Experts from the Johns Hopkins Bloomberg School of Public Health answer questions related to the Ebola virus and epidemic, including basic virology, infection risk in the U.S., contact tracing challenges and other topics.
- Updates from Liberia - Tolbert Nyenswah
- Response to the Outbreak - Gilbert Burnham
- Behavior Communications - Susan Krenn
- The Book on Ebola, Part II - David Quammen
- The Book on Ebola, Part I - David Quammen
- Ethics and Ebola - Nancy S. Kass
- Comparing Ebola to HIV/AIDS - David D. Celentano
- U.S. Hospital Preparedness - Albert Wu
- Nigeria's Containment - William Brieger
- An Ebola Vaccine - William J. Moss
- Protective Gear - Adam Kushner
- Quarantine Basics - Steve P. Teret
- Ebola Basics - Diane E. Griffin
- U.S. Risk - Andrew S. Pekosz
- Contact Tracing - David W. Dowdy
Updates from Liberia
Are you concerned that as Ebola cases fall in Liberia, interest and support from abroad will fade and with it hopes for rebuilding the health system?
We are having these conversations with donors as we speak. We have built very strong relationships with organizations… and they understand that the need for donors during the post-Ebola time of rebuilding will be great.
To ensure that plans are in place… the Ministry of Health, along with other government agencies and partners, is conducting an assessment to review progress toward the 10 Year National Health Policy and Plan established in 2011. The assessment will provide updated objectives and short- and long-term cost estimates in terms of the restoration of essential health services and strategies.
Why did health workers and the public distrust the government at the beginning of the outbreak?
Initially, Infection Prevention & Control (IPC) training and materials were slow to roll out to health facilities, leading to infections among health workers who lacked information—or the proper materials—to protect themselves when an Ebola patient presented. This has been addressed through widespread IPC trainings across the country, and by overcoming logistical hurdles to distribute IPC materials to health facilities. As logistics and training have improved, we’ve seen a significant reduction in health care worker infections, with few, if any, being reported at this stage of the outbreak.
In terms of the public, the outbreak was unprecedented and hit us hard, causing panic; other countries in the world could not have been prepared for what Liberia faced, either. We had to work very hard to engage the affected communities, to educate them and to gain their trust as we scaled up our response. That took time and patience, but now we have a sufficient number of Ebola treatment facilities, beds and laboratory capacity to test specimens more quickly and communities are largely pleased.
Currently are in Phase II of the EVD outbreak in Liberia, emphasizing intense community engagement. We have seen remarkable acceptance and action on the part of the Liberian public. For example, recently we’ve had an average of about 1.4 cases confirmed per day, but an average of about 25 cases reported a day. This is good; this shows that the public is being proactive about reporting illnesses, and that suspected cases are not languishing in communities, potentially infecting others. Now, cases are being isolated sooner, and people are receiving treatment earlier—ensuring a better chance at survival. Thus, I would say at this stage that we have the public’s trust – and are continuing to earn it.
Has the Ebola crisis led to stronger ties with other countries?
To a large extent, the crisis has prompted the development of stronger health communication and surveillance ties with other governments across Africa. With experience in EVD management, East Africa has contributed human resources to Liberia. A Ugandan government team of medical experts has played a key role in the fight against Ebola. Besides the African Union joint support to Liberia, Nigeria, Uganda, Kenya, Egypt, South Africa and Namibia have been tremendously helpful in supporting Liberia.
Back in August, you said West Africa needs more outside support to develop clinical trials of vaccines and Ebola treatments. Since then, you've been working with colleagues at Johns Hopkins to connect to drug manufacturers for experimental treatments and vaccines. How is that going?
