The world’s challenges have changed since 13 March 2020, when the World Health Organization (WHO) declared the coronavirus a pandemic, thus foreboding the beginning of a health crisis with humanitarian, economic, social, security and political impacts. The need for concerted global efforts to early warning for infectious diseases and epidemics through effective surveillance systems emerged. Hence, epidemiological surveillance has become the country’s top priority to prevent and contain the spread of diseases and minimize their repercussions.
Despite the fact that the coronavirus epidemic was not the first of its kind nor was the deadliest, the world’s memory is weak. History shows us that there were epidemics more fatal than the coronavirus, including the “Black Death” (bubonic plague), smallpox, and Spanish flu, in addition to others which are still ongoing to date such as Acquired Immune Deficiency Syndrome (AIDS). It is very likely that much of the improvement in humanity’s ability to reduce the risk of coronavirus is due to the development of epidemiological surveillance strategies and methods.
Epidemiological Surveillance and its Role in Public Health
According to the WHO and the US Centers for Disease Control and Prevention (CDC), surveillance is defined as the systematic and continuous collection, analysis, and interpretation of health data in order to contribute to the planning and implementation of public health activities for disease prevention and control through effective and timely access to data.
Surveillance can be for communicable diseases; such as epidemics and infectious diseases, and for noncommunicable or chronic diseases that last for long periods; such as heart diseases, cerebrovascular accident (Cerebral stroke), cancer, diabetes, and respiratory diseases.
Figure 1: Epidemiological Surveillance Scheme
Surveillance typically comprises six core activities: detection, recording, confirmation, reporting, analysis, and reactions, carried out through four supporting activities: communication, training, supervision and provision of resources.
Surveillance has several methods:
a) Indicator-based Surveillance: the traditional surveillance method, based on data reported patients and disease records in each country. Its advantages include low-cost and clarifying reference data to identify trends and results. However, it is criticized with the lack of data inclusion, whether because of insufficiency symptoms, or not seeking hospital treatment.
b) Active or Effective Surveillance: carried out through active case detection and laboratory surveillance, via blood tests as well as investigative health research. Despite the quality and accuracy of this method, it is very costly.
c) Guard Surveillance: relies on health data issued by specific institutions or groups, so that it is able to monitor diseases and epidemics. Yet, it is limited to the specific groups that are monitored, and hence results obtained cannot be generalized.
d) Surveillance of Rumors: following unofficial sources of information (blogs, discussion groups, media, rumors, social media). It is an inexpensive tool, in addition to being an early warning to the authorities of disease outbreaks.
e) Surveillance of Syndromes: through the monitoring of pathological syndromes, defining the condition, or through indicators such as: absenteeism or increased demand for the purchase of certain medications. This method allows early warning through automated systems.
f) Network Surveillance using Artificial Intelligence: the most complex and the most predictive in forecasting epidemics, trends and modeling and evaluating public health response.
Monitored cases are classified by different surveillance systems, usually divided into three categories:
- Possible Case: only clinical criteria are met, namely the specific symptoms and vital signs of the disease.
- Probable Case: clinical and epidemiological criteria are met, and initial laboratory tests, if any.
- Confirmed Case: depends on all possible and probable case criteria, as well as confirmed laboratory analyses.
The role of epidemiological surveillance in public health is to provide timely information that can be used in health actions by decision makers, officials and society to crown public health policy and programs. Effectiveness of the surveillance system can be measured by:
- Sensitivity of the Epidemiological Surveillance System: the ability of the system to detect most of the correct positive cases and minimize false negative cases.
- Positive Predictive Value of an Epidemiological Surveillance System: the ability of the system to detect most of the correct positive cases, and minimize false positive cases.
- Data Timing: time specified between the appearance of the case until it is registered at the responsible authority for the application and verification of the preventive requirements.
- Data Representation: The ratio of the population covered by the epidemiological surveillance system to the total population in a specific geographical area.
