Wednesday, April 9, 2003
Good morning, Mr. Chairman and Members of the Committee. I thank you for the invitation to participate today in this timely hearing on a critical public health issue: severe acute respiratory syndrome (SARS). Today I will update you on the status of the spread of this emerging global infectious disease threat and on the Department of Health and Human Services' (HHS) response to it, primarily through the Centers for Disease Control and Prevention (CDC) and the National Institute for Allergy and Infectious Diseases (NIAID) at the National Institutes for Health (NIH), in cooperation with the World Health Organization (WHO) and other domestic and international partners.
On April 4, 2003, President Bush issued an Executive Order to update the list of communicable diseases that are quarantinable, to include SARS. The Order also delegated to me the authority to approve Surgeon General regulations designed to prevent introduction of communicable diseases into the U.S. and to approve quarantine sites selected by the Surgeon General. While we have no plans at this time to seek any use of the expanded authority, we took the step of issuing the Executive Order as a prudent precaution, so that we would be ready to meet a severe public health risk involving SARS in the event that one should develop in the future - which we are, of course, working to prevent.
As we have seen repeatedly, infectious diseases are a continuing threat to our nation's health. Although some diseases have been conquered by modern advances, such as antibiotics and vaccines, new ones are constantly emerging, such as Nipah virus, West Nile Virus, vancomycin-resistant Staphylococcus aureus (VRSA), and hantavirus pulmonary syndrome. SARS is the most recent reminder that we must always be prepared for the unexpected. SARS also highlights that U.S. health and global health are inextricably linked and that fulfilling HHS's domestic mission–to protect the health of the U.S. population–requires global awareness and collaboration with international partners to prevent the emergence and spread of infectious diseases.
Emergence of SARS
Since late February 2003, CDC has supported WHO in the investigation of a multi-country outbreak of unexplained atypical pneumonia referred to as severe acute respiratory syndrome (SARS). As of April 7, 2003, at 4:00 p.m., a total of 2,460 probable or suspected cases of SARS have been reported to WHO from 17 countries other than the United States and 98 of these persons have died. In the United States, there have been 149 suspect SARS cases reported from 30 states. Of these 149 suspect cases among U.S. residents, 141 have traveled to mainland China, Hong Kong, Singapore, or Hanoi, Vietnam. Five (5) had household contact with a suspected SARS case, and 3 are healthcare workers who provided medical care to a suspected case. Cases in the United States have had relatively less severe manifestations of SARS compared to cases reported in other countries. A total of 52 suspect SARS cases have been hospitalized, of whom 5 remain hospitalized. None of the suspected cases in the United States have died.
In February, the Chinese Ministry of Health notified WHO that 305 cases of acute respiratory syndrome of unknown etiology had occurred in Guangdong province in southern China since November 2002. In February 2003, a man who had traveled in mainland China and Hong Kong became ill with a respiratory illness and was hospitalized shortly after arriving in Hanoi, Vietnam. Health-care providers at the hospital in Hanoi subsequently developed a similar illness. During late February, an outbreak of a similar respiratory illness was reported in Hong Kong among workers at a hospital; this cluster of illnesses was linked to a patient who had traveled previously to southern China. On March 12, WHO issued a global alert about the outbreak and instituted worldwide surveillance for this syndrome, characterized by fever and respiratory symptoms.
On Friday, March 14, CDC activated its Emergency Operations Center (EOC) in response to reports of increasing numbers of cases of SARS in several countries. On Saturday, March 15, CDC issued an interim guidance for state and local health departments to initiate enhanced domestic surveillance for SARS; a health alert to hospitals and clinicians about SARS; and a travel advisory suggesting that persons considering nonessential travel to Hong Kong, Guangdong, or Hanoi consider postponing their travel. CDC Director Julie Gerberding and I conducted a telebriefing to inform the media about SARS developments.
