pandemics and epidemics: Rome tween individual and general disease, including a notion of cause and, as a consequence, of treatment These physicians concluded that individual diseases, affecting a single patient, result from the alimentary habits of the patient (even though several individuals using the same diet can suffer of the same disease) Such diseases could be cured by changing the diet and compensating for the insufficiencies or rectifying the improper diet General diseases, affecting an entire group, are provoked, it was thought, by a corruption of the air (the so-called miasmas, that is, impurities floating in the air and resulting from any kind of pollution) They could be cured by applying a proper pharmaceutical therapy that rectified the damages caused by the disease There was no notion of a treatment that could eliminate the cause of the disease The concept of the impact of the environment on the health conditions of a population is further refined in the famous Hippocratic treatise Airs, Waters, Places, traditionally dated to the second half of the fift h century b.c.e and attributed to a physician from the school of Kos A distinction was made between the constant conditions of a place (provoking the endemic diseases, that is, those peculiar to a particular population or place) and the occasional conditions, independent from the place itself, but coming from external factors and causing a general disease The word epidêmios was applied to diseases affecting a large number of patients, without implying any notion of contagion The word constitutes the title of seven books in the so-called Hippocratic collection describing the diseases present in a specific place at a moment of the year and affecting a certain number of patients ROME BY ALAIN TOUWAIDE Historical sources, including those of the Roman historian Livy (64 or 57 b.c.e.–12 or 17 c.e.), the Greek philosopher Dionysius of Halicarnassus (born ca 60 b.c.e.), and the Greek historian Polybius (ca 200–ca 118 b.c.e.), report outbreaks of epidemic diseases in the Roman world shortly after the foundation of the Roman Republic (509 b.c.e.) at a higher frequency than those in the Greek world This apparently higher frequency might be the result of better record keeping; Roman historians relied on the tradition of annales, which recorded the notable events of each year According to the descriptions by the historians who recorded the annales, epidemics often were linked with military expeditions, wars, food shortages, famines, and natural calamities affecting crops In some cases epidemic diseases also were described as coming from cattle While some of these epidemics arose from local conditions, others were introduced into the Roman world from the west or the south The Athenian epidemic in 430 b.c.e might have been carried westward; Rome was struck in 428 b.c.e., according to Livy In Sicily epidemics were said to have been introduced repeatedly by troops from the Athenian expedition of 413 b.c.e through the outbreak in 212 b.c.e among Roman and Carthaginian troops 827 The best-known epidemic in the Roman world was the so-called Antonine plague This was a series of epidemics, including two major outbreaks, in 165 c.e and in 180 c.e., respectively, that struck the Roman population under the Antonine emperors (138–192 c.e.) The disease was introduced into the Roman world from Mesopotamia by the troops from the expedition against the Parthians, which began in 162 c.e and was led by Lucius Aurelius Verus (r 161–169 c.e.) In 165 c.e the Roman troops were affected by the disease and retreated They spread the disease westward to Italy and Rome The epidemic progressed to Gaul and into Germany as far as the Rhine The emperors Lucius Verus and Marcus Aurelius (r 161–180 c.e.) died of the epidemic The Greek physician Galen (129–ca 199 c.e.), who stayed in Rome at that time, escaped from the city and did not return until 169, when he was summoned by the emperor The death toll is thought to have been extremely high throughout the empire Thrace, for example, supposedly lost half of its population Such a mortality rate has been attributed to the high level of urbanization of the Roman Empire, as opposed to the fragmentation of the Greek world in smaller cities The nature of epidemic diseases in Rome has been addressed frequently in medical and historical literature Because the epidemics of 428 b.c.e in Rome supposedly came from the East, and since the so-called plague of Athens of 430 b.c.e has been identified as smallpox, one conclusion is that the Roman epidemic represented the introduction of smallpox to the West A similar hypothesis has been made for the Antonine plague According to this view, this was the second attack of smallpox in the West, which proceeded according to a pattern of diff usion east to west from Mesopotamia Another identification of the plague of Athens as typhoid fever, however, contradicts the traditional history of the diff usion of smallpox The categorization of diseases according to their geographical diff usion, chronological frequency, and statistical importance was initiated by Galen He developed a threefold categorization: First, sporadic diseases are those of a single individual at a certain moment Second, epidemic diseases affect a high number of individuals at the same time in a single place Third, endemic diseases are those that are perpetually common in a single place A few more general notions, probably of popular wisdom, can be found in the Historia naturalis (Natural History), by the Roman scholar Pliny (23–79 c.e.) They include the observation that diseases followed certain patterns; for example, epidemics moved from south to north and almost never in the opposite direction, they did not start during the winter, and they never lasted more than three months As in the Greek world, the cause of epidemic disease was considered to be miasmas, or particles of a corrupted nature floating in the air that people inhaled Therapeutic methods among the Romans reproduced those of Greek medicine but were augmented with a new pharmaceutical strategy: compound medicines associating many ingredients This strategy,