In the past months we’ve been working to reach consensus regarding protocol, ethics and regulation. Phase 1 data from studies conducted in the US, Europe and sub-Saharan Africa shared with the Liberian Technical and Consultative Advisory Groups clearly indicated promising immunogenic responses. [This] led to a proposal to combine the Phase II/III approach in Liberia. Now, Liberia-US Technical Teams are finalizing protocols to submit to ethical and regulatory entities for approval, recruiting and hiring hundreds of Liberians to support the project structure, rehabilitating designated health centers, upgrading lab facilities, developing a clinical research program at the Liberian Institutes for Biomedical Research (LIBR), and providing mentoring and training opportunities to Liberians. Discussions are underway to ensure acceptable liability insurance for Liberian investigators and study volunteers, and the government is developing a legal framework.
Are clinical trials to test 2 leading experimental Ebola vaccines in Liberia still set to launch this month, and if so could the (thankfully) dwindling number of cases in Liberia make it harder to prove the efficacy of the vaccine?
Vaccine trials are still set for implementation. The Official Launch of the EVD vaccine trial is expected to commence by the end of January or early February, at either JFK or Redemption Hospital. A reduction in the cases could be a challenge for the vaccine trial, but will not necessarily affect the quality of the study.
Earlier you mentioned that you'd like to see the use of cell phone data and geo-spatial mapping to better understand patterns and boost the government response. Are you seeing that yet?
We’ve been working with partners on several technology-driven initiatives. For example, the CDC analyzed cell phone tower traffic in Liberia to pinpoint potential outbreaks (where clusters of people called the national Call Center), and to gauge the effectiveness of social mobilization campaigns. UNMEER/UNFPA are equipping contact tracers with close to 3,000 mobile phones. And the US National Geospatial Intelligence Agency (NGA) has compiled data through geospatial mapping, placed online to boost the international response to Ebola. We’re confident that many of these initiatives will last beyond the EVD response, and will support the broader health system as we continue to rebuild essential health services.
Tolbert Nyenswah, Liberia’s National Ebola Incident Manager and Assistant Minister/Deputy Chief of the Ministry of Health & Social Welfare, caught up with Global Health Now (GHN) to post an update on response efforts since he first talked to GHN last summer.
Response to the Outbreak
How have various global health players—donor communities, governments and aid agencies—fallen short in response to the Ebola crisis and have there been any noteworthy successes?
It was mainly a failure to recognize early and move fast on the epidemic, before it got out of hand. In the early stages, straightforward proven public health measures could probably have stopped it.
In terms of successes, Red Cross community efforts are getting good results. The organization developed the Safe and Dignified Burials program, which trains community members to bury Ebola victims using safety protocols that honor local burial customs. It’s cut back transmission greatly. Red Cross volunteers have done contract tracing and social mobilization, building awareness about Ebola in some of the areas most resistant to foreign health workers. They’ve also developed support programs for survivors and families.
Ten months into the epidemic, what should the priorities be to control the crisis and prevent another one?
We are close to having enough treatment beds now. What’s missing are basic community public health tools—surveillance, active case finding and good epidemiology. This is only now getting started in Sierra Leone, and hasn’t been done much in other affected countries.
What lessons have been learned from the disaster/humanitarian response to the Ebola epidemic?
The approach should be a quick response with full resources. At the same time, do not assume that an epidemic will behave like those in the past. There are no short cuts around a population-based strategy and civil society organizations like the Red Cross and MSF who can recruit volunteers quickly. Organizations with committed personnel have the strategic advantage to see their interventions through.
Government health systems need to be strengthened and more advanced regions can help others. A Ugandan epidemiologist, for example, is visiting districts in Sierra Leone, helping them to develop effective Ebola management strategies.
Gilbert Burnham, MD, PhD, MS, is an International Health professor and expert in emergency preparedness and disaster response. He is leading a three-country evaluation of Red Cross community activities in Guinea, Sierra Leone and Liberia.
Why is communication critical in controlling the Ebola epidemic?
