Module 2: WHO and CDC Global Surveillance Systems

WHO Surveillance and Statistics

A division of the World Health Organization (WHO) known as the Global Health Observatory (GHO) uses its network of partnerships across its 194 member states to compile data on the state of health around the world.(1) The WHO focuses on the Millennium Development Goals and collects data to assess how its global health initiatives in those areas are progressing.(2) The WHO Department of Health Statistics and Information Systems of the Innovation, Information, Evidence and Research Cluster publishes “World Health Statistics,” an annual global health report.(3) The main way that the GHO collects data for this publication is by censes, surveys, and vital registration systems. In places where a full range of data cannot be found or collected, the GHO says that the “use of statistical modeling and other techniques have been used to fill data gaps”.(4)

“World Health Statistics” paints a picture of the health status of various populations across the globe. The WHO says that it bases its assessment of health status on the following characteristics of the studied populations:(5)

• Life expectancy and mortality
• Cause-specific mortality and morbidity
• Selected infectious diseases
• Health service coverage
• Risk factors
• Health workforce, infrastructure and essential medicines
• Health expenditure
• Health inequities
• Demographic and socioeconomic statistics
• Health information systems and data availability

Revision of the IHR (2005)

According to the WHO, the International Health Regulations (IHR) are an “international legal instrument that is binding on 194 countries across the globe”, and their purpose is “to help the international community prevent and respond to acute public health risks that have the potential to cross borders and threaten people worldwide”.(6) The IHR are trying to prevent widespread health catastrophes that could emerge from infectious disease, chemical, or nuclear origins.(7) The IHR were revised in 2005 (and became active in 2007), and these revisions gave countries more responsibility for keeping track of and reporting any disease that had the potential to spread globally and damage the world’s health and economy.(8) The revised IHR called for the enhancement of public health surveillance in each country, as well as increased international cooperation to make global public health responses more timely and effective.(9) The WHO, with other partner agencies like the CDC’s Global Disease Detection Program, is working alongside countries to help them to develop culturally appropriate surveillance systems, and to gather the resources necessary to follow IHR guidelines.(10) The goal is to create a more integrated global system in which information about potential public health emergencies is more easily passed between regions. Increased connection and standardization of the global health surveillance system will improve the ability of countries to identify, investigate, report, and respond to public health threats as a global unit.(11) 

CDC’s Global Disease Detection Program

Working closely with the WHO on the implementation of IHR worldwide is the Global Disease Detection Program (GDD) of the CDC.(12) The CDC calls the GDD its “principal and most visible program for developing and strengthening global capacity to rapidly detect, accurately identify, and promptly contain emerging infectious disease and bioterrorist threats that occur internationally”.(13) Achieving these goals depends on a strong, interconnected network of public health agencies. In many developing countries, there is a shortage of public health experts helping to implement the IHR. Experts in public health are particularly essential today because of the increase in novel and emerging infectious diseases. The GDD is trying to build the global health surveillance network by providing developing countries with the monetary and human resources necessary for rapid detection and response to disease outbreaks. All efforts are aimed at achieving global health security.

The GDD was established in 2004 when the U.S. government allocated funding to the CDC for the building of such a program.(14) The creation of the GDD was largely the result of the SARS outbreak in 2003, when 8,098 people around the world became sick from the airborne viral respiratory illness.(15) The SARS epidemic sparked a new interest in and fear of novel diseases that are zoonotic (originating from animal hosts) and can be transmitted between people. Because of the ease of travel today, diseases that originate in lower income countries, where humans are often in constant and direct contact with animal hosts, have the potential to spread quickly all over the world. The WHO designated the GDD as the program that would help implement its new IHR guidelines to prevent emerging pathogenic outbreaks from becoming pandemics.(16)

Infrastructure of the GDD

The GDD program’s structure consists of Regional Centers located in every WHO region. Centers are responsible for disease surveillance and response in their respective areas. These regional centers are interconnected via the Global Outbreak Alert Response Network (GOARN), and they report gathered information to the GDD Operations center at CDC headquarters in Atlanta, Georgia.(17)

The CDC headquarters in Atlanta is where the Technical Support Corps (TSC) scientists are based. The TSC consists of approximately 20 members who are experts in a variety of fields (including epidemiology, infectious disease, and information technology). The TSC offers ongoing support and rapid aid to the regional centers in the event of a highly complicated or novel public health situation.(18) The GDD also interacts with many other internal partners, including the Field Epidemiology Training Program, the Influenza Program, the National Center for Emerging and Zoonotic Infectious Diseases, the National Center for Immunization and Respiratory Diseases, and the Office of Public Health Preparedness and Response.(19)

http://www.cdc.gov/globalhealth/gdder/gdd/regionalcenters.htm

The GDD is always looking to expand in order to cover more areas with surveillance to improve global health security. GDD Regional Center locations presently include China, Egypt, Guatemala, Kazakhstan, Thailand, Kenya, India, and South Africa. Center locations are selected based on characteristics such as a history of high mortality and morbidity from infectious disease, the country’s attitude towards and commitment to CDC collaboration, previous presence of the CDC or other U.S. government agencies, and the ability of the country to reach the surrounding region.(20) The six core areas where the CDC expects these centers to expand public health capacity in their respective locations are emerging infections, field epidemiology, pandemic influenza preparedness, emergency preparedness and risk communication, laboratory systems strengthening, and zoonotic infections.(21)

Five Core Activities of the GDD:(22)

Outbreak Response: create a highly functional surveillance system in which outbreak investigations and responses are rapid, and interventions successfully confine and control the health event

Surveillance: strengthen surveillance systems, especially in areas lacking adequate resources, to ensure timely identification, assessment, and ongoing observation of potential public health threats

Pathogen Discovery: identify new and potentially threatening pathogens with cutting edge technology and research that prevents their spread and negative global impact

Training: the training of human resources to ensure that those involved in the GDD are proficient in field epidemiology and best practices in laboratory maintenance and management

Networking: grow and reinforce the system of surveillance and response by encouraging collaboration between agencies and governments and the pooling of resources

With the partnership between the WHO, the CDC, and other global health agencies, surveillance systems can be improved upon to support global health security.

Go To Module 3: Fundamentals of Epidemiology >>

Footnotes