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

northern Europe inside humans.¹¹¹ P. vivax existed in Britain in the past in the Westminster 481 n. 101); Strabo 5.2.10.228C noted the predominance of emmer over naked wheats in the mountains of Umbria in his own time: [Ó ∞Ombrik&] ‹pasa d’ eÛda≤mwn Ó c*ra, mikr‘ d’

øreiotvra, zei9 m$llon ∂ pur‘ toŸß ånqr*pouß trvfousa (the whole of Umbria is prosperous, but rather hilly; it feeds men with emmer rather than wheat); De Felice (1965: 121); ch.

on Movimento dei prezzi delle derrate alimentari, in Monografia (1881: 350, 354–6); Toubert (1973: i.

244) noted references to far in the Statuti della Provincia Romana from the thirteenth and fourteenth centuries ; Perrino and Hammer (1984).

¹¹⁰ Cited by Mutapi et al. (2000), who observed themselves that there appear to be immunological cross-reactions between malaria and schistosomiasis.

¹¹¹ Malaria parasites generally overwinter in human hosts rather than vector mosquitoes (Hackett (1937: 209–12) ) because sporozoites tend to degenerate after about a month inside the salivary glands of mosquitoes (Garnham (1966: 369) ). This traditional view has been confirmed and reinforced by recent research employing the new techniques of molecular biology (e.g. Babiker et al. (1998) and (2000), Hamad et al. (2000) ) which has shown that subclinical asymptomatic infections do persist in some people, during seasons of the year when 152

Demography of malaria

and Lambeth districts of London, in the coastal marshes of Kent and Essex, the East Anglian Fens, parts of the south coast, possibly also Bridgewater in Somerset and the Ribble valley in Lancashire, and probably as far north as the East Lothian area of Scotland.

Robert Hamilton described the course of the typical epidemics of vivax malaria at King’s Lynn in the late eighteenth century.

if a very wet winter and spring are succeeded by a very hot and dry summer, in which the ditches and marshes are nearly dried up, it is generally epidemical, and spreads widely around us. It most commonly appears about the middle of August, and lasts till the ditches are filled with water, the marshes somewhat covered, which, with a frost, usually puts a period to its raging in that form, for that season; for it now generally changes to the type of a genuine intermittent. This is it’s [ sic]common mode of termination, as the winter advances; but when it rages with extensive violence, during the autumnal months, it puts on a variety of morbid degeneracies, many of which, by persons unaccustomed to its Proteus-like changes of type, would be taken for a very different disease.¹¹²

Hamilton’s description illustrates in a historical context the very important conclusion reached in Chapter 2 above about the importance of quotidian fevers. It was only in the final stages of the annual epidemic that the tertian periodicity manifested itself. Until then the fevers of vivax malaria generally took a quotidian form.

Similarly Sydenham stated that epidemical agues in the autumn were at first accompanied by a continual fever.¹¹³ Hamilton emphasized the association of P. vivax malaria with marshes which tended to dry up during the summer, an association also found in Italy. He observed that what he called the ‘marsh remittent fever’

of England was the same disease as the tertian fever of Minorca.

Hamilton also noted that during the epidemic of 1783, a very hot year, many agricultural labourers were attacked during the harvest. In addition, he made interesting observations about the possibility of contagion at a time when the miasmatic theory of ‘bad air’

still prevailed. He commented that the marsh fever was observed to spread through large families, starting with one or two cases, mosquito activity is low, at levels undetectable by microscopic examination of blood smears, not only in the case of P. vivax but also in the case of P. falciparum, even in geographical regions with low levels of transmission of malaria (traditionally thought to be an impediment to the development of acquired immunity). P. falciparum malaria now seems to be in many cases a more chronic disease than generally used to be thought, cf. Garnham (1966: 413).

¹¹² Hamilton (1801: 27–8).

¹¹³ Meynell (1991: 124).

Demography of malaria

153

‘which looked very much like the effects of contagion’. The use of ‘Peruvian bark’ (cinchona) as a treatment was also discussed.

This probably played a major role in the decline of vivax malaria in England.¹¹⁴

The last major epidemic of malaria in England occurred in 1857-9, during two very hot summers, but three-quarters of the population of the Isle of Grain in Kent suffered from malaria in 1876.

Cases of malaria occurred as recently as 1921 in that locality, following the reintroduction of P. vivax by soldiers returning from the campaign in the Balkans in 1916. The possibility of the reintroduction of malaria to the Isle of Grain was a matter of concern to the local public-health authorities in Kent as recently as 1952–4.¹¹⁵

Malaria could have been transmitted in England by Anopheles atroparvus and A. plumbeus.¹¹⁶ P. vivax malaria is generally regarded in modern medical literature as a considerably milder disease than P.

falciparum. It seldom kills well-nourished, otherwise healthy people by itself. The Hippocratic Epidemics noted that tertian fever was not dangerous (see Ch. 2 above). More recent historical evidence from Italy supports this view. For example, Cipolla described the reaction of Alessandra Macinghi Strozzi, who in 1459, upon learning that her son in exile at Naples had tertian fever, ‘took comfort because you do not die of tertian fever, unless other illnesses intervene’. The last four words are crucial, because her son did die after all.¹¹⁷ The evidence from the English parish studies suggests that in historical contexts where it could operate in synergy with other infectious diseases, and where its targets probably suffered from malnutrition, P. vivax malaria produced extraordinary changes in the mortality regimes of human populations.¹¹⁸ Sydenham observed the association in infants of rickets and ‘coughs and other symptoms of being in a consumption’ alongside autumnal ¹¹⁴ Hamilton