Disease Surveillance Evolution of Disease

Disease Surveillance Evolution of disease surveillance systems: A brief historical perspective Long before the causes of modern pathologies were fully understood, governments tried to track the spread of communicable diseases. The first official attempts to do so existed in the forms of death records in Europe from the 1700s.

In 19th century England, public health specialists began to study "variations in mortality rates from diseases such as cholera, dysentery, or workplace-related death (e.g., due to mining accidents)" to see if they "suggested socioeconomic, work-related, and environmental causes" (Ritz, Tager, & Balms 2005). This data, which eventually resulted in such findings as the association of cholera with fetid sewage in the drinking water, proved to be invaluable in tracking and ultimately curing many major infectious diseases. Likewise, in the U.S. In 1878, "Congress authorized the U.S.

Marine Hospital Service (the forerunner of today's Public Health Service {PHS}) to collect morbidity reports on cholera, smallpox, plague, and yellow fever from U.S. consuls overseas; this information was used to institute quarantine measures to prevent the introduction and spread of these diseases into the United States" (Historical perspective, 1996, MMWR). Soon after, reports were regularly published on these pathogens because of the likelihood of the deadly and potentially epidemic nature of the diseases.

"By 1928, all states, the District of Columbia, Hawaii, and Puerto Rico were reporting 29 infectious diseases to the Surgeon General" (Historical perspective, 1996, MMWR). By 1946, all state health offices submitted statistics on the reports of diseases considered to be threats to the public health via telegram. However, "because the reporting frequency varied for different conditions (i.e., weekly, monthly, or annually), the precise number of conditions considered nationally reportable in 1946 is unclear" (Historical perspective, 1996, MMWR).

Although surveillance has remained a consistent principle of public health improvement, the specific diseases flagged to be significant have varied over the years. In 1996, "gonorrhea, acquired immunodeficiency syndrome (AIDS), salmonellosis, shigellosis, hepatitis a, tuberculosis, primary and secondary syphilis, Lyme disease, hepatitis B, and pertussis" were the most significant, in contrast to previous eras where illnesses such as polio and smallpox were tracked (Historical perspective, 1996, MMWR). Some of these illnesses have unique features which make them particularly difficult to track as subjects of surveillance. For example, Lyme tests are often unreliable.

Also, "many viruses and bacteria cause nonspecific syndromes or symptom complexes that include most diarrheal and respiratory symptoms" (Ritz, Tager, & Balms 2005). This is also true of tracking the efficacy of treatments: "in cases where there are long delays between the implementation of an intervention and the reduction in disease incidence or morbidity, it may be difficult to quantitate precisely (or even accurately) the extent to which the intervention altered the outcome of the disease" (Ritz, Tager, & Balms 2005).

This is particularly manifest in treatments which are multifaceted and are taken over time (like AIDS 'drug cocktails') or require environmental controls to be effective (like preventing malaria or other mosquito-borne illnesses). However, despite the innate challenges in tracking diseases, a number of new trends have emerged to enhance the capacity of government agencies to do so. One is through technology: a recent study of patterns of Google searches for influenza-like illness, gastroenteritis, and chickenpox found that "one well-chosen query was sufficient to provide.