Malaria and Rome: A History of Malaria in Ancient Italy

by Robert Sallares

  (1585–90) did not make the Pontine region any healthier. Sixtus V

  was brave enough or foolish enough to visit his own bonifications while they were in progress, and his death was attributed by some contemporary authors to tertian fever contracted during his visit.⁸¹

  There is some detailed information available for the demography of the human population of the Pontine Marshes at the time of the last major attempt at drainage before Mussolini finally succeeded, namely the attempt by Pope Pius VI in the late eighteenth century.

  These records show that mortality significantly increased following the drainage operations.⁸² Almost certainly the operations in 160

   produced the same result. Even the reassessments by Traina and Leveau of ancient attitudes towards marshes, which attempt to put them in the most favourable light possible (and in doing so fail to comprehend that many Mediterranean wetlands were rendered almost uninhabitable by malaria in the past), are forced in the end to admit that drainage schemes in antiquity produced limited results.⁸³ Herlihy, discussing the problems of Pisa in the face of malaria during the Renaissance, observed acutely that ‘of course the expenditure of much wealth and energy upon public works does not prove that conditions are salubrious but only that the ⁸⁰ Hackett (1937: 18); Sambon (1901 a: 198).

  ⁸¹ Doni (1667: 139–40); Nicolai (1800: 138).

  ⁸² Corti (1989) for modern demographic research; Nicolai (1800: bks iii and iv) gave a contemporary view of Pius’ bonifications.

  ⁸³ Hackett (1937: 17). Traina (1986: 712) concluded that: tutte le opere di sistemazione idraulica anteriori al XVII secolo, in Occidente, sono delle migliorie più che delle bonifiche vere e proprie; in ogni caso, il mondo antico conosceva la bonifica idraulica, non quella integrale. Leveau (1993: 16) affirmed that ‘ en fait l’Antiquité n’a pas connu le drainage total au sens où nous l’envisageons. Les véritables assèchements ont commencé au XVIIIe siècle et il serait faux de croire que les terres conquises aient été le plus souvent drainées à l’époque romaine puis reconquises par le marais au Moyen Age’.

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  13. The entrance (near Ponte Palatino) to the Cloaca Maxima, ancient Rome’s biggest sewer, complete with modern graffiti. Ancient Rome had drainage problems from the beginning of its history.

  problem is great’.⁸⁴ Lake Velinus, first drained by M. Curius Dentatus in the early third century , was a typical example of the results of drainage in antiquity. Varro commented on how rapidly grass grew on the drained plain. As a result it was famous for animal husbandry, especially horse breeding, but Cicero stated that the drainage of the plain left the soil moist. That is not surprising if it could sustain rapid plant growth. This type of drainage would not have defeated the mosquito vectors of malaria, and might have even favoured them.⁸⁵

  In antiquity networks of cuniculi (underground tunnels connected by vertical shafts to the surface) were constructed in various parts of Etruria and Latium. The character of these waterworks resembles the famous Cloaca Maxima, which was originally constructed to turn a stream running through the Roman Forum into a canal. Pliny the Elder described the large investment of labour ⁸⁴ Herlihy (1958: 47).

  ⁸⁵ Cicero, Letters to Atticus 90.5, ed. Shackleton-Bailey (1965–70): Lacus Velinus a M. Curio emissus interciso monte in Nar〈 em〉 defluit; ex quo est illa siccata et umida tamen modice Rosea. Pratesi and Tassi (1977: 98–103) described the modern environment of the Lake Velinus region; Varro, RR 1.7.10.

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  required for the construction of the sewers of Rome, which he attributed to Tarquinius Priscus.⁸⁶ Both the purpose(s) and date(s) of the cuniculi have been hotly debated. This type of hydraulic technology was widely distributed in central Italy. The view has been expressed that the Etruscans devised it and passed it on to the Latins, although other historians have suggested that it is a mistake to assume Etruscan influence lies behind everything that the Latins did. The largest of the cuniculi, namely the emissaries for the Lago di Nemi and the Lago di Albano, might have had some religious significance, in view, for example, of the tale told by ancient authors of the prophecy that the Romans would not capture Veii until they had drained the Alban Lake.⁸⁷ Some cuniculi are connected to Etruscan roads, although others are linked to Roman villas, while a few are definitely post-classical, but in most cases dating criteria are elusive. In fact, different scholars have placed them in every century from c.800 to c.400 . Ampolo expressed the view that the cuniculi of Veii, which have received the most intense scrutiny, were mainly built in the fifth and fourth centuries , either side of the Roman conquest of Veii, for drainage purposes.