Prevention is critical to controlling the Ebola epidemic and communication is critical to prevention. Communication is the best tool we have to help communities and individuals understand and effectively manage risk and to inform people when and where to access services. Communication through local leaders has proven extremely effective in catalyzing the community response, as was evidenced in Lofa County in Liberia.
What communication strategies and campaigns have successfully impacted behavior change? Do any work universally, or do all need to be tailored for different populations?
Harmonized multi-layered (national, district/county, community levels) and multimedia campaigns, informed by data and theory, are most effective in changing behavior. Any campaign, though, must be tailored to the local context and specific behavioral objectives to be impactful. With Ebola, basic prevention messages, such as hand hygiene will be useful to many, but completely insufficient for a family with Ebola in their home. For a community with Ebola in it, you need much more specific prevention messages as well as appropriate care-seeking behavior.
What communication resources are available for health care workers and leaders?
There are call centers that have FAQs and scripts, but are geared more to the general public. Efforts are also underway to establish toll-free networks specifically for health workers to seek professional advice, information and perhaps even counseling and support services. In Liberia, a collection of cell numbers for all health care workers is being used to send SMS messages with relevant information. Radio distance learning is being considered to supplement current training efforts in Liberia. At the global level, the Ebola Communication Network, supported by the Health Communication Capacity Collaborative (HC3 Project), has a terrific set of resources for health workers and others.
Susan Krenn is Executive Director of the Johns Hopkins Center for Communication Programs, and a lecturer in Health, Behavior and Society at the Johns Hopkins Bloomberg School of Public Health.
The Book on Ebola, Part II
It's hard for media outlets not to let Ebola dominate global health news lately. How should the media cover the current Ebola crisis?
They should emphasize that Ebola 2014 is a very dramatic event in a larger pattern, and if we do contain it, the story isn’t over. We need to keep the public alert.
There’s been a lot of fear about Ebola; people believe that Ebola causes victims to bleed out and shed bloody tears—all these grotesque ideas—which are myths, created to a great degree by the book The Hot Zone, I’m afraid. Unfortunately, that has added to the terror we see now and the media needs to correct that. Ebola is a horrible disease; it kills a high percentage of the people it infects. But it’s not a preternatural miasma; it’s not a monster movie—it’s just a virus that causes disseminated intravascular coagulation and organ shutdown.
Given all of your work over many years trying to raise awareness on the risks of such outbreaks, is it frustrating for you to see attention finally pick up when Ebola lands in America?
It’s a bit frustrating but not surprising at all. It’s also understandable, given what people have been told about Ebola, that they’d be freaked out by a case in Dallas. Suddenly people want to know, is Ebola going to come and get us? Well, that’s the wrong question. The right question is: How do we stop Ebola? And we stop it by stopping it in West Africa.
Let’s bounce back to early 2003, when SARS coronavirus hopped rides to Toronto, Hanoi, Singapore, and Beijing within the space of a day, thanks to a super spreader in Hong Kong’s Metropole Hotel. SARS was a dangerous event that could have turned into a devastating global pandemic—but a strong public health response and fast diagnostic science stopped it at about 800 deaths. But the affected cities all have strong governments and public health infrastructure. If it had gone to Monrovia, Kinshasa, Montevideo, São Paulo, for example, it could have been a lot worse.
What were some of the most fascinating things you saw and learned in your research, trekking through Central African forests?
One point I’d like to emphasize is that Ebola comes from a reservoir host somewhere in the forest. Ebola 2014 results from the way people interact with the forest and wild animals, and the next outbreaks will probably come from the forest, too. That is crucial information that could help us prevent the next big one, whether it’s MERS 2015, or a brand new virus—Borneo Coronavirus 2016, or Congo Hemorrhagic Rodent Virus 2017, perhaps.
Of course we have to respect cultural elements, and realize that changing a burial practice, for example, is not an easy thing for people to do when their loved ones are dying. The same is true with wildlife contact. When African people eat wildlife, we call it bushmeat—a word with a negative onus. When people in the U.S., as in Montana where I live, eat wild meat, we call it game, and there’s no negative onus—but it’s the same thing.
