Global Microbial Threats in the 1990s

Global Microbial Threats in the 1990s

III. How can we help build a global network for infectious disease reporting and response?

To avert the threat of emerging infections and prevent their spread into the United States, or into any other countries, health officials must be aware when epidemics occur anywhere in the world. However, reliable information can only be secured through clinical and laboratory-based surveillance that links medical and public health workers into a cooperative worldwide network. "Laboratory-based surveillance" implies that diagnostic tools and technicians are available to analyze blood, sputum, or stool samples from sick people or animals. The public health workers in the network must include epidemiologists who can investigate the nature and extent of microbial threats. Moreover, the global network should also incorporate prevention efforts by coordinating investigations into the environmental and human factors that promote the evolution and emergence of infectious microbes.

Many elements of a potential global network do exist - but need to be linked, coordinated, and strengthened, working in partnership with other countries and with WHO. Many U.S. Government department and agencies - including DoD, CDC, USAID, NIH, USDA, NASA, and NOAA - maintain field stations and laboratories in Africa, Asia, and the Americas. The introduction of inexpensive communications linkages among these facilities - by fax, by phone, by Internet - could provide an initial framework for global infectious disease reporting. This skeletal network could be expanded over time to include many other national and international resources. For instance, the U.S. State Department and the Peace Corps maintain medical facilities in remote areas that could be brought into the network as important sentinel outposts. Internationally, the network would include links with national health ministries, with hospitals and laboratories operated by other nations, with foreign research centers such as the French Pasteur Institutes, with American and foreign non-governmental organizations (NGOs), and with WHO Collaborating Centres around the world.

A Network for Global Disease Surveillance

Four strategic objectives are necessary to establish a global system for disease surveillance and response:

Surveillance. Strengthen existing surveillance systems so that changes in the incidence of known illnesses are routinely reported, and information on the emergence of new or unusual diseases is readily available to the ministries of health in other nations, WHO, and CDC. Reliable lines of communication must be established to ensure that surveillance information is received promptly enough to control outbreaks before they spread.

Diagnostic Tests. Work with WHO, national public health authorities, universities, and research centers to implement WHO's country-level objectives. This entails determining which "common" diseases should be diagnosed within a country and which "uncommon" ones should be referred to reference laboratories. It also requires that diagnostic tests be made available through a regional laboratory referral and distribution system.

Develop simpler, more cost-effective procedures to determine the causes of disease. Ideally, these procedures should be simple enough for use in the field when laboratory facilities are not available.

Support basic and applied research on infectious microbes, especially on pathogens for which there are no reliable diagnostic tests. The new tools of biotechnology should be exploited to speed these efforts.

Response. Enhance the capabilities of U.S. Government agencies and existing disease-specific networks (see "International Resources Related to Infectious Diseases") to respond to recognized outbreaks identified through improved surveillance. Also, rebuild and coordinate the relevant technical resources of U.S. Government agencies such as CDC, DoD, USAID, and FDA.

Diseases that are transmitted by different routes will necessarily require different control strategies. Types of response may include sanitation and hygiene measures, controlling populations of disease vectors (for example, malaria-carrying mosquitoes or rabid raccoons), drug treatment, vaccination or post-exposure prophylaxis, or education to decrease human behaviors that cause spread.

Surveillance to Detect New Diseases

Unexplained disease symptoms or clinical circumstances that may suggest a need for further investigation when clusters of cases occur include:

Each nation should be encouraged to report, as early as possible, new events or trends in human or animal, diseases that are affecting its own population.

Interdisciplinary Research to support Control and Prevention.

Form linkages between Encourage collaborative research to determine the causes of epidemics, devise strategies for control and prevention, and identify environmental and climatic conditions that favor the emergence of pathogenic microbes.

Prevention Through Immunization: The Search for an Effective Pneumonia Vaccine

The largest killer of infants and young children in developing countries are acute respiratory infections, mainly pneumonia, which claim the lives of an estimate 3.8 million children under age 5 every year. While appropriate case-management, using common antibiotics, has been very successful in treating these diseases, the emergence of antimicrobial resistant strains suggest that this success may be relatively short-lived. One way to avoid problems with resistance is to prevent the infection from occurring, using safe and effective vaccines.

Through its Children's Vaccine Initiative Project, USAID is initiating a major new program to evaluate newly developed vaccines that may protect children in underdeveloped countries. These vaccines are aimed against major bacterial and viral causes of pneumonia, including Streptococcus pneumoniae and Haemophilus influenzae b. Studies in the industrialized world and preliminary studies in developing countries suggest that these vaccines, especially new "conjugated" versions, hold great promise.


How can the United States Accomplish These Surveillance Objectives?

To build an effective international surveillance and response network, a U.S. Government Interagency Task Force should be established and granted the authority and resources to implement the following actions:

Work in partnership with other countries, with WHO, and with other international organizations to improve worldwide disease surveillance, reporting, and response by

These activities can be closely linked with our domestic surveillance networks through CDC, which is responsible for infectious disease surveillance within the United States. In addition, several "vertical" (disease-specific) networks that are currently sponsored by WHO (see WHO) can be integrated into these regional networks.

