The 1919-21 influenza pandemic in Greenland

In Alaska, the 1918-20 influenza pandemic was devastating, with mortality rates up to 90% of the population, while in other arctic regions in northern Sweden and Norway mortality was considerably lower. We investigated the timing and age-patterns in excess mortality in Greenland during the period 1918-21 and compare these to other epidemics and the 1889-92 pandemic. We accessed the Greenlandic National Archives and transcribed all deaths from 1880 to 1921 by age, geography, and cause of death. We estimated monthly excess mortality and studied the spatial-temporal patterns of the pandemics and compared them to other mortality crises in the 40-year period. The 1918-21 influenza pandemic arrived in Greenland in the summer of 1919, one year delayed due to ship traffic interruptions during the winter months. We found that 5.2% of the Greenland population died of the pandemic with substantial variability between counties (range, 0.1% to 11%). We did not see the typical pandemic age-pattern of high young-adult mortality, possibly due to high baseline mortality in this age-group or remoteness. However, despite substantial mortality, the mortality impact was not standing out relative to other mortality crises, or of similar devastation reported in Alaskan populations.

Secular trends of suicide risk for residents in mainland China (2004 to 2019): An updated age-period-cohort analysis

BACKGROUND

The overall suicide rate in China has dropped substantially since the 1990s, but a slowdown in the decrease and even a reversing trend was observed in specific groups in recent years. This study aims to investigate the latest suicide risk in mainland China by using the age-period-cohort (APC) analysis.

METHOD

This population-based multiyear cross-sectional study included Chinese ages 10 to 84 years using data from the China Health Statistical Yearbook (2005-2020). Data were analyzed by the APC analysis and intrinsic estimator (IE) technique.

RESULTS

The data satisfactorily fit the constructed APC models. The cohort effect indicated a high risk of suicide among people birth in 1920-1944 and a sharp decline in the 1945-1979 cohort. The lowest risk occurred in the 1980-1994 cohort before a sharp increase in generation Z (birth years in 1995-2009). The period effect showed a declining trend since 2004. The age effect indicated that the suicide risk increased over time, except for a gradual decline from age 35 to 49. The suicide risk increased greatly in adolescents and reached the highest among the elderly.

LIMITATIONS

The aggregated population-level data and the non-identifiability of the APC model could result in bias in the accuracy of results in this study.

CONCLUSIONS

This study successfully updated the Chinese suicide risk from the age, period and cohort perspective using the latest available data (2004-2019). The findings enhance the understanding of suicide epidemiology and provide evidence supporting policies and strategies at the macro-level for suicide prevention and management. Immediate action is needed to focus on a national suicide prevention strategy that targets generation Z, adolescents and the elderly which will require a collaborative effort by government officials, public/community health planners and health care agencies.

Mapping the plague through natural language processing

Pandemic diseases such as plague have produced a vast amount of literature providing information about the spatiotemporal extent, transmission, or countermeasures. However, the manual extraction of such information from running text is a tedious process, and much of this information remains locked into a narrative format. Natural Language processing (NLP) is a promising tool for the automated extraction of epidemiological data, and can facilitate the establishment of datasets. In this paper, we explore the utility of NLP to assist in the creation of a plague outbreak dataset. We produced a gold standard list of toponyms by manual annotation of a German plague treatise published by Sticker in 1908. We investigated the performance of five pre-trained NLP libraries (Google, Stanford CoreNLP, spaCy, germaNER and Geoparser) for the automated extraction of location data compared to the gold standard. Of all tested algorithms, spaCy performed best (sensitivity 0.92, F1 score 0.83), followed closely by Stanford CoreNLP (sensitivity 0.81, F1 score 0.87). Google NLP had a slightly lower performance (F1 score 0.72, sensitivity 0.78). Geoparser and germaNER had a poor sensitivity (0.41 and 0.61). We then evaluated how well automated geocoding services such as Google geocoding, Geonames and Geoparser located these outbreaks correctly. All geocoding services performed poorly - particularly for historical regions - and returned the correct GIS information only in 60.4%, 52.7% and 33.8% of all cases. Finally, we compared our newly digitized plague dataset to a re-digitized version of the plague treatise by Biraben and provide an update of the spatio-temporal extent of the second pandemic plague outbreaks. We conclude that NLP tools have their limitations, but they are potentially useful to accelerate the collection of data and the generation of a global plague outbreak database.

