Impact of the 1742–1743 Plague Epidemic on Global Excess Deaths and Social Dynamics in the City of Córdoba and Along the Camino Real Between Buenos Aires and Lima

Abstract

The 1742–1743 plague epidemic profoundly impacted populations along the Camino Real, the main colonial trade route connecting Buenos Aires and Lima, with Córdoba, Argentina, as a critical focal point. This research examines the multidimensional repercussions of the epidemic, emphasizing its demographic, social, and economic consequences. Utilizing parish records as primary sources, this study quantifies the excess mortality, revealing a dramatic increase, with death rates in Córdoba peaking at 12 times the pre-epidemic average in May 1743. Marginalized groups, particularly enslaved and Indigenous populations, were disproportionately affected, which exacerbated existing social inequalities. Through a comprehensive analysis of historical data, this study contributes to understanding epidemic responses in colonial Latin America, illuminating how public health crises intersect with demographic and socio-economic structures. The findings provide insights that are relevant to contemporary public health perspectives on crisis management and resilience, highlighting how historical epidemics offer valuable understanding into the social dynamics of health emergencies.

1. Introduction

The 1742–1743 plague epidemic stands as a pivotal event that wrought extensive demographic upheaval along the Royal Road (Camino Real), the principal conduit for commerce between Buenos Aires and Lima. Historically, epidemics, notably plagues, have profoundly shaped human societies, a phenomenon that is well-documented from medieval Europe onwards [1]. Despite extensive documentation within the European milieu, the ramifications of plagues during the 18th century in South American colonies remain comparatively neglected in scholarly discourse [2]. This study endeavors to delineate the demographic and social ramifications of the plague across this vital trade route, postulating that the confluence of human and commodity circulation may have precipitated the rapid propagation of the disease [3].

Archival evidence indicates that the plague devastated populations across various locales, including Córdoba and Buenos Aires, severely disrupting economic and social structures. Contrary to regions where climatic variables or global trade dynamics typically facilitated disease transmission, this epidemic was likely exacerbated by intra-regional movements and the indispensable exchange of goods along the Royal Road, linking the Viceroyalty of the Río de la Plata to the Peruvian highlands [4,5].

Given the rudimentary nature of 18th-century record-keeping and the complex interplay of religious, cultural, and local factors influencing cause-of-death records, employing excess mortality as a metric provides a robust and reliable estimate of the epidemic’s impact. As highlighted by Arrizabalaga (1999) [6], recorded death causes in pre-industrial societies were often social constructions rather than clinical diagnoses. Moreover, the lack of laboratory verification and the prevalent underreporting of diseases further muddles the historical epidemiological landscape, as noted by Simonsen (2006) [7]. This methodological approach leverages the observed mortality during the epidemic against the expected mortality under normative conditions, enabling a quantitative assessment of the epidemic’s breadth and its skewed impact on marginalized groups, including enslaved and Indigenous populations.

This analytical framework not only transcends the limitations of historical data but also enriches our comprehension of how epidemics sculpt public health and socio-economic frameworks, yielding insights that are pertinent to contemporary public health strategies. Despite the profound impacts of this epidemic, there remains a paucity of comprehensive scholarly investigations examining its regional influence along the Royal Road. Limited microanalytical studies like those conducted by Celton (1993) in Córdoba and Fanchín in Buenos Aires have provided valuable localized insights [8], yet the broader regional implications remain underexplored. Additionally, Jesuit records from the Chiquitos missions note an outbreak in San Miguel (Bolivia) at the end of 1741, suggesting a pattern of epidemic spread across multiple interconnected locations along the Royal Road [9,10]. Documented accounts, including those by Frías and Montserrat (2017) [11], attest to the disease’s virulent nature and the community’s reliance on spiritual and traditional remedies, reflecting a limited understanding of its transmission dynamics, as shown in Figure 1.

This research adopts a multidimensional approach to scrutinize the demographic, social, economic, and cultural repercussions of the plague, utilizing parish death records, population censuses, and other documentary sources to quantify its mortality and evaluate the epidemic’s broader social disruptions. The objective of this study is to calculate the excess mortality associated with the plague epidemic and explore its broader social implications, highlighting the resilience of local communities amid extensive mortality and social upheaval. A comprehensive analysis of the plague’s historical impact along this critical colonial trade route not only enhances our understanding of similar historical events but also provides a foundation for examining relationships between epidemics, population dynamics, and socio-economic structures in colonial Latin America.

