Novel Influenza A (H1N1) Novel Influenza A (H1N1) United States, 2009 United States, 2009 ACHA 2009 Annual Meeting ACHA 2009 Annual Meeting May 27 May 27 th th , 2009, San Francisco , 2009, San Francisco Jane Seward, M.B.B.S., M.P.H Jane Seward, M.B.B.S., M.P.H Acting Deputy Director Acting Deputy Director National Center for Immunization and Respiratory Diseases National Center for Immunization and Respiratory Diseases Centers for Disease Control and Prevention Centers for Disease Control and Prevention The findings and conclusions in this presentation are those of the authors The findings and conclusions in this presentation are those of the authors and do not necessarily represent the views of the Centers for Disease and do not necessarily represent the views of the Centers for Disease Control and Prevention Control and Prevention
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Novel Influenza A (H1N1)Novel Influenza A (H1N1)
United States, 2009United States, 2009
ACHA 2009 Annual Meeting ACHA 2009 Annual Meeting May 27May 27thth, 2009, San Francisco, 2009, San Francisco
Jane Seward, M.B.B.S., M.P.HJane Seward, M.B.B.S., M.P.HActing Deputy DirectorActing Deputy Director
National Center for Immunization and Respiratory DiseasesNational Center for Immunization and Respiratory DiseasesCenters for Disease Control and PreventionCenters for Disease Control and Prevention
The findings and conclusions in this presentation are those of the authors and do not necessarily The findings and conclusions in this presentation are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Preventionrepresent the views of the Centers for Disease Control and Prevention
OutlineOutline
Influenza and influenza virusInfluenza and influenza virus Antigenic changes and pandemic Antigenic changes and pandemic
virusesviruses Novel influenza A H1N1 Novel influenza A H1N1
U.S. U.S. GlobalGlobal
Guidance documentsGuidance documents Institutions of Higher LearningInstitutions of Higher Learning
Vaccine and next stepsVaccine and next steps SummarySummary
InfluenzaInfluenza
Highly infectious viral illnessHighly infectious viral illness First pandemic in 1580 First pandemic in 1580 At least 4 pandemics in 19th centuryAt least 4 pandemics in 19th century Estimated 21 million deaths worldwide in pandemic Estimated 21 million deaths worldwide in pandemic
of 1918-1919of 1918-1919 Virus first isolated in 1933Virus first isolated in 1933
Seasonal Influenza, U.S. Seasonal Influenza, U.S. Annual Average Disease BurdenAnnual Average Disease Burden
15 – 60 million cases15 – 60 million cases(5 – 20% of U.S. population)(5 – 20% of U.S. population)
200,000 hospitalizations200,000 hospitalizations
36,000 deaths36,000 deaths
Prevention of Influenza, Recommendations of ACIPMMWR 2008; 57 (RR-7)
Hemagglutinin and neuraminidase antigens change with Hemagglutinin and neuraminidase antigens change with timetime
Changes occur as a result of point mutations in the virus Changes occur as a result of point mutations in the virus gene (antigenic drift), or due to exchange of a gene segment gene (antigenic drift), or due to exchange of a gene segment with another subtype of influenza virus (antigenic shift)with another subtype of influenza virus (antigenic shift)
Impact of antigenic changes depend on extent of change Impact of antigenic changes depend on extent of change (more change usually means larger impact)(more change usually means larger impact) Antigenic drift Antigenic drift
in 2002-2003, A/Panama/2007/99 (H3N2) virus was in 2002-2003, A/Panama/2007/99 (H3N2) virus was dominantdominant
A/Fujian/411/2002 (H3N2) appeared in late 2003 and A/Fujian/411/2002 (H3N2) appeared in late 2003 and caused widespread illness in 2003-2004 caused widespread illness in 2003-2004
Antigenic ShiftAntigenic Shift major change, new subtypemajor change, new subtype caused by exchange of gene segmentscaused by exchange of gene segments may result in pandemicmay result in pandemic
Example of antigenic shiftExample of antigenic shift H2N2 virus circulated in 1957-1967H2N2 virus circulated in 1957-1967 H3N2 virus appeared in 1968 and completely H3N2 virus appeared in 1968 and completely
replaced H2N2 virusreplaced H2N2 virus
Influenza Type A Antigenic ShiftsInfluenza Type A Antigenic Shifts
YearYear
18891889
19181918
19571957
19681968
19771977
SubtypeSubtype
H3N2H3N2
H1N1H1N1
H2N2H2N2
H3N2H3N2
H1N1H1N1
Severity ofSeverity ofPandemicPandemic
ModerateModerate
SevereSevere
SevereSevere
ModerateModerate
MildMild
Avian-human pandemic
reassortant virus
Avianvirus
Human virus
Avian reassortant
virus
Avianvirus
Reassortment in swine
Reassortment in humans
