Malaria and Rome: A History of Malaria in Ancient Italy
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He singled out the areas of the Campus Martius, between the Aventine and the Palatine hills, and the area between the Tiber and the Aventine as particularly dangerous (although the summit of the Aventine hill itself was healthy), as well as the area of the Ostian Gate, although the Leonine region was the worst of all.
Doni had no difficulty recognizing the continuous and semitertian fevers described by Asclepiades and Galen (quoted below) as the cause of the problems in his own time.¹⁸ The view expressed by Doni, Donatus, and later writers such as Lancisi, de Tournon, Colin, and North that a dense human population reduces the frequency of malaria is an instance of a correlation that does not necessarily indicate causation.¹⁹ Of relevance here is the standard view in statistics that the fact that two sets of data are correlated does not prove that one of them is causing the other.
Since most people in the early modern period chose, if possible, to live in relatively healthy areas, most areas of dense habitation ¹⁷ Doni (1667: 8–9): Quaecunque loca crebris aedificiis ambiuntur, atque editiora sunt, et in Septentrio-nem, atque Orientem spectant, et longius a Tiberi absunt, salubriora: vice versa quae seiuncta sunt, et remota a frequentioribus tectis, situque sunt humili, ac maxime in convallibus; tum propiora Tiberi, in Meridiem, atque Occasum solis spectantia, minus salubria a peritioribus habentur.
¹⁸ Doni (1667: 6). Doni’s work was partly written in response to the sixteenth century book of Alessandro Petronio (translated into Italian by Paravicini (1592) ), a doctor from Cività Castellana who worked in Rome. He acknowledged that quotidian fevers and lethargy were common in Rome ( si vedano spesso—Paravicini (1592: 200) ), although he thought that semitertian fevers were rare, but nevertheless suggested that fevers as a whole were much less frequent in Rome than the ailments upon which he wished to concentrate, namely excess of humours in the head ( capiplenio) and indigestion! He wished to concentrate on ailments which could possibly be influenced by his focus on diet, lifestyle, and exercise. Of course headache and indigestion are much commoner than major infectious diseases in all human populations, but the fact remains that only major infectious diseases have significant demographic consequences!
¹⁹ e.g. Donatus (1694: bk iii. ch. 21, pp. 273–4): Quaedam alia de Vaticano memorantur, haud sane firmis auctoritatibus nixa, praeter frequentia in eo campo sepulchra, et insalubre Coelum, quod noster aetas propter Civium, tectorumque frequentiam salubrius experitur.
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30. Via della Reginella, connecting Via del Portico d’Ottavio to Piazza Mattei, is a relic of the old Jewish Ghetto in Rome, a district that was walled until 1848. Despite its location, close to the River Tiber, and the poor living standards of its inhabitants, there was little or no malaria there.
This may be attributed to the densely packed houses, with no gardens between them, and so a lack of mosquito breeding sites.
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were fairly healthy. However, that does not prove that a high human population density by itself is enough to defeat malaria, and the comments of the ancient medical writers (to be discussed shortly) indicate that that was not the case in ancient Rome. The classic example given in early modern discussions of malaria in Rome was the Jewish ghetto. This district remained walled until 1848. It had a high population density and was free of malaria even though it was situated close to the Tiber, in the vicinity of Isola Tiberina. The key to understanding the situation in the ghetto is not the human population density as such, or the height of the buildings in it, but the absence of gardens in between the buildings. Irrigated gardens where Romans grew vegetables during the heat of the Mediterranean summer made a significant contribution to feeding the population of the city. However, they also furnished ideal breeding sites for mosquitoes, and this was explicitly noted in both ancient and early modern literary sources. For example, the anonymous author of a discourse on mal’aria written near the end of the eighteenth century observed that gardens were one of the deadliest producers of ‘bad air’ and noted the abundance of mosquitoes in gardens.²⁰ Similarly in antiquity Pliny the Elder noted the abundance of mosquitoes ( culices) in well-watered gardens and recommended measures to try to drive them away.²¹ This is a crucial piece of evidence because it identifies irrigated gardens, particularly those in which trees or bushes provided resting and hiding places for mosquitoes, as important breeding sites for mosquitoes in and around the city of Rome.²² The elimination of gardens from many parts of Rome during the development of the modern city, as it changed in the direction of the modern situation in which most people live in blocks of flats without gardens, was an important factor in the eradication of malaria from Rome.
