That brings us to the question of the method of infection. In the case of measles, there is usually a history of direct contact with a mea-sles. patient, either in the prodromal or the eruptive stage of the disease. Infection by indirect means, such as an intermediary, animate or inani mate, is the exception. This may be taken to indicate fairly conclu sively that the exciting cause of measles is short-lived; that is, its infec tivity is of exceedingly limited duration.
The opposite is true of scarlet fever. Beyond question the virus is conveyed from one person to another by means of the desquamation, the clothing of the sick, and through the agency of a third person. It is not possible to state whether the desquamating epidermis is infective of itself or only when it serves as a carrier for the secretions (ear, mouth). Stickler proved the infectivity of the pharyngeal mucus. lie succeeded in infecting twelve well children by injecting pharyngeal mucus sub cutaneously. The virulence of the scarlet fever virus remains undimin ished for years. Numerous instances in the literature in support of this, statement can be cited.
The conditions existing in Vienna are hardly such as permit of investigations on this point. Scarlet fever is endemic, cases are met with at all times, and one can not, therefore, with any certainty, exclude unusual methods and sources of infection. The following case is an apt illustration, occurring, as it did, in a locality absolutely free from scarlet fever in epidemic form: Rosa B. had scarlet fever at the age of four and a half years. She was taken to the hospital and succumbed to the infection. Her clothing was disinfected thoroughly, except a fur coat and cap and a pair of shoes, which the mother feared might be ruined by the disinfection. These articles were kept in a box in the attic of her home for two years, when a sister of the deceased patient. was able to wear them. Four (lays after
the little girl first donned this clothing she became ill with a moderately severe ease of scarlet fever.
As a matter of fact, probably only a small percentage of cases are of such origin, but these cases do occur. Asa rule, infection occurs only by direct contact with the patient, even in scarlatina sine eruptione, the anginose form. At which stage of the disease infection is most apt to occur can not be determined. However, in the so-called house infections it has been demonstrated that in most instances it is possible to prevent a spread of the disease to bed neighbors if the patient is isolated on the first day of the eruption. It is hardly probable, therefore, that there is any danger of infection during the incubation period (Vogl).
One of the most distressing things in connection with scarlet fever is the fact that by no known means can it be determined for long a time the patient remains a source of infection. We have observed a number of instances in which children, even after a six or eight weeks' stay in a hospital, numerous baths and disinfection of their clothing, returned home and promptly infected other children of the family.
Marie S., twelve years old. Mild attack of scarlet fever. Discharged on fortieth (lay; no desquamation. This was on December 11th. Three days later, December 14th, Gisela, thirteen years old, December 1Sth, Margaret, four years old, and December 23d, Albert, six years old, (rave evidence of a mild scarlatinal infection.
Whether the infective virus is contained in the secretions (nose, mouth, ears) or in the dust of the ward, which is carried away on the body and clothing, is a moot question.