Model surveillance and response projects can be established in such regions as the Middle East, Sub-Saharan Africa, Southeast Asia, South America, and Eastern Europe and the Newly Independent States of the former Soviet Union. An example of a proposed regional network in the Middle East is shown on map .

Some vulnerable areas of the world (such as rain forest communities in South America, Africa, and the South Pacific) are relatively isolated. An assessment of gaps in the global communications network should be undertaken to avoid excluding such communities. While WHO should initiate and support this survey, U.S. agencies such as CDC, DoD, and USAID can supply the technical advice and expertise to help ensure its success.

To identify and control unusual diseases such as those caused by hantaviruses or Ebola virus, clinical diagnoses must be confirmed using diagnostic tests. For example, to stem the spread of Ebola virus in Zaire in May 1995 (see Lessons Learned From the Ebola Virus Outbreak in Zaire), the international team of epidemiologists needed to distinguish between fever patients infected with Ebola virus and febrile patients infected by other microbes. The team shipped blood samples to CDC biohazard laboratories in Atlanta, which had the necessary diagnostic capability.

Many countries, both industrialized and developing, have medical and research institutions which can serve as significant resources in combating emerging diseases.

It is also crucial to develop and implement strategies that extend the useful life span of antibiotics and other drugs by retarding the development of resistance. This entails behavioral research on how to ensure correct drug use and biomedical research on the development of alternative drugs and drug regimens.

Although international efforts must be coordinated to prevent global pandemics, disease surveillance must be the responsibility of each sovereign nation. To ensure that the United States is notified when an unusual outbreak occurs, we must encourage and support other countries' efforts in national disease surveillance and respond when asked for assistance. It is especially important to engage in information-sharing and dialogue with less developed countries. The improvement of domestic disease surveillance and response capabilities in other countries and regions is discussed in Section VI.

Helping other countries to help themselves by improving domestic disease surveillance and response capabilities in other countries and regions is discussed in Section VI. It is also important to identify those individuals and offices in each country who have responsibility for participating in international infectious disease surveillance efforts.

WHO Collaborating Centres operated in the United States by Government agencies or by American universities require support to build or rebuild their capacity to serve as reference laboratories within a larger and more active global infectious disease network. A list of the relevant WHO Collaborating Centres is included in an inventory of resources compiled by the CISET working group.

Proposed legislative changes for the implementation of this recommendation are discussed in Section V. First, CDC's mandate to protect the health of U.S. citizens should be expanded to include outbreak investigations and selected responses to epidemics overseas in coordination with appropriate U.S. agencies, including state and local health departments, USAID, DoD, etc. In disaster relief operations involving infectious diseases where USAID/OFDA has the lead, CDC will operate as part of the U.S. effort as appropriate. Second, a responsible lead agency or agencies should be provided with the authority, emergency procurement powers, and financial resources to coordinate interagency responses to foreign disease outbreaks that have the potential to spread globally.

Strengthen the U.S. capacity to combat emerging infectious diseases by

A U.S. Government inventory compiled by the CISET Working Group on Emerging and Re-emerging Diseases is available as a guide for this activity.

State and local health departments require support to restore the surveillance and response capacity that has eroded over the past two decades. This recommendation is discussed in detail in Section VI of this report.

The U.S. Government and private sector should work together to establish a better investment environment for the production of urgently needed medical products. This can be accomplished by combining the resources of national and international government institutions with the technical expertise in the U.S. pharmaceutical industry and in other sectors of the private health-care industry. Improvement of the U.S. capacity for emergency production or procurement of diagnostic tests, drugs, antisera, and vaccines is discussed in Section IV.

Research and training are the foundation of an effective disease surveillance and response system. Scientific studies provide the fundamental knowledge base used to develop diagnostic tests to identify diseases, drugs to treat them, and vaccines to prevent them. At the present time, many of the brightest young American microbiologists are leaving the field, discouraged by the lack of jobs and research funds.

Specific recommendations to strengthen the infectious disease research infrastructure in the United States are provided in Section VII.

As much as possible, individuals should be armed with the practical knowledge to protect themselves and their families from infectious diseases. U.S. agencies should work with foreign governments, multilateral organizations, NGO's, and the news media to improve public communication and avoid misinformation and panic. NGO's that might participate in this effort include women's groups, international organizations concerned with children's health, medical missionary organizations, U.S. corporations, and medical and public health associations.

The likelihood of the importation of infectious diseases can be decreased by: expanding screening and quarantine facilities at U.S. ports of entry; making information about ill passengers more accessible to health authorities; encouraging greater cooperation in this area between local, state, and federal health departments; and strengthening the training of American physicians and microbiologists in the recognition of "tropical" diseases and in travel medicine.

No single U.S. agency has the authority and resources to investigate epidemics in other countries. However, each agency can and does respond within its own disciplines. It is strongly recommended that the disease surveillance efforts of U.S. agencies be coordinated through an interagency task force chaired by one or more lead agencies, as discussed in Section V.

The role of the Task Force in fostering a dialogue with private industry and with academic and private sector researchers is discussed in Section IV.

Return to CISET Report Home Page