4
Diseases in Humans: Early Warning Systems

Effective disease surveillance systems that can detect outbreaks of emerging zoonotic diseases in human populations early are critical for giving health officials the opportunity to rapidly respond and apply interventions to control the outbreak as soon as possible. Representatives from several global infectious disease surveillance systems that operate to detect diseases in human populations, and which were identified by the committee during the workshop planning period, were invited to present an overview of these systems and the lessons that have been learned in (1) what is needed to improve the effectiveness of these systems, (2) how they could be linked to animal disease surveillance systems, and (3) the challenges that have been encountered and overcome in the conduct of disease surveillance, and identifying remaining gaps.

The discussion of animal disease surveillance in the earlier session clearly emphasized the close link between the health of wild and domestic1 animals and the health of humans. The ideal disease surveillance system, described by those focusing on animal health, was an interconnected system across species where outbreaks in animal populations could be detected and risks of human exposure could be identified early on and addressed to minimize or prevent disease in humans. Surveillance for zoonotic diseases in humans is similarly focused on early warning. The next section summarizes

1

Domestic animals are animals that have been bred selectively in captivity and thereby modified from their ancestors for use by humans who control the animals’ breeding and food supply (see http://asci.uvm.edu/course/asci001/domestic.html).



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4 Diseases in Humans: Early Warning Systems E ffective disease surveillance systems that can detect outbreaks of emerging zoonotic diseases in human populations early are critical for giving health officials the opportunity to rapidly respond and apply interventions to control the outbreak as soon as possible. Representa- tives from several global infectious disease surveillance systems that operate to detect diseases in human populations, and which were identified by the committee during the workshop planning period, were invited to present an overview of these systems and the lessons that have been learned in (1) what is needed to improve the effectiveness of these systems, (2) how they could be linked to animal disease surveillance systems, and (3) the challenges that have been encountered and overcome in the conduct of disease surveillance, and identifying remaining gaps. The discussion of animal disease surveillance in the earlier session clearly emphasized the close link between the health of wild and domestic1 animals and the health of humans. The ideal disease surveillance system, described by those focusing on animal health, was an interconnected system across species where outbreaks in animal populations could be detected and risks of human exposure could be identified early on and addressed to minimize or prevent disease in humans. Surveillance for zoonotic diseases in humans is similarly focused on early warning. The next section summarizes 1 Domestic animals are animals that have been bred selectively in captivity and thereby modified from their ancestors for use by humans who control the animals’ breeding and food supply (see http://asci.uvm.edu/course/asci001/domestic.html). 

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 GLOBAL SURVEILLANCE OF ZOONOTIC DISEASES the presentations that were made to provide an overview of several global infectious disease surveillance systems and lessons learned. GLOBAL PUBLIC HEALTH INTELLIGENCE NETWORK Several options are available to monitor and track emerging zoonotic diseases in humans. Marlo Libel, of the Pan American Health Organiza- tion, described one that uses an automated process to track and filter news reports of outbreaks from around the world. The Global Public Health Intelligence Network (GPHIN), which was originally developed by the Public Health Agency of Canada in collaboration with the World Health Organization (WHO), is a web-based system to which users can subscribe for a fee. Users include governments around the world as well as nongovernmental agencies and organizations. Current subscribers include the Centers for Disease Control and Prevention (CDC), WHO, the World Organization for Animal Health (OIE), the Food and Agriculture Organi- zation of the United Nations, the European Centre for Disease Prevention and Control, and the European Commission. According to the GPHIN website, the network has multilingual capacity and monitors news sources and translates documents in seven languages (Arabic, English, French, Russian, Simplified and Traditional Chinese, and Spanish) via the Internet; with plans to add languages in the future. Libel noted that Portuguese and Farsi have been added to the multilingual capacity. Monitoring continues 24 hours a day, 7 days a week. Sources include websites, news wires, and other Internet-based information outlets. GPHIN tracks not only outbreaks of human disease, but also information related to animal and plant diseases, such as Streptococcus suis and soybean rust. Also tracked are contamination of food and water; natural disasters; product or drug safety; and chemical or biological exposures caused by terrorism or accident. The system automatically filters the information, Libel explained, iden- tifying duplicate reports and assigning a relevancy score, based on criteria built into the program. According to its website, “if the filtering identifies information about an event of significant public health risk, this informa- tion is automatically forwarded to GPHIN users by e-mail. The results of the relevancy filtering is then analyzed by the Agency’s [Public Health Agency of Canada] GPHIN officials to ensure accuracy of the automated process.” Libel noted that additional analyses by the human experts pre- cede any publication with an alert that is then distributed automatically to subscribers. GPHIN is designed to pay particular attention to a small number of human diseases that are of particular concern for even one case per the International Health Regulations: influenza, polio, Severe Acute Respira-

