What We Should Know About Ebola and Other Global Disease Outbreaks
Thousands of miles away from the “hot zone” in West Africa, Americans have, for weeks, been watching the unfolding Ebola crisis with growing alarm — and, in some cases, panic. Since the crisis began earlier this summer, more than 6,500 cases of Ebola and more than 3,000 deaths have been reported.
As some feared, the virus has now reached U.S. soil. On September 30, the Centers for Disease Control and Prevention (CDC), along with the Texas Department of Health, confirmed the first case of Ebola to be diagnosed in the United States in a person who had traveled to Dallas, Texas from Liberia.
As we head into fall, Ebola continues to devastate West Africa, and President Barack Obama has dedicated U.S. military help to get the virus under control. But while Ebola is a public health and humanitarian crisis, the risk of an Ebola outbreak is still very low in the United States, say officials with the CDC and public health experts specializing in infectious disease at The University of Texas Health Science Center at Houston (UTHealth).
Here’s what they say we should know about Ebola and other global disease outbreaks:
While Ebola continues to spread…
“The chances of us having an Ebola epidemic here are minimal,” says Joseph McCormick, M.D., regional dean of the UTHealth School of Public Health Brownsville Regional Campus. McCormick, an epidemiologist who responded to the first Ebola outbreak in 1976 in Zaire (now Congo) and later outbreaks in neighboring countries, explains that Ebola isn’t likely to become a pandemic because it spreads through contact with bodily fluids (blood, vomit, feces) from someone who is visibly ill. He adds that while Ebola is a frightening, life-threatening disease without a prevention or cure (although a new vaccine is in the works and the drug ZMapp shows promise in aiding recovery), not everyone with Ebola dies. Case in point: American health care workers Dr. Kent Brantly and Nancy Writebol were released from Emory University Hospital in Atlanta last month and are recovering. Two more Americans currently are stable and undergoing treatment in the U.S.
Much of the spread in West Africa has occurred because medical facilities are not equipped with adequate protective measures, such as isolation units, latex gloves, disinfectants, disposable gowns and shoe covers, masks and eye protection. Compounding the problem is person-to-person transmission in crowded poor neighborhoods. Also, many families following cultural traditions prepare the bodies of Ebola victims for burial — exposing themselves to the virus and upping their risk of infection.
…don't forget about the flu...
Respiratory viruses, such as influenza, have more potential for pandemic, because they spread through the air when an infected person coughs or sneezes, says Catherine Troisi, Ph.D., an associate professor of Management, Policy & Community Health and Epidemiology at UTHealth School of Public Health. A person might also pick up a respiratory virus by touching a surface or object that has virus on it and then touching one’s own mouth, eyes or nose. Some of these viruses can live on surfaces for several hours.
“With most of these types of viruses, you are infectious before you have symptoms,” Troisi adds. “They are very hard to control because you don’t know who is spreading them.”
Not only does influenza spread easily, it can mutate, so that no one is completely immune. The consequences can be deadly. One of the worst pandemics in history was the great influenza pandemic of 1918, which killed more people than World War I. And even a normal flu season claims its fair share of victims. The CDC estimates that, over the past several years, flu-associated deaths ranged from a low of about 3,000 to a high of about 49,000 people each year.
…and other viruses that are worth monitoring.
Other respiratory viruses may have pandemic potential. The 2003 epidemic of severe acute respiratory syndrome (SARS), caused by a coronavirus, sickened more than 8,000 people worldwide and killed more than 700. While no cases of SARS have been reported since 2004, Middle East Respiratory Syndrome (MERS-CoV), a viral respiratory illness also caused by coronavirus, is worth watching, Troisi says.
And public health officials are closely monitoring the spread of EV-D68, a strain of enterovirus that has sent hundreds of children in 41 states (and counting) to the hospital with respiratory symptoms. Health officials say it seems to be most affecting children with a history of asthma or breathing problems.
We are learning more about containing outbreaks…
We don’t have to look as far back as 1918 for an example of a pandemic. The 2009 influenza epidemic hit the United States hard — causing more than 12,000 deaths nationwide and 240 deaths in Texas. Sixty of those deaths were in children. The most vulnerable were pregnant women and people with underlying conditions such as obesity and diabetes.
“We learned a lot about how to respond to a major disease outbreak that year,” Troisi says, reflecting on the epidemic. “As a result we increased our lab and epidemiologic monitoring capabilities.”
In Houston, influenza monitoring programs now track cases of children treated at pediatrician offices for flu-like symptoms. Public health agencies can look at the monitoring data to assess how widespread flu is in the community. When a disease threatens to spread worldwide, the World Health Organization and CDC employ similar monitoring methods on a global basis and collaborate with public health agencies, government and aid organizations to help control the spread of the disease.
Depending on the severity of the outbreak, public health officials may recommend steps including mass vaccinations and medical treatment, social isolation (closing down public places like malls and movie theaters), quarantines and flight restrictions.
…but “new” viruses will continue to emerge.
This summer, the first cases of chikungunya, a mosquito-borne disease that causes fever and joint pain (but is not spread from person to person) and MERS showed up on U.S. shores. Such outbreaks of “new” diseases make the news with increasingly regularity — but they are only new to us. Diseases like Lassa fever, Ebola and HIV lived benignly in animals in Africa for years before jumping to humans (Ebola in fruit bats, HIV in non-human primates such as chimpanzees, and Lassa in a species of rodents). Though it doesn’t make headlines like Ebola, Lassa is spread through the same region in West Africa, and has caused thousands of deaths every year since it was first isolated in a patient in 1969.
As the world rapidly modernizes, we can expect the emergence of more unfamiliar diseases.
“We have been seeing, in the last 30 to 40 years, a lot of emerging infectious disease for many reasons — societal reasons, climate change, and urbanization and because people are coming in contact more with animals,” Troisi says.
We need to prepare ourselves…
How should we prepare for disease outbreaks? We can immunize ourselves and our children annually with the influenza vaccine, and keep up to date on recommended immunizations. “Herd immunity” helps slow the spread of disease. Unfortunately, infectious diseases long thought to be eradicated — such as measles and whooping cough — are reemerging, because a growing number of parents are opting out of routine childhood immunization.
To prevent disease from spreading during cold and flu season or during a disease outbreak, we should practice good hygiene — washing hands, covering coughs, disinfecting household surfaces and not going to school or work when sick. Wearing masks doesn’t help much, Troisi says, because many airborne viruses are small and can penetrate the mask.
…and support public health.
From a public health perspective we can continue to perfect our emergency response system —making sure we have a solid communication plan and enough facilities, supplies and trained medical staff to deal with an infectious disease crisis. When the Ebola crisis broke this summer, hospitals, local public health agencies and health care organizations in Houston, including UTHealth, collaborated on how they would respond to a local outbreak of Ebola, says Robert Emery, Dr.P.H., UTHealth vice president for Safety, Health, Environment & Risk Management. UTHealth also tracks university-sponsored travel to countries with disease outbreaks, and requires people who have symptoms to report to employee health departments. Keeping a close watch on international disease outbreaks is important because, “We are only a plane flight away from anywhere in the world,” Emery says. “We need to be prepared.”
A strong public health infrastructure is a crucial element of our preparedness. Sadly, public health agencies have experienced cuts in funding and workforce over the last several years, Troisi says.
“It is really a matter of public safety, but many people don’t think about it like that,” Troisi says. “We would never cut fire or police, but we continue to cut public health. And that’s what protects us from outbreaks.”