In 1557, however, a great flood caused the Tiber to change its course, so that it no longer flowed under the walls of the castle, but some half a mile farther west; and its old bed (Fiume Morto) has ever since then served as a breeding ground for the malarial mosquito (Anopheles claviger).
In the north, however, the hot lowlands are malarial and unsuited to north European settlement, while the dry, elevated plateaus are celebrated for their healthiness, those of Catamarca having an excellent reputation as a sanatorium for sufferers from pulmonary and bronchial diseases.
Malarial fevers make their appearance in places where the forest has been recently felled, or where the surface earth has been disturbed.
The Chinese immigrants suffer chiefly from fever of a malarial type, from beri-beri, a species of tropical dropsy, and from dysentery.
The valley regions are tropical, and malarial fevers are common.
The absence or extreme paucity of mosquitoes no doubt accounts for the infrequency of malarial fever in the interior.
Remittent is a not unusual form of the malarial process in tropical and subtropical countries, and in some localities or in some seasons it is more common than intermittent.
Milder cases of malarial fever are apt to become dangerous from the complications of dysentery, bronchitis or pneumonia.
Of the mortality due to malarial disease a small part only is referable to the direct attack of intermittent, and chiefly to the fever in its pernicious form.
But probably the greater part of the enormous total of deaths set down to malaria is due to the malarial cachexia.
The malarial cachexia that follows definite attacks of ague consists in a state of ill-defined suffering, associated with a sallow skin, enlarged spleen and liver, and sometimes.
From the time of Hippocrates onwards the malarial or periodical fevers have engaged the attention of innumerable observers, who have suggested various theories of causation, and have sometimes anticipated - vaguely, indeed, but with surprising accuracy - the results of modern research; but the true nature of the disease remained in doubt until the closing years of the 19th century.
On the 6th of November in that year he plainly saw the living parasites under the microscope in the blood of a malarial patient, and he shortly afterwards communicated his observations to the Paris Academie de Medecine.
The labours of Golgi, Marchiafava, Celli and others established the nature of the parasite and its behaviour in the blood; they proved the fact, guessed by Rasori so far back as 1846, that the periodical febrile paroxysm corresponds with the development of the organisms; and they showed that the different forms of malarial fever have their distinct parasites, and consequently fall into distinct groups,.
For instance, the swampy character of malarial areas is explained by their breeding in stagnant water; the effect of drainage, and the general immunity of high-lying, dry localities, by the lack of breeding facilities; the danger of the night air, by their nocturnal habits; the comparative immunity of the upper storeys of houses, by the fact that they fly low; the confinement of malaria to well-marked areas and the diminution of danger with distance, by their habit of clinging to the breeding-grounds and not flying far.
Perhaps the converse is more feasible in some circumstances - that is to say, preventing mosquitoes from having access to malarial persons, and so propagating the parasite in themsevles.
Koch has suggested that the disinfection of malarial persons by quinine would have the desired effect, but other authorities of greater experience do not consider it practicable.
There are undrained, swampy districts in Campeche, in the vicinity of the Terminos Lagoon, where malarial diseases are prevalent, and the same conditions prevail along the coast where mangrove swamps are found.
But while the province in many parts presents a landscape of luxuriant beauty, it is a prey to the ravages of disease, principally malarial fevers due to the extensive swamps formed by waters stagnating in the forests, and to the frequent incursions of the Goklan and Yomut Turkomans, who have their camping-grounds in the northern part of the province, and until about 1890 plundered caravans sometimes at the very gates of Astarabad city, and carried people off into slavery and bondage.
Other flies act as diseasecarriers, including the mosquitoes (Anopheles), which not only carry malarial germs, but also form a secondary host for these parasites.
In the autumn months malarial fever is prevalent in all thickly forested tracts and also in the rice country; but on the whole the province is considered to be healthy, and as the rains break fairly regularly in June and produce an immediate fall in the temperature, severe heat is only experienced for a period of from two to three months.
There are the usual malarial, bilious and intermittent fevers, and liver, stomach and intestinal complaints prevalent in tropical countries; but unhygienic living is, in Cuba as elsewhere, mainly responsible for their existence.
The climate is hot, humid and malarial on the coast, but is pleasant on the more elevated lands of the interior.
Malarial fever is not prevalent, and it is interesting to note that there are no swamps or standing waters on the island.
The valleys and coast belt, though practically free from malarial fever, are hot and humid, and fires in dwelling houses are seldom required even in the coolest months; the lower plateaus are cool and the air dry; the uplands are bracing and often very cold, with snow on the ground in winter.
Horsesickness, a kind of malarial fever, which takes an epidemic form in very wet seasons, causes considerable loss.
The banken veld district is also generally healthy though hotter than the plateaus, and malarial fever prevails in the lower valleys.
Malarial fever is also prevalent throughout the low veld, but above 3000 ft.
It is situated on the Bay of Calvi, in a malarial region, and is the port in Corsica nearest to France, being 109 m.
Since the beginning of the 10th century strenuous efforts have been made to improve the sanitary condition by a new system of drainage, a better water service, the filling up of marshes wherein the malarial mosquito breeds, and in other directions.
In spite of the difficulties of communication with the interior, and the malarial marshes which surround the town, it has become important for the export of grain (chiefly maize).
It is believed that his disease was a malarial form of recurrent quinsy acting upon an extremely neurotic system.
The action of quinine on the blood itself - quite apart from its action on malarial blood - is of great complexity and importance.
There is therefore no purpose to be served by administering quinine during a malarial paroxysm.
Quinine is much less efficacious in the treatment of post-malarial symptoms, such as neuralgia and haematuria, when no parasites can be detected in the blood.
Until far on in the 18th century the malarial jungle and paddy fields closely hemmed in the European mansions; the vast plain (maiddn), now covered with gardens and promenades, was then a swamp during three months of each year; the spacious quadrangle known as Wellington Square was built upon a filthy creek.
The diseases for which it was chiefly taken were malarial fever, dysentery, diarrhoea, spitting of blood, rheumatism and elephantiasis.
The climate of the plains is hot and malarial, and the rainfall heavy.
In the marshy localities malarial fever occurs but is rarely (in modern times) of a severe type.
The army diseases of the Civil Wars were chiefly typhus and malarial fevers, but plague was not unknown among them, as at Wallingford Castle (Willis, " Of Feavers," Works, ed.
Among the native races the prevailing diseases, apart from those of a malarial origin, are chiefly such as arise from bad and insufficient food, from intemperance, and from want of cleanliness.
In this zone malarial fevers prevail in winter.