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 DISEASES IN HUMANS tory Syndrome, smallpox, all of which are examples considered to pose an international public health emergency. “We have to have a system in the countries able to detect any case, one case” of those four diseases, Libel said. For another set of diseases—including cholera, pneumonic plague, yellow fever, Ebola, meningitis, and others—a variety of criteria have been established for analysts to determine whether an outbreak is a “public health emergency of international concern.” Once GPHIN issues an alert, further investigation begins. Table 4-1 shows the number of disease events that were reported to and verified by WHO between 2001 and 2008, based on alerts from GPHIN. TABLE 4-1 Disease Events Verified by World Health Organization, January 2001 to April 2008 Total events 2001 2002 2003 2004 2005 2006 2007 2008 2,415 192 244 509 374 324 296 321 155 SOURCE: Libel (2008). GLOBAL OUTBREAK ALERT AND RESPONSE NETWORK Once the GPHIN system has identified an outbreak, Libel explained, the Global Outbreak Alert and Response Network (GOARN) goes into action. Also developed under the auspices of WHO, GOARN is a network of 200 partners, institutions, and organizations worldwide that provide coordination, expertise, and technical support for rapid identification, con- firmation and response to outbreaks of international importance. Libel listed GOARN’s primary goals as the following: • Assist countries with disease control efforts by ensuring rapid, appropriate technical support to affected populations; • Investigate and characterize disease events and assess the potential for rapidly emerging epidemic disease threats; and • Support national outbreak preparedness by ensuring that responses contribute to sustained containment of epidemic threats. To provide a sense of the scope of GOARN’s efforts, Libel noted that the network and its partners coordinated responses in 63 countries, mobi- lizing more than 500 experts in response to 97 events between 2000 and 2007. Figure 4-1 provides an overview of the structure of the GOARN network.

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 GLOBAL SURVEILLANCE OF ZOONOTIC DISEASES The GOARN process begins with an initial screening and verification of the reported outbreak, followed by an assessment of the risk the outbreak poses. A response strategy is quickly developed, and necessary operations begin. One key to the value of GOARN is the capacity to provide a wide range of special, scientifically based expertise and advice, targeted to the outbreak, which may include: • Operational and technical coordination; • Logistics, security, and finance; • Laboratory support; • Epidemiological investigation; • Infection control and containment; • Clinical management; • Field communications; • Information management, media relations, and social mobilization; and • Expertise in environmental health or medical anthropology. The availability of this pool of expertise is particularly important in countries with few resources, and has been instrumental in the effective response to outbreaks such as the Marburg virus in Africa. Another benefit, he explained, is that WHO can also use informal sources of information Regional d ize Tr ial ks Pr ainin Networks ec r og ram g Sp etwo N s Steering Committee Collabo- + WHO rating Operational Centres Support Team (FIMS) Nat i Cen onal Os tres NG UNOs FIGURE 4-1 Structure of the Global Outbreak Alert and Response Network. SOURCE: Libel (2008). Figure 4-1 replaced R01393