The observations of the early modern authors as a whole prove the importance of malaria not necessarily as a regular direct agent of mortality (although there certainly were some major epidemics from time to time), but as a determinant of settlement patterns ²⁰ Anon. (1793: 56): zanzare, e tutti gli animali indicatori e propagatori della corruzione. Tommasi-Crudeli (1892: 127) discussed the connection between malaria and market gardening in Rome.
²¹ Pliny, NH 19.58.180: infestant et culices riguos hortos, praecipue si sint arbusculae aliquae; hi galbano accenso fugantur (Mosquitoes also infest irrigated gardens, especially if there are some shrubs; they are driven away by burning the resin of galbanum.).
²² Pliny, NH 36.24.123 noted the abundant supplies of water to gardens in Rome.
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in the city of Rome (at a time when the urban population was much smaller than during the Roman Empire). For example Gian Girolamo Lapi argued in the eighteenth century that intermittent fevers were no more frequent in Rome than in many other Italian cities and that it was safe to visit Rome in summer, even though he acknowledged that the air of the Roman Campagna was very unhealthy. However, even Lapi admitted that a majority of the citizens of Rome ( la maggiore parte) were afraid of ‘bad air’, being unwilling to sleep in the villas in and around the city or even to move from one district of the city to another.²³ Malaria forced people to congregate in the healthier districts of the city, at a time when the unoccupied sections of the city amounted to about two thirds of the area within the Aurelian walls. Ellis Cornelia Knight mentioned a law in early modern Rome banning landlords from expelling tenants during the summer, so that no one should be forced to end up living in the dangerous parts of the city in summer.
Her words clearly show malaria acting as a determinant of settlement patterns even though she believed, like Lapi, that those parts of the city where people congregated were safe.
Seldom any rain falls during the months of July and August, and the air is perfectly calm . . . mephitic exhalations abound at this season of the year in the neighbourhood of any stagnant waters, and in the unfrequented parts of Rome, particularly over the catacombs. The few inhabitants who remain there are subject to fevers and agues, but their number is very inconsiderable; and no danger is to be apprehended where fires are kept up by any considerable number of houses. For this reason the cottagers of the Campagna usually leave their dwellings during summer, and sleep, either at Rome under the porticoes of the palaces and public edifices, or in the towns nearest to their little possessions. If they persist in remaining too long they get agues; and the greatest number of patients in the Roman hospitals, for the months of July, August, and September, consists of peasants from the circumiacent fields . . . During this month [sc. September], and the two preceding it, noone can be compelled to change his dwelling; as there is a law to that effect, for the purpose of preventing the pernicious consequences supposed to ensue, from the necessity of leaving a well-inhabited part of the town for one less salubrious.²⁴
Many later authors followed Doni’s approach to medical geography. Léon Colin produced a map of the frequency of malaria among the French troops stationed in various quarters of Rome in ²³ Lapi (1749: 11–16).
²⁴ Knight (1805: 4).
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31. The Colosseum lay in a valley between the Esquiline, Palatine, and Caelian hills in Rome. Such lowlying localities were favourable to malaria in the past.
1864.²⁵ Celli cited the work of the doctor Maggiorani, who as recently as 1870 ‘considered not only the valleys of Rome, such as the Forum, the Colosseum, the Prati di Castello and the villa Borghese, to be centres from which arose pestiferous exhalations, but also declared that the populated hills of Rome were not immune from fever’. Celli also drew attention to a map of malaria in Rome in 1884 produced by two doctors, Lanzi and Torrigiani, who listed ‘even the quarters of Trastevere, Pincio, Viminale, Esquilin, Celio, Testaccio, Palatine’ as malarious.²⁶ This all too brief survey of literature on the medical geography of the city of ²⁵ A. Gabelli, Prefazione in Monografia (1881: l–li); North (1896: 238–42); Colin (1870: 88–9); Marchiafava and Bignami (1894: 23–7) on Colin’s classification of the malarial fevers which he observed in Rome. Beauchamp (1988: 258) made the observation that malaria is spreading today in developing countries which are experiencing rapid urbanization.
