Pandemic planning breaks down at the community level
Lack of data, direction: States confused on local measures
Epidemiologists looking at state plans for pandemic influenza are finding much variation but one disturbing commonality: the lack of clear consensus about implementing infection control measures in the community. When you take a massive national infection prevention effort down from 30,000 feet to the grass roots, you find a dearth of data and plenty of devils in the details. And in an era of an "all-hazards" mentality, the planning problems likely mirror a lack of preparedness against other airborne pathogens and bioterrorism agents.
Indeed, a recently published study of state pandemic plans warns that the United States could end up with a "patchwork of plans that will not adequately detect and control [flu] or other reaspiratory disease pandemics."1
In addition, the vast majority of states are relying on passive surveillance systems such as the National Sentinel Physician Surveillance to alert them to pandemic influenza, the study found. However, such systems may not detect local epidemics until they are well established, warns lead researcher Scott Holmberg, MD, MPH, senior infectious disease epidemiologist at Research Triangle Institute (RTI) International in Atlanta. There are more aggressive systems and use of syndromic surveillance in some areas, but in the main the states appear to expect to pick up pandemic flu as early as possible with passive surveillance and then try to stop transmission. Some models suggest this approach will be sufficient, but Holmberg is skeptical. "Those are highly theoretical models and, in the real world, we never detect cases in such real time and are able to immediately intervene," he says.
Holmberg and co-researchers reviewed the individual pandemic plans of the 49 states that have posted them on the Internet, looking at such areas as vaccination, early epidemic surveillance and detection, and plans for containment of pandemic influenza.1 They found "confusion and lack of specificity exist in these posted state plans in proposing practical containment measures in the community."
"Some states seem to be better prepared than others, but there is still a lot of confusion about what is the best way to prepare," he says. Almost all of the states' plans address a wide range of issues regarding command and control, surveillance, vaccination, antiviral drugs, communication, and emergency management. (See table.)
"They are really strong in showing lines of control and command, assigning who is responsible for what activity," Holmberg tells Bioterrorism Watch. "They also are very strong on hospital procedures because the SARS epidemic did give us some experience with what hospitals should do. But they sort of fall apart when you get into the community because we just don't have the information. Some of the states — in particular, I can mention Maine and California — actually bemoan this fact in their [plan] documents. So it's not a lack of concern but a lack of clear direction and information."
The Maine plan discusses the possibilities of using quarantine measures in the community and SARS-like precautions that would include masking on public transportation.
The national Health and Human Services Pandemic Influenza Plan has several recommendations for infection control in the hospital setting but is weaker and nonspecific in other areas such as control of influenza in the community, Holmberg notes.2 Accordingly, that lack of specificity is reflected in the state plans as well.
Since it is unlikely that effective vaccine will be available immediately if avian influenza A (H5N1) mutates into an efficient transmitter between humans, "nonpharmaceutical" containment steps need to be considered, Holmberg emphasizes. But only about a third of the state plans are explicitly considering recommending self-isolation of adults with influenza-like symptoms and keeping children with such symptoms home from school and day care. "Even in this increasingly computer-based economy, in which a considerable percentage of persons can work from home most of the time, this simple stratagem is not addressed in most state plans," the analysis states. "Other simple recommendations for use in the community, such as avoiding mass gatherings; shopping on off hours; and household and workplace strategies such as frequent hand washing, avoiding hand shaking, and keeping towels separate, are often neglected in state plans."
The study found that 17 (35%) states explicitly plan or are considering recommending (voluntary) personal social isolation on the community level, such as staying at home or keeping children at home if they feel sick. Eighteen (37%) other states cite federal or state regulations that indicate that health authorities may close schools, businesses, and other institutions during a severe outbreak, although they are not required to resort to such closures. In addition, 15 (31%) other states also indicate legal ability to quarantine people, households, or institutions. Given the high cost and limited supply of neuraminidase inhibitor antiviral drugs and an uncertain supply and effectiveness of future vaccines, only 12 (25%) states plan or consider using either chemoprophylaxis (such as oseltamivir) or vaccination of household and other close nonhospital contacts in their plans to retard epidemic influenza.
