There is a definite value attached to the diagnosis not only of malaria, but also as to the type of the infection.
If the type is sub-tertian we know that we have to deal with what is generally by far the most severe form, and a form in which at any time alarming symptoms may develop.
This diagnosis, therefore, justifies maximal doses of quinine by the mouth, or better still grs. ix. of the bihydrochloride intramuscularly each day, until the symptoms abate and the temperature comes down.
It is a remarkable fact that, in sub-tertian infections, quinine may have little effect when taken by the mouth, although a prompt beneficial result may be seen when injected intramuscularly. Further, patients who have suffered from quartan or benign tertian infection have, strange to say, if they wish after returning to England to remain free from attack, to continue the systematic use of quinine longer than those whose infection was sub-tertian.
In the case of quartan the use of quinine should be continued for three years, in benign tertian two years, whilst only one year's systematic use seems to be sufficient after sub-tertian.
