Authors

  1. Todd, Betsy MPH, RN, CIC

Article Content

In the first weeks after Hurricane Katrina devastated the U.S. Gulf Coast on August 29, 2005, the increased risk of infection was one of many concerns. With water and sewage systems disrupted, personal hygiene hard to maintain, and a large population displaced into crowded venues (some of which were never intended to be evacuation centers), conditions were ripe for the rapid spread of disease. Interventions employed after Katrina offer a glimpse into the organization of infection control, an essential aspect of disaster response.

 

Officials at the Centers for Disease Control and Prevention (CDC) led preventive efforts in the hurricane-ravaged areas, supporting on-site clinicians and the region's battered public health infrastructure. The CDC sent 3,500 beds to the affected areas, along with critical medications for diabetes, heart disease, high blood pressure, anxiety, and diarrhea. Many of these drugs were in place within hours of the hurricane's passage. In addition, 50 tons of medical supplies from the Strategic National Stockpile were sent to Mississippi. These "12-hour Push Packages" included oral and iv antiinfective drugs (antibiotics, antitoxins, and vaccines), as well as antiseptics, analgesics, iv administration sets, catheters, respiratory therapy equipment, and other supplies.

 

Infection control in a teeming evacuation center is an enormous task. Principles and practices that are routine in most health care settings had to be applied to thousands of people under harshly unsanitary conditions without an established infrastructure-no laboratory, radiology, or pharmacy services; disabled telephone systems; and few specialist physicians or NPs.

 

While attending to the urgent needs of countless people in three states for shelter, food, clean water, and emotional support, relief workers also had to identify the highest-risk survivors. The elderly, people with HIV or other immunocompromising conditions, pregnant women, people with diabetes, infants, and disabled people were at increased risk for infection in the crowded and initially unsanitary shelters.

 

The CDC's announcements on its Web site and at press conferences repeatedly emphasized the critical importance of vigorous and consistent hand hygiene (see http://www.bt.cdc.gov/disasters/handhygiene.asp). Health care workers in many of the evacuation centers used alcohol-based hand sanitizers, which played an essential role in these settings.

  
FIGURE. Contractors ... - Click to enlarge in new windowFIGURE. Contractors hired by the Federal Emergency Management Agency gather the remains of New Orleans residents who died as a result of Hurricane Katrina, September 16, 2005. Contrary to popular belief, corpses generally do not pose a public health hazard, although there is a small risk of exposure to blood-borne and enteric pathogens to workers in repeated contact with dead bodies.

Because ongoing and systematic data collection is essential to monitoring illness trends and implementing infection control measures, systems for enhanced disease surveillance were put into place immediately. The CDC, along with local and state public health authorities, gathered data from functioning hospitals and clinics in the area, health posts, mobile units, and first-responder logs. 1 The CDC then analyzed this and other information (for example, data from American Red Cross responders) and directed disease-control strategies.

 

As was the case after the December 2004 South Asian tsunami, 2 infection control efforts after Hurricane Katrina focused on diarrhea, upper respiratory infection, rashes, and wounds. These were evaluated against a backdrop of the most likely infecting organisms, considering those known to be endemic to the region, the time of year, and conditions after the disaster (contaminated water, poor sanitation, and open wounds). Despite early rumor, there was virtually no risk of epidemic cholera, typhoid, or malaria. Diseases that are rare in the United States do not suddenly break out in hurricane-flooded areas.

 

After a natural disaster, corpses generally do not pose a public health hazard. However, for rescue workers, military personnel, volunteers, and others in repeated close contact with dead bodies, there is a small risk from exposure to blood-borne pathogens (such as hepatitis B and C viruses and HIV) and enteric pathogens (such as Escherichia coli), and possibly Mycobacterium tuberculosis. 3 Following standard precautions, including the use of appropriate protective gear, was essential.

 

A dispatch from Morbidity and Mortality Weekly Reports described infectious disease problems in the first three weeks after the hurricane. 4

 

There were clusters of illness characterized by diarrhea and vomiting in evacuation centers in seven states; amazingly, only about 1,000 of more than 200,000 evacuees were affected, including a small norovirus outbreak among evacuees in Texas-the only real "outbreak" that required additional containment efforts.

 

About 200 cases of conjunctivitis (probably viral) were reported. While these infections had little potential for serious complications, they were another reflection of crowded living conditions and illustrated the importance of hand hygiene in preventing the spread of disease.

 

Upper respiratory infections and pneumonias also were reported, including one case of pertussis in an infant. (Contact tracing uncovered no other cases of pertussis.) At least one undiagnosed case of tuberculosis, in a homeless evacuee from New Orleans, was identified. Extensive follow-up tracked people who were being treated for tuberculosis before the storm.

 

Wound infections were a significant issue. Methicillin-resistant Staphylococcus aureus (MRSA)-infected wounds were reported in about 30 children and adults at an evacuation center in Texas. These early reports did not specify the antibiotic-resistance pattern of the MRSA isolates, but wound and skin infections are typical of "community" strains (as opposed to the even more invasive hospital strains) of MRSA.