Science writer David Quammen continues his interview. Quammen has recently published Ebola: The Natural and Human History of a Deadly Virus, which places the Ebola outbreak within the broader context of emerging zoonotic diseases.
The Book on Ebola, Part I
Early on in the debate over travel restrictions, you warned of the dangers of such isolationist measures. Why are quarantine measures announced by states a bad idea?
It stirs complex conflicts involving civil liberties as well as public health, which many of us saw coming. I believe that closing borders completely would be not only impracticable, but counterproductive, because we if we close borders entirely then we won’t be able to get human and material resources needed to fight the outbreak in West Africa.
One of the most unfortunate things about the quarantine kerfuffle is that it distracts from the crucial efforts to contain Ebola. No one will be completely safe anywhere until we stop it in West Africa. Still, I respect the complexity of the decisions that people in the government are making. Voluntary quarantining seems like a reasonable notion for some. But people following voluntary quarantining, then going out to restaurants and riding the subway, undermine that case.
What is the mainstream media missing in its Ebola coverage and what do most people in the West not understand about Ebola?
People don’t understand that Ebola 2014 is not a one-time concern; it’s part of a pattern of emerging zoonotic diseases. It’s not random misfortune; there is a cause and effect related to human activity and the disruption of ecosystems.
We need to solve Ebola 2014, but it isn’t the next big one, it’s just a dress rehearsal—one that is going poorly and showing us that our preparation is in disarray. To change that, we might need legislation specifying who is in charge, more investment in infectious disease research and monitoring, and clear, consistent protocols. It’s a terrible crisis, but it also represents a dark opportunity to educate the public. We have their attention, and we need to honor that with real information rather than just scaremongering.
Ace science writer David Quammen has released an Ebola-specific excerpt of his book Spillover: Animal Infections and the Next Human Pandemic. To help frame the 2014 Ebola outbreak within the broader context of emerging zoonotic diseases, Quammen recently published Ebola: The Natural and Human History of a Deadly Virus with a thought-provoking, updated and expanded introduction.
Ethics and Ebola
Nancy S. Kass
From an ethical standpoint, how do you think authorities handled the case of Kaci Hickox, the Maine nurse who defied state-ordered quarantine orders in New Jersey and Maine after returning from treating Ebola patients in West Africa?
Imposing a quarantine sent exactly the wrong message to the public. Communications during emergencies (or perceived emergencies) should be accurate, transparent, and consistent. These messages were inconsistent with those from public health authorities and likely increased public confusion about how the virus is transmitted. Further, when someone is quarantined, ethically, it must be imposed in the least restrictive way. That means home quarantine is preferable when possible; and—especially in the United States—should ensure adequate food, shelter, and ability to interact with outsiders.
What are the ethical concerns in using an experimental drug such as ZMapp to treat Ebola patients?
While Americans given ZMapp recovered, we have no information to suggest their recovery had anything to do with this drug. If people in West Africa, for example, are given ZMapp on a widespread basis, without the ability to test whether it works, we risk investing less in other treatments, and we risk communities becoming less vigilant with public health prevention measures. This might be the silver bullet, and it might not be. It’s really important to find that out.
What ethical concerns are likely to arise as a potential Ebola vaccine is on the fast track to development, possibly bypassing standard testing protocol?
It is ethically troubling to give people at high risk for Ebola a placebo, and it is ethically troubling to not test it rigorously. That Americans received Ebola treatments without placebo only complicates how any decisions are viewed. But these study design questions are only the beginning. We also must consider who the target population should be: health care workers are often mentioned, but family members of Ebola patients might also be good candidates. If health care workers are enrolled, do investigators have responsibilities to give them the highest quality protective equipment? And if participants become infected, are duties of care to them different than they would have been outside of the trial in the local environment?