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 DISEASES IN HUMANS outside of the country’s official Ministry of Health to ensure facilitation of dialogue to contribute to the verification process of an outbreak in a timely manner. This allowance has been of significant value, especially from regions in which governments have sometimes been cautious about releas- ing formal public health reports. This is an important change, Libel noted, that allows for necessary communication among countries and a thorough verification process. Libel identified other specific benefits of GOARN activities and efforts that fall under some of the larger areas bulleted above. Specific benefits include: enhancing dialogue with country governments and other international stakeholders to build trust; strengthening credibility and transparency; alleviating costs to mobilize or best use resources and providing surge capacity; and providing access to information exchange, best practices and technology transfers, and equitable and appropriate participation in field missions. All of these factors may contribute to the incentive of a country to respond to or control a disease outbreak with the best scientific advice and evidence to protect their human and animal populations. GOARN has become a trusted “operational arm of the Inter- national Health Regulations” and has been welcomed around the world, Libel said. PROGRAM FOR MONITORING EMERGING DISEASES (PROMED-MAIL) Another system that tracks information about disease outbreaks around the world was described by Peter Cowen, of North Carolina State Univer- sity. ProMED-mail, or the Program for Monitoring Emerging Diseases, is a project of the International Society for Infectious Diseases set up in 1994 to provide a means of quickly disseminating information about infectious disease outbreaks. This free service has more than 40,000 subscribers in 160 countries. The subscribers are the source of the information handled by the system. Subscriptions are available in multiple languages includ- ing English, Russian (ProMED-RUS), Spanish (ProMED-ESP), Portuguese (ProMED-Port), and French (ProMED-FRA). There are also pages dedi- cated to translations in Chinese and Japanese. ProMED-MBDS is a special service of ProMED mail (in English) for the Mekong Basin Disease Surveil- lance (MBDS) group of countries. Volunteer rapporteurs and moderators with expertise in 22 areas are the backbone of the system. Spending as much as 3 to 6 hours a day on the effort, rapporteurs search the Internet for information, including official WHO reports, about emerging diseases and verify that information. Information is passed on to volunteer subject- matter experts, such as Cowen, a veterinarian who serves as an animal and zoonotic disease moderator. Based on the expert moderator’s analysis, the information may then be posted to the group via ProMED-mail.

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 GLOBAL SURVEILLANCE OF ZOONOTIC DISEASES The map presented in Figure 4-2 shows the number of pathogens reported by region, and, Cowen explained, reveals the gaps in the system. He is particularly concerned that much of Africa and the Middle East, as well as areas of Southeast Asia, are not well covered by the system. Figure 4-3 shows the representation of the disease for which ProMED has disseminated information in 2007–2008. Cowen pointed out advantages, gaps, and challenges of the system. The system archives every posting, and most postings contain a comment to put the data in context. Therefore, a researcher interested in tracking how a particular outbreak developed and was identified would find the archive a valuable resource. The archives also show the communication among mod- erators that led to the decisions about whether to post the data. One significant challenge is the cost of running ProMED-mail, which Cowen said is a nonprofit operating “on a shoestring” and is almost entirely reliant on volunteers. Similar to other web-based systems, they are challenged to deal with the volume of daily postings. Not only do they need to determine the importance of the data, but they need to project whether those data have the potential to overload the technical system. But per- sonal communication is key to success, he said in closing: “If we are ever going to do real monitoring for emerging diseases, I think it is important that we develop collegial relationships, we get to know each other. These things are always done person to person, and certainly one of the reasons ProMED-mail works is that we know each other very well and we trust each other.” From the vantage point of an animal health professional, he Russia Canada Kazakhstan United States China Iran Algeria India Sudan Number Pathogens 50…60+ Brazil 40…50 Australia 30…40 20…30 10…20 ≤0…10 FIGURE 4-2 Pathogens reported by global location via ProMED. SOURCE: Reprinted with permission from John Brownstein. Figure 4-2.eps color