 

Twenty-four cases of wounds infected with Vibrio vulnificus and Vibrio parahaemolyticus-organisms endemic to warm coastal waters-resulted in six deaths. These organisms are in the same family as Vibrio cholerae, which causes cholera, but these other Vibrio infections do not resemble cholera and are not spread from person to person. Preexisting conditions such as heart or liver disease that increased the risk of infection were reported in 72% of cases. 5

 

Mosquito-borne infections such as West Nile virus were not an issue immediately after the hurricane because mosquitoes and their larvae were also hard hit by the storm. However, the CDC immediately began work with state and local officials to reinstate lapsed vector-control programs.

 

Outbreaks of vaccine-preventable illnesses such as varicella, measles, mumps, and rubella were not expected. But because crowded conditions would promote rapid spread among nonimmune individuals, shelter workers maintained active surveillance for fever and rashes. Vaccination against influenza became a priority as the flu season approached.

 

In the weeks after the hurricane, extensive mold growth in water-damaged homes raised concerns of potential respiratory effects. The CDC and the Louisiana Department of Health and Hospitals found that 46% of inspected homes had visible mold growth and that residents and workers did not use respiratory-protection equipment consistently. 6 In October 2005 the CDC published guidelines on preventing mold-associated illness in the hurricane-affected areas (see http://www.bt.cdc.gov/disasters/mold/report/pdf/2005_moldreport.pdf).

 

Considering the horrific situation in many Gulf Coast cities immediately after Katrina, infection control efforts were extraordinary at preventing the spread of disease-underlining once again that hand hygiene, standard precautions, and disease surveillance are effective basic elements of preventive health care.

 

REFERENCES

 

1. Surveillance for illness and injury after hurricane Katrina-New Orleans, Louisiana, September 8-25, 2005. MMWR Morb Mortal Wkly Rep 2005;54(40):1018-21. [Context Link]

 

2. Lim JH, et al. Medical needs of tsunami disaster refugee camps. Fam Med 2005;37(6):422-8. [Context Link]

 

3. Morgan O. Infectious disease risks from dead bodies following natural disasters. Rev Panam Salud Publica 2004;15(5):307-12. [Context Link]

 

4. Infectious disease and dermatologic conditions in evacuees and rescue workers after Hurricane Katrina-multiple states, August-September, 2005. MMWR Morb Mortal Wkly Rep 2005;54(38):961-4. [Context Link]

 

5. Vibrio illnesses after Hurricane Katrina-multiple states, August-September 2005. MMWR Morb Mortal Wkly Rep 2005;54(37):928-31. [Context Link]

 

6. Health concerns associated with mold in water-damaged homes after Hurricanes Katrina and Rita-October 2005. MMWR Morb Mortal Wkly Rep 2006;55(2):41-4. [Context Link]

Preparing for the Next Disaster

Will you be ready?

 

In the first 48 hours after any disaster, local responders are central to the population's health and safety. Linda Young Landesman, in her book Public Health Management of Disasters, offers points to consider in preparing for disaster response 1:

 

* With the ease of global transport, ever-evolving emerging pathogens, and the threat of bioterrorism, the potential for epidemic disasters is greater than ever.

 

* More and more hospitals order supplies only on an "as needed" basis and don't warehouse them on site. Fewer hospital supplies therefore will be immediately available for disaster response.

 

* The outsourcing of services like laundry leaves hospitals with fewer of the on-site resources that will be needed immediately after a disaster.

 

* Today's hospitalized patients are sicker than ever, which will make it difficult after a disaster to rely on a strategy of patient discharge in order to provide the additional beds that will be needed.

 

* More people than ever rely on health care outside of hospitals. Providers such as home care agencies, off-site clinics, freestanding dialysis centers, and other such programs need formal disaster plans, just as hospitals do.

 

REFERENCE

 

1. Landesman L. Public health management of disasters: the practice guide. 2nd ed. Washington, DC: American Public Health Association; 2005. [Context Link]

CDC Recommends Flu Drugs Be Halted

Influenza A isolates resistant to amantadine, rimantidine.

 

Because of a sharp rise in the percent of influenza A isolates resistant to the drugs amantadine (Symmetrel) and rimantidine (Flumadine), the Centers for Disease Control and Prevention (CDC) recommends that neither drug be used for the prophylaxis or treatment of influenza A in the United States for the remainder of the 2005-06 influenza season. Neuraminidase inhibitors oseltamivir (Tamiflu) and zanamivir (Relenza), which are effective against both influenza A and B, should be used instead, the CDC says.

 

Viral resistance to amantadine and rimantidine can occur spontaneously or emerge rapidly during treatment. Resistance increased from 1.9% of isolates tested during the 2003-04 flu season to 11% during the 2004-05 season, according to the CDC. This year, 91% of 120 influenza A isolates (H3N2) from patients in 23 states were found to be resistant. (Neuraminidase inhibitor resistance to influenza A remains rare worldwide.) Increased drug resistance has not affected the transmissibility or virulence of influenza A.

 

Initial studies indicate that avian influenza A viruses (H5N1) isolated from humans are naturally resistant to amantadine and rimantadine.

 

Viral testing will continue throughout the flu season, and recommendations for the 2006-07 season will be updated as needed. For more information, visit http://www.cdc.gov/flu.

 

Liptov AS, et al.. J. Virol 2004;78(17):8951-9.