In Europeans an attack of dengue very often leads to a condition of debility necessitating temporary change of climate, or even return to Europe. In both Europeans and natives the attendant lowering of the resisting powers predisposes to other and more dangerous diseases, such as malaria, dysentery, phthisis, and so forth; consequently dengue, otherwise a benign disease, may become a source of public danger. It is probable that it is in this indirect way that the general mortality is increased during a visitation of this disease, as has been observed in several epidemics.
Morbid anatomy.— On account of the low mortality, post-mortem records are few. Nogué, who observed two epidemics of dengue in Cochin China (1895-96), made four post-mortem examinations in this disease. In these, pulmonary and intracranial inflammation were the special features. The meningitis amounted to adhesions and sero-purulent infiltration of the pia mater.
Diagnosis.— Dengue must not be confounded with yellow fever, rötheln, scarlatina, measles, syphilitic roseola, influenza, cerebro- spinal meningitis, seven-days' fever, rheumatic and malarial fevers. A knowledge of the distinctive features of these diseases, and the fact that dengue is attended with a rash and with articular pains, and that it occurs in great and rapidly spreading epidemics, should prevent any serious error in diagnosis. According to Ashburn and Craig, there is a well-marked leucopenia in dengue averaging 3,800 per c.mm., with relative increase of the small leucocytes. This in some circumstances may prove an aid to diagnosis.
Treatment.— Were it possible to secure perfect isolation for the individual during an epidemic of dengue, doubtless he would escape the disease. Even comparative isolation is attended with diminished liability. In Amoy, in the epidemic of 1872, those foreigners who lived in a more or less isolated suburban situation were very much less affected than were those who lived in the native town, or than those whose occupations threw them much into