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 DISEASES IN HUMANS FIGURE 4-3 ProMED-mail disease report summary, 2007–2008. SOURCE: Reprinted with permission from4-3.eps Figure John Brownstein. bitmap stated his hopes for greater integration among systems developed within different fields. DEPARTMENT OF DEFENSE GLOBAL EMERGING INFECTIONS SURVEILLANCE AND RESPONSE Another disease surveillance system was developed by the U.S. Depart- ment of Defense (DoD) to monitor and respond to infectious diseases that are a threat to military personnel or their families, that reduce medical readiness, or that present a risk to national security (DoD-GEIS, 2008). Tracy DuVernoy of the DoD, explained that the Global Emerging Infections

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0 GLOBAL SURVEILLANCE OF ZOONOTIC DISEASES Surveillance and Response system (GEIS) was established by a Presidential directive in 1996, in response to growing recognition of the potential threat that infectious diseases pose to the health of U.S. military. GEIS collaborates with partners both within the DoD and in other federal agencies, universi- ties, and elsewhere. Its goals are: • Disease surveillance and detection; • Response and readiness; • Integration and innovation; and • Cooperation and capacity building. GEIS has established five priorities, DuVernoy explained: respiratory illnesses (particularly influenza), febrile illnesses (particularly malaria and dengue fever), enteric (acute diarrheal) disease, antimicrobial resistance, and sexually transmitted infections. The GEIS network includes partners and laboratory facilities in many parts of the world (see Figure 4-4). To illustrate how the system operates, DuVernoy described GEIS’s global influenza surveillance system, which has three elements. First, the A Global Network Armed Forces Institute of Pathology WRAIR/NMRC Germany Korea Egypt Navy Hub Air Force Hub Thailand Kenya Peru Indonesia DoD’s Unique Assets—Overseas presence due to laboratories FIGURE 4-4 Overview of Department of Defense Global Emerging Infections Sur- veillance and Response System (DoD-GEIS). SOURCE: DuVernoy (2008). Figure 4-4.eps redone from ppt

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 DISEASES IN HUMANS sentinel surveillance component has 71 surveillance sites around the world. Second, population surveillance monitors DoD personnel in all service branches, as well as civilian populations at four clinics located near the California–Mexico border. Third, the international surveillance system con- sists of Department of Defense medical research laboratories in five loca- tions overseas, with approximately 850 staff. These laboratories conduct surveillance of influenza and other diseases in their regions. DuVernoy described three other DoD disease surveillance efforts that have been funded by GEIS: the Early Warning Outbreak Recognition Sys- tem (EWORS), Alerta, and the Electronic Surveillance System for the Early Notification of Community-based Epidemics (ESSENCE). EWORS is a computer-based system through which hospitals can serve as sentinels, as hospitals collect and monitor data about emerging diseases. The multi- lingual network was first operational in Indonesia and has expanded. Alerta is a surveillance system that was developed for the Peruvian Navy, and later expanded to include the Army. DuVernoy also noted that DoD is now fund- ing new integrated surveillance activities in Peru in its recognition of the growing importance of the interaction between human and animal health. In this effort, they are attempting to pilot the Alerta system to incorporate not only human surveillance, but also animal disease information by work- ing with both the ministries of agriculture and of public health. ESSENCE, which was developed in the 1990s, but expanded after September 2001, is a secure system for collecting and analyzing near real-time data in the Washington, DC, area to provide early warning of bioterrorism and other disease threats. DuVernoy closed with the observation that the global coverage pro- vided through these systems has been “an incredible asset” and that the systems can be very flexible. Collaboration with ministries of health and agriculture in other countries, with CDC, and with many other organiza- tions and universities has greatly enhanced the potential for the system. On the other hand DuVernoy added that their “efforts are still not well integrated on the animal side” because the primary mission is to protect the active-duty forces. Another gap is that population coverage is not always consistent. Children are not well represented in the surveillance programs, nor are people who live in remote areas. At the same time, the system may be too sensitive within other populations, she said, yielding too many alerts for events that pose little risk.