Nancy E. Kass, ScD, is the Phoebe R. Berman Professor of Bioethics and Public Health at the Berman Institute of Bioethics and Johns Hopkins Bloomberg School of Public Health.
Comparing Ebola to HIV/AIDS
David D. Celentano
How is public panic about the Ebola outbreak reminiscent of initial fears of HIV/AIDS?
The public reaction to Ebola is far more hysterical than the experience we had with HIV/AIDS. We had no idea that HIV was a virus for 3-4 years, and the epidemiology had to be worked out. Ebola we understand, but the panic we are seeing is scientifically difficult to understand, here in the US.
Is it useful to discuss the Ebola epidemic in the context of the early days of the HIV/AIDS epidemic?
The only truly relevance of the early days of HIV/AIDS was the lack of knowledge of what we were confronting and hence what we were doing for patients, and how that led to intense stigma and discrimination. Remember that Haitians were identified as one of the “risks” for HIV. Clearly, being Haitian was not a risk factor, but poverty and unprotected sex were more common in Belle Glade, Florida than in Boca Raton.
What lessons have we learned about HIV/AIDS that apply to Ebola?
Contact tracing, quickly adopting prevention strategies, and trying to avoid stigma and discrimination come to mind. Perhaps more relevant is our experience with SARS 10 years ago, when health care providers, especially in the Toronto epidemic, were so commonly infected. Infection control strategies, the proper donning and removal of personal protective equipment, and hand-washing were particularly important.
David D. Celentano, ScD, MHS, is Professor and Charles Armstrong Chair of Epidemiology at the Johns Hopkins Bloomberg School of Public Health, with joint appointments in International Health, Health, Society and Behavior, Health Policy and Management, and the Johns Hopkins University School of Medicine.
U.S. Hospital Preparedness
Does every U.S. hospital need to prepare for Ebola cases or just certain designated centers?
Every US hospital does not need to prepare a dedicated unit to care for Ebola patients. However, every hospital must be prepared to screen patients for Ebola risks, have protective equipment on hand for use by health care workers, and have protocols and training in place for the use of that equipment.
How do healthcare workers distinguish Ebola cases from other illnesses, especially during flu season in the U.S.?
It can be difficult to distinguish one febrile illness from another. Healthcare workers should take a careful history to capture information about travel to the West African countries of Liberia, Guinea and Sierra Leone, and about potential contact with Ebola patients or other people with febrile illnesses while in those countries.
Considering that U.S. healthcare workers have contracted Ebola, have U.S. hospitals been lax in their handling of cases? How could they improve?
In the very few cases in which US healthcare workers contracted Ebola from infected patients, adequate protocols and precautions were not yet in place. Importantly, healthcare workers were not trained in the appropriate donning and doffing of protective gear around the care of Ebola patients. There are now training materials, produced by the Johns Hopkins Armstrong Institute, available online.
Albert Wu, MD, MPH, is director of the Center for Health Services and Outcomes Research, the PhD Program in Health Services Research & Policy, and the Certificate Program in Quality, Patient Safety & Outcomes Research. He is also professor of Health Policy and Management and a practicing general internist.
On October 20, the WHO declared Nigeria Ebola free. There had not been a reported case in 42 days. What does this news, coming out of Lagos, a city with such a large population, represent?
Nigeria has the largest population in sub-Saharan Africa (more than 170 million) and a large portion is urban. What is unique about the current Ebola outbreak in West Africa is its large urban spread, unlike in all but one previous outbreak in east/central Africa. Lagos itself is the largest city in sub-Saharan Africa known for its tightly packed slums, and even tightly packed lower middle class neighborhoods. These are the types of areas where the Ebola wildfire caught hold in Monrovia, Liberia.