Cases of SARS continue to be reported from around the world. The disease is still primarily limited to travelers to Hong Kong, Hanoi, Singapore, and mainland China; to health care personnel who have taken care of SARS patients; and to close contacts of SARS patients. Based on what we know to date, we believe that the major mode of transmission is through droplet spread when an infected person coughs or sneezes. However, we are concerned about the possibility of airborne transmission and also the possibility that objects that become contaminated in the environment could serve as modes of spread.
HHS Response to SARS
CDC continues to work with WHO and other national and international partners to investigate this ongoing emerging global infectious disease threat. This is a major challenge, but it is also an excellent illustration of the intense spirit of collaboration among the global scientific community to combat a global epidemic.
CDC is participating on teams assisting in the investigation in mainland China, Hong Kong, Taiwan, Thailand, and Vietnam. In the United States, we are conducting active surveillance and implementing preventive measures, working with numerous clinical and public health partners at state and local levels. As part of the WHO-led international response thus far, CDC has deployed approximately 30 scientists and other public health professionals internationally and has assigned almost 300 staff in Atlanta and around the United States to work on the SARS investigation.
CDC has issued interim guidance to protect against spread of this virus for close contacts of SARS patients, including in health care settings or in the home. We have also issued interim guidance for management of exposures to SARS and for cleaning airplanes that have carried a passenger with suspected SARS. We have issued travel advisories and health alert notices, which are being distributed to people returning from China, Hong Kong, Singapore, and Vietnam. We have distributed more than 200,000 health alert notice cards to airline passengers entering the United States from these areas, alerting passengers that they may have been exposed to SARS, should monitor their health for 10 days, and if they develop fever or respiratory symptoms, they should contact a physician.
Communication Vital to Coordinated Response
WHO is coordinating daily communication between CDC laboratory scientists and scientists from laboratories in Asia, Europe, and elsewhere to share findings, which they are posting on a secure Internet site so that they can all learn from each other's work. They are exchanging reagents and sharing specimens and tissues to conduct additional testing. Our evidence and that of many of our partners indicates that a new coronavirus is the leading candidate for the cause of this infection.
Rapid and accurate communications are crucial to ensure a prompt and coordinated response to any infectious disease outbreak. Thus, strengthening communication among clinicians, emergency rooms, infection control practitioners, hospitals, pharmaceutical companies, and public health personnel has been of paramount importance to CDC for some time. In the past three weeks, CDC has had multiple teleconferences with state health officials to provide them the latest information on SARS spread, implementation of enhanced surveillance, and infection control guidelines and to solicit their input in the development of these measures and processes. On Thursday April 3, 2003, CDC, FDA, NIH, and the National Vaccine Program Office officials participated in a teleconference hosted by the Pharmaceutical Research and Manufacturers of America with more than 70 representatives from major pharmaceutical industries and vaccine manufacturers to discuss potential SARS diagnostics, clinical interventions, and vaccine production.
On Friday, April 4, WHO sponsored, with CDC support, a clinical video conference broadcast globally to discuss the latest findings of the outbreak and prevention of transmission in healthcare settings. The faculty was comprised of representatives from WHO, CDC, and several affected countries who reported their experiences with SARS. The video cast is now available on-line for download. Dr. Gerberding and I, as well as other senior scientists and leading experts at CDC, have held numerous media telebriefings to provide updated information on SARS cases, laboratory and surveillance findings, and prevention measures. CDC is keeping its website current, with multiple postings daily providing clinical guidelines, prevention recommendations, and information for the public.
CDC Prevention Measures
Currently, CDC is recommending that persons postpone non-essential travel to mainland China, Hong Kong, Singapore, and Hanoi, Vietnam. Persons who have traveled to affected areas and experience symptoms characteristic of SARS should contact a physician. Health care facilities and other institutional settings should implement infection control guidelines that are available on CDC's website.