2. Materials and Methods

To assess the demographic impact of the 1742–1743 plague epidemic on Córdoba, excess mortality was utilized as a principal metric. Given the diagnostic constraints of 18th-century medical practices, this measure offers a robust approach by encompassing both direct mortality from the disease and indirect mortality linked to the epidemic’s social and healthcare disruptions.

2.1. Estimation of Excess Mortality

Excess mortality estimation was based on data from parish records in Córdoba, selected for their consistency and reliability. This model contrasts death counts during the epidemic with those observed in pre- and post-epidemic periods, enabling a precise quantification of mortality attributable to the plague.

2.2. Review of Primary Sources

The primary data source comprised parish death records from Córdoba, categorized into three comparative temporal phases [12]:

• Pre-epidemic period: January 1740–December 1741;
• Epidemic period: January 1742–December 1743;
• Post-epidemic period: January 1744–December 1745.

To address incomplete entries in death records, such as a missing age or marital status, additional records, including baptismal and marriage registers from the same parishes, were consulted to confirm and supplement individual data points.

2.3. Comparative and Cross-Referencing Analysis

Mortality data from parish records were cross-referenced with complementary sources, including local census data and colonial administrative records, to provide a comprehensive view of the region’s social and economic conditions during and following the epidemic. In particular, the 1744 census data yielded critical insights into demographic shifts and the population structure post-epidemic.

2.4. Considerations on the Record-Keeping System

While a detailed examination of the period’s record-keeping systems lies outside this study’s scope, the methodological approach taken herein addresses and adjusts for inconsistencies between absolute death counts and relative mortality estimates. This process supports cross-regional comparisons and strengthens the interpretative framework for understanding excess mortality in relation to socio-economic impacts of the epidemic.

Given the inherent challenges in relying on historical data, excess mortality was selected as an objective and quantifiable measure that captures the epidemic’s cumulative impact on population dynamics, reflecting both direct and indirect consequences on public health.

3. Results

3.1. Epidemiological Characteristics of the Plague in Córdoba

3.1.1. Comparative Mortality

Table 1. Comparative mortality rates during the pre-epidemic, epidemic, and post-epidemic phases of the 1742–1743 plague in the city of Córdoba.

Month	Pre Peste 1740/1	Plague 1742/3	Post Peste 1744/5
January	10 (8.3%)	29 (7.6%)	13 (9.5%)
February	7 (5.8%)	18 (4.7%)	12 (8.8%)
March	4 (3.3%)	18 (4.7%)	15 (10.9%)
April	5 (4.1%)	46 (12.1%)	8 (5.8%)
May	4 (3.3%)	48 (12.6%)	9 (6.6%)
June	7 (5.8%)	33 (8.7%)	10 (7.3%)
July	10 (8.3%)	21 (5.5%)	14 (10.2%)
August	9 (7.4%)	41 (10.8%)	9 (6.6%)
September	11 (9.1%)	31 (8.2%)	12 (8.8%)
October	12 (9.9%)	38 (10.0%)	15 (10.9%)
November	22 (18.2%)	34 (8.9%)	6 (4.4%)
December	20 (16.5%)	23 (6.1%)	14 (10.2%)
Total	121 (100%)	380 (100%)	137 (100%)

illustrates the mortality dynamics across the pre-epidemic, epidemic, and post-epidemic periods, evidencing a pronounced increase in deaths during the plague outbreak in Córdoba (1742–1743). Specifically, the mortality rose to 3.1 times that of the pre-epidemic period, with a peak in May 1743 reaching 12 times the pre-epidemic level. In total, 380 deaths occurred during the epidemic compared to 121 and 137 deaths in the pre- and post-epidemic phases, respectively, underscoring the epidemic’s acute impact on the population.

3.1.2. Mortality by Sex, Age, and Marital Status

Table 2. Mortality distribution by sex, age, and marital status.

