Global Microbial Threats in the 1990s
III. How can we help build a global network for infectiousdisease 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 mustbe aware when epidemics occur anywhere in the world. However,reliable information can only be secured through clinical andlaboratory-based surveillance that links medical and publichealth workers into a cooperative worldwide network."Laboratory-based surveillance" implies that diagnostic tools andtechnicians are available to analyze blood, sputum, or stoolsamples from sick people or animals. The public health workers inthe network must include epidemiologists who can investigate thenature and extent of microbial threats. Moreover, the globalnetwork should also incorporate prevention efforts bycoordinating investigations into the environmental and humanfactors that promote the evolution and emergence of infectiousmicrobes.
Many elements of a potential global network do exist - but needto be linked, coordinated, and strengthened, working inpartnership 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 andlaboratories in Africa, Asia, and the Americas. The introductionof inexpensive communications linkages among these facilities -by fax, by phone, by Internet - could provide an initialframework for global infectious disease reporting. This skeletalnetwork could be expanded over time to include many othernational and international resources. For instance, the U.S.State Department and the Peace Corps maintain medical facilitiesin remote areas that could be brought into the network asimportant sentinel outposts. Internationally, the network wouldinclude links with national health ministries, with hospitals andlaboratories operated by other nations, with foreign researchcenters such as the French Pasteur Institutes, with American andforeign non-governmental organizations (NGOs), and with WHOCollaborating Centres around the world.
A Network for Global Disease Surveillance
Four strategic objectives are necessary to establish a globalsystem for disease surveillance and response:
Surveillance. Strengthen existing surveillance systems so thatchanges in the incidence of known illnesses are routinelyreported, and information on the emergence of new or unusualdiseases is readily available to the ministries of health inother nations, WHO, and CDC. Reliable lines of communication mustbe established to ensure that surveillance information isreceived promptly enough to control outbreaks before they spread.
Diagnostic Tests. Work with WHO, national public healthauthorities, universities, and research centers to implementWHO'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. Italso requires that diagnostic tests be made available through aregional laboratory referral and distribution system.
Develop simpler, more cost-effective procedures to determine thecauses of disease. Ideally, these procedures should be simpleenough for use in the field when laboratory facilities are notavailable.
Support basic and applied research on infectious microbes,especially on pathogens for which there are no reliablediagnostic tests. The new tools of biotechnology should beexploited to speed these efforts.
Response. Enhance the capabilities of U.S. Government agenciesand existing disease-specific networks (see "International Resources Related to Infectious Diseases") to respondto recognized outbreaks identified through improved surveillance.Also, rebuild and coordinate the relevant technical resources ofU.S. Government agencies such as CDC, DoD, USAID, and FDA.
Diseases that are transmitted by different routes willnecessarily require different control strategies. Types ofresponse may include sanitation and hygiene measures, controllingpopulations of disease vectors (for example, malaria-carryingmosquitoes or rabid raccoons), drug treatment, vaccination orpost-exposure prophylaxis, or education to decrease humanbehaviors that cause spread.
Surveillance to Detect New Diseases
Unexplained disease symptoms or clinical circumstances that maysuggest a
need for further investigation when clusters of casesoccur include:
Each nation should be encouraged to report, as early as possible,new events or trends in human or animal, diseases that areaffecting its own population.
Interdisciplinary Research to support Control and Prevention.
Form linkages between
Encourage collaborative research to determine the causes ofepidemics, devise strategies for control and prevention, andidentify environmental and climatic conditions that favor theemergence of pathogenic microbes.
Prevention Through Immunization: The Search for an EffectivePneumonia Vaccine
The largest killer of infants and young children in developingcountries are acute respiratory infections, mainly pneumonia,which claim the lives of an estimate 3.8 million children underage 5 every year. While appropriate case-management, usingcommon antibiotics, has been very successful in treating thesediseases, the emergence of antimicrobial resistant strainssuggest that this success may be relatively short-lived. One wayto avoid problems with resistance is to prevent the infectionfrom occurring, using safe and effective vaccines.
Through itsChildren's Vaccine Initiative Project, USAID is initiating amajor new program to evaluate newly developed vaccines that mayprotect children in underdeveloped countries. These vaccines areaimed against major bacterial and viral causes of pneumonia,including Streptococcus pneumoniae and Haemophilus influenzae b. Studies in the industrialized world and preliminary studies indeveloping countries suggest that these vaccines, especially new"conjugated" versions, hold great promise.
RECOMMENDATIONS OF THE CISET WORK GROUPHow can the United States Accomplish These SurveillanceObjectives?
To build an effective international surveillance and responsenetwork, a U.S. Government Interagency Task Force should beestablished and granted the authority and resources to implementthe following actions:
Work in partnership with other countries, with WHO, and withother international organizations to improve worldwide diseasesurveillance, reporting, and response by
These activities can be closely linked with our domesticsurveillance networks through CDC, which is responsible forinfectious disease surveillance within the United States. Inaddition, several "vertical" (disease-specific) networks that arecurrently sponsored by WHO (see WHO) can be integrated intothese regional networks.
Model surveillance and response projects can be established insuch regions as the Middle East, Sub-Saharan Africa, SoutheastAsia, South America, and Eastern Europe and the Newly IndependentStates of the former Soviet Union. An example of a proposedregional network in the Middle East is shown on map .
