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

Iberian peninsula. McCormick provides an interesting discussion of alternative hypotheses. The suggestion that thalassaemia was brought to the Mediterranean by the Mongols or Huns is in fact quite impossible because the thalassaemia mutations of East Asian populations are quite different from those of Mediterranean populations (this was not known at the time the idea was proposed because DNA sequencing was not yet possible at that time). How-

⁸⁸ Ascenzi and Balistreri (1977) discussed this question inconclusively.

⁸⁹ Weatherall (1997). About 200 different thalassaemia and 120 different G6PD mutations are now known.

⁹⁰ Ampolo (1976).

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ever, the idea that thalassaemia might have been brought to Italy during the Byzantine period, as part of the internal diaspora of the Byzantine Empire which is the subject of the book containing McCormick’s article, is more plausible. Nevertheless it remains the case that there were substantial population movements in Europe before the Byzantine period, and malaria was active in both Greece and Italy before the Byzantine period. Consequently it is virtually certain that the human genetic response to malaria commenced before the Byzantine period.⁹¹

A skeleton with a probable diagnosis of heterozygosity for b-thalassaemia was excavated at the Roman villa of Settefinestre.

This skeleton might have belonged to an imported slave and is not a direct proof of the presence of malaria there, since thalassaemia is an inherited condition. Nevertheless it is a sign that the slave labour force of the Roman villas in western central Italy was in contact with malaria during the time of the Roman Empire. Marsh vegetation first appears in the palaeobotanical record at Settefinestre in the third century . However this alone cannot be used to date the spread of malaria at Settefinestre because Anopheles mosquitoes do not necessarily require large marshes for breeding, as has already been seen (Ch. 4. 2 above).⁹² The commonest DNA mutation for G6PD deficiency in Mediterranean populations has been identified in the human skeletal remains from the infant cemetery at Lugnano in Teverina in Umbria, dating to the fifth century , using ancient DNA (see Ch. 4. 2 above).⁹³ Undoubtedly over the next few years the application of the techniques of molecular biology to human skeletal remains excavated on archaeological sites will greatly increase our knowledge of the history of these human genetic adaptations to malaria in antiquity.

Both dietary and genetically determined nutritional deficiencies occurred in the past in western central Italy. Both interacted with malaria. The aforementioned work on dietary deficiencies and ⁹¹ Cao et al. (1989); McCormick (1998: 25–31). We can invisage three phases in the spread of thalassaemia and G6PD mutations in Italy: 1. archaic Greek colonization (particularly important in southern Italy, less important in northeastern Italy); 2. further immigration from the eastern Mediterranean in the Byzantine period (probably particularly important in northeastern Italy, around Ravenna); 3. the indigenous spread of antimalarial mutations owing to the pressure of natural selection by P. falciparum malaria in situ (in southern Italy since the fifth century  at least, in northeastern Italy since the medieval period).

⁹² Mallegni and Fornaciari (1985) on the skeleton number 26.203 from Settefinestre, a young woman nearly seventeen years old, diagnosed as suffering from thalassaemia; Celuzza (1993: 25–6, 230).

⁹³ Sallares, et al. (2002).

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malaria was principally directed at the effects of malnutrition on the malaria parasite, without considering its effects on the human host. Thus there was a tendency in some medical literature to argue that malnutrition in the host reduced the severity of malaria infections. It may well be true that the severity of clinical symptoms is reduced if the host is significantly malnourished, because the reproduction rate of the parasites is reduced. However, it is undeniable that malnutrition is bad for the host, and any malaria infection is also bad for the host.⁹⁴ Recent re-evaluations of this problem suggest that the combination of malnutrition and malaria does increase human morbidity and mortality, even if the parasites suffer as well from malnutrition. Zurbrigg argued that acute hunger (as indicated by elevated grain prices) was statistically significantly associated with recurrent severe malaria epidemics in the Punjab between 1868 and 1940. The correlation was strongest in areas of the Punjab where crop failure was mainly caused by drought, thus bearing the closest resemblance to the conditions of semi-arid Mediterranean climate regions. She also argued that a link between severe malaria and starvation was frequently observed in the Punjab. It is likely, even if there is no specific evidence for it, that a similar link occurred in the famines that certainly occurred sometimes in Italy in antiquity, for example the great famine during the Gothic Wars in the sixth century  described by Procopius, which forced people to eat bread made from acorns and to resort to cannibalism.⁹⁵

Tognotti studied the diet of people who lived in areas of holoendemic malaria on Sardinia. The diet of such people was frequently short of meat, fish and dairy products, which often ended up in the towns even where animal husbandry was important. The fundamental component of the diet was bread, accompanied by prickly pears (not available in antiquity), other fruit, legumes, and mushrooms. Researchers on Sardinia felt that malnutrition was positively, not negatively, correlated with malaria.⁹⁶ Similarly researchers who worked in Rome and the Roman Campagna

generally reckoned that poor malnutrition was associated with ⁹⁴ I. A. McGregor in Wernsdorfer and McGregor (1988: i. 753–67).

⁹⁵ Zurbrigg (1994) and (1997); Procopius, BG 2.20.15–33.

⁹⁶ Tognotti (1996: 106) quoted a doctor who said that: ad Orosei…la frequenza dei casi di malaria era in ‘ragione diretta della scarsa alimentazione’. Levi (1945: 19) described the diet of the inhabitants of a region with endemic malaria in Lucania.

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malaria. For example, Celli thought that peasants in the Roman Campagna in the nineteenth century had a very poor diet, eating a lot of maize (not available in antiquity), but not much else, although he thought that shepherds had a somewhat better diet, including both wheat and milk.⁹⁷ Other researchers and travellers reached similar conclusions. Gregorovius