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 GLOBAL SURVEILLANCE OF ZOONOTIC DISEASES ARBONET The national surveillance system for arboviral diseases,2 ArboNET, was described by Marc Fischer of CDC. The system was developed in 1999 in response to the emergence of West Nile virus in the United States, was expanded to cover other arboviral diseases in 2003, and is maintained by CDC’s Division of Vector-borne Infectious Diseases. Diseases covered in this system are listed in Box 4-1. ArboNET has four primary objectives, which are to: • Monitor the epidemiology, incidence, and geographic spread of West Nile virus and other arboviruses; • Provide timely information regarding arboviral disease to public health officials, government leaders, researchers, clinicians, and the public; • Support prevention and control efforts and stimulate research on arboviral diseases; and • Evaluate funding needs. ArboNET collects several types of data: human disease cases, screening of donated blood, veterinary data, and data on wild birds, sentinel chickens, and mosquitoes. Sources include health care providers, veterinarians, and commercial laboratories who report information to a state or local health department. ArboNET staff collect a variety of information on human patients and blood donors, including demographic information, details of illness, and outcome. They are working to collect additional information on medical risk factors, underlying conditions, any immunosuppressive medications the individual has taken, and details of any laboratory testing. Data collected on animals include species, location, types of virus, and dates of symptoms and collection. Because arboviral diseases are nationally notifiable3 diseases in the 2 Arthropod-borne viruses or “arboviruses” are a diverse array of agents that share the unique characteristic of transmission by blood-feeding arthropods, including ticks, mosquitoes, sand flies, and biting midges. More than 100 arboviruses are known to infect humans and over 40 to infect domestic animals. Infection can result in a wide range of disease syndromes, including systemic febrile illnesses, encephalitides, and hemorrhagic fevers. Examples of impor- tant human pathogens include the four dengue viruses, West Nile virus, yellow fever virus, and Japanese encephalitis virus. Rift Valley fever, Nairobi sheep disease, Venezuelan equine encephalitis, and Bluetongue are examples of veterinary diseases caused by infection with arboviruses (Miller et al., 2008). 3 A notifiable disease is one for which regular, frequent, timely information on individual cases is considered necessary to prevent and control that disease. Each year a list of nation- ally notifiable diseases is agreed on and maintained by the Council of State and Territorial Epidemiologist and CDC. Diseases that are considered nationally notifiable may or may not be designated by a given state as notifiable (reportable) in the state. States may use the national notifiable diseases list as well as other information, such as state-specific health priorities, to

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 DISEASES IN HUMANS BOX 4-1 Examples of Arboviruses Tracked in ArboNET Cache Valley California serogroup Chikungunya Colorado tick fever Dengue Eastern equine encephalitis Jamestown Canyon Japanese encephalitis LaCrosse Powassan St. Louis encephalitis Venezuelan equine encephalitis West Nile Western equine encephalitis SOURCE: Fischer (2008). United States, the state, local, and district health departments (including those in commonwealths of the United States) enter any disease surveillance data they receive into an electronic database that is uploaded weekly to CDC. CDC analyzes the data and disseminates it regularly. Dissemination includes weekly updates that are transmitted through listserves that go to health departments, to the USGS NWHC as weekly, monthly, and annual summary reports, and as publications in peer-reviewed journals. Fischer explained that there are some differences in the way data on neuroinvasive diseases and non-neuroinvasive diseases are reported. All arboviral diseases are legally reportable throughout the United States, but more complete data are available for those that are neuroinvasive (e.g., encephalitis or acute flaccid paralysis) than for those that are not. For the neuroinvasive disease, the data are used to calculate rates of disease, project the total number of cases and infections, and compare trends over time. Figure 4-5 shows the incidence of West Nile virus neuroinvasive disease in the United States in 2007. guide their determination of which conditions/diseases to make notifiable in their state. Thus, the list of state-specific notifiable diseases may vary across states and in a given state; the list may vary over time as well. Disease reporting is currently mandated by legislation or regula- tion only at the local or state level (CDC, 2001).

