It is rare to see, in the course of an acute malaria , symptoms on the part of the respiratory tract that would justify this name. Some observers of considerable experience deny their occurrence absolutely (Colin, Roux).
Baccelli, Kelsch and Kiener, and more frequently the older writers, have, nevertheless, described a pneumonic subcontinued, and though the observations of the older writers may be questioned on account of the lack of proper methods, we accept those of Morton without hesitatio*: " Febris intermittens primo insultu peripneumoniam acutissimam simulans."
The disease begins with a severe chill, rapidly rising temperature, and a violent stabbing pain in a circumscribed area of the thorax. The marked dyspnea, cyanosis, and especially the orthopnea are striking. Percussion of the thorax elicits a normal note, and only rarely a small area of circumscribed dulness. An oscul tation discovers fine moist rales over one whole lung; rarely localized. The breathing is usually vesicular, never bronchial. Vocal fremitus is unchanged.
The cough is dry and short; expectoration, wanting or scanty. When present, it consists of hemorrhagic clumps or of a tenacious, sanguinolent mucus. The condition persists as long as the fever paroxysm and ceases with it. The objective symptoms also disappear with the fall of temperature.
With a relapse, the whole symptom complex may recur. In this case the pulmonary affection may be in the same or a different location. The objective symptoms, excepting the dyspnea, are sometimes entirely wanting.
With all its violent symptoms it usually runs a favorable course, yet cases with a fatal termination during a paroxysm have been observed.
Apart from the more frequent irregularities in the fever, these mixed infections present no particular clinical characteristics, and we will, therefore, refrain from a detailed discussion.
These cases are not very frequent. Thayer reports that in Johns Hopkins Hospital, among 1618 malarial patients, only 31 showed a mixed infection. In the majority of these the ordinary tertian parasites were associated with those of estivo autumnal fever.
Experiments on mixed infections were done by Di Mattei. He injected patients manifesting one species with blood containing a second species (quartan parasites and crescents). He found, remarkable to say, that the new parasites just introduced supplanted the others and produced a corresponding type of fever.
A few observations indicate (Livio Vincenzi) that the two different species may alternate in causing fever symptoms, which would seem to show that one species is in a condition of latency while the other thrives. It is, therefore, impossible to exclude mixed infection by one examination of the blood.