  Veii itself was apparently healthy then (see Ch. 3 above), but that does not necessarily have anything to do with the cuniculi. Ampolo also observed that drainage was particularly important for olive cultivation in Latium in antiquity. Quilici Gigli concluded that the cuniculi of the Velletri region, immediately north of the Pontine Marshes, were more sophisticated than those around Veii and were constructed during the period of intense Roman activity in the Pontine region in the fourth century  (see Ch. 6 below). This is the most plausible solution to the problem, but there are other hypotheses. Attema reckoned that the cuniculi of Velletri were created in the sixth century  to facilitate arable farming. He also discussed Blanchère’s ideas.⁸⁸

  In the nineteenth century de la Blanchère had raised the question of whether the cuniculi played a role in the history of malaria ⁸⁶ Pliny, NH 36.24.104–8 on the sewers of Rome; in NH, 3.16.120 he attributed a canal in the Po delta to the Etruscans.

  ⁸⁷ Livy 5.15.2–16.1, 16.8–11, and Dionysius Hal. AR 12.10–13 on the emissary from the Alban Lake.

  ⁸⁸ Blanchère (1882 a) and (1882 b); Tommasi-Crudeli (1881 a) and (1882); Celli (1933: 12–16, 19–20); Ampolo (1980: 36–8); Potter (1979: 84–7) and (1981: 9–11); Quilici (1979: 322); Nicolet (1988: 57); Attema (1993: 65–76); Thomas and Wilson (1994: 143). Cornell (1995: 164–5) argued that the cuniculi cannot be dated; Quilici Gigli (1997: 194–8).

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  in central Italy in antiquity. However, their geographical distribution was not correlated with the distribution of malaria, which reached its greatest intensity along the coast, but with a particular geology. This can readily be seen by comparing Judson and Kahane’s map of the distribution of the cuniculi with the map of the distribution of malaria in Latium in 1782 given by Bonelli.

  Judson and Kahane argued that most of the cuniculi are associated with a particular type of impermeable soil, namely the brown Mediterranean soil of the mesophytic forest. This pedological formation is most abundant in the southern and western slopes of the Alban Hills and around Veii, overlying volcanic tufo. Consequently Angelo Celli and more recently Franco Ravelli were probably right to argue that the cuniculi were mainly built before the spread of malaria in western central Italy and were not intended as a defence against malaria. The cuniculi were not designed to eliminate malaria, and certainly did not have that effect either in antiquity or more recently. In some cases they might conceivably have even facilitated the spread of malaria, if they were built before that happened, as the commonest view among historians maintains. If the connection with malaria is discarded, various possibilities for the function(s) of the cuniculi remain. Judson and Kahane suggested that most of the cuniculi were intended to improve certain types of badly drained land for agricultural purposes. This has been a popular opinion. However, Franco Ravelli, an expert on irrigation systems, has argued that the cuniculi were intended principally to capture and purify water for drinking purposes. He observed that they are mostly dry today and suggested that they were constructed in a period in the middle of the first millennium  when there was more rainfall than there is today (see Ch. 4. 5 below).⁸⁹

  Another important environmental factor for the larvae of Anopheles mosquitoes
is the degree of salinity or freshness of the water. In Italy in antiquity marshes that were frequently flooded with seawater, such as those around Ravenna, were healthy, while those which did not have any natural or man-made connection with the sea, such as the Pontine Marshes, were pestilential. Similarly in early modern England marshes that were closed off from the sea tended to become breeding grounds for the mosquito ⁸⁹ Bonelli (1966: 678–9); Judson and Kahane (1963); Ravelli and Howarth (1988) and (1989).

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  species A. atroparvus, a vector of malaria.⁹⁰ Vitruvius described the situation in Italy as follows:

  When ditches have been excavated to provide outlets for (marsh) water to the seashore, and the sea rises during storms, overflows into the marshes and mixes the marsh water with seawater, the reproduction of the typical fauna of marshes becomes impossible . . . The Gallic marshes around Altinum, Ravenna, Aquileia, and other towns in such situations, next to marshes, illustrate this point, because they are extraordinarily healthy.