Possible Pathways for Generation of Possible Pathways for Generation of Pandemic Influenza VirusesPandemic Influenza Viruses
Triple Reassortant Swine Influenza A (H1) Triple Reassortant Swine Influenza A (H1) Viruses in Humans, U.S., Dec 2005- Feb 2009Viruses in Humans, U.S., Dec 2005- Feb 2009
11 sporadic cases of infections in humans11 sporadic cases of infections in humans Age range 16 months – 48 years (median 10 years)Age range 16 months – 48 years (median 10 years) Incubation period 3 – 9 daysIncubation period 3 – 9 days Symptoms fever (90%), cough (100%), headache Symptoms fever (90%), cough (100%), headache
(60%) and diarrhea (30%)(60%) and diarrhea (30%) All recoveredAll recovered 9 cases had exposure to pigs9 cases had exposure to pigs One suspected case of human to human One suspected case of human to human
transmissiontransmission
Shinde V et al., NEJM 2009:361
Novel Influenza A Virus InfectionsNovel Influenza A Virus Infections
Novel influenza A virus infections are human infections Novel influenza A virus infections are human infections with influenza A virus subtypes that are different from the with influenza A virus subtypes that are different from the currently circulating human subtypes (A/H1 and A/H3)currently circulating human subtypes (A/H1 and A/H3)
Swine origin influenza Swine origin influenza virus (S-OIV) infection in virus (S-OIV) infection in humans is a novel humans is a novel influenza A virus influenza A virus infectioninfection
April 17, 2009, 2 children in April 17, 2009, 2 children in Counties in Southern Counties in Southern California with febrile California with febrile respiratory illnesses respiratory illnesses confirmed to be a swine confirmed to be a swine influenza A H1N1 virus influenza A H1N1 virus infectionsinfections
No contact with pigsNo contact with pigs No links between the 2 casesNo links between the 2 cases Source of infection unknownSource of infection unknown MMWR dispatch April 21stMMWR dispatch April 21st
April 24April 24thth, 6 additional cases , 6 additional cases reported from southern CA and reported from southern CA and TX including 2 cases in the same TX including 2 cases in the same familyfamily
Outbreaks of severe respiratory Outbreaks of severe respiratory disease and deaths in Mexico disease and deaths in Mexico reported due to the same reported due to the same influenza virusinfluenza virus
April 26April 26thth: Public health : Public health emergency declared DHHSemergency declared DHHS
United States, March 28--May 4, 2009United States, March 28--May 4, 2009Number of confirmed (N = 394)* andNumber of confirmed (N = 394)* andprobable (N = 414) cases of novel probable (N = 414) cases of novel influenza A (H1N1) virus infection influenza A (H1N1) virus infection with known dates of illness onset with known dates of illness onset
Mexico, March 11--May 3, 2009Mexico, March 11--May 3, 2009Number of confirmed (N = 822) andNumber of confirmed (N = 822) andSuspected (N = 11,356) cases of novel Suspected (N = 11,356) cases of novel influenza A (H1N1) virus infection influenza A (H1N1) virus infection with known dates of illness onset with known dates of illness onset
Age Distribution of Confirmed CasesAge Distribution of Confirmed Cases (N=532)(N=532)
< 5 years< 5 years 18% 18% 5-9 years5-9 years 12% 12% 10-19 years10-19 years 40% 40% 19-50 years19-50 years 35% 35% ≥ ≥ 51 years51 years 5%5%
Dawood FS et al., NEJM 2009:361 (May 7)
www.cdc.gov/H1N1flu
The Lancet: Volume 373, Issue 9674, Page 1495 (2 May 2009-8 May 2009)The Lancet: Volume 373, Issue 9674, Page 1495 (2 May 2009-8 May 2009)
Surveillance TransitionSurveillance Transition
State reportingState reporting From line list to aggregate reportingFrom line list to aggregate reporting
Total cases, deaths, hospitalizationsTotal cases, deaths, hospitalizations Population-based surveillance using existing Population-based surveillance using existing
surveillance systemssurveillance systems
LaboratoryLaboratory State confirmation testing of novel H1N1State confirmation testing of novel H1N1
Guidance to PH lab clinicians has been distributedGuidance to PH lab clinicians has been distributed CDC is focusing on validation of state lab testing and CDC is focusing on validation of state lab testing and
viral isolation and genetic testingviral isolation and genetic testing
U.S. Human Cases of H1N1 Flu InfectionU.S. Human Cases of H1N1 Flu Infection
As Of May 26, 2009As Of May 26, 2009
6,764 cases, 10 deaths in 48 states including DC6,764 cases, 10 deaths in 48 states including DC
Percentage of Visits for ILI Reported by the U.S. Percentage of Visits for ILI Reported by the U.S. Outpatient ILI Surveillance Network (ILINet)Outpatient ILI Surveillance Network (ILINet)