Epidemiological Surveillance in Egypt
Egypt has witnessed several deadly epidemics such as malaria, the plague, and cholera. During the last century, epidemic was dealt with through distancing or isolation, closing institutions (such as schools and colleges), transportation termination, and quarantining. During the reign of Muhammad Ali Pasha, several preventive measures were decided upon to protect Egypt from epidemics and prevent disease outbreaks. In 1812, with the outbreak of the plague epidemic in Istanbul, ships from Istanbul were placed under sea quarantine and an infectious disease hospital was established in Damietta. With the emergence of cholera in Egypt in 1831, the world’s first headquarter of the international quarantine council was established in cooperation with the European powers, whose goal was not only to apply quarantine to arrivals from Europe and not to disrupt Egyptian trade, but also to create an accurate database of all sea vessels leaving Alexandria towards any of the countries participating in the Council. A quarantine was also established next to the Egyptian ports of Alexandria, Suez and Damietta, where travelers (merchants and otherwise) were subject to 14 days quarantine and may reach up to 40 days before permission to enter the country.
Nowadays, the General Directorate of Epidemiology and Surveillance, through several teams in departments, health directorates, public and private hospitals, within the National Electronic Disease Surveillance System (NEDSS), collects data from 542 hospitals nationwide in addition to the hotline for infectious diseases. This system originated in the late 1990s with the support of the Ministry of Health and Population (MOHP), WHO and the USA.
The Egyptian Epidemiological Surveillance System also encompasses the Center for Medical Research and Regenerative Medicine (ECRRM), established by Presidential Decree 605/ 2017, for the purpose of biological surveillance to trace change in the genes of epidemics and pathogenic microbes, to predict any genetic mutation or biological danger.
Epidemiological surveillance activities in Egypt are regulated by the Law on Health Precautions for the Prevention of Infectious Diseases 137/ 1958, which is compatible with the International Health Regulations 2005 (IHR 2005). Accordingly, authorities determine lists of diseases being monitored, so that each list are treated according to their nature. As such, Group A includes highly contagious diseases, which must be reported daily, while Group B is for diseases which are reported weekly. The list is updated based on epidemiological conditions and updates. Article 13 of Chapter IV on preventive measures in the emergence of infectious diseases requires reporting infectious cases by the following personalities: (a) every doctor who has witnessed the case, (b) the patient’s guardian, (c) the business management, the institution head or the driver of the means of transport if the disease appears or is suspected in the course of the patient’s presence in a place thereof, and (d) the mayor, the sheikh or the representative of the administrative authority, respectively.
Traditionally, surveillance in Egypt has adopted an indicator-based method, and then evolved to include Community Event-Based Surveillance (CEBS), a type of network surveillance that regularly and quickly captures information from the community about events that pose a potential risk to public health. CEBS is concerned with following reports, rumors and other information about health events that can pose a serious risk to public health. Information obtained in this way is neither regulated nor normative; however, this system has proven effective in detecting unusual events that may indicate an outbreak. Information obtained can come through multiple sources, most importantly:
c. Scan media tools by tracking keywords such as: poisoning, garbage, rotten food, epidemic, death of birds or animals, sewerage, infection, mosquitoes, environmental health, sanitation, virus, quarantine, fever, hospital admission…
d. List of major websites such as: Al-Masry Al-Youm, Akhbar AlYoum, Al-Youm Al-Sabea, as well as Google Alerts.
Event-based surveillance was applied in three stages:
- The first phase was based on paper reports, through hotline and media scanning. It was in 2015.
- The second phase expanded to include electronic reports through media survey and community-based monitoring based on events. It began in 2016 and was completed in 2019.
- The third phase is that of automatic research, through media scanning and event-based community monitoring. It was implemented since 2020.
Figure 3: Stages of the development of Egypt’s CEBS
This system has proven to be the most powerful disease surveillance and early warning systems in Arab countries, the Middle East and Africa, based on the assessment of both the WHO Regional Office and the US CDC in September and October 2018, as well as March 2020.
Figure 4: The MOHP General Department of Epidemiology and Surveillance