²⁶ Celli (1933: 167); Pinto (1882: 19–24) also described the healthy and unhealthy parts of Rome.
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Rome proves that numerous parts of the city were affected by malaria in the fairly recent past. If we return to reconsider the already quoted text of Cicero, de republica, on the healthy location of Rome, it becomes evident that Cicero, in spite of his attack on Rullus for wanting to settle army veterans in the pestilential territory of Salpi in Apulia (see Ch. 10 below), was really no more interested in the health of the masses than he was in any other aspects of their wel-fare. When he described Rome as healthy, he was only thinking of the hilltop districts where the aristocracy lived, and ignored the lowlying areas where many poor Romans lived and worked.²⁷
This conclusion, at least, should not surprise historians with more conventional interests in political history.
To evaluate Cicero’s statement, it also must be remembered that owing to sediment deposition in the intervening valleys by Tiber floods and deliberate infills in both antiquity and modern times, the hills of Rome were more impressive as hills in the early stages of Roman history than they are today.²⁸ The Esquiline, the highest of the seven hills of Rome, is only 65 metres above sea level, although the Janiculum (usually not counted among the seven hills) reaches 82 metres above sea level. Baccelli categorized the unhealthy lowland areas as having a topsoil which was always damp, though not actually waterlogged, with evaporation from the surface, overlying a stratum of impermeable cappellaccio, with substantial run-off of water from the hills of Rome, in other words a geology resembling that in areas of the Campagna Romana where cuniculi were constructed in antiquity.²⁹ In the early eighteenth century Lancisi had already noticed a correlation between certain types of soil and unhealthy locations. Scobie pointed out that the streets of ancient Rome were wet owing to the overflow from fountains and public water basins. This probably also created breeding sites for mosquitoes right inside the city. Moreover it is easy to underestimate the number of lakes inside the city. The lake which Nero constructed for his Golden House ( Domus Aurea) should not be allowed to dis-tract attention from all the other numerous bodies of water within the limits of the city, including for example the Velabrum, which was still navigated by boat at the end of the first century , and ²⁷ Galen noted that at Pergamum in Asia Minor the rich lived on the hill (Nutton (2000 b: 70) ).
²⁸ Ammerman (2000).
²⁹ Baccelli (1881: 156–7).
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Table 8. Distribution of lakes within the city of Rome
Region
Name of region
Number
number
of lakes
1
Porta Capena
81
2
Caeleomontium
65
3
Isis et Serapis
65
4
Templum Pacis
71
5
Exquiliae
74
6
Altosemita
73
7
Via Lata
76
8
Forum Romanum Magnum
120
9
Circus Flaminius
120
10
Palatium
90
11
Circus Maximus
20
12
Piscina Publica
80
13
Aventinus
89
14
Transtiberim
180
Source: Curiosum urbis Romae regionum, xiiii. Libellus de regionibus urbis Romae, ed. Nordh (1949). There are minor discrepancies in the figures between the Curiosum and the other list, the Notitia, and the repetition of certain figures may also raise some doubts about the accuracy of the data, but there is no doubt about the overall impression.
the lacus Caprae in the Campus Martius.³⁰ According to late antique catalogues of the features of the fourteen regions of the city of Rome, there were no less than 1,204 lakes within the city.