Some vulnerable areas of the world (such as rain forestcommunities in South America, Africa, and the South Pacific) arerelatively isolated. An assessment of gaps in the globalcommunications network should be undertaken to avoid excludingsuch communities. While WHO should initiate and support thissurvey, U.S. agencies such as CDC, DoD, and USAID can supply thetechnical advice and expertise to help ensure its success.
To identify and control unusual diseases such as those caused byhantaviruses or Ebola virus, clinical diagnoses must be confirmedusing diagnostic tests. For example, to stem the spread of Ebolavirus in Zaire in May 1995 (see Lessons Learned From the Ebola Virus Outbreak in Zaire), the international teamof epidemiologists needed to distinguish between fever patientsinfected with Ebola virus and febrile patients infected by othermicrobes. The team shipped blood samples to CDC biohazardlaboratories in Atlanta, which had the necessary diagnosticcapability.
Many countries, both industrialized and developing, have medicaland research institutions which can serve as significantresources in combating emerging diseases.
It is also crucial to develop and implement strategies thatextend the useful life span of antibiotics and other drugs byretarding the development of resistance. This entails behavioralresearch on how to ensure correct drug use and biomedicalresearch on the development of alternative drugs and drugregimens.
Although international efforts must be coordinated to preventglobal pandemics, disease surveillance must be the responsibilityof each sovereign nation. To ensure that the United States isnotified when an unusual outbreak occurs, we must encourage andsupport other countries' efforts in national disease surveillanceand respond when asked for assistance. It is especially importantto engage in information-sharing and dialogue with less developedcountries. The improvement of domestic disease surveillance andresponse capabilities in other countries and regions is discussedin Section VI.
Helping other countries to help themselves by improving domesticdisease surveillance and response capabilities in other countriesand regions is discussed in Section VI. It is also important toidentify those individuals and offices in each country who haveresponsibility for participating in international infectiousdisease surveillance efforts.
WHO Collaborating Centres operated in the United States byGovernment agencies or by American universities require supportto build or rebuild their capacity to serve as referencelaboratories within a larger and more active global infectiousdisease network. A list of the relevant WHO Collaborating Centresis included in an inventory of resources compiled by the CISETworking group.
Proposed legislative changes for the implementation of thisrecommendation are discussed in Section V. First, CDC's mandateto protect the health of U.S. citizens should be expanded toinclude outbreak investigations and selected responses toepidemics overseas in coordination with appropriate U.S.agencies, including state and local health departments, USAID,DoD, etc. In disaster relief operations involving infectiousdiseases where USAID/OFDA has the lead, CDC will operate as partof the U.S. effort as appropriate. Second, a responsible leadagency or agencies should be provided with the authority,emergency procurement powers, and financial resources tocoordinate interagency responses to foreign disease outbreaksthat have the potential to spread globally.
Strengthen the U.S. capacity to combat emerging infectiousdiseases by
A U.S. Government inventory compiled by the CISET Working Groupon Emerging and Re-emerging Diseases is available as a guide forthis activity.
State and local health departments require support to restore thesurveillance and response capacity that has eroded over the pasttwo decades. This recommendation is discussed in detail inSection VI of this report.
The U.S. Government and private sector should work together toestablish a better investment environment for the production ofurgently needed medical products. This can be accomplished bycombining the resources of national and international governmentinstitutions with the technical expertise in the U.S.pharmaceutical industry and in other sectors of the privatehealth-care industry. Improvement of the U.S. capacity foremergency production or procurement of diagnostic tests, drugs,antisera, and vaccines is discussed in Section IV.
Research and training are the foundation of an effective diseasesurveillance and response system. Scientific studies provide thefundamental knowledge base used to develop diagnostic tests toidentify diseases, drugs to treat them, and vaccines to preventthem. At the present time, many of the brightest young Americanmicrobiologists are leaving the field, discouraged by the lack ofjobs and research funds.
Specific recommendations to strengthen the infectious diseaseresearch infrastructure in the United States are provided inSection VII.
As much as possible, individuals should be armed with thepractical knowledge to protect themselves and their families frominfectious diseases. U.S. agencies should work with foreigngovernments, multilateral organizations, NGO's, and the newsmedia to improve public communication and avoid misinformationand panic. NGO's that might participate in this effort includewomen's groups, international organizations concerned withchildren's health, medical missionary organizations, U.S.corporations, and medical and public health associations.
The likelihood of the importation of infectious diseases can bedecreased by: expanding screening and quarantine facilities atU.S. ports of entry; making information about ill passengers moreaccessible to health authorities; encouraging greater cooperationin this area between local, state, and federal healthdepartments; and strengthening the training of Americanphysicians and microbiologists in the recognition of "tropical"diseases and in travel medicine.
No single U.S. agency has the authority and resources toinvestigate epidemics in other countries. However, each agencycan and does respond within its own disciplines. It is stronglyrecommended that the disease surveillance efforts of U.S.agencies be coordinated through an interagency task force chairedby one or more lead agencies, as discussed in Section V.
The role of the Task Force in fostering a dialogue with privateindustry and with academic and private sector researchers isdiscussed in Section IV.
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