What Is Syndromic Surveillance?

The definition of symptom monitoring has not been unified. In the narrow sense, it generally refers to the monitoring of the frequency of specific clinical symptoms (such as fever, diarrhea, respiratory symptoms, etc.) in a specified population, and emphasizes non-specific symptom-based monitoring.

Symptom monitoring

Symptom monitoring, narrowly refers to not relying on a specific diagnosis, broadly refers to clinical symptoms, and disease-related phenomena.

Definition of Symptom Monitoring

The definition of symptom monitoring has not been unified. In the narrow sense, it generally refers to the monitoring of the frequency of specific clinical symptoms (such as fever, diarrhea, respiratory symptoms, etc.) in a specified population, and emphasizes non-specific symptom-based monitoring.

At present, general symptom detection also includes clinical symptoms and disease-related phenomena, mainly including: (1) hospital emergency room (ED) patient visits (including the number of visits, the patient's main complaint, and the doctor's preliminary diagnosis); (2) pharmacy Sales of over-the-counter drugs (OTC); (3) Medical related supplies (including sales of medical masks, toilet paper, etc.); (4) Absenteeism rate of schools or units; (5) Illness or death of animals; (6) Public health Laboratory test results; (7) Forensic results of unexplained deaths; (8) Emergency medical assistance 120 telephone records. Symptom classification and diagnosis are the basic components of a symptom monitoring system. Although most researchers have made a wide choice of symptoms, the unification of the definition of symptoms has just begun. Respiratory symptoms, gastrointestinal symptoms, skin symptoms, and nervous system symptoms have been continuously used for symptom monitoring.

Fundamentals of Symptom Monitoring

Traditional disease surveillance systems are based on hospital diagnosis and laboratory tests.There is usually a lag time between the symptom report or sample collection and the final diagnosis of the disease, while bioterrorism or other public health emergencies Coping requires quick identification and response. The application of symptom monitoring can track the scale and speed of disease outbreaks, monitor disease trends, alert public health emergencies through suspicious diseases (or symptoms), and remind people to take effective measures in a timely manner to reduce morbidity and mortality, and reduce economic losses. The early-onset symptom curve and disease outbreak curve can be represented graphically (Figure 1). Symptom monitoring aims to identify early symptoms

The threshold of the number of cases, which will be td earlier than the threshold determined by traditional monitoring methods. The ability of symptom monitoring to give early warning depends on the scale of the disease outbreak, the scope of the affected population, the definition of symptoms and various data resources, the criteria for starting an early warning investigation, and the ability of medical-related institutions to detect and report special cases. At the same time, for examining symptom monitoring and assessing the status of symptom monitoring, disease prevention and control agencies must have corresponding procedures and programs.

Analysis and early warning applications

Symptom monitoring has been widely used in recent years, which has promoted the improvement of early warning capabilities for diseases and related events to a certain extent and reduced losses. In 1995, Milwaukee, USA was hit by a heat wave, resulting in an increase in heat-related mortality compared to the same period.Later, an early warning program for high temperatures was introduced. This program requires that appropriate measures be taken once environmental signals or weather forecasts indicate that a heat wave is coming. The program was continuously improved, and the heat-related morbidity or mortality rate when the heat wave hit again in 1999 decreased by 50% compared to 1995. In response to possible bioterrorist attacks, during the 2002 Korea-Japan World Cup, both Japan and South Korea established a symptom monitoring system based on hospital emergency room data. To understand the scope of the anthrax spore bioterrorism attack, the United States has initiated monitoring of OTC sales through the Internet. In 2003, Hogan WR et al. Monitored the outbreak of respiratory and digestive tract infections in children through the sale of electrolyte-based over-the-counter drugs. In the summer of 2003, a direct report from Wisconsin of the United States found a case of a shepherd dog with fever and blisters on the body.They immediately linked the case to similar cases in other states and tracked the sales network of this group of dogs to diagnose in the laboratory.

Measures have been taken to control the further spread of the disease. Utah used hospital outpatient and emergency data for bioterrorism surveillance at the 2002 Winter Olympics. The above reports indicate that symptom monitoring has played a role in responding to various public health emergencies. With the continuous research in this field, there will be better application prospects.

Symptom monitoring outlook

Symptom monitoring is receiving more and more attention, but symptom monitoring cannot replace traditional public health monitoring or doctor diagnosis.At the same time, due to the limitations of signal detection methods, unnecessary economic losses caused by harm may be overestimated, Due to the relatively low frequency of infectious diseases, various methods of monitoring the symptoms have not been able to obtain practical inspection and evaluation in a timely manner. In view of this, the author believes that the following aspects of research and application should be strengthened: (1) Drawing on the experience of traditional disease surveillance and using the obtained data, establish a joint system that integrates traditional disease surveillance and symptom monitoring, complementing each other and developing in a long-term coordinated manner. (2) Make full use of today's advanced network information technology, develop more advanced online direct reporting and information processing systems, and improve the speed of response to early information. (3) Strengthen the close cooperation between disease prevention and control agencies and other relevant departments (such as the drug retail department, hospital emergency rooms, public health laboratories, schools, etc.), establish a unified data collection and analysis system, and strengthen information sharing. (4) Strengthen the research on the statistical analysis methods of data analysis and refinement, as far as possible to ensure the reliability of the analysis results and improve the early warning ability, and at the same time, strengthen the research on the evaluation of monitoring operation effects. (5) learning from the experience and methods of foreign symptom monitoring,

Research and establish a symptom monitoring system suitable for China's national conditions, so that it can reflect the real situation of public health in a timely, reliable and comprehensive manner. (6) Strengthening environmental and disease surveillance

Combined research, select appropriate symptoms and signs for long-term monitoring, and combine indoor and outdoor atmospheric environmental monitoring data, meteorological data, cause of death monitoring data, and disease spectrum

Comprehensive monitoring of monitoring data, personal health files, etc., statistical analysis of data from different sources, and early warning of the impact of the environment on people's health.

Provide scientific basis for government decision-making and provide guidance for ordinary people's daily life, with a view to fundamentally improving the environment and improving the quality of life of the people.

At present, there are few researches on symptom monitoring in China, and the research on the methodology and evaluation criteria of the definition of symptoms and signs, statistical analysis, etc. needs to be continued.