Hirsch in his monumental pioneering book on disease epidemiology was correct to state that ‘the Campagna di Roma . . . together with the city of Rome, forms one of the chief seats of the disease’, although it was on its way out of the city by then. By the end of the nineteenth century it was thought that infection no longer occurred within the walls of Rome itself, although numerous cases were still brought to hospitals in the city, such as the Santo Spirito, from the Roman Campagna, where it was still endemic. As recently as 1886, 66% of the communities of Latium were still classified as suffering from endemic malaria.³¹ Perhaps the most interesting account of a specific malaria epidemic in early modern Rome was given by Lancisi. In the second book of his famous work, published in 1717, ³⁰ Varro, de lingua latina 5.43; Quilici (1979: 72–5).
³¹ Hirsch (1883: i. 214); Celli (1900: 86); the Inchiesta Jacini gave detailed information on the distribution of malaria in Latium.
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32. Ospedale di Santo Spirito, the main hospital in Rome which received cases of malaria in the past. Also visible are the Lungotevere in Sassia river walls. The construction of effective river walls in the nineteenth century prevented malaria by stopping the River Tiber from flooding surrounding areas and so creating mosquito breeding sites.
he described at length the severe malaria epidemic which reached its height in August–September 1695. It affected principally the districts of the city closest to the Tiber, such as Trastevere and the Vatican. Lancisi mentioned all the main factors which have already been noted as prerequisites for malaria epidemics in the city of Rome (heavy rainfall which increased the volume of the Tiber, a Tiber flood, south winds, water overflowing from fountains, etc.). He noted that visitors to Rome were particularly badly affected, and described in detail the symptoms of the malarial fevers observed in that year.³² During the time of the Roman Empire the district of Trastevere, where the port facilities of ancient Rome along the Tiber have recently been discovered, according to newspaper reports, was intensively occupied. Procopius states that the Romans constructed so many houses in Trastevere that the ³² Lancisi (1717: esp. 193–7, 204–7, 244–6). Corradi (1865: ii. 278–84) reckoned that the epidemic of 1695 was a combination of malarial and petecchial fevers, and followed Haeser’s description of it as febbre intermittente gastrico-tifico (on which see Ch. 5. 2).
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33. The Roman Forum was another lowlying district of the city of Rome, where there was a risk of malaria infection according to Horace.
River Tiber appeared to be in the middle of the city, instead of marking the boundary with hostile Etruscan territory as it h
ad done in the earliest stages of Roman history.³³
In the light of the evidence of the medical geography of early modern Rome, it is not surprising that Rome was also troubled in antiquity. The Roman Forum was a dangerous place in antiquity, just as it was in 1870 according to Maggiorani. Horace described it as a place where one was likely to be infected with malaria in summer.³⁴ Similarly Juvenal testifies to the prevalence of malaria in Rome.³⁵ His evidence suggests that mixed infections with three different species of human malaria in the same person at the same time were common in ancient Rome, just as they were in those parts of Italy in more recent times where malaria was endemic. The importance of this piece of information is that it indicates a very ³³ Procopius, BG 1.9.10: ojk≤aß sucn¤ß ƒn cwr≤8 t‘ åntipvraß deim3menoi mvson t[ß pÎlewß tÏ toı Tibvridoß pepo≤hntai eıma. Dionysius Hal. AR 4.13.3–5 described the great extent of the suburbs of Rome.
³⁴ Horace, Epist. 1.7.8–9: officiosaque sedulitas et opella forensis adducit febris et testamenta resignat (and courteous officiousness and work in the Forum bring on fevers and open wills) .
³⁵ Juvenal, Sat. 4.56–7: iam letifero cedente pruinis autumno, iam quartanam sperantibus aegris (Already deadly autumn is giving way to winter frosts, and sick people are now hoping for a quartan fever.), cf. Juvanal, 10.221.
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high transmission rate of malaria. Ill people in ancient Rome hoped for a quartan fever in late autumn because it signified a return to good health. Quartan fevers caused by P. malariae outlast more dangerous infections with P. falciparum and P. vivax, when all three are present at the same time in the same person, even though the quartan periodicity is masked by the more powerful rhythms of P. falciparum and of P. vivax, which both invade a larger proportion of erythrocytes than P. malariae does.