Archiving time series sewage samples as biological records of built environments

This commentary encourages the regular archiving of nucleic-acid-stabilized serial samples of wastewaters and/or sewage. Stabilized samples would facilitate retrospective reconstitution of built environments’ biological fluids. Biological time capsules would allow retrospective searches for nucleic acids from viruses such as SARS-CoV-2. Current resources for testing need not be diverted if samples are saved in case they become important in the future. Systematic storage would facilitate investigation into the origin and prevalence of viruses and other agents. Comparison of prevalence data from individual and clinical samplings with community wastewater would allow valuable comparison, contrast and correlation among different testing modalities. Current interest is focused on SARS-CoV-2, but archived samples could become valuable in many contexts including surveys for other infectious and chemical agents whose identity is not currently known. Archived time series of wastewater will take their place alongside other biological repositories and records including those from medical facilities, museums, eDNA, living cell and tissue collections. Together these will prove invaluable records of the evolving Anthropocene.

Understanding what shapes disease control: An historical analysis of foot-and-mouth disease in Kenya

Interpreting the interplay between politics, social demographics and epidemiology is essential for understanding how a disease's occurrence and control evolve over time. Foot-and-mouth disease (FMD) virus was first detected in Kenya in 1915 and serotyped in 1932. This review aims to describe and appraise initiatives to control FMD in Kenya since its independence from British rule in 1964, using information from the scientific literature. We describe the historical dynamics of FMD epidemiology in the country and determine socio-political factors that have shaped the control strategies used. PubMed, Scopus, CAB abstracts, Science Direct, Web of Science and Google Scholar were used to search and retrieve papers, using predetermined search criteria encompassing FMD, Kenya and disease control programme descriptors. In total 1234 papers were identified and screened for relevance using the World Health Organization's guidelines for rapid review. Ultimately 69 references from this search were included, and information extracted and consolidated. These papers highlight that following independence, there was a structured effort to control FMD consisting of a compulsory subsidised vaccination programme in the Rift Valley with movement controls and quarantine when outbreaks occurred. This programme led to an initial decrease in recorded FMD outbreaks. However, endemic circulation continued and this programme was discontinued due to multiple factors, including political deprioritisation and changes in the structure of veterinary services. Only low levels of active surveillance have been applied since 1964; most surveillance is passive and relies on outbreak reports. Currently control focuses on outbreak management and a mixture of public- and privately-funded vaccination. This review highlights critical drivers influencing disease control programme implementation including veterinary service structure, the active participation of stakeholders with farming systems and availability of affordable and matched FMD vaccine. Additionally, it appraises the availability of historical information and draws attention to gaps in the historical record.

Introducing activities of the Archives of Infectious Diseases History (AIDH) project: Historical epidemiology

The AIDH is a project as a historical epidemiology. The AIDH aims to collect, maintain, and manage past epidemiological materials and to offer these materials to persons who are interested in the history and in the fields of tropical medicine and global health. In this paper, we introduce our purpose and activities and show a hypothesis about lymphatic filariasis with Brugia malayi in Japan as a case of historical epidemiology. We hope to build fruitful ties between historians and scholars of tropical medicine and global health workers through an interdisciplinary approach to the history of control of infectious diseases.

Testing the waters: Syndemic gastrointestinal distress in Lambaréné, Gabon, 1926-1932

This paper argues that a cluster of pathogens, hazardous labor conditions, and environmental constraints rendered chronic gastrointestinal distress fatal for African laborers living near Lambaréné, Gabon during the 1920s. Application of syndemic theory and epidemiological methods on patient records at Hospital Schweitzer, the central hospital of the region, explain how a seemingly simple diagnosis of chronic gastrointestinal distress belied a complex web of worsening biological and social outcomes for laborers in the tropical forests of central Gabon. An analysis of the syndemic suffering of GI patients reveals how the dysentery pathogen became tied to the peaks and valleys of the colonial economy, and in particular, the colonial extraction of tropical hardwoods. These processes culminated in the summer of 1929 when the highest number of timber exports coincided with the deadliest months of dysentery outbreak for the patient population at Hospital Schweitzer. This case study proposes syndemics as an effective theoretical framework to research historical precedents of the entanglement of people, pathogens, and illness.

Historical trends in breast Cancer among women in China from age-period-cohort modeling of the 1990-2015 breast Cancer mortality data

Background

Evidence on historical trends extracted embedded in recent data can advance our understanding of the epidemiology of breast cancer for Chinese women. China is a country with significant political, socioeconomic, and cultural events since the 1900s; however, no such studies are reported in the literature.

Methods

Age-specific mortality rates of breast cancer during 1990–2015 in China were analyzed using APC modeling (age-period-cohort modeling) method. Net effect from birth cohort was derived to measure cancer mortality risk during 1906–1990 when no mortality data were collected, and net effect from time period was derived to measure cancer mortality risk during 1990–2015 when data were collected. Model parameters were estimated using intrinsic estimator, a novel method to handle collinearity. The estimated effects were numerical differentiated to enhance presentations of time/age trend.

