Endemic (epidemiology) in the context of "Shingles"

The fall of the Western Roman Empire, also called the fall of the Roman Empire or the fall of Rome, was the loss of central political control in the Western Roman Empire, a process in which the Empire failed to enforce its rule, and its vast territory was divided among several successor polities. The Roman Empire lost the strengths that had allowed it to exercise effective control over its Western provinces; modern historians posit factors including the effectiveness and numbers of the army, the health and numbers of the Roman population, the strength of the economy, the competence of the emperors, the internal struggles for power, the religious changes of the period, and the efficiency of the civil administration. Increasing pressure from invading peoples outside Roman culture also contributed greatly to the collapse. Climatic changes and both endemic and epidemic disease drove many of these immediate factors. The reasons for the collapse are major subjects of the historiography of the ancient world and they inform much modern discourse on state failure.

In 376, a large migration of Goths and other non-Roman people, fleeing from the Huns, entered the Empire. Roman forces were unable to exterminate, expel or subjugate them (as was their normal practice). In 395, after winning two destructive civil wars, Theodosius I died. He left a collapsing field army, and the Empire divided between the warring ministers of his two incapable sons. Goths and other non-Romans became a force that could challenge either part of the Empire. Further barbarian groups crossed the Rhine and other frontiers. The armed forces of the Western Empire became few and ineffective, and despite brief recoveries under able leaders, central rule was never again effectively consolidated.

An epidemic (from Greek ἐπί epi "upon or above" and δῆμος demos "people") is the rapid spread of disease to a large number of hosts in a given population within a short period of time. For example, in meningococcal infections, an attack rate in excess of 15 cases per 100,000 people for two consecutive weeks is considered an epidemic.

Epidemics of infectious disease are generally caused by several factors including a change in the ecology of the host population (e.g., increased stress or increase in the density of a vector species), a genetic change in the pathogen reservoir or the introduction of an emerging pathogen to a host population (by movement of pathogen or host). Generally, an epidemic occurs when host immunity to either an established pathogen or newly emerging novel pathogen is suddenly reduced below that found in the endemic equilibrium and the transmission threshold is exceeded.

The Atlantic slave trade or transatlantic slave trade involved the transportation by slave traders of enslaved African people to the Americas. European slave ships regularly used the triangular trade route and its Middle Passage. Europeans established a coastal slave trade in the 15th century, and trade to the Americas began in the 16th century, lasting through the 19th century. The vast majority of those who were transported in the transatlantic slave trade were from Central Africa and West Africa and had been sold by West African slave traders to European slave traders, while others had been captured directly by the slave traders in coastal raids. European slave traders gathered and imprisoned the enslaved at forts on the African coast and then brought them to the Western hemisphere. Some Portuguese and Europeans participated in slave raids. As the National Museums Liverpool explains: "European traders captured some Africans in raids along the coast, but bought most of them from local African or African-European dealers." European slave traders generally did not participate in slave raids. This was primarily because life expectancy for Europeans in sub-Saharan Africa was less than one year during the period of the slave trade due to malaria that was endemic to the African continent. Portuguese coastal raiders found that slave raiding was too costly and often ineffective and opted for established commercial relations.

The colonial South Atlantic and Caribbean economies were particularly dependent on slave labour for the production of sugarcane and other commodities. This was viewed as crucial by those Western European states which were vying with one another to create overseas empires. The Portuguese, in the 16th century, were the first to transport slaves across the Atlantic. In 1526, they completed the first transatlantic slave voyage to Brazil. Other Europeans soon followed. Shipowners regarded the slaves as cargo to be transported to the Americas as quickly and cheaply as possible, there to be sold to work on coffee, tobacco, cocoa, sugar, and cotton plantations, gold and silver mines, rice fields, the construction industry, cutting timber for ships, as skilled labour, and as domestic servants. The first enslaved Africans sent to the English colonies were classified as indentured servants, with legal standing similar to that of contract-based workers coming from Britain and Ireland. By the middle of the 17th century, slavery had hardened as a racial caste, with African slaves and their future offspring being legally the property of their owners, as children born to slave mothers were also slaves (partus sequitur ventrem). As property, the people were considered merchandise or units of labour, and were sold at markets with other goods and services.

A pandemic (/pænˈdɛmɪk/ pan-DEM-ik) is an epidemic of an infectious disease that has a sudden increase in cases and spreads across a large region, for instance multiple continents or worldwide, affecting a substantial portion of the human population. Widespread endemic diseases with a stable number of infected individuals such as recurrences of seasonal influenza are generally excluded as they occur simultaneously in large regions of the globe rather than being spread worldwide.

Throughout human history, there have been a number of pandemics of diseases such as smallpox. The Black Death, caused by the Plague, caused the deaths of up to half of the population of Europe in the 14th century. The term pandemic had not been used then, but was used for later epidemics, including the 1918 H1N1 influenza A pandemic—more commonly known as the Spanish flu—which is the deadliest pandemic in history. The most recent pandemics include the HIV/AIDS pandemic, the 2009 swine flu pandemic and the COVID-19 pandemic. Almost all these diseases still circulate among humans though their impact now is often far less.

The second plague pandemic was a major series of epidemics of plague that started with the Black Death, which reached medieval Europe in 1346 and killed up to half of the population of Eurasia in the next four years. It followed the first plague pandemic that began in the 6th century with the Plague of Justinian, which ended in the 8th century. Although the plague died out in most places after 1353, it became endemic and recurred regularly. A series of major epidemics occurred in the late 17th century, and the disease recurred in some places until the late 18th century or the early 19th century. After this, a new strain of the bacterium gave rise to the third plague pandemic, which started in Asia around the mid-19th century.

By the early 19th century, the threat of plague had diminished, though it was quickly replaced by the spread of another deadly infectious disease in the first cholera pandemic, beginning in 1817, the first of several cholera pandemics to sweep through Asia and Europe during the 19th and 20th centuries. One of the last epidemics to strike the Balkans during the second plague pandemic was Caragea's plague, between 1813 and 1814. The Swiss explorer Johann Ludwig Burckhardt witnessed the plague epidemics that ravaged Hejaz and Egypt between 1812 and 1816. He wrote: "In five or six days after my arrival [in Yanbu] the mortality increased; forty or fifty persons died in a day, which, in a population of five or six thousand, was a terrible mortality."Malta had its second most severe plague epidemic in the epidemic of 1813–1814, which killed around 4,500 people.