All these diseases are characterized by a more or less stuporous state.
Oroya Fever.—It was formerly supposed that this fever was the first stage of verruga, but it is now considered as a distinct disease entity, caused by a protozoon of bacillary form which invades the red cells. With pains of various joints and bones we have a gradual rise of temperature which after a few days reaches 103° to 104°F. and tends to become remittent or continuous.
There is a remarkable and excessive destruction of the red cells which may fall to a million or less per c.mm. The fever after about three weeks begins to fall by lysis. Enlargement of liver, spleen and lymphatic glands are common. Pain over the bones, especially the sternum, is often excruciating.
Epidemic jaundice shows an irregular pyrexia of from 102° to 103°F. with jaundice about the second or third day.
Trench Fever.—Cases of varying types of fever, some charts more or less resembling the dengue ones, while others show repeated relapses of short duration, have been designated trench fever.
In tularaemia we have an irregular fever course of rather rapid onset, extending over two or three weeks. There is very little evidence of toxaemia. Convalescence is tedious.
Typhoid fever and the paratyphoid infections are far from uncommon in the tropics and present clinical courses at variance with those observed in temperate climates. The temperature charts in such cases are irregular and atypical.
It must be remembered that paratyphoid infections may show marked gastro-intestinal symptoms and that the rose rash of such cases tends to be far more profuse than that of typhoid.
Intestinal Parasites.—There are many conditions which seem to be productive of febrile attacks as evidenced by the disappearance of the fever upon removing such cause. Thus patients presenting abdominal distress and a fever of varying type may be completely relieved of all symptoms upon evacuating the larvae of various flies following purgation. This condition is designated intestinal myiasis.