We know that individuals with SARS can be very infectious during the symptomatic phase of the illness. However, we do not know how long the period of contagion lasts once they recover from the illness, and we do not know whether or not they can spread the virus before they experience symptoms. The information our epidemiologists have suggests that the period of contagion may begin with the onset of the very earliest symptoms of a viral infection, so our guidance is based on this assumption. SARS patients who are either being cared for in the home or who have been released from the hospital or other health care settings and are residing at home should limit their activities to the home. They should not go to work, school, or other public places until at least ten days after they are fully asymptomatic.
If a SARS patient is coughing or sneezing, he should use common-sense precautions such as covering his mouth with a tissue, and, if possible and medically appropriate, wearing a surgical mask to reduce the possibility of droplet transmission to others in the household. It is very important for SARS patients and those who come in contact with them to use good hand hygiene: washing hands with soap and water or using an alcohol-based hand rub frequently and after any contact with body fluids.
For people who are living in a home with SARS patients, and who are otherwise well, there is no reason to limit activities currently. The experience in the United States has not demonstrated spread of SARS from household contacts into the community. Contacts with SARS patients must be alert to the earliest symptom of a respiratory illness, including fatigue, headache or fever, and the beginnings of an upper respiratory tract infection, and they should contact a medical provider if they experience any symptoms.
NIH Research Efforts
Complementing the efforts of the CDC and WHO, the National Institute of Allergy and Infectious Diseases (NIAID), a component of NIH, also has a significant role in the efforts against SARS, notably by rapidly addressing the issues of vaccine development, drug screening, and clinical research.
To reiterate my earlier statement, as with Hepatitis C, HIV/AIDS, Ebola, West Nile virus and a host of other "new" diseases, the SARS outbreak has reminded us that the emergence or reemergence of infectious diseases is a constant threat. And as has been the case with other emerging diseases, we anticipate that the strong NIAID research base in disciplines such as microbiology, immunology and infectious diseases will facilitate the development of interventions such as diagnostics, therapies, and vaccines to help counter SARS.
In line with assertions by CDC and WHO, NIAID also notes the mounting evidence that SARS is caused by a novel coronavirus that may have crossed species from an animal to humans. This hypothesis is based on the detection and isolation of coronaviruses from unrelated patients from different countries, and on the finding that several SARS patients have mounted an immunological response to coronavirus as they proceeded from the acute illness to the recovery or convalescent stage. While some questions remain -- for example, there is some evidence that a second virus may contribute to the pathogenesis of SARS -- the existing evidence for a causative role for a coronavirus justifies the ongoing development of diagnostic tools, therapies and vaccines that target coronaviruses.
Coronaviruses are best known as one of the causes of the "common cold," which is generally a very benign condition, very rarely resulting in life-threatening disease. The coronavirus suspected to be associated with SARS is a new type of coronavirus that has not been previously identified.
I would note that no evidence of genetic "tampering" of the virus implicated in SARS has been detected, based on analyses of the genomic sequence data of the samples from SARS patients examined so far. As even more extensive genomic sequence data become available for the SARS virus, it will be possible to further distinguish natural origin from the possibility that the SARS agent was created in a laboratory or even as a bioweapon. Until then, we will keep our minds open to these possibilities, however remote.
SARS Research OpportunitiesNIAID maintains a longstanding commitment to conducting and supporting research on emerging infectious diseases, such as SARS, with the goal of improving global health. In carrying out its global health research mission, the Institute supports a myriad of activities, including intramural and extramural research, and collaborations with international agencies and organizations. Since the first SARS reports, NIAID has worked rapidly to identify opportunities for accelerating or expanding research to improve the diagnosis, treatment, and prevention of SARS. These areas include:
Surveillance and epidemiology. NIAID supports a long-standing program for surveillance of influenza viruses in Hong Kong, led by Dr. Robert Webster of St. Jude's Children's Research Hospital in Memphis. Dr. Webster and his team in Hong Kong have collaborated with WHO, CDC and others in helping to illuminate the SARS outbreaks in Asia. In addition, at the request of WHO, NIAID assigned a staff epidemiologist to provide epidemiologic and logistical assistance during the early stages of the epidemic.