	Pre-Plague 1740/1	Plague 1742/3	Post-Plague 1744/5
Gender, female %	51.2%	53.7%	53.3%
Age, adult (≥18) %	66.9%	83.9%	67.9%
Marital status, single %	43.8%	18.4%	33.6%

presents the mortality distribution by sex, age, and marital status, revealing differential impacts across these demographic factors. Female mortality slightly increased during the epidemic, reaching 53.7% of deaths compared to 51.2% pre-epidemic and 53.3% post-epidemic, suggesting a marginally higher vulnerability among women. A notable shift in age distribution indicates that adults (≥18 years) comprised 83.9% of deaths during the epidemic, compared to 66.9% pre-epidemic and 67.9% post-epidemic, while child mortality decreased from 33.1% pre-epidemic to 14.7% during the outbreak. Marital status data show a marked decline in the proportion of single individuals affected, from 43.8% pre-epidemic to 18.4% during the epidemic, possibly due to varying exposure risks, alongside a high percentage of missing data (73.9%) likely resulting from documentation challenges amid the health crisis.

3.1.3. Social Structure and Mortality

The mortality distribution by social status in

Table 3. Mortality distribution by social status.

Social Status	Pre Peste 1740/1	Plague 1742/3	Post Peste 1744/5
Noble	23 (19.0%)	19 (5.0%)	51 (37.2%)
Enslaved	39 (32.2%)	135 (35.5%)	20 (14.6%)
Free	18 (14.9%)	52 (13.7%)	9 (6.6%)
In Service	11 (9.1%)	43 (11.3%)	8 (5.8%)
Poor/Foreigner	5 (4.1%)	10 (2.6%)	11 (8.0%)
Poor	13 (10.7%)	53 (13.9%)	3 (2.2%)
Orphan	-	2 (0.5%)	-
Total	121 (100%)	380 (100%)	137 (100%)

highlights a significant vulnerability among enslaved individuals, who accounted for 35.5% of deaths during the epidemic. This marked increase compared to the pre- (32.2%) and post-epidemic periods (14.6%) underscores the severe impact on marginalized groups, particularly those in servitude. Additionally, mortality among the poor and service workers rose during the epidemic, reflecting the broader social crisis and exacerbated inequalities. In contrast, noble mortality decreased during the epidemic, followed by an increase post-epidemic, indicating varying levels of resilience across social classes.

3.1.4. Ethnic Composition

Table 4. Ethnic distribution of mortality in Córdoba.

Ethnicity	Pre Peste 1740/1	Plague 1742/3	Post Peste 1744/5
Spanish	22 (18.2%)	64 (16.8%)	29 (21.2%)
Creole	23 (19.0%)	74 (19.5%)	22 (16.1%)
Indigenous/African	58 (47.9%)	138 (36.3%)	36 (26.3%)
Pardo	9 (7.4%)	89 (23.4%)	44 (32.1%)
Mulatto	5 (4.1%)	1 (0.3%)	4 (2.9%)
Mestizo	4 (3.3%)	14 (3.7%)	2 (1.5%)
Total	121 (100%)	380 (100%)	137 (100%)

details the mortality by ethnicity, showing that Indigenous- and African-descent populations were disproportionately affected during the epidemic, constituting over 60% of mortality cases. The increased mortality among the “pardo” group (23.4% during the epidemic) further suggests a significant role of ethnic structures in the vulnerability and resilience patterns observed, with the data reflecting deep-rooted social and ethnic disparities in susceptibility to the epidemic’s impact.

4. Discussion

This study provides a comprehensive analysis of the 1742–1743 plague epidemic’s demographic and social impacts on Córdoba and the Royal Road, highlighting excess mortality as a pivotal indicator. The data show a mortality increase of up to 3.1 times the pre-epidemic level, peaking at 12 times the epidemic level in May 1743. This sharp rise underscores both the epidemic’s severity and its amplification of social vulnerabilities within the affected population. Historical data further indicate that the epidemic’s reach extended beyond Córdoba, significantly affecting Buenos Aires and various rural regions along the Royal Road, marking a widespread demographic crisis with socioeconomic disruptions across a broad geographical area [11].