As one of the key speakers at the JHSPH Ebola symposium pointed out last month, Nigeria was ‘lucky’ in that Patrick Sawyer, the man who brought Ebola to the country from Liberia, sought care from a private clinic. Even though the doctor and other staff became infected, they too did not live in the slums and would not have entered into such areas with such high transmission potential. It was easy to identify the few contacts that had close contact with the Nigerian index case and provide appropriate and timely monitoring and intervention.
Even though one doctor ‘escaped’ to Port Harcourt, another large city, he again was not likely to mix with people in the slums, and hence the likely spread was ‘naturally’ contained.
What did Nigeria do right? We read about rapid isolation, contact tracing and, for those at risk, daily monitoring.
Yes–all of the above, though I was concerned that one doctor was able to 'escape,' as I said, to Port Harcourt.
Would this have been possible without the infrastructure of the polio-vaccine campaign, as was reported in some outlets?
I don’t believe this had anything to do with the polio campaign since it was not an issue of monitoring masses in the community, but a few socially well-placed individuals. Polio has had its own problems with resistance of western/cosmopolitan interventions like health care and education by people in the northern states. The country has been known for persistent appearance of wild polio virus. Nigeria has seen only 6 cases to date this year, down from previous years.
Can you speak to the outreach program that Nigeria undertook, and how it helped curb Ebola there?
This intense and rapid level of response is interesting. One would not doubt that Nigeria has the human resources to do this, but Nigeria’s response to other problems has not always been as timely and thorough. It would be interesting to learn more about the motivations behind this valuable but unusual response.
William Brieger, DrPH '92, MPH, is a senior malaria specialist at JHPIEGO and professor of International Health at the Johns Hopkins Bloomberg School of Public Health.
An Ebola Vaccine
William J. Moss
Is the only way to contain the Ebola epidemic through a vaccine?
Prior Ebola outbreaks were contained without a vaccine through early identification and isolation of infected persons, educational campaigns and implementation of preventive measures, particularly among health care workers. These measures could effectively contain the current Ebola epidemic. The current challenge is one of scale, given the rapidly increasing number of infectious cases, wide geographic spread in areas with poor access and infrastructure, and community mistrust and stigma. A vaccine would be a welcome tool in the fight against Ebola but perhaps not an essential one. The global public health community needs to remain focused on implementing currently available control strategies as vaccine development and testing move forward.
What is the status of Ebola vaccine clinical trials—how promising are they?
Several Ebola vaccines are under evaluation in clinical trials, and regulatory approval processes will be expedited to move promising vaccines forward. Initial clinical trials—currently underway in the U.S. and Europe—are assessing vaccine safety and the ability of the vaccine to elicit strong immune response, and preliminary findings are promising. The more difficult task will be demonstrating vaccine effectiveness, i.e., whether the vaccine protects people from infection. These trials may start as early as January 2015 but will face many challenges.
What are the main challenges in developing and distributing an effective Ebola vaccine?
The challenges are multiple but not insurmountable, and include biological characteristics of the virus, limited understanding of protective immunity, applicability of studies in animal models, design and conduct of human clinical trials, ethical issues of trials in the mist of an outbreak, regulatory and licensure hurdles, and eventual decisions as to how best to use limited vaccine supplies. Should an effective Ebola vaccine become available, high coverage in the general population will not be feasible. Containment through ring vaccination around small outbreaks is one option. Perhaps the most important benefit of an Ebola vaccine would be through the protection of health care workers and family members caring for infected individuals, enhancing recruitment of much needed health care providers.
William J. Moss, MD, is a professor in Epidemiology, International Health and Molecular Microbiology and Immunology at the Johns Hopkins Bloomberg School of Public Health and director of epidemiology with the Johns Hopkins International Vaccine Access Center.
What are the main concerns related to protective gear used in caring for Ebola patients in the U.S. and in Africa?
In the U.S., we need to train health care workers so they understand and are proficient with the donning and doffing procedures for personal protective equipment (PPE).
No skin can be exposed while wearing the gear. Temperatures inside the gear can get very high, causing dehydration and exhaustion which leads to possible mistakes and infection of the worker. The suits are effective barriers, but the process of removing the gear without getting contaminated can be difficult.
In West Africa, the main issue is supplies. International aid organizations working at established Ebola treatment centers may have sufficient supplies and protocols, but the rural areas and small villages lack personnel, infrastructure, training, equipment and supplies, often because of problems with distribution and transport.
What can be done to improve protective suiting and other safety equipment for health care workers dealing with Ebola?
Multiple things are being done, including intensive training and developing better guidelines and protocols. Opportunities to improve the current PPE gear include developing better donning and doffing methods and solutions to improve cooling and hydration.
The Emergency Ebola Design Challenge [held at Johns Hopkins Oct. 24-26 to create better PPE gear] selected eight multidisciplinary teams from 65 participants, and then chose four concepts to carry forward.
Is protective gear and equipment especially critical when it comes to treating Ebola patients?
Protective gear and equipment are essential in caring for Ebola patients. The viral load is so high and so potentially contagious from patient fluids (blood, mucus, vomit, diarrhea) that if the gear and equipment are not ideal, the heath worker can easily become contaminated.
Many health care workers in West Africa have died from Ebola and this has added an additional problem to containing the epidemic. Health care workers and their families need to be assured that they will be safe and can care for patients.
Adam Kushner, MD, MPH, FACS, is a surgeon, associate in International Health and founder of Surgeons OverSeas, who has led several surgical missions to West Africa and other countries.
Kushner and Sherry Wren, MD, FACS, FCS, chief of surgery at the Palo Alto VA Hospital and a Stanford University professor, wrote the surgical protocol for possible or confirmed Ebola cases, endorsed by the American College of Surgeons and other professional medical societies in the U.S. and Africa.
Steve P. Teret
What is quarantine?
Quarantine is a centuries-old public health intervention, supported by law, in which individuals believed to have been exposed to a contagious disease, but who are not yet exhibiting symptoms of the disease are separated from the general population. Individuals who are exhibiting symptoms of the disease are isolated. The conditions of quarantine and isolation may differ.
Does quarantine infringe on individual rights?
Quarantine certainly does restrict some individual rights that we normally enjoy, but it is done so for the protection of the common good, as is true for many public health measures (e.g., childhood vaccination). The United States Supreme Court in 1905 stated in Jacobson v. Massachusetts that “…the liberty secured by the Constitution of the United States to every person within its jurisdiction does not import an absolute right in each person to be, at all times and in all circumstances, wholly freed from restraint. There are manifold restraints to which every person is necessarily subject for the common good.”
Can quarantine laws balance the affected individuals’ rights with protecting the public’s health?
Yes. In the “Model State Emergency Health Powers Act,” crafted by The Centers for Law and the Public’s Health at the request of CDC after September 11, 2001, and portions of which were adopted as statutory law by most states in the exercise of their police powers, care was taken to balance individual rights and the protection of the public’s health. Under the Act, quarantine must be done by the least restrictive means necessary to prevent the spread of a contagious disease. The health status of those quarantined must be monitored, their needs must be met, and due process must be afforded to those who have been quarantined.
Stephen P. Teret, JD, MPH, is a professor of Health Policy and Management at the Johns Hopkins Bloomberg School of Public Health and Co-Director of the Johns Hopkins Center for Law and the Public’s Health.
Diane E. Griffin
What is the basic profile of the Ebola virus?
Ebola virus is an enveloped negative-strand RNA virus that belongs to the filovirus family of viruses. There are several strains of Ebola virus. The Zaire strain is causing the current outbreak in West Africa and is the most virulent (i.e. causes the most severe disease) of the strains of Ebola virus. It should be noted that Ebola is not a human virus. It only intermittently is transmitted to humans or monkeys from its normal reservoir, probably bats, where it causes little disease.