Diagnostics. Significant progress has been made by the CDC in developing a diagnostic test for SARS. As part of these efforts, NIAID-sponsored researchers in Hong Kong also devised a diagnostic test based on PCR technology as well as a diagnostic tool using the immunofluorescence assay technique. In other research, the NIAID-funded Respiratory Pathogens Research Unit (RPRU) at Baylor College of Medicine has developed methods to detect known human coronaviruses using cell culture and molecular diagnostic tools and can also assess the host immune response to known coronavirus infections. In 2003 NIAID will expand this capacity for research on emerging acute viral respiratory diseases, including pandemic influenza and SARS.
Vaccine Research. As the SARS epidemic continues, it will be necessary to consider a broad spectrum of vaccine approaches, as well as immunotherapy. NIAID is supporting the rapid development of vaccines to prevent SARS through both our extramural and intramural programs, including the NIAID Vaccine Research Center. Initially, these efforts are focusing on the development of an inactivated (or killed) virus vaccine. However, other approaches will soon follow, including novel approaches such as gene-based vaccines including DNA and replication defective adenoviral vectors, and live attenuated vaccines, as more knowledge about the cause of SARS and its etiology becomes available.
NIAID scientists have received samples of the SARS coronavirus from CDC and have initiated efforts to develop a vaccine. Fortuitously, vaccines against common veterinary coronaviruses are routinely used to prevent serious diseases in young animals, such as a vaccine given to pigs to prevent serious enteric coronavirus disease. These models could prove useful as we develop vaccines to protect humans.
To further accelerate SARS vaccine research and development efforts, NIAID is initiating contracts with companies, institutions and other organizations who have relevant technologies, cell lines and containment facilities; supporting the development of reagents needed for vaccine development; and developing animal models such as mice and relevant species of monkeys.
Therapeutics Research. As the nation began its focus on SARS, NIAID responded rapidly to a request from CDC to evaluate candidate antiviral therapeutic agents through a collaborative antiviral drug-screening project at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID). NIAID also has initiated discussions with the pharmaceutical industry about candidate antiviral drugs, and is reviewing a proposal for a clinical trial of antiviral therapy to be conducted by investigators of the NIAID Collaborative Antiviral Study Group and the NIH Clinical Center.
Clinical Research. Clinicians treating SARS patients have not yet identified treatment strategies that consistently improve prognosis, beyond good intensive and supportive care. Antibiotics do not work, a fact that is consistent with SARS being a viral disease. However, some improvement has been noted in certain patients treated with a combination of ribavirin and corticosteroids, which are given together in an effort to simultaneously block viral replication and modify the immune system reaction to the virus.
At the NIH Clinical Center in Bethesda, MD, and through the NIAID Collaborative Antiviral Study Group, NIH is preparing to admit SARS patients for evaluation and treatment, should this become necessary. This will be an opportunity to evaluate the efficacy of antiviral and immune-based therapies in patients with SARS. We also plan to evaluate approaches to improve management of patients with severe forms of the disease, including the passive transfer of antibodies from SARS patients who have recovered from the disease.
In addition to ensuring state-of-the-art treatment of potential patients, our clinical experts will be able to study the clinical characteristics of patients with SARS. We are particularly interested in answering key questions about the disease mechanisms of SARS. For example, are acute respiratory distress and mortality entirely caused by the presence of virus, or could it be that the response of the immune system is causing the severe outcomes in some patients? This is a central question to address because it may open up an avenue for immunomodulation treatment in addition to antiviral drugs.