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 GLOBAL SURVEILLANCE OF ZOONOTIC DISEASES Incidence per million .01-9.99 10-99.99 ≥100 Puerto Rico Any WNV Activity FIGURE 4-5 Incidence of West Nile Virus Human Neuroinvasive Disease in the United States, 2007. SOURCE: Fischer (2008). Figure 4-5.eps map is bitmap color text added as text Animal data are not reportable, but are just as important as the human data. Fischer noted that collection and verification of these data vary by jurisdiction. He noted that slightly more than 500 animals (primarily horses) were identified and tested positive for West Nile virus in 2007. More than 1,800 birds tested positive; over half were American crows. The presence of virus in mosquito populations is not reportable, but many health departments use traps to monitor the presence of West Nile—nearly 8,100 mosquito pools tested positive for the virus in 2007. The strengths of ArboNET are that it is a comprehensive system that collects human, animal, and ecological data, and that it can provide detailed data down to the county level, Fischer said. ArboNET also provides inci- dence and geographic temporal trend data for neuroinvasive diseases, as well as a broad picture of arboviral transmission activity and migration. With these data it is possible to see where disease reservoirs and vectors are occurring. Collaborations among CDC, state and local health depart- ments, and blood services agencies, as well as rapid turnaround, allow for quick response. However, Fischer also pointed out that ArboNET is a passive surveil- lance system and that it provides only minimal clinical and laboratory data.

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 DISEASES IN HUMANS Thus it is not possible to confirm that patients meet case definitions. More- over, potentially long delays between the time cases occur and the time they are reported are beyond the network’s control. Some of the data (human fever cases, animal and ecological data) are not reportable or notifiable by law; the results are variable and may not be representative. Finally, this system works differently than those used for other notifiable disease, which limits the potential for coordination. Fischer closed with a few questions about how the system might be improved: • Would human fever data provide a more complete picture of where human disease is occurring? • Do animal and ecological data help predict human disease and provide timely warning of local outbreaks? • Can the data be used to develop predictive models for arboviral disease risk factors or trends? • Can the data be used to help perform clinical trials or postmarket- ing surveillance for a West Nile virus vaccine? • Can the system help detect the introduction or emergence of a new domestic arbovirus (e.g., dengue fever, Chikungunya, Japanese encephalitis, or Zika)? EMERGING INFECTIONS NETWORK The final system presented was the Emerging Infections Network (EIN), which was described by Phil Polgreen of the University of Iowa. A project of the Infectious Diseases Society of America (and funded by CDC), EIN is a network of infectious disease specialists who contribute clinical data to assist CDC in identifying emerging diseases. In essence, Polgreen explained, EIN began with the goal of establishing a permanent system to allow rapid communication about symptoms that clinicians were seeing, how they were responding, and so forth—both among clinicians and with CDC. The goal was not to replicate systems already in place, but to fill in gaps. EIN now has approximately 1,200 members who are pediatricians or internists throughout the United States, as well as approximately 130 public health officials. At any given time, Polgreen explained, four or five conversations may be underway on the listserve about symptoms that physicians are concerned about, many of which are not necessarily about emerging infectious diseases, but rather day-to-day clinical challenges. For example, he noted that the moderated listserve discussions addressed community-associated Methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Clostridium difficile before official reports were available, based on novel, difficult-to-treat symptoms that were reported at the time.

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 GLOBAL SURVEILLANCE OF ZOONOTIC DISEASES EIN also conducts periodic surveys (73 have been done since 1997) as urgent issues emerge. These may be about drug shortages or toxicities, but also diseases such as Hantavirus Pulmonary Syndrome or West Nile. The surveys help establish the scope of a problem, common treatment responses, and other information to support CDC in determining what steps it needs to take. In Polgreen’s view, the system would be even more useful if it were expanded to include electronic communities in other countries and veteri- nary providers, and if more communications among members were facili- tated. Part of the solution would be technological. The current volume of e-mails and surveys is already high, but certain tools could be used to link groups and databases and thus help to focus, aggregate, and disseminate information more effectively. Polgreen observed that work is being done on electronic networks in other contexts that could provide useful ideas. DISCUSSION The session closed with a panel discussion of early warning systems. Presenters were asked to reflect on whether the current ad hoc arrange- ment is adequate, to identify any gaps they see, and to suggest pathways to improving disease surveillance. An Ad Hoc System The presentations made clear that, as a participant observed, “there are a lot of networks out there. There are a lot of listserves doing a lot of things.” On the other hand, though, there is some overlap and redundancy, and in many cases critical communication and coordination that would make these networks of greater value is lacking. The discussion began with a question to the representatives of the disease surveillance systems that were presented in this session: “do you all interact with one another?” The panelists responded that they do sometimes, but not in any regular, coordinated way. The panelists acknowledged the complexity involved with conducting surveillance all over the world and coordinating findings and responses. One panelist noted that “most of these surveillance systems have arisen because of opportunity.” Participants noted that redundancies may exist, and the result may not be ideal, but whether some kind of “global design” would be preferable is not completely clear. The current arrangement “has certain attributes, which, if you designed it top-down, you might not be able to design in.” It may not be possible to develop a system that “fits all the needs out there,” another panelist, “nor will there be buy-in from everybody on a global system.”

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 DISEASES IN HUMANS Even within a single country, there are a range of preferences and needs, so different systems have been developed to meet them. Many countries have complicated approaches to collecting public health data, and it is important that disease surveillance efforts and programs provide countries and officials with a strong, positive incentive to participate. A neutral, cred- ible, scientifically-technical agency can substantiate response and control efforts by country officials, and help them in their preparedness efforts. Even under the best-case scenario when country officials have responded appropriately and in a timely manner, some ministers of health have lost their jobs because there was a disease outbreak in the first place. On the other hand, it may be more difficult for a single entity or structure to sustain that trust in every part of the world. Contemplating these complexities, several participants made the point that “our efforts might be better directed at trying to understand what the data are telling us rather than getting different forms of data.” Gaps On the other hand, a number of participants commented on important gaps in the current system. Looking broadly, participants noted that in terms of the widely shared goal of “looking at humans and animals and plants together, we are not really doing that enough. We are just beginning to do this.” One aspect of that challenge is that the national notifiable dis- ease system, at least in the United States, addresses only part of the surveil- lance challenge. Adding or linking to diseases in animal populations to the broader picture will require additional effort. The other major gap relates to geography and resources. The basic problem of “developing countries not being able to pay for” disease sur- veillance efforts translates into a range of problems, noted one participant. Another pointed out that developing countries may lack “sufficient funds for computers, a reliable working electrical system, and access to the Inter- net.” Thus communications are a challenge, data are not collected and reported, and information about evidence of disease or health practices is difficult to disseminate. Developing countries frequently lack personnel capacity to carry out surveillance to detect outbreaks, to conduct disease outbreak investigations, and to respond once an outbreak is identified, and international groups may face additional challenges in “quickly iden- tifying the best people” on the ground to participate in a rapid response. Consequently, some regions are poorly represented in surveillance systems, which are often hotspot regions with a high likelihood of emerging dis- eases where surveillance is most needed. In short, participants agreed that is critical to build capacity for sustainable, long-term disease surveillance and response.

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 GLOBAL SURVEILLANCE OF ZOONOTIC DISEASES Discussants noted several creative responses to resource challenges, including the use of cell phones to improve communication in remote areas as more countries invest in cell phone technology. By applying such inno- vative solutions to known obstacles, existing disease surveillance systems have the virtue of some flexibility. On the other hand, though, many seemed to agree that “we have to go beyond just sending out alerts and receiving signals and learn how to put people in touch with each other.” New tech- nologies and Internet tools may make significant improvements possible, but “what we really need is information, usable information.” In the end, one participant noted that it will be key to identify the critical priorities. The existing networks prove that disease surveillance is clearly achievable if it becomes a priority within the broader context of disease prevention, response, and control.