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

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 had 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 Âeıma. 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.

Mathematical models of the interaction of P. malariae and P. falciparum in the human bloodstream suggest that P. malariae struggles to establish itself if P. falciparum is already present in an individual.

This explains the situation in tropical countries today. P. malariae has often been judged to be quite rare in environments where P.

falciparum is active all the year round, using the traditional diagnostic technique of microscopic examination of blood smears on slides (although the modern techniques of molecular biology now suggest that it is in fact commoner even in tropical environments than used to be thought). However, the same mathematical models also yield the very important result that if a P. malariae infection occurs before an infection with P. falciparum, then P. malariae can establish itself, very significantly reduce the severity of a subsequent infection with P. falciparum because of cross-species immunological reactions, and outlast P. falciparum.³⁶ The interaction of the two diseases is very significant. Livy tells us that many of the survivors of an epidemic (doubtless involving other diseases as well as malaria) in 174 

ended up with quartan fever.³⁷ This constitutes evidence for the presence of endemic quartan fever in Latium by then. It is likely that frequent infections with P. malariae earlier in that particular year reduced the severity of a major epidemic of falciparum and vivax malaria in the late summer and autumn of that year. The survivorship rate might have actually increased in the short term, contrary to what would have been expected if P. malariae had not been present at all. However, it must