Why is Ebola so lethal? So easily transmissible via bodily fluids?
Ebola causes severe, often fatal disease because it replicates (grows) very efficiently in cells that become infected. From the initial site of infection, the virus spreads through the blood to multiple organs in the body where it can cause severe damage that may result in hemorrhage and/or failure of the liver, kidneys and lungs. The ability to grow efficiently leads to very large amounts of virus in bodily fluids so that exposure to even small amounts of these fluids can lead to infection.
What are the implications of mutations of the Ebola virus?
Viruses such as Ebola virus that have RNA genomes are all prone to rather frequent mutation. Viruses with mutations that are advantageous may be selected over time either in the infected person or the population infected while those with mutations that are disadvantageous to the virus will not be perpetuated. Many mutations are probably neutral or unimportant. It is very difficult to predict how mutation will affect Ebola virus, but it is unlikely that there will be a fundamental change in the type of disease caused or the transmissibility of the virus.
Diane E. Griffin, MD, PhD, is the Alfred and Jill Sommer Professor and Chair of the W. Harry Feinstone Department of Molecular Microbiology and Immunology at the Johns Hopkins Bloomberg School of Public Health.
Andrew S. Pekosz
Are people in the U.S. at risk for Ebola?
People in the US have virtually zero risk of catching Ebola because you need to be in close contact with a person who is infected with Ebola and showing symptoms to get infected. In the U.S., you are more likely to be hospitalized or die from influenza.
Should the U.S. expect more Ebola cases in the future?
As long as the epidemic is going on in West Africa, there will always be a risk of an imported case of Ebola. There are screening mechanisms in place at various airports to identify travelers with fever or other symptoms of illness so there are measures in place to limit travel of people who have been exposed to Ebola but since it can take 2-21 days until symptoms of Ebola show, there is a small window of time in which an Ebola-exposed person could travel without being identified as being infected.
Should there be a ban on commercial flights from West Africa as some politicians have called for?
These types of bans usually cause more harm than good because they also limit the movement of aid and volunteers into and out of stricken areas. It also fosters a feeling of isolation and distrust in those countries, which in turn makes dealing with the epidemic more difficult. We have had only had two imported cases of Ebola in the US so our existing travel screenings seem to working well. Stopping the spread of Ebola in West Africa should be a global health priority and it needs to be done as effectively as possible.
Andrew Stanley Pekosz, PhD, is an associate professor of Molecular Microbiology and Immunology at the Johns Hopkins Bloomberg School of Public Health.
David W. Dowdy
What is contact tracing?
The idea behind contact tracing is to find all people that have been in contact with an infectious person. As you can imagine, it's hard enough for the index patient to remember every person s/he has contacted since developing symptoms, much less figuring out how to identify and contact those people. It's one thing to track down someone's family members, another thing entirely to find everyone who may have been on a minibus with that person as s/he traveled to the hospital.
Is contact tracing working in the Ebola battle?
Contact tracing is working in countries like the US, where people have relatively few contacts, and we have good systems in place (from diseases like TB) to carry out these investigations. None of the imported cases of Ebola in the USA have led to sustained transmission, partially as a result. But in the countries most affected by Ebola, health systems simply don't have the capacity to carry out contact tracing on a mass scale—so contact tracing alone will never be sufficient to win the battle against Ebola.
What lessons can you draw from your TB contact tracing for Ebola?
Contact tracing is difficult! In the world of TB, we often try to trace contacts within a month—and even that can be challenging, especially for people who don't have addresses or phones, may not be home at a given time, etc. With Ebola, that's longer than the incubation period, meaning that any contacts who had actually been infectious would already have started to transmit the disease to others.
David W. Dowdy, MD, PhD ’08, ScM ’02, is the B. Frank and Kathleen Polk Assistant Professor in Epidemiology at the Johns Hopkins Bloomberg School of Public Health.