Results

Breast cancer mortality rate per 100,000 women increased from 6.83 in 1990 to 12.07 in 2015. After controlling for age and period, the risk of breast cancer mortality declined from 0.626 in 1906–10 to − 1.752 in 1991–95 (RR = 0.09). The decline consisted of 3 phases, a gradual phase during 1906–1940, a moderate phase with some fluctuations during 1941–1970, and a rapid phase with large fluctuations during 1971–1995. After controlling for age and cohort, the risk of breast cancer mortality increased from − 0.141 in 1990 to 0.258 in 2015 (RR = 1.49) with an acceleration after 2005. The time trends revealed by both the cohort effect and the period effect were in consistency with the significant political and socioeconomic events in China since the 1900s.

Conclusions

With recent mortality data in 1990–2015, we detected the risk of breast cancer mortality for Chinese women over a long period from 1906 to 2015. The risk declined more than 90% from the highest level in 1906–10 to the lowest in 1990–95, followed by an increase of 49% from 1990 to 2015. Findings of this study connected historical evidence with recent data, supporting further research to exam the relationship between development and risk of breast cancer for medical and health decision-making at the population level and prevention and treatment at the individual level.

Historical trends in suicide risk for the residents of mainland China: APC modeling of the archived national suicide mortality rates during 1987-2012

PURPOSE

Distinctive and dramatic changes in the history of China with a rapid suicide decline in recent years present an opportunity to investigate the risk of suicide. In this study, we investigated suicide risk with a historical perspective with archived data to inform suicide research and prevention policies and strategies.

METHOD

Documented age-specific suicide mortality rates in 1987-2012 were decomposed into age, period, and cohort effect using APC-modeling method and intrinsic estimator (IE) technique. The estimated effects were further analyzed by numerical differentiation.

RESULTS

The data satisfactorily fit the constructed APC models. Cohort effect indicated that suicide risk in China fluctuated at very high levels during 1903-1967, followed by a sharp decline during 1968-1977, and reached the lowest level in 1983-1987 before increased again. Period effect confirmed the declining trend since 1987. Three sunny cohorts with reduced suicide risk and four cloudy cohorts with increased risk were, respectively, associated with significant cultural, social, political, and economic events in China since the 1900s.

CONCLUSIONS

The mega trends in the suicide risk at the population level are closely related to significant historical events in China. Suicide is anticipated to increase because of the growing risk for the young cohorts (particularly young females) as the country further develops. Study findings suggest the significance of national strategies for suicide prevention and control, including maintenance of social harmony and stability, provision of more opportunities for development, enhancement of social integration, and restriction of suicide facilitating factors.

At the intersection of medical geography and disease ecology: Mirko Grmek, Jacques May and the concept of pathocenosis

Environmental historians are not sufficiently aware of the extent to which mid twentieth-century thinkers turned to medical geography-originally a nineteenth-century area of study-in order to think through ideas of ecology, environment, and historical reasoning. This article outlines how the French-Croatian Mirko D. Grmek (Krapina, 1924-Paris, 2000), a major thinker of his generation in the history of medicine, used those ideas in his studies of historical epidemiology. During the 1960s, Grmek attempted to provide, in the context of the Annales School's research program under the leadership of Fernand Braudel, a new theoretical framework for a world history of disease. Its development was inspired by several sources, most notably the French-American Jacques M. May (Paris 1896-Tunisia, 1975), who was then pioneering an opening up of medical geography and movement towards the concept of disease ecology. The cornerstone of Grmek's "synthetic approach" to the field was the notion of "pathocenosis". The diverse uses of this notion in the course of time-from his early agenda focused on a longue durée history of diseases in Western Antiquity to his last, relating to the new epidemiological threat of (re)emerging infectious diseases, specifically HIV/aids-enables us firstly, to note how concepts of ecology sat uneasily alongside those of medical geography; secondly, to assess the reach and limits of his theoretical contribution to historical epidemiology; and thirdly, to understand better the uneven fortunes of his concept of pathocenosis at the end of the twentieth and beginning of the twenty-first centuries.

