Malaria and Rome: A History of Malaria in Ancient Italy, Robert Sallares [reading a book TXT] 📗

Anopheles mosquitoes. Nevertheless there was always a potential for the spread of malaria in the vicinity because of Tiber floods. The opinion of Meiggs, namely that Ostia must have been healthy during the time of the Roman Empire simply because it was a flourishing town, is an untenable argument from silence.¹⁰⁵ It is very hard to believe that Ostia was perfectly healthy in the second century , at the time when Galen regarded malaria as endemic in the city of Rome itself (see Ch. 8 below), and there certainly are explicit signs that Ostia was at the very least becoming unhealthy in late antiquity. St. Augustine’s mother, Monica, died from malaria at Ostia, after an illness lasting nine days, on the way from Rome back to Africa, while Augustine himself also contracted malaria at Rome.

Justinian’s general Belisarius suffered from a life-threatening fever at Ostia in  536.¹⁰⁶ The cases of Belisarius, Augustine, and his mother are classic illustrations of the general principle that immigrants were more vulnerable than natives in areas where malaria was endemic. The spread of malaria at Ostia intensified in post-classical times, as sediment deposition created and enlarged an alluvial plain on both sides of the river near its mouth, steadily reducing the size of the large early Holocene lagoons behind the coastal barrier on either side of the river. Procopius noted the abandonment of Ostia in favour of Portus on the other side of the Tiber in late antiquity owing to silting of the harbour. Modern research in geomorphology has confirmed that the major extension of the ancient coastline seawards towards its current location has occurred principally since about  1500, when the modern marine-delta area began to move beyond the coastal barrier separating the ancient lagoons from the sea.¹⁰⁷ However, the letters of ¹⁰⁴ Grandazzi (1997: 74–83).

¹⁰⁵ Meiggs (1973: 101, 233).

¹⁰⁶ St. Augustine, Confessions 9.8, 11: decubuit febribus . . . die nono aegritudinis suae . . . anima illa religiosa et pia corpore soluta est (she developed fevers . . . on the ninth day of her illness . . . that religious and holy soul was released from her body); 5.9: ingravescentibus febribus (fevers becoming worse); Procopius, BG 3.19.

¹⁰⁷ LeGall (1953: 24–5, 320–2); Bellotti et al. (1995); Dionysius Hal. AR 3.44; Procopius BG

1.26.3–13.

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St. Peter Damian prove that there was endemic malaria in Ostia as in Rome by the middle of the eleventh century , when he wanted to relinquish the bishopric of Ostia because of the unhealthiness of Ostia (see Ch. 8 below). Consequently environmental changes favourable to the mosquito vectors of malaria had already occurred in the vicinity of Ostia before the major modern progradation of the Tiber delta. The spread of malaria at Ostia was associated with the filling in of the lagoons behind the ancient coastal barrier after they had become isolated from the sea. Early modern writers unanim-ously concurred that the area of the notorious Maccarese swamp north of Ostia was virtually uninhabitable.¹⁰⁸ This state of affairs may go back to antiquity in the light of Silius Italicus’ description of Fregenae, which can be identified with modern Maccarese.¹⁰⁹

Just like the lagoons behind the coastal barrier near Ostia, the Pontine Marshes in southern Latium were also cut off from the sea.

Pliny the Younger confirms Vitruvius’ description of the hydrology of these marshes and indicates that the water table was very high at his villa near Laurentum. Anopheles mosquitoes do not lay their eggs in seawater or water with a high salinity level, although Grassi carried out experiments which showed that their larvae can survive in a 2:1 mixture of fresh water: seawater. Similarly Celli noted that Anopheles larvae did occur in the weaker sulphurous waters of Sezze, a town whose problems with malaria have already been noted. However, they were not found in the strong sulphurous waters of Tivoli in Latium, the famous Aquae Albulae which were reputed in antiquity to be very good for healing wounds, although there must have been mosquito breeding sites somewhere in the neighbourhood, since malaria impeded the operation of the quarry which produced lapis tiburtina near Tivoli in the nineteenth ¹⁰⁸ Hare (1884: i. 40–1) wrote as follows: ‘the peasants do all their field labour here in gangs, men and women together . . . they have…the constantly recurring malaria to struggle against, borne up every night by the poisonous vapours of the marsh, which renders Ostia almost uninhabitable even to the natives in summer, and death to the stranger who attempts to pass the night there’, cf. Tomassetti (1910: ii. 496–507). Knight (1805: 100) wrote that ‘the air is particularly unhealthy, and the town is chiefly inhabited by galley slaves, who work in the salt mines’. Blewitt (1843: 524) wrote that at Ostia ‘during the summer heats . . . the neighbouring coast is severely afflicted with malaria’. Mammucari (1991: 156–7, 162–3) reproduced paintings of the Maccarese forests and marshes by Onorato Carlandi and Cesare Bertolla made before Mussolini’s bonifications.

¹⁰⁹ Silius Italicus 8.575: obsessae campo squalente Fregenae (Fregenae surrounded by a plain overgrown with weeds through neglect).

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century.¹¹⁰ The precise chemical composition of water is very important.

Hackett commented as follows on the complexity of biological phenomena: ‘for the most part the reasons for these secular oscillations in the curve of malaria endemicity are inscrutable, because the internal adjustment of the elements composing a biological situation in dynamic balance is inconceivably complicated’.¹¹¹ His words are still as true today as when they were written (see Ch. 9

below for discussion of the idea of ‘secular oscillations’). Nevertheless research over the last thirty years has made it absolutely certain that the coastal environments of Italy were not static, but were, rather, changing continuously from antiquity right up to the bonifications of modern times. Writing at the end of the last century, Celli was unable to conceive of major environmental changes in the