Our findings reveal that marginalized groups, notably enslaved individuals and Indigenous populations, were disproportionately impacted, representing a substantial proportion of recorded deaths. This pattern highlights the epidemic’s dual impact: it not only intensified mortality but also deepened pre-existing social inequalities. Elevated mortality rates within these groups reflect increased exposure and vulnerability due to limited access to resources and occupational roles within the labor force, which heightened their infection and mortality risks. A notable rise in mortality among enslaved individuals—from 32.2% pre-epidemic to 35.5% during the epidemic—demonstrates the epidemic’s profound effect on this group. Over 60% of the recorded deaths involved individuals of African or Indigenous descent, underscoring the influence of ethnic composition on vulnerability and resilience. These findings emphasize the importance of integrating social and economic dimensions into historical epidemic assessments, offering insights relevant to modern public health strategies.

Furthermore, integrating parish death records with census data sheds light on shifts in the population structure. Adults accounted for a significantly higher proportion of deaths during the epidemic, a demographic shift that is likely linked to varied exposure risks across age groups and occupational roles. This shift suggests how epidemics alter population composition and may lead to subsequent social reorganization.

4.1. Mortality Rate Analysis

The mortality rate analysis further contextualizes the impact of this epidemic. The First Census (1778) [13], ordered by the viceroyalty, documented 7283 inhabitants in Córdoba, excluding rural areas, and was aimed at informing colonial administration. In contrast, the Second Census (1813) [14], conducted post-independence, recorded approximately 8500 inhabitants, with a significant female majority (61%), possibly reflecting the effects of war and male migration. Based on these censuses, we calculated an average annual growth rate of 0.44% from 1778 to 1813, allowing for retrospective population estimates: approximately 6158 in 1740 and 6296 in 1745. The mortality rates across biennial periods reveal the epidemic’s substantial impact:

• Pre-epidemic biennium (1740/1): 9.82 deaths per 1000 inhabitants annually;
• Epidemic biennium (1742/3): 30.51 deaths per 1000 inhabitants annually, marking a 200% increase;
• Post-epidemic biennium (1744/5): 10.88 deaths per 1000 inhabitants annually, indicating partial demographic recovery.

This pattern parallels the COVID-19 pandemic, during which Córdoba’s pre-pandemic mortality rate (2018/9) was approximately 8.6 per 1000 inhabitants. In the 2020/2021 biennium, the pandemic led to a marked increase in mortality, with an estimated 8.6% excess mortality. Although the mortality rates had declined by 2022, this increase underscored the pandemic’s impact on Córdoba’s demographic structure, disproportionately affecting vulnerable groups and exacerbating pre-existing inequalities—a trend consistent with observations in other regions and countries [15].

This comparison between the 1742–1743 plague and the COVID-19 pandemic illustrates how historical and contemporary epidemics trigger sharp increases in mortality during crises, followed by stabilization phases that leave enduring demographic and social effects. Monitoring the mortality across crisis phases is crucial to understanding these events’ full scope and for developing effective resilience and recovery strategies for future health emergencies.

The use of excess mortality as a key measure in this study aligns with modern epidemiological methodologies applied in contemporary epidemic research. This approach captures the extensive disruptions that epidemics impose on health and social systems. Despite the limitations of historical data, it enables valuable cross-temporal comparisons—such as with COVID-19—enhancing our understanding of epidemic impacts over time [16].

By addressing a significant gap in the historiography of South American epidemics, this study contributes to a deeper understanding of the relationships between disease, demographic transitions, and socio-economic structures in colonial Latin America. The findings underscore broader implications for contemporary public health, particularly the critical role of resilience and adaptability in mitigating the effects of public health crises [17].

The analysis of mortality trends, combined with the resilience demonstrated by affected populations, underscores Córdoba’s ability to recover and adapt following the epidemic. The 1778 census provides an invaluable window into the long-term transformations within Córdoba’s jurisdiction [18], highlighting the resilient reconfiguration of its agrarian and demographic structure several decades after the devastating plague epidemic of 1742–1743. Although the epidemic significantly increased mortality and altered social dynamics, census information shows diversification in production units and a recovery in the population structure, suggesting successful adaptation to the challenges posed by the epidemic. This resilience and adaptability underscore not only Córdoba’s recovery capacity but also how catastrophic events can influence the long-term evolution of social and economic structures.

