Interim CDC Guidance for
Nonpharmaceutical Community Mitigation in Response to Human Infections
with Swine Influenza (H1N1) Virus
April 28, 2009 02:45 PM ET
These
recommendations are based on current information and are subject to
change based on ongoing surveillance and continuous risk assessment.
Background
This
document provides interim planning guidance for state, territorial,
tribal, and local communities that focuses on several nonpharmaceutical
measures that might be useful during this outbreak of swine influenza A
(H1N1) virus aimed at reducing disease transmission and associated
morbidity and mortality.
Human cases of swine influenza A
(H1N1) virus infection have been identified in several states and in
other countries. This is a novel influenza A virus that has not been
identified in people before, and human-to-human transmission of the
virus appears to be ongoing. Unlike the experience in Mexico, the
United States is currently observing a less severe clinical spectrum of
disease with infection by the identical virus strain. As of April 26,
2009, of the confirmed cases of swine influenza A (H1N1) virus
infection, only two confirmed case-patients were hospitalized and none
have died in the United States. Mexican health officials have reported
several hundred suspect cases, including several deaths associated with
confirmed swine influenza A (H1N1) virus infection. In Mexico, many
patients have experienced rapidly progressive pneumonia, respiratory
failure requiring mechanical ventilation and acute respiratory distress
syndrome (ARDS). Therefore, the experience of these two countries has
been markedly different to date. Getting better information to explain
these differences is a high priority for the ongoing investigation.
The previously published United States government guidance on community mitigation
relies on knowledge of the Pandemic Severity Index (PSI) to
characterize the severity of a pandemic and identify the
recommendations for specific interventions that communities may use for
a given level of severity, and suggests when these measures should be
started and how long they should be used.
The substantial
difference in the severity of the illness associated with infections
from the same virus, the relatively low number of cases detected in the
United States, and insufficient epidemiologic and clinical data to
ascribe a PSI, present a formidable challenge in terms of assessing the
threat posed by this novel influenza A virus until additional
epidemiologic and virologic information is learned.
Novel
influenza A virus infections in humans, including swine influenza A
(H1N1) virus, represent a pandemic threat. Recognizing the historical
precedent for the emergence of a pandemic influenza virus which could
have waves of disease with different morbidity and mortality and
epidemiologic profiles, public health departments in the United States
must remain vigilant.
It is prudent for communities to
act in the absence of sufficient data to protect their citizens and
take advantage of a narrow window of opportunity for intervention. CDC
recommends that affected states with at least one laboratory-confirmed
case of swine influenza A (H1N1) virus infection consider activating
community mitigation interventions for affected communities. As public
health officials in the United States learn more about this emerging
virus, updated guidance will be issued in conjunction with our state,
local, tribal and territorial partners.
Recommendations
When Human Infection with Swine Influenza A (H1N1) Virus is Confirmed in a Community
Strongly Recommend Home Isolation of Cases:
- Persons
who develop influenza-like-illness (ILI) (fever with either cough or
sore throat) should be strongly encouraged to self-isolate in their
home for 7 days after the onset of illness or at least 24 hours after
symptoms have resolved, whichever is longer. Persons who experience ILI
and wish to seek medical care should contact their health care
providers to report illness (by telephone or other remote means) before
seeking care at a clinic, physician’s office, or hospital. Persons who
have difficulty breathing or shortness of breath or are believed to be
severely ill should seek immediate medical attention.
- If ill persons must
go into the community (e.g., to seek medical care) they should wear a
face mask to reduce the risk of spreading the virus in the community
when they cough, sneeze, talk or breathe. If a face mask is
unavailable, ill persons needing to go into the community should use a
handkerchief or tissues to cover any coughing.
- Persons
in home isolation and their household members should be given infection
control instructions: including frequent hand washing with soap and
water.Use alcohol-based hand gels (containing at least 60% alcohol)
when soap and water are not available and hands are not visibly dirty.
When the ill person is within 6 feet of others at home, the ill person
should wear a face mask if one is available and the ill person is able
to tolerate wearing it.
Regarding Household Contacts:
- Household contacts who are well should:
- remain home at the earliest sign of illness;
- minimize contact in the community to the extent possible;
- designate a single household family member as the ill person’s caregiver to minimize interactions with asymptomatic persons.
School Dismissal and Childcare Facility*Closure:
- Dismissal
of students should be strongly considered in schools with a confirmed
or a suspected case epidemiologically linked to a confirmed case.
- Decisions
regarding broader school dismissal within these communities should be
left to local authorities, taking into account the extent of ILI in the
community.
- If the school dismisses students or a
childcare facility closes, they should also cancel all school or
childcare related gatherings and encourage parents and students to
avoid congregating outside of the school.
- Schools and
childcare facilities should dismiss students for a time period to be
evaluated on an ongoing basis depending upon epidemiological findings.
- Schools
and childcare facilities should consult with their local or state
health departments for guidance on reopening.If no additional confirmed
or suspected cases are identified among students (or school-based
personnel) for a period of 7 days, schools may consider reopening.
- Schools
and childcare facilities in unaffected areas should begin to prepare
for the possibility of school dismissal or childcare facility closure.
This includes asking teachers, parents and officials in charge of
critical school-associated programs (such as meal services) to make
contingency plans.
Other Social Distancing Interventions:
- Large
gatherings linked to settings or institutions with laboratory-confirmed
cases should be cancelled, for example a school event linked to a
school with cases;other large gatherings in the community may not need
to be cancelled at this time.
- Additional social distancing measures are currently not recommended.
- Persons
with underlying medical conditions who are at high risk for
complications of influenza may wish to consider avoiding large
gatherings.
These recommendations are subject to change as additional epidemiological and clinical data become available.
*Childcare
facility: centers and facilities that provide care to any number of
children in a nonresidential setting, large family childcare homes that
provide care for seven or more children in the home of the provider and
small family childcare homes that provide care to six or fewer children
in the home of the provider.
Additional information can be found at the following Web sites: