The United States Intelligence Community (IC) has a long history of producing assessments on infectious diseases. Most of these papers are distributed to government administrators and inform the choices of policymakers. Three of these assessments stand out as analytical products that have had important impact on the awareness, funding and treatment of infectious diseases around the world. The first paper is the National Intelligence Estimate on the Global Infectious Disease Threat, the second paper is the assessment on the Next Wave of HIV/AIDS, and the third paper was the assessment on SARS. This page summarizes the findings of these three papers and provides information about their impact.
National Intelligence Estimate on the Global Infectious Disease Threat In January, 2000, The National Intelligence Council released its National Intelligence Estimate on the Global Infectious Disease Threat. This paper examined the re-emergence of the threat from infectious diseases worldwide and its implications for the United States.
It stated that infectious diseases were a leading cause of death, accounting for a quarter to a third of the estimated 54 million deaths worldwide in 1998, and that the spread of infectious diseases results as much from changes in human behavior—including lifestyles and land use patterns, increased trade and travel, and inappropriate use of antibiotic drugs—as from mutations in pathogens.
Additionally, the paper found that new and reemerging infectious diseases will pose a rising global health threat and will complicate US and global security over the next 20 years. These diseases will endanger US citizens at home and abroad, threaten US armed forces deployed overseas, and exacerbate social and political instability in key countries and regions in which the United States has significant interests.
Twenty well-known diseases—including tuberculosis (TB), malaria, and cholera—have reemerged or spread geographically since 1973, often in more virulent and drug-resistant forms. At least 30 previously unknown disease agents have been identified since 1973, including human immunodeficiency virus (HIV), Ebola, hepatitis C, and Nipah virus, for which no cures are available. Of the seven biggest killers worldwide, TB, malaria, hepatitis, and, in particular, HIV/AIDS continue to surge, with HIV/AIDS and TB likely to account for the overwhelming majority of deaths from infectious diseases in developing countries by 2020. Acute lower respiratory infections—including pneumonia and influenza—as well as diarrheal diseases and measles, appear to have peaked at high incidence levels.
Regional trends Developing countries will continue to experience the greatest impact from infectious diseases—because of malnutrition, poor sanitation, poor water quality, and inadequate health care—but developed countries also will be affected.
Impact within the United States Although the infectious disease threat in the United States remains relatively modest as compared to that of noninfectious diseases, the trend is up. Annual infectious disease-related death rates in the United States have nearly doubled to some 170,000 annually after reaching an historic low in 1980. Many infectious diseases—most recently, the West Nile virus—originate outside U.S. borders and are introduced by international travelers, immigrants, returning U.S. military personnel, or imported animals and foodstuffs. In the opinion of the U.S. Institute of Medicine, the next major infectious disease threat to the United States may be, like HIV, a previously unrecognized pathogen. Barring that, the most dangerous known infectious diseases likely to threaten the United States over the next two decades will be HIV/AIDS, hepatitis C, tuberculosis, and new, more lethal variants of influenza. Hospital-acquired infections and foodborne illnesses also will pose a threat.
Some 4 million Americans are chronic carriers of the hepatitis C virus, a significant cause of liver cancer and cirrhosis. The U.S. death toll from the virus may surpass that of HIV/AIDS in the next five years. TB, exacerbated by multidrug resistant strains and HIV/AIDS co-infection, has made a comeback. Although a massive and costly control effort is achieving considerable success, the threat will be sustained by the spread of HIV and the growing number of new, particularly illegal, immigrants infected with TB. Influenza now kills some 30,000 Americans annually, and epidemiologists generally agree that it is not a question of whether, but when, the next killer pandemic will occur. Highly virulent and increasingly antimicrobial resistant pathogens, such as Staphylococcus aureus, are major sources of hospital-acquired infections that kill some 14,000 patients annually. The doubling of U.S. food imports over the last five years is one of the factors contributing to tens of millions of foodborne illnesses and 9,000 deaths that occur annually, and the trend is up.
Sub-Saharan Africa 65% of all deaths in Sub-Saharan Africa come from infectious diseases. Rudimentary health care delivery and response systems, the unavailability or misuse of drugs, the lack of funds, and the multiplicity of conflicts are exacerbating the crisis. Investment in health care in the region is minimal, less than 40 percent of the people in countries such as Nigeria and the Democratic Republic of the Congo (DRC) have access to basic medical care, and even in relatively well off South Africa, only 50–70% have such access, with black populations at the low end of the spectrum. It will remain the most vulnerable region. The death rates for many diseases, including HIV/AIDS and malaria, exceed those in all other regions. Sub-Saharan Africa's health care capacity—the poorest in the world—will continue to lag.
Sub-Saharan Africa also has an estimated 90 percent of the global malaria burden. Cholera, dysentery, and other diarrheal diseases also are major killers in the region, particularly among children, refugees, and internally displaced populations. Forty percent of all childhood deaths from diarrheal diseases occur in Sub-Saharan Africa. The region also has a high rate of hepatitis B and C infections and is the only region with a perennial meningococcal meningitis problem in a "meningitis belt" stretching from west to east. Sub-Saharan Africa also has yellow fever, while trypanosomiasis or "sleeping sickness" is making a comeback in the DROC and Sudan, and the Marburg virus also appeared in DRC for the first time in 1998. Ebola hemorrhagic fever strikes sporadically in countries such as the DRC, Gabon, Côte d'Ivoire, and Sudan.
Asia and the Pacific Multidrug resistant TB, malaria, and cholera are rampant in this area. The spread of HIV/AIDS, with its immunosuppression, will lead to a dramatic increase in infectious disease deaths. By 2010, the region could surpass Africa in the number of HIV infections.
Although the more developed countries of Asia and the Pacific, such as Japan, South Korea, Australia, and New Zealand, have strong records in combating infectious diseases, infectious disease prevalence in South and Southeast Asia is almost as high as in Sub-Saharan Africa. The health care delivery system of the Asia and Pacific region—the majority of which is privately financed—is particularly vulnerable to economic downturns even though this is offset to some degree by much of the region's reliance on traditional medicine from local practitioners. In South and Southeast Asia, reemergent diseases such as TB, malaria, cholera, and dengue fever are rampant, while HIV/AIDS, after a late start, is growing faster than in any other region.
TB caused 1 million deaths in the Asia and Pacific region in 1998, more than any other single disease, with India and China accounting for two-thirds of the total. Several million new cases occur annually—most in India, China and Indonesia—representing as much as 40 percent of the global TB burden. HIV/AIDS is increasing dramatically, especially in India, which leads the world in absolute numbers of HIV/AIDS infections, estimated at 3–5 million. China is better off than most of the countries to its south, but it too has a growing AIDS problem, with HIV infections variously estimated at 100,000 to 4000,000. and spreading rapidly. Regionwide, the number of people infected with HIV could overtake Sub-Saharan Africa in absolute numbers before 2010.
Former Soviet Union (FSU) and Eastern Europe These areas will see a substantial increase in infectious disease incidence and deaths. In the FSU especially, the steep deterioration in health care and other services owing to economic decline has led to a sharp rise in diphtheria, dysentery, cholera, and hepatitis B and C. TB has reached epidemic proportions throughout the FSU, while the HIV-infected population in Russia alone could exceed 1 million by the end of 2000 and double yet again by 2002. The sharp decline in health care infrastructure in Russia and elsewhere in the former Soviet Union (FSU) and, to a lesser extent, in Eastern Europe—owing to economic difficulties—are causing a dramatic rise in infectious disease incidence. Death rates attributed to infectious diseases in the FSU increased 50% from 1990 to 1996, with TB accounting for a substantial number of such deaths. Access to health care ranges from 50 to 70% in most European FSU states, including Russia and Ukraine, and from 40 to 50% in FSU states located in Central Asia. WHO estimates are consistent, that only 50–80% of FSU citizens had regular access to essential drugs in 1997, as compared to more than 95% a decade earlier as health care budgets and government-provided health services were slashed. Health care access is better in Eastern Europe, particularly in more developed states such as Poland, the Czech Republic, and Hungary, where it ranges from 70 to 90%, while only 50-70% have access in countries such as Bulgaria and Romania. More than 95 percent of the population throughout the East European region had such access in 1987, according to WHO.
Crowded living conditions are among the causes fueling a TB epidemic in the FSU, especially among prison populations—while surging intravenous drug abuse (IVDA) and rampant prostitution are substantially responsible for a marked increase in HIV/AIDS incidence. There were 111,000 new TB infections and 25,000 deaths in Russia alone in 1996, a growing number of them multidrug resistant. The number of new infections for the entire FSU in 1996 was 188,000, while East European cases totaled 54,000.
Diphtheria reached epidemic proportions in the FSU in the first half of the decade, owing to lapses in vaccination. Cholera and dysentery outbreaks are occurring with increasing frequency in Russian cities, such as St. Petersburg and Moscow, and elsewhere in the FSU, such as in Tbilisi, owing to deteriorating water treatment and sewerage systems. Hepatitis B and C, spread primarily by IVDA and blood transfusions, are on the rise, especially in the non-European part of the FSU. Polio also has reappeared owing to interruptions in vaccination, with 140 new cases in Russia in 1995.
Latin America There is distinct progress in infectious disease control in this region, including the eradication of polio, but uneven economic development has contributed to widespread resurgence of cholera, malaria, TB, and dengue. These diseases will continue to take a heavy toll in tropical and poorer countries.
Latin American countries are making considerable progress in infectious disease control, including the eradication of polio and major reductions in the incidence and death rates of measles, neonatal tetanus, some diarrheal diseases, and acute respiratory infections. Nonetheless, infectious diseases are still a major cause of illness and death in the region, and the risk of new and reemerging diseases remains substantial.