STATISTICS OF SICKNESS I. From the standpoint of public health, statistics of sickness or morbidity statistics are the vital statistics of greatest im portance. These show the occurrence of disease and its rela tive prevalence in different localities and at different times.
This information is primarily secured by a system of report ing cases of illness known as notification. The responsibility for making these reports is primarily placed on the practicing phy sicians, and to a lesser extent on the householder or family head in the absence of an attending physician. Laws or regula tions requiring these reports should specify that all real or suspected cases or carriers should be reported within 24 hours of their recognition or suspicion. Reports may be either by phone or mail, but the former method should always be confirmed in writing. As previously brought out, modern methods of disease control are based upon a prompt knowledge of how, when and where cases of preventable diseases are occurring. Consequently physicians in Submitting their reports to health authorities are rendering a very important service in disease control In this country the so-called model morbidity law now furnishes the basis for most reporting of this character. While adequate penalties should be provided for failure to make the necessary reports, yet health authorities will find it advantage ous to make reporting as easy as possible for busy practitioners. One very helpful aid in this connection is the printing of re port blanks on post cards and keeping the physicians adequately supplied with these (Fig. 132). The communicable diseases were the first group whose reporting was generally required, and in addition we frequently find the occupational diseases in these lists and sometimes cancer and pellagra. The follow ing considerations should govern health authorities in selecting diseases to be placed upon the reportable list: r. The disease should be one of public health importance either from the standpoint of causing death or disability.
2. It should be a disease whose means of prevention are fully understood and which may be effectively combatted, or 3. One for which highly effectively prophylactic or thera
peutic agents exist. Thus cases of dog bites should be reported not because rabies spreads from man to man, but because prompt immunization will protect the person bitten from possible rabies in the biting animal.
4. If the disease is of itself trivial or unimportant, it may be indirectly of importance. Such as for example the confusion of chicken-pox with mild small-pox or German measles with scarlet fever. These should therefore be reported so that a differential diagnosis may be made by experienced observers.
5. If an exotic disease, it should be one that could gain a permanent foothold if introduced. Thus yellow fever should be reportable in the gulf states where stegomyia mosquitoes abound, but no purpose is gained by placing yellow fever on the list of reportable diseases in Montana, where stegomyia is not found.
Notification in order to be of maximum value must be as complete as possible. We have already called attention to un recognized sources of infection which must be sought out by the initiative of the health authorities. Various checks are em ployed to indicate the degree with which physicians are dis charging their notification duties. Thus all death certificates in which the ascribed cause is one of the reportable diseases should be compared with the morbidity report files to ascertain that the death was previously reported as a case. If not so previously reported, investigation will usually reveal that some one has been negligent. Case mortality ratios may also be used as a check. Thus from every death of typhoid reported, the morbidity files should reveal approximately ten reported cases of the disease. The reporting of the recognized cases by the physicians permits the health authorities to investigate the contacts for missed cases and carriers, and this detect infected persons who would otherwise pass unrecognized and uncontrolled.