⁹ Yellow fever caused brief summer epidemics in some Mediterranean cities in the eighteenth and nineteenth centuries. For example, Palloni (1804) described a yellow-fever epidemic at Livorno. It killed over 700 people out of a total population of about 70,000, but did not survive the winter or spread beyond the part of the town closest to the sea. The disease obviously arrived on board a ship.
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of evidence for malaria than biographical accounts of the illnesses of individuals, such as Alexander the Great or various Roman or Byzantine emperors, which frequently provide too little detail for a reliable retrospective diagnosis.¹⁰
The periodicity of malarial fevers is caused by the synchronized process of schizogony (or merogony, a type of asexual reproduction unique to parasitic protozoa) at the end of which erythrocytes burst, releasing new merozoites into the bloodstream to invade other red blood cells. However, it is important to bear in mind that in practice the characteristic periodicity is not in fact observed in many cases, owing to infections with multiple generations of parasites whose developmental cycles are not synchronized. Experiments in which malaria was deliberately transmitted by infected mosquitoes to patients suffering from syphilis and afterwards cured with quinine ( Treponema pallidum, the pathogen of syphilis, cannot tolerate the temperatures generated by malarial fevers inside the human body) were carried out for many years at Horton Hospital in Epsom in England. These experiments proved that in malaria caused by P. falciparum, the most dangerous species of malaria, most attacks take the form of subcontinuous or quotidian (peaking every twenty-four hours) fevers. It was also demonstrated that even in the milder type of malaria caused by P. vivax the periodicity of the fever is generally quotidian in primary infections throughout the course of the attack. The periodicity of vivax malaria is only tertian from the beginning of the attack in relapses. The tertian and quartan periodicities are the clearest symptoms of malaria found in historical sources. References to quotidian fevers have less diagnostic value because of the possibility of confusion with other diseases, for example typhoid fever (see Ch. 5. 2 below). However, it must be recognized that modern experimental research in medicine indicates that references to the tertian and quartan periodic fevers in ancient sources only reveal the tip of the iceberg of malaria in antiquity. This is a very important conclusion for the interpretation of the ancient evidence. A large proportion of all cases of both P. falciparum and P. vivax malaria, including virtually all primary infections, would have taken a quotidian form in antiquity just as they do today.¹¹
¹⁰ Illustrations of the biographical approach: Engels (1978) on Alexander; Lascaratos and Marketos (1997) on the Byzantine emperor Andronicus III Palaeologus.
¹¹ Covel and Nicol (1951) and Shute (1951) on the work at Horton Hospital, which 12
Types of malaria
As a general rule, it may be said that the longer and the more regular the periodicity, the less dangerous the disease. It was well known in antiquity that quartan fevers were usually not dangerous (although P. malariae is now known to cause quartan malarial nephrosis, a severe kidney disease), but nevertheless lasted longer than other malarial fevers. P. falciparum infections do not last much longer than a year (but cf. Ch. 5. 4 below for recent modifications to this standard view found in the textbooks), and P. vivax infections do not last for longer than three to six years. However, there are cases in modern medical literature of individuals who had recrudescences with clinical symptoms of P. malariae over fifty years after the original infection. One woman from Karpathos in Greece was infected with quartan fever at the age of three in 1925, and then had no further attacks until she reached the age of seventy-two, when a recrudescence occurred following treatment for another medical condition with an immunosuppressive drug. Presumably in this particular case the human immune response was strong enough to keep the infection asymptomatic after the initial attack for seventy years, but not powerful enough to eliminate the parasites from the body completely. This suggests that P. malariae can effectively persist throughout the entire life span of the human host. The asymptomatic persistence of P. malariae infections has been frequently revealed in modern cases by the use of infected blood in transfusions. Celsus affirmed that quartan fevers did not kill anyone, although Antonio Benivieni of Florence (1443–1502), one of the earliest practitioners of pathological anatomy, described one fatal case of quartan fever in the fifteenth century .¹² The periodic episodes of fever during a malarial infection are probably a followed the Nobel Prize-winning discovery of the malaria treatment for syphilis by Julius Wagner-Jauregg in Vienna in June 1917 (Whitrow 1990; see also Ch. 5. 2 below). Recent textbooks on malaria reiterate these conclusions, stating for example that ‘tertian periodicity is rarely seen in falciparum malaria: persistent spiking fever or a daily (quotidian) febrile paroxysm is more usual’ (Gilles and Warrell (1993: 37) ).
¹² Garnham (1966: 275–6) and the monograph of Kibukamusoke (1973) on the kidney disease; L. H. Miller in Wernsdorfer and McGregor (1988: i. 729); Lentini and Tecce (1955), Guazzi and Grazi (1963), Garnham (1966: 271–2), Vinetz et al. (1998), and Chadee et al. (2000) on longevity of quartan fever; Garnham (1966: 45–9) on definitions of the terms relapse, recrudescence, and recurrence in malariology; Celsus, de medicina 3.15.6: quartana neminem iugulat (quartan fever kills no one); Oribasius, synopsis ad Eustathium 6.13, ed. Raeder: toŸß tetarta∏on nosoıntaß pr5wß £gein (those who are sick with quartan fever have a mild disease); Galen 17A.226–7K and 17B.341–3K; Benivieni (1528/9), 59; Carmichael (1989: 34–5) discussed Benivieni.
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non-specific immune response by the human body in an attempt to bring the infection under control, by making it too hot for the parasites to thrive.¹³
It is agreed by