  However, stagnant marshes which do not have outlets either in the form of rivers or ditches, like the Pontine Marshes, putrefy as they stand and emit noxious and pestilential vapours in such places.⁹¹

  Similarly Strabo noted that Ravenna, although situated within marshes and dissected by rivers, received plenty of seawater during the tides, which periodically cleansed the marshes and eliminated ‘bad air’, dusaer≤a in Greek. Other ancient authors also described Ravenna. Sidonius Apollinaris noted that seawater came right up to the city’s gates on one side, while on the other side the water in the channels was extremely dirty. The larvae of Anopheles mosquitoes prefer clear water.⁹² There was a shortage of good drinking ⁹⁰ Dobson (1997). Compare the account in Pausanias 7.2.11, ed. Rocha-Pereira (1989), of how the silting up of the channel next to the city of Myus in Ionia by the river Maiander created an inland marsh cut off from the sea. The marsh became a breeding site for hordes of mosquitoes, forcing the abandonment of the city. This had happened by the time of Strabo 14.1.10.636C. Atarneus also suffered the same fate.

  ⁹¹ Vitruvius 1.4.11–12: Fossis enim ductis aquae exitus ad litus, et mare tempestatibus aucto in paludis redundantia motionibus concitata marisque mixtionibus non patitur bestiarum palustrium genera ibi nasci . . . exemplar autem huius rei Gallicae paludes possunt esse, quae circum Altinum, Ravennam, Aquileiam, aliaque quae in eiusmodi locis municipia sunt proxima paludibus, quod his rationibus habent incredibilem salubritatem. Quibus autem insidentes sunt paludes et non habent exitus profluentes neque flumina neque per fossas, uti Pomptinae, stando putescunt et umores graves et pestilentes in is locis emittunt. The words of the jurist Iuventius Celsus in Digest 17.1.16 are also sometimes quoted as evidence that Ravenna was healthy in the second century : cum Aurelius Quietus hospiti suo medico mandasse diceretur, ut in hortis eius quos Ravennae habebat, in quos omnibus annis secedere solebat, sphaeristerium et hypocausta et quaedam ipsius valetudini apta sua inpensa faceret (since Aurelius Quietus is said to have instructed a doctor, a guest of his, to make (at Quietus’s own expense) a ball-court, a sweating-room, and whatever else would be conducive to his own health, in the doctor’s own gardens at Ravenna which he was accustomed to visit every year). See also Borca (1996) with abundant further bibliography on Ravenna.

  ⁹² Sidonius Apollinaris, Ep. 1.5.5–6 to Heronius; Jordanes, de origine actibusque Getarum 29, 148–51, ed. Mommsen (1882), Monumenta Germaniae Historica. Auctorum Antiquissimorum Tomi v.

  Pars Prior; Martial 3.56; Procopius, BG 1.1.16–23 (discussed critically by Fabbri (1991: 9–10) ); Michelini (1995); Manzelli (1997). Mazzarino’s idea, discussed by Michelini, that Ravenna owed its healthiness to the construction of the port of Augustus there for the Adriatic fleet, is untenable because Vitruvius makes it clear that other towns in the region, such as Aquileia and Altinum, were equally healthy. Consequently a factor specific to Ravenna itself cannot explain the salubrity of the entire region.

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  Rovigo

  Adria

  N

  o

  P

  River

  GRANDE

  BONIFICA

  FERRARESE

  Ferrara

  Comacchio

  A d r i a t i c

  Valli di

  Comacchio

  S e a

  Ravenna

  E M I L I A

  Imola

  PINETA

  DI CLASSE

  Faenza

  Cervia

  Forli

  R O M A G N A

  Cesena

  Rimini

  SAN MARINO

  Stia

  Map 3. Ravenna and Emilia-Romagna

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  water at Ravenna because of these hydrological conditions. Strabo regarded as a marvel the fact that the air over the marshes of Ravenna was healthy.⁹³ This suggests that most marshes in other parts of Italy were not healthy.

  The coastal regions of northeastern Italy and the Po delta became heavily infested with both P. falciparum and P. vivax malaria in the late medieval period, as extensive alluviation gradually isolated towns like Ravenna and its marshes from the sea, thereby changing their chemical composition and altering mosquito breeding sites. Ravenna today is about ten kilometres from the sea, and the waterlogged Roman strata in the town are up to ten metres below the current ground level. Already in late antiquity and the early Byzantine period the immediate vicinity of the town had begun to dry up.⁹⁴ At that time Ravenna had a flourishing medical school which produced a series of commentaries on and Latin translations of the works of the Greek medical writers. It is quite possible that human interference with the natural environment, such as the bonifications attempted by Theoderic at the end of the fifth century , played a role in the deterioration of the situation.