Basic Research. NIAID currently is supporting 18 grants on coronavirus research. Also, the study of patients, as well as specimens in NIAID laboratories, will facilitate studies of the natural history of the SARS agent and its potential animal reservoir, and help to illuminate the risk factors and epidemiology of SARS. NIAID will support and conduct basic research studies on the pathogenesis of the disease and viral replication mechanisms, in order to identify targets for antiviral drugs, diagnostic tests and vaccines. Finally, the Institute will support and conduct genomic sequencing, proteomics and informatics of coronaviruses.
Of note, an existing NIAID animal model of a virus infection that causes a disease in mice very similar to SARS has been identified. The relevance of this animal model will be evaluated and may prove an important tool for defining treatment approaches to SARS that involve modulation of the immune system.
Infrastructure. A central concern when working with the SARS virus or SARS patients is the availability of facilities with the required safety level for the clinicians and staff, as well as for the community. Our ongoing plans to develop high-level containment facilities will facilitate SARS research, as well as planned studies of potential bioterror agents and other emerging diseases.
Emerging Global Microbial Threats
Since 1994, HHS, through CDC, has been engaged in a nationwide effort to revitalize national capacity to protect the public from infectious diseases. Progress continues to be made in the areas of disease surveillance and outbreak response; applied research; prevention and control; and infrastructure-building and training. However, SARS provides striking evidence that a disease that emerges or reemerges anywhere in the world can spread far and wide. It is not possible to adequately protect the health of our nation without addressing infectious disease problems that are occurring elsewhere in the world.
Last month, the Institute of Medicine (IOM) published a report describing the spectrum of microbial threats to national and global health, factors affecting their emergence or resurgence, and measures needed to address them effectively. The report, Microbial Threats to Health: Emergence, Detection, and Response, serves as a successor to the 1992 landmark IOM report Emerging Infections: Microbial Threats to Health in the United States, which provided a wake-up call on the risk of infectious diseases to national security and the need to rebuild the nation's public health infrastructure. The recommendations in the 1992 report have served as a framework for HHS's infectious disease programs for the last decade, both with respect to its goals and targeted issues and populations. Although much progress has been made, especially in the areas of strengthened surveillance and laboratory capacity, much remains to be done. The new report clearly indicates the need for increased capacity of the United States to detect and respond to national and global microbial and viral disease threats, both naturally occurring and intentionally inflicted, and provides recommendations for specific public health actions to meet these needs. The emergence of SARS, a previously unrecognized infectious disease threat, has provided a strong reminder of the threat posed by emerging infectious diseases.
The SARS experience reinforces the need to strengthen global surveillance, to have prompt reporting, and to link this reporting to adequate and sophisticated diagnostic laboratory capacity. It underscores the need for strong global public health systems, robust health service infrastructures, and expertise that can be mobilized quickly across national boundaries to mirror disease movements. As CDC carries out its plans to strengthen the nation's public health infrastructure, it will collaborate with state and local health departments, academic centers and other federal agencies, health care providers and health care networks, international organizations, and other partners. We have made substantial progress to date in enhancing the nation's capability to detect and respond to an infectious disease outbreak; however, the emergence of SARS has reminded us yet again that we must not become complacent. We must continue to strengthen the public health systems and improve linkages with domestic and global colleagues. Priorities include strengthened public health laboratory capacity; increased surveillance and outbreak investigation capacity; education and training for clinical and public health professionals at the federal, state, and local levels; and communication of health information and prevention strategies to the public. A strong and flexible public health infrastructure is the best defense against any disease outbreak.
Furthermore, despite ongoing research efforts and early successes, we still have much to learn about the disease. NIAID-sponsored coronavirus research, studies of other viral diseases, and clinical research already have provided results that are relevant to our quest for tools to detect, treat and prevent SARS. In the weeks and months ahead, NIH will continue to collaborate with the CDC and the Food and Drug Administration, as well as other relevant agencies to accelerate and expand our research aimed at improving the diagnosis, prevention, and treatment of SARS.
Thank you very much for your attention. I will be happy to answer any questions you may have.
Last Revised: April 16, 2003