Malaria and Rome: A History of Malaria in Ancient Italy (29 page)

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Demography of malaria

but are not so frequent in Latium and Tuscany. The problem arises of whether thalassaemia was introduced into Italy by Greek colonists in the eighth century  or alternatively had been present in human populations in Italy since the Neolithic period.⁸⁸ These two possibilities are not necessarily mutually exclusive, since it is now known that numerous independent mutations for thalassaemia (and G6PD deficiency) in response to malaria have occurred in many different parts of the world.⁸⁹ Nevertheless, since high frequencies of thalassaemia in mainland Italy are mainly concentrated in regions that were colonized by Greeks, it is likely that Greek colonization did indeed play a critical role in the spread of thalassaemia in Italy. In view of Ampolo’s convincing arguments about the free movement of individuals (e.g. Demaratus of Corinth) and groups from state to state in archaic central Italy, there is little doubt that there were plenty of opportunities for gene flow between populations in the archaic period.⁹⁰ Nevertheless the fact that different genotypes conferring degrees of resistance to malaria attained high frequencies in different regions demonstrates that Latium and Tuscany had a different population history in antiquity from the other areas in question, never having been colonized by Greeks or Phoenicians. Presumably the original Greek colonists of Magna Graecia brought common mutations for thalassaemia and G6PD deficiency with them from Greece. It has been suggested that the two commonest mutations for b-thalassaemia in Mediterranean populations were both spread by colonization.

According to this hypothesis the b+IVS nt 110 mutation occurred in Greece and was then spread to southern Italy by Greek colonists, while the b°39 mutation originated in the Levant and was carried westwards by Phoenician colonists to North Africa, Sardinia, and the 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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Demography of malaria

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 wrote as follows:

If you live among them, you will see, too often, hunger-stricken human beings coming out of this paradise to meet you . . . [the peasant] would starve if it were not for the meal of the Indian corn [sc. maize], which is his sole nutriment.⁹⁸

North carried out a short experiment which suggested to him that ‘a few ounces of well-cooked red meat, and a liberal allowance of good red wine, will have an effect, equal, if not superior, to a large dose of quinine’.⁹⁹ North’s experiment was not a double blind test, as is generally expected in modern medical research, and his conclusion undoubtedly understates the seriousness as a disease of malaria in non-immune individuals. In fact, the belief in the value of red meat and red wine against malaria, a disease of red blood (cells), was ultimately yet another instance of sympathetic magic.

Other similar experiments yielded completely different results.

For example, in 1897 Cirio, who had made his fortune in the fruit-canning industry, brought a colony of non-immune farming families from the Veneto in the north of Italy to the Pontine territory and provided them with very large rations of meat, wine, and other commodities to test this theory.¹⁰⁰ Although the results of the experiment were disastrous, they do not necessarily exclude the possibility that malnutrition might exacerbate the severity of malarial infections, perhaps particularly in individuals with some degree of immunity. The increasing use of quinine, especially after the Italian government made it available to all free of charge by ⁹⁷ Celli (1900: 170–2); Mallegni and Fornaciari (1985) found that the skeletons from Settefinestre had a high zinc content and a low strontium content, indicative of a diet rich in meat and short of vegetables. They rightly interpreted these results in terms of a pastoral economy in the Maremma in late antiquity. Ciuffoletti and Guerrini (1989: 97–100) described the traditional diet of the inhabitants of the Maremma. Similarly Arlacchi (1983: 176–9) commented on the very poor nutritional state in the nineteenth and early twentieth centuries of the inhabitants of the Crotonese, a population severely affected by malaria. He noted the consequence that the average height of these people was 10 cm less than the regional average, cf. Douglas (1955: 130).

⁹⁸ Gregorovius (1902: 82).

⁹⁹ North (1896: 161).

¹⁰⁰ Snowden (1999: 33–4); Hackett (1937: 28).

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Demography of malaria

a series of laws passed in the years 1900–4, a few years after North’s research, was probably the most important single factor in the reduction of mortality from malaria in Italy.¹⁰¹ Nevertheless North’s primitive experiment and the general experience of observers at the time indicate how important malnutrition may have been in the past. De Felice, after considering comments on the matter in the writings of the early modern Roman agronomists, concluded that animals were better fed, on the lush pastures of Latium, than most of the local inhabitants!¹⁰²

Of course the early modern period had its own peculiar problems, which were not necessarily shared by antiquity. Gregorovius attributed the poor diet of peasants in Latium to the economic effects of high taxation. Reliance on maize, imported from the western hemisphere after Columbus, introduced the possibility of pellagra. This was not a problem in antiquity.¹⁰³ Nevertheless the general impression given, namely that malnutrition did significantly aggravate the effects of malaria in the Roman Campagna in the early modern period, is very important. The balance of probability is that the sort of malnutrition now being revealed by the Italian studies of the Vallerano skeletal population in the second century  increased both mortality and morbidity from malaria in western central Italy in Roman times. One vital but imponderable question about antiquity is the question of how well fed were slaves.

There is no way of knowing if the recommendations for rations given by the ancient Roman agronomists were widely followed in practice, but even if they were, slaves might still have had an impoverished diet. In his recent discussion of this topic, de Martino concluded that the recommendations of the agronomists would have given slaves a very poor diet:

It can be inferred, based on the sources, that there was without doubt a ¹⁰¹ Florence Nightingale noted how it emerged during a papal visit to the Santo Spirito hospital in Rome in January 1848 that patients were actually only being given half the quantities of drugs prescribed to them in order to save money, in spite of the hospital’s enormous endowments (Keele (1981: 183) ). The fact that drugs were known does not necessarily mean that they were available in the right quantities (and at the right price) to those who needed them. That is why the laws of 1900–3 were so important. Corso (1925) gives the text of these laws. Pope Innocent III founded the Santo Spirito hospital near Castel S.

Angelo in 1198 (
Regula ordinis S. Spiritus in Saxia
, ed. Migne,
Pat. Lat.
vol. 217, cols 1130–57).

¹⁰² De Felice (1965: 96): ‘
Per tutto il Settecento e buona parte dell’Ottocento si può dire che in gran parte del Lazio il bestiame era meglio alimentato della massa dei contadini
’.

¹⁰³ Livi-Bacci (1986) on pellagra.

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great scarcity of animal protein, insufficient fats and a lack of very important vitamins, C and D, with A being very rare.¹⁰⁴

A clinical trial in Papua New Guinea concluded that symptomatic episodes of
P. falciparum
malaria were about 30% less frequent in young children who received vitamin-A supplements than in those who received placebos.¹⁰⁵ Much older writers also raised the question of the importance of nutrition in relation to malaria. Carmichael described one case that was reported in the Necrologi
(or death registers) of Milan, in which the death of a fifty-year-old man on 7 August  1479 was attributed by one doctor to ‘simple tertian fever with a bad regimen’. A second doctor who also examined this case concluded that the poor diet must have played a significant role, since tertian fevers alone were usually not fatal.¹⁰⁶