The geography of smallpox in England before vaccination: A conundrum resolved

Smallpox is regarded as an ancient and lethal disease of humans, however very little is known about the prevalence and impact of smallpox before the advent of vaccination (c.1800). Here we use evidence from English burial records covering the period 1650-1799 to confirm a striking geography to smallpox patterns. Smallpox apparently circulated as a childhood disease in northern England and Sweden, even where population densities were low and settlement patterns dispersed. However, smallpox was a relatively rare epidemic disease in southern England outside the largest cities, despite its commercialised economy and the growing spatial interconnectedness of its settlements. We investigated a number of factors hypothesised to influence the regional circulation of smallpox, including exposure to naturally occurring orthopox viruses, settlement patterns, and deliberate preventative measures. We concluded that transmission was controlled in southern England by local practices of avoidance and mass inoculation that arose in the seventeenth and eighteenth centuries. Avoidance measures included isolation of victims in pest houses and private homes, as well as cancellation of markets and other public gatherings, and pre-dated the widespread use of inoculation. The historical pattern of smallpox in England supports phylogenetic evidence for a relatively recent origin of the variola strains that circulated in the twentieth century, and provides evidence for the efficacy of preventative strategies complementary to immunisation.

Racial inequality in the annual risk of Tuberculosis infection in the United States, 1910-1933

Tuberculosis (TB) mortality rates in the USA fell rapidly from 1910 to 1933. However, during this period, racial disparities in TB mortality in the nation's expanding cities grew. Because of long delays between infection and disease, TB mortality is a poor indicator of short-term changes in transmission. We estimated the annual risk of TB infection (ARTI) in 11 large US cities to understand whether rising inequality in mortality reflected rising inequality in ARTI using city-level TB mortality data compiled by the US Department of Commerce from 1910 to 1933. We estimated ARTI for African-Americans and whites using pediatric extrapulmonary TB mortality data for African-Americans and whites in our panel of cities. We also estimated age-adjusted pulmonary TB mortality rates for these cities. We find that the ratio of ARTI for African-Americans vs. whites increased from 2·1 (95% CI = 1·7, 2·4) in 1910 to 4·2 (95% CI = 3·4, 5·2) in 1933. This change mirrored the increasing inequality in age-adjusted pulmonary TB mortality during this period. These findings may reflect the combined effects of migration, inequality in access to care, increasing population density, and racial residential segregation in northern cities during this period.

Beyond the Cut Hunter: A Historical Epidemiology of HIV Beginnings in Central Africa

In the absence of direct evidence, an imagined "cut hunter" stands in for the index patient of pandemic HIV/AIDS. During the early years of colonial rule, this explanation goes, a hunter was cut or injured from hunting or butchering a chimpanzee infected with simian immunodeficiency virus, resulting in the first sustained human infection with the virus that would emerge as HIV-1M. We argue here that the "cut hunter" relies on a historical misunderstanding and ecological oversimplification of human-chimpanzee (Pan Troglodytes troglodytes) interactions that facilitated pathogenic transmission. This initial host shift cannot explain the beginnings of the HIV/AIDS pandemic. Instead, we must understand the processes by which the virus became transmissible, possibly between Sangha basin inhabitants and ultimately reached Kinshasa. A historical epidemiology of the late nineteenth and twentieth centuries, provides a much-needed corrective to the major shortcomings of the cut hunter. Based on 62 oral historical interviews conducted in southeastern Cameroon and archival research, we show that HIV emerged from ecological, economic, and socio-political transformations of the late nineteenth and twentieth centuries. The gradual imposition of colonial rule built on and reoriented ecologies and economies, and altered older patterns of mobility and sociality. Certain changes may have contributed to the initial viral host shift, but more importantly, facilitated the adaptation of HIV-1M to human-to-human transmission. Our evidence suggests that the most critical changes occurred after 1920. This argument has important implications for public health policy, underscoring recent work emphasizing alternative pathways for zoonotic spillovers into human beings.

An unholy disease in the Holy Land: the history of anthrax between the Jordan River and the Mediterranean Sea (1909-2012)

The history of recorded cases of anthrax in human beings and animals from 1909 to 2012 in the area between the Jordan River and the Mediterranean Sea is reviewed. The disease was endemic until the middle of the 20th century, but the incidence decreased thereafter, with only sporadic cases from the 1980s onwards. Human cases have not been diagnosed in the region since 1984 and the number of episodes of animal disease has reduced to less than one per year. This decline is mostly due to the disruption of the infective cycle by improved veterinary control, including vaccination, treatment and outbreak management. A policy of reactive vaccination for 10 years of affected herds and herds grazing in their proximity has been applied. No new outbreaks have been observed in such herds after the cessation of vaccination, despite continued grazing on the same sites, so it is assumed that spore survival in such areas is shorter than 10 years. This is independent of the soil composition, which is calcareous throughout most of the relevant area. However, reemergence of anthrax, even after decades, has occurred following disturbance and heavy rainfall.