Fig. 145.—General type of fever onset in the various tropical diseases.
Malarial Cachexia.—Attacks of an irregular type of fever are frequently noted in the malarial cachectic, especially setting in upon some exposure to dampness or chilling, to alcoholic excesses or to excessive fatigue. Cases are also met with in the tropics, particularly among natives, where fever plays no apparent part in the profound anaemia of these ague-cake victims. It is this absence of fever which many consider the evidence of immunity to malaria in the native with his anaemia and large spleen.
Such cases often show crescents in their blood and act as reservoirs of virus for mosquito infection.
Latent Malaria.—Following treatment, or even when quinine has not been exhibited, cases of malaria often cease to show clinical symptoms or even laboratory findings until a relapse develops in case a cure has not been effected. As noted elsewhere, these relapses, in which the febrile manifestations are prominent, often follow exposure to tropical sunlight, wetting, etc. Besides such frank manifestations, we may have numerous symptoms, that exhibit periodicity, arising in the course of nonfebrile latent malaria.
Yaws.—While fever of a more or less irregular type frequently occurs at the onset of both primary and secondary stages, especially just before the secondary general eruption, yet the course of yaws as it runs over months or years is afebrile.
Verruga.—The recent views as to verruga being a separate condition, and not the secondary stage of a typhoid-like fever, Carrion’s disease, removes from its clinical features the fever characteristics generally noted.
Diseases with Subnormal Temperatures.—There are certain diseases in which marked lowering of the temperature may be a feature of some stage.
The algid stage of cholera is that which gives to cholera the picture of a living death with the cadaveric features and icy breath. Again in the choleraic type of algid pernicious malaria we may have a subnormal temperature.