4.2. Environmental and Socioeconomic Transmission Factors

The patterns observed in this epidemic echo historical findings on plague dynamics in the Americas. As noted by Ruiz (2001), natural plague foci have long existed in regions of South America, including areas of northern Peru and semi-arid zones in northeastern Brazil, where social and environmental factors play critical roles in plague outbreaks [19]. Much like these other foci, the plague in Córdoba and along the Royal Road may have been exacerbated by conditions that fostered the spread of infectious agents, particularly through the movement of people and goods along this essential trade route. Ruiz’s observations on plague-prone regions underscore how environmental disruptions—such as changes in rainfall, deforestation, and shifts in rodent populations—often contribute to the reemergence of plague by altering human interactions with disease reservoirs and vectors.

In addition, Rosso (2011) [20] explores how Indigenous populations in Jesuit reductions faced epidemic threats that were exacerbated by changes in their lifestyle and social structures, where the enforced sedentary existence in missions increased susceptibility to contagion. Within these reductions, a complex interplay of Indigenous and European health practices often influenced the spread and management of epidemics, a dynamic observable in various areas along the Royal Road. Similarly, Serrano (2016) [21] highlights how climatic and ecological variables in colonial Veracruz affected the transmission of the matlazahuatl epidemic, with warmer regions demonstrating different vulnerability patterns compared to colder, high-altitude areas. Serrano’s analysis suggests that variability in temperature and humidity could influence not only the spread of disease but also community resilience through adaptive responses to environmental stressors.

The extensive socioeconomic interactions along the Royal Road, combined with a dense network of trade and migration, likely intensified the epidemic’s spread and its impact on vulnerable populations. By considering both environmental and social factors, this study illuminates how specific historical contexts, such as the Royal Road, may have uniquely contributed to epidemic dynamics, amplifying mortality and revealing underlying inequalities. Integrating such historical insights enriches our understanding of the impacts of epidemic, enabling a more nuanced approach to crisis management in public health.

4.3. Limitations and Methodological Considerations

The application of excess mortality as a key metric aligns with contemporary epidemiological methodologies, capturing the extensive disruptions that epidemics impose on health and social systems. However, the limitations of historical data must be considered, as pre-industrial death records often lack diagnostic specificity and are influenced by cultural, religious, and social interpretations, which may not align with modern diagnostic standards. As Bernabeu-Mestre et al. (2003) [22] point out, the recorded causes of death in pre-industrial societies are frequently shaped by social and religious beliefs rather than by clinical accuracy, posing challenges to mortality attribution.

Despite these limitations, excess mortality remains a robust tool for estimating overall mortality when precise causes are difficult to establish. It captures both direct deaths from disease and indirect mortality stemming from social and healthcare system disruptions, thereby offering a comprehensive view of an epidemic’s demographic and social impact. This methodological approach emphasizes the need for resilient social systems to mitigate the impacts of epidemics and highlights the enduring importance of public health infrastructure that is capable of addressing diverse vulnerabilities. Integrating historical insights with contemporary public health strategies underscores the necessity for adaptive responses to health crises, accounting not only for immediate biological effects but also for long-term social and economic repercussions.

Epidemics, as complex social phenomena, exert effects that extend beyond their biological impact. By reshaping daily life and social structures, they prompt societies to reassess individual and collective responses to crisis [23]. This reassessment exposes underlying social inequalities and resilience patterns, underscoring the enduring need for resilient communities that are capable of responding to future global health threats [24].

5. Conclusions

This study reveals the profound demographic and social impacts of the 1742–1743 plague epidemic on Córdoba and the Royal Road, with the excess mortality reaching up to 12 times the pre-epidemic levels at its peak. The epidemic disproportionately affected marginalized groups, such as enslaved individuals and Indigenous populations, exposing and exacerbating pre-existing social inequalities. By using excess mortality as a key measure, this study aligns with modern epidemiological methods and provides a historical perspective on the impacts of epidemics that remain relevant today.

Although the analysis is limited by the quality of historical records, the findings underscore the transformative social effects of epidemics, which extend beyond biological events to influence population dynamics and societal structures. Ultimately, examining these historical patterns enhances our preparedness and response to future health crises, a fact which reinforces the need for resilient and equitable public health strategies.