The national plan suggests social distancing and respiratory cough etiquette and discusses mask use. Part of the problem in giving more detailed direction is that there is insufficient data to clearly answer the following questions posed by Holmberg and colleagues:
- What is the typical intro-household or institutional attack rate, and would vaccination or chemoprophylaxis of contacts retard or stem outbreaks?
- How well do masks work for pandemic influenza in the community, and when and for how long should they be used?
- Does closing a school or other institution actually reduce community-level illness and death?
- Does earlier detection of influenza in a community lead to behavior changes that could stem an outbreak?
"Clearly, the findings of this paper imply that we need a coordinated federal central response that gives some clearer direction as to what the various states and localities need to be doing," Holmberg says. "There is not a heck of a lot of epidemiolgic information out there on what [practices] would actually retard an epidemic in the community. "We don't know whether closing the elementary schools will actually substantially impact an epidemic once it gets going. These [measures] all seem to make sense, but we really don't know whether they work or to the extent that they would."
A former medical epidemiologist at the Centers for Disease Control and Prevention, Holmberg notes that the CDC has some studies under way to try to answer the questions. In addition to research, he advises forming expert panels to determine if masks, school closings, social isolation, and several other community strategies would be useful in reducing the illness and death caused by pandemic influenza.
For example, the CDC fielded the question of public masking after the practice was prominently featured in a TV movie about a flu pandemic. The answer as posted on www.pandemicflu.gov is: "For health care workers exposed to infected patients, N95 respirators are recommended. Surgical masks are recommended for patients who are infected to help reduce the potential for spread of virus when these people cough or sneeze. [The federal government] will continue to review and update as needed its public health guidance on the use of masks and respirators by the general public and at-risk workers."
However, a 2000 draft of a CDC pandemic plan concluded that use of masks to prevent transmission of influenza in the community is "not likely to be effective."
The current official position in the federal pandemic plan is that masks are essentially optional in the community. "The benefit of wearing masks by well persons in public settings has not been established and is not recommended as a public health control measure at this time. In contrast to health care workers who necessarily have close contact with ill patients, the general public should try to avoid close contact with ill individuals. Nevertheless, persons may choose to wear a mask as part of individual protection strategies that include cough etiquette, hand hygiene, and avoiding public gatherings. Mask use may be most important for persons who are at high risk for complications of influenza and those who are unable to avoid close contact with others or must travel for essential reasons such as seeking medical care."
However, the issue is further complicated by the fact that the federal plan recommends educating the public on how to use and dispose of masks appropriately. "This education should emphasize that mask use is not a substitute for social distance or other personal protection measures," the federal plan states. The specter of hoarding comes up with a further note that local officials will have to ensure that "mask use in communities does not limit availability for health care settings where the importance and effectiveness of [masks] has been documented." The fact that the seemingly simple question of mask use opens up such a panoply of issues underscores that more research and direct guidance are needed to clear up the confusion at the state level.
"[The CDC] has funded some proposals to go ahead and start looking at any community-based interventions that might help during a flu epidemic," Holmberg says. "I think the issue of masks is very hard to study because during a nonepidemic or nonpandemic situation it will be very difficult to get people to wear masks. On the other hand, some of the these things might be a little bit easier to look at like sending people home form work or kids home from school when they are sick. We need to do some studies while — hopefully — we still have some time."
References
- Holmberg SD, Layton CM, Ghneim GS, et al State Plans for Containment of Pandemic Influenza. Emerg Infect Dis [serial on the Internet]; 2006 Sep. On the web at www.cdc.gov/ncidod/EID/vol12no09/06-0369.htm.
- U.S. Department of Health and Human Services. Pandemic influenza plan. 2005 Nov 4 [cited 2006 Jun 19]. On the web at www.hhs.gov/pandemicflu/plan/.
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