  Doni described Ravenna as afflicted with severe malaria in the seventeenth century.⁹⁵In the eighteenth century Francesco Ginanni wrote a comprehensive study of the natural history of the marshy woodlands in the vicinity of Ravenna. He noted the abundance in the woods in summer of the two species of mosquito that had been named Culex cinereus and Culex fuscus by Linnaeus, and observed that they bit humans frequently. However, it is striking that his account of the mosquitoes of Ravenna is located far away in his large book from his description of the ‘bad air’ of the region; Ginanni completely failed to connect mosquitoes with malaria. Nevertheless he ⁹³ Strabo 5.1.7.213C: πsti m†n oˆn ka≥ toıto qaumastÏn t0n ƒnq3de, tÏ ƒn 1lei toŸß åvraß åblabe∏ß e”nai.

  ⁹⁴ Fabbri (1991: 19) described the developments in the early Byzantine period as follows: in sostanza è una situazione di progressivo inaridimento idrico quello che la città vive nell’alto Medievo: una situazione di sempre più precarie condizioni igienico-ambientali, specialmente favorevoli allo stabilirsi della malaria in forma endemica. Già in queste condizioni si possono ricercare le premesse di fenomeni di depopola-mento e di crisi economia e funzionale. Squatriti (1992) is an interesting account of attitudes to marshes in early medieval Ravenna, but without any serious study of malaria or the relevant ancient sources. The most recent synthesis of Italian demographic history advocates a completely different view, so far as malaria in early medieval Italy is concerned: ‘ la malaria . . . si diffuse in vaste aree della penisola per effetto del degrado ambientale che trasformó in stagni e paludi gran parte delle pianure costiere e molte vallate interne’ (G. Pinto in del Panta et al. (1996: 18).

  ⁹⁵ Cavarra (1993) and Bio (1994) described the medical culture of Ravenna; CIL 11.10 for Theoderic’s activities at Ravenna ( sterili palude siccata); Doni (1667: 86, 89).

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  did accurately describe the environmental conditions that favoured endemic malaria, observing that the marshes of Ravenna tended to dry out in summer each year but retained some moisture, permitting plant growth.�
��⁶ Ginanni described the seasonality of malaria around Ravenna in the eighteenth century as follows:

  The period of considerable danger from bad air in these pine woods usually runs from the summer solstice until the autumn equinox. However, it sometimes varies from year to year, because if the season is very hot, bad air begins as early as May and continues until the middle of October; nevertheless it regularly terminates during the first heavy and repeated autumn rains, which fill the already nearly desiccated beds of adjacent marshes with fresh water.⁹⁷

  Ginanni argued that the ‘air’ of the town of Ravenna itself was healthier than its reputation suggested, although he acknowledged that ‘bad air’ was endemic in the surrounding area. Attempts to defend the reputation of settlements afflicted by malaria are frequently found in Italian local history. Ginanni observed that the unhealthiness of the air did not prevent numerous people living on the rich agricultural land in the vicinity of the Po delta. He even attempted to quantify mortality risks and concluded that the local inhabitants were much less likely to die from an infection of malaria than visitors to the area.⁹⁸ The reasons for that are now known; not only would those who survived childhood infections have developed acquired immunity, but the population of the area also has a high frequency of genetic mutations such as thalassaemia that confer some resistance to malaria (see Ch. 5. 3 below). This is evidence for intense pressure exercised by malaria as an agent of natural selection in the past in this region.⁹⁹ In fact, the distribution ⁹⁶ Ginanni (1774), ch.on Acque (pp. 105–21), chapter on Aere (pp. 122–34), section on mosquitoes (pp. 431–2). Jordanes, de origine actibusque Getarum, 57, shows that the famous pine forest along the coast south of Ravenna, described by Boccaccio, Dante, Byron, and other writers, already existed in late antiquity, since Theoderic encamped ‘about three miles from the city in the place called Pineta’ ( tertio fere miliario ab urbe loco qui appellatur Pineta).

  ⁹⁷ Ginanni (1774: 132): l’aere aliquanto pericoloso di queste Pinete è per l’ordinario dal solstizio di Estate infino all’equinozio di Autunno. Ma varia talora col variar delle annate, perché se calda molto è la stagione, vi principia l’aria pericolosa anche nel Maggio, e continua a mezza Ottobre; regolarmente però ella cessa d’esserlo nelle prime pioggie copiose, e replicate d’Autunno, che riempono d’acque dolci i letti, già quasi prosciugati de’vicini paduli.