregated by water source. Typhoid transmission peaked in late summer/early fall. Seasonality varied by water source, with the greatest variation occurring in cities with reservoirs. We then fit hierarchical regression models to measure associations between long-term transmission and annual financial investments in water and sewer systems. Overall historical $1 per capita ($16.13 in 2017) investments in the water supply were associated with approximately 5% (95% confidence interval: 3-6%) decreases in typhoid transmission, while $1 increases in the overall sewer system investments were associated with estimated 6% (95% confidence interval: 4-9%) decreases. Our findings aid in the understanding of typhoid transmission dynamics and potential impacts of water and sanitation improvements, and can inform cost-effectiveness analyses of interventions to reduce the typhoid burden.

Estimating transportation role in pandemic diffusion in Nigeria: A consideration of 1918-19 influenza and COVID-19 pandemics.

BACKGROUND: The focus of the study is to assess the role of different transport means in the importation and diffusion of 1918-19 influenza and a novel 2019 corona virus designated as COVID-19 in Nigeria. METHODS: The study provides a review of the means by which the two pandemics were imported into the country and the roles the transport means of each period played in the local spread of the epidemics. RESULTS: The study notes that seaports and railways, being the emerging transportation modes in the country were significant to the importation and local diffusion of 1918-19 influenza, respectively, while air transport is significant to the importation of the current COVID-19 pandemic. CONCLUSIONS: The study concludes that increasing preference for the transport at a given epoch is significant to the diffusion of prevailing epidemic in the epoch.

[The road from the "antituberculosis armory" to the Huipulco Tuberculosis Sanatorium in Mexico City, 1920-1940]. / Del "armamento antituberculoso" al Sanatorio para Tuberculosos de Huipulco en la Ciudad de México, 1920-1940.

This article discusses the various proposals and strategies to prevent the transmission of pulmonary tuberculosis in the City of Mexico from the 1920s decade onwards, when it was launched the first long-term campaign against the disease, and analyses the limitations and challenges faced until 1940. It looks upon the motives that led the need to contain the transmission of the disease to occupy a dominant role after ten years of civil war; it focuses on the models and strategies implemented, and examines the challenges faced by the construction and operation of the Huipulco Tuberculosis Sanatorium, a key component of the fight against tuberculosis at the international level since long ago.

Este artículo estudia las diferentes propuestas y estrategias para prevenir los contagios de la tuberculosis pulmonar implementadas en la Ciudad de México a partir de la década de 1920, al comenzar la primera campaña de largo aliento contra esa enfermedad, y analiza las limitaciones y problemas a los que ésta se enfrentó hasta 1940. Se destaca por qué la contención de los contagios de esa enfermedad ocupó un lugar prioritario después de diez años de guerra civil; se presta atención a los modelos y estrategias implementados y se examinan los problemas por lo que atravesó la construcción y el funcionamiento del Sanatorio para Tuberculosos de Huipulco, sustento clave de la lucha antituberculosa desde tiempo atrás a nivel internacional.

An Uneasy Pleasure: Representing the Dangers of Skin-to-skin Contact in Eighteenth-century London 'The William Bynum Prize Essay'.

This article considers the social function of contagious disease as moderator of class relationships in England during the first half of the eighteenth century and takes into account the ways in which the 'communicability' of the plague, great pox (syphilis) and smallpox (variola) was used by authors to crystallise social interaction and tension along class lines. The essay begins by examining the representation of the plague, syphilis and smallpox in the medical tradition, before shifting its attention to the practice of maritime quarantine, as laid out by Richard Mead in his Short Discourse Concerning Pestilential Contagion (1720). By foregrounding medical writing on contagion through skin contact, I suggest that pornographic texts such as John Cleland's The Memoirs of a Woman of Pleasure (Fanny Hill) (1748) had an interventionist function. Cleland is often charged with sanitising the true horrors of sex work in this period. This article proposes that if we take the time to appreciate the way infectious cutaneous diseases were believed to operate and spread we can recognise the moments in which he not only alludes to disease but invokes it for structural and thematic purposes. In proposing this, I am challenging the dominant interpretation that the problematic realities of eighteenth-century prostitution, especially disease, are subordinated to the narrative's greater interest in erotic pleasure.

[Next-generation vector control]. / La lutte contre les vecteurs : quel avenir ?

Vector control is a cornerstone of vector-borne infectious disease control, a group of emerging and re-emerging diseases of major public health concern at a global scale. The history and evolution of mosquito disease vectors control, mainly based on the use of chemical insecticides, is emblematic of the successes, failures, lessons learned and experiences gained in setting-up and implementing vector control, and of the challenges that pave the way to sustainable disease vector management. This paper provides a non-exhaustive and non-exclusive overview of some of the most promising cutting-edge technical and strategic innovations that are committed to this endeavour, assessing the strength of scientific evidences for proof of concept, perspectives for scaling-up, and expected impact and outcomes in a rapidly changing world.