5 questions: Weiss on public health post-Katrina
Eric Weiss
The devastation of Hurricane Katrina raises the risk of a host of medical problems: outbreaks of infectious diseases, sicknesses caused by environmental hazards, exacerbation of pre-existing chronic conditions and widespread post-traumatic stress disorder. Eric A. Weiss, MD, assistant professor of surgery (emergency medicine), has been explaining these potential public health consequences to reporters from the Wall Street Journal, San Francisco Chronicle, Associated Press and other media outlets. Paul Costello, executive director of the Office of Communication & Public Affairs, asked him for an overview of the situation.
1. What are the health risks for people in New Orleans?
Weiss: Though a large-scale outbreak of infectious disease has yet to materialize on the Gulf Coast, we are still concerned that a public health crisis may yet unfold.
The health dangers can be divided up into several categories which include: infectious diseases from the polluted waters; infectious diseases from living in emergency shelters; environmental health hazards from toxins; acute exacerbations of chronic illness from loss of medications and access to medical care, and mental health issues.
The mix of human waste, chemicals, oil and other contaminants being pumped out of New Orleans poses immediate and long-term threats to health and the environment. Recent samples of New Orleans floodwater show that it contains high levels of bacteria associated with raw sewage. Many common intestinal illnesses can occur by ingesting the sewage-laden water and in some cases by just being in the water without protective clothing.
Tetanus is another concern among Hurricane Katrina survivors and emergency responders. Tetanus is most commonly reported in older persons who are less likely to be adequately vaccinated. Diabetics are also at increased risk. Tetanus is about three times more common in diabetics and fatalities are about four times more common. Tetanus immunization is thus a primary and immediate concern for health-care providers working in the area.
Anytime you have a large number of people living in an evacuation shelter, you have a concern for the spread of infectious diseases. Some of the shelters have already seen cases of norovirus, which produces a type of gastroenteritis (vomiting and diarrhea). Spread of respiratory viruses is also increased in this type of environment. This is why public health officials are working to facilitate the administration of vaccines, including influenza and Hepatitis A, to evacuees living in crowded group settings.
Some victims of Katrina who suffer from chronic illnesses such as diabetes, congestive heart failure, kidney failure and chronic lung disease may have lost their medications. One of the biggest and most important challenges facing health-care workers is getting these individuals back on their regular medications and facilitating access to consistent medical care.
The mental health toll from Katrina could turn out to be one of the most significant problems that we see. Victims of the flood and evacuation may have frequent and intense psychological problems similar to those that plague troops returning from war. Post-traumatic stress disorder, a disease that raises the risk of suicide by sixfold, may occur in up to a third of the victims of the Gulf Coast catastrophe.
2. What's the status of the waterborne pathogen similar to cholera that has been blamed for a number of deaths in New Orleans?
Weiss: Vibrio vulnificus is a bacterium that is a rare cause of illness in the United States. The illness is very different from cholera, which is caused by a different bacterium—Vibrio cholerae. These cases are still being investigated, but it is reasonable to conclude that they could be a consequence of the hurricane and flooding because this organism lives in saltwater and can get into the body through wounds on the skin.
V. vulnificus infections do not spread directly from one person to another and are a serious health threat predominantly to persons with underlying illness, such as liver disease or a compromised immune system. Infection can occur after a wound is exposed to warm coastal waters where the V. vulnificus organism is a natural inhabitant. Infection may also be acquired by eating raw or undercooked seafood (especially oysters) from those waters.
Symptoms of infection with V. vulnificus typically begin within one to three days after exposure. Among healthy individuals, ingestion of V. vulnificus can cause vomiting, diarrhea and abdominal pain. If exposed by contamination of an open wound, redness, swelling and pain develop at the site of the wound and then can progress to affect the entire body. In immune-compromised patients, infection can cause a life-threatening illness characterized by fever, hypotension, septic shock and hemorrhagic bullae.
Wounds exposed to seawater should be washed with soap and water as soon as possible. Infected wounds should be treated immediately with local wound care and systemic antibiotics. When this infection is suspected, treatment with a combination of a third-generation cephalosporin (e.g., ceftazidime) and doxycycline is recommended.
3. How serious a health problem is the pollution in Lake Pontchartrain and the Gulf?
Weiss: The Environmental Protection Agency and the Centers for Disease Control are trying to determine the answer to this question. Results of the EPA's first round of testing were no surprise, and they reinforced warnings that everyone still in the city take precautions to avoid getting the water on their skin—especially into cuts or other open wounds—much less in their mouths.
The first tests turned up elevated levels of E. coli and other coliform bacteria and lead. But these are only preliminary tests from residential areas and not industrial sites where other toxic contaminants exist. Thus we still don't know what else is contained in the water.
Rescue workers should wear protective clothing and gloves before entering flooded areas and be careful not to splash the dirty water into their faces. Clean water and soap should be used to wash exposed skin as soon as possible.
Once the water is drained out of the city, contamination is expected to persist. Bacteria can live on surfaces and in puddles and pose an ongoing threat of disease. The moisture left behind in the city can spawn mold that can trigger asthma, allergy and sinus problems. Chemicals and heavy metals can settle into the sediments of Lake Pontchartrain and later be stirred up during subsequent storm or construction activity.
4. What steps are needed to prevent outbreaks of viral and bacterial illnesses in the shelters?
Weiss: The key is adequate sanitation and good personal hygiene. Whenever there are large numbers of people in an evacuation center such as the Astrodome, there are concerns about infection from various micro-organisms. Upper and lower respiratory viruses like influenza, group A streptococcus and even tuberculosis can spread easily in this type of environment. There are also concerns about virus-producing diarrhea illnesses such as Norwalk Virus, which is caused by consuming feces-contaminated water or food, or coming into contact with someone who is contaminated.
These centers need to emphasize hand washing and try to isolate individuals with respiratory and diarrhea illnesses. Antimicrobial alcohol gels and soap and clean water should be made readily available. Other infection-control measures include encouraging shelter occupants to: cover their mouth and nose with tissues when they cough or sneeze, and dispose of the tissues in the trash; follow good hygienic practices during food preparation; not share eating utensils, drinking containers or personal toiletries; dispose of razor blades and needles used for medications in containers designed for sharps disposal, and bathe and wash clothes regularly.
Vaccines for influenza and hepatitis A should be offered to evacuees living in crowded group settings, unless the person has documentation of having already received them. This is because transmission of these diseases is much more common in crowded evacuation centers than in individual homes.
5. What is the medical center currently doing to assist hurricane victims?
Weiss: We are working with the regional hospital council to assist in the relief effort, at the request of the U.S. Health and Human Services Department. Many individuals at Stanford and Lucille Packard Children's hospitals have expressed interest in participating on a team to provide staffing for one of the mobile 250-cot triage shelters that are being set up in the southeast. We are taking names and information to determine what staffing Stanford might be able to add to the project. Vicki Running and Sandi Edgar are the individuals coordinating this effort at Stanford and LPCH.
In addition, the National Institutes of Health has been charged to focus on patients with high-risk, high-acuity disease. It is collaborating with the Association of American Colleges to provide a physician consultation network. Dean Pizzo asked me to coordinate this effort at Stanford. If requested, we can provide a list of specialists who can be consulted. We may also receive selected patients, who would likely be in these high-risk groups.
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