138 
EIGHTH REPORT. 
reported, and it is certainly necessary first to have a case reported be¬ 
fore steps can be taken for its isolation. Accordingly the success of 
isolation as a preventive measure depends upon the prompt notification 
of the cases to the local health officer and this notification in turn de¬ 
pends upon a number of factors, as follows: 
1. The severity of the disease. 
2. The duration of the disease. 
3. The difficulty of diagnosis. 
4. The duration of the infective period. 
In cases of a severe disease or one which is considered severe by those 
outside of the medical profession, notification is usually prompt. As 
an example of this class, smallpox may be mentioned. Whenever a per¬ 
son is suspected of having smallpox, the health officer can not act too 
promptly. Not only the householder reports the case, but even the 
neighbors make it their business to aid in the notification; but when 
on the other hand measles is the disease in question, no one seems to 
care. The feeling prevails that measles is a mild disease and every 
child ougli to have it, and ,so in the case of measles, isolation as a pre¬ 
ventive measure fails almost entirely, and yet measles claims many 
more deaths annually than does that much-dreaded disease smallpox. 
The second factor, duration of disease, works against isolation in much 
the same way. When people know that their quarantine is to be com¬ 
paratively short they are willing to be locked up, but the longer the 
quarantine the more anxious are they to avoid it; as a consequence 
diphtheria is more liable to be reported than scarlet fever and the 
latter disease will be reported when one of longer duration would be 
suppressed. 
The difficulty of diagnosis is an important factor to the success or 
failure of isolation. Typical cases of diphtheria, scarlet fever and small¬ 
pox are easily recognized and are for the most part reported, but the 
milder cases escape detection and consequently isolation. Mild diph¬ 
theria is called tonsilitis, scarlet fever is often designated as stomach 
rash, erythema or even urticaria, and is allowed to run at large, whereas 
the cases of mild smallpox are diagnosed as Cuban itch, impetigo con¬ 
tagiosa, chicken-pox and what not. 
The fourth factor that has a bearing on isolation, the duration of the 
infective period of the disease, is of importance in those diseases that 
are communicable early in their course, even before a definite diagnosis 
can be made. For example, measles is infective before the appearance 
of the eruption and mumps before the parotiditis has appeared, and 
consequently even if these diseases are notifiable some exposures will 
take place before the cases can be isolated, whereas in the case of small¬ 
pox there is little chance for infection before the appearance of the 
eruption. 
Taking all these factors into consideration, what can be done to make 
isolation effective? First of all, every disease that is communicable and 
dangerous to the public health should be mentioned in the law, making 
the disease notifiable. Secondly, all suspicious cases should be reported 
so that the health officer may see them and protect the public if, in 
his opinion, the disease is dangerous. Doubtful cases of diphtheria 
should be decided by a bacteriological examination of a throat culture. 