ILINet Data by RegionILINet Data by Region
Ongoing and Current Seasonal Influenza Ongoing and Current Seasonal Influenza Surveillance – Mortality 122 U.S. CitiesSurveillance – Mortality 122 U.S. Cities
Epidemiology/Surveillance Novel Influenza A (H1N1) - 21 May 2009 1100 EDT
U.S. WHO/NREVSS Collaborating Laboratories Summary, 2008-09
* Percentage of all positive influenza specimens that are Novel Influenza A(H1N1) or Influenza A (unable to subtype) for the week indicated
www.cdc.gov/H1N1flu www.cdc.gov/H1N1flu
Anti-viral Resistance
Recent PublicationsRecent Publications
CDC Goals and Interim Guidance related CDC Goals and Interim Guidance related to Novel Influenza A H1N1to Novel Influenza A H1N1
Goals: prevent transmission and reduce disease Goals: prevent transmission and reduce disease severityseverity
Guidance documents:Guidance documents: Surveillance case definitions, laboratory testingSurveillance case definitions, laboratory testing Schools, colleges, and universitiesSchools, colleges, and universities Pregnant and breastfeeding womenPregnant and breastfeeding women Travel industryTravel industry Emergency personnelEmergency personnel Clinician guidance for patients and specific audiencesClinician guidance for patients and specific audiences Infection control guidance for healthcare facilitiesInfection control guidance for healthcare facilities Correctional and detention facilitiesCorrectional and detention facilities
Laboratory TestingLaboratory Testing
Real-time PCR assay to detect seasonal influenza A, B, H1, Real-time PCR assay to detect seasonal influenza A, B, H1, H3 and avian H5 serotypes is approved by FDA and H3 and avian H5 serotypes is approved by FDA and distributed in December 2008 to U.S’s public health distributed in December 2008 to U.S’s public health laboratories and WHO’s global influenza surveillance laboratories and WHO’s global influenza surveillance networknetwork
CDC has developed primers and probes specific for swine CDC has developed primers and probes specific for swine influenza (H1 and H3 subtypes) – protocol available at CDC influenza (H1 and H3 subtypes) – protocol available at CDC websitewebsite
Under Project BioShield act of 2004, FDA has issued an Under Project BioShield act of 2004, FDA has issued an emergency use authorization, allowing the use of this assay emergency use authorization, allowing the use of this assay by state public health laboratoriesby state public health laboratories
Preventive MeasuresPreventive Measures
Cover your nose and mouth with a tissue Cover your nose and mouth with a tissue when you cough or sneezewhen you cough or sneeze
Throw the tissue in the trash after you use itThrow the tissue in the trash after you use it Wash your hands often with soap and water, Wash your hands often with soap and water,
especially after you cough or sneeze. especially after you cough or sneeze. Alcohol-based hand cleaners are also Alcohol-based hand cleaners are also effectiveeffective
Avoid close contact with sick peopleAvoid close contact with sick people Avoid touching your eyes, nose or mouth. Avoid touching your eyes, nose or mouth.
Germs spread this wayGerms spread this way If you get influenza-like illness symptoms, If you get influenza-like illness symptoms,
stay home from work or school except to stay home from work or school except to seek medical care and limit contact with seek medical care and limit contact with others to keep from infecting them others to keep from infecting them
How Influenza Viruses Are Thought To Be How Influenza Viruses Are Thought To Be SpreadSpread Probably through respiratory Probably through respiratory
droplets: droplets: CoughingCoughing SneezingSneezing Touching respiratory droplets on Touching respiratory droplets on
self, another person, or an self, another person, or an object, then touching mucus object, then touching mucus membranes (e.g., mouth, nose, membranes (e.g., mouth, nose, eyes) without washing handseyes) without washing hands
Droplet nuclei (airborne Droplet nuclei (airborne transmission) may also occurtransmission) may also occur
Length of ContagiousnessLength of Contagiousness
Likely similar to seasonal influenza viruses but data Likely similar to seasonal influenza viruses but data are neededare needed One day before ill person develops symptoms to One day before ill person develops symptoms to
up to 7 days after they get sick up to 7 days after they get sick Children may shed virus for longer periodsChildren may shed virus for longer periods
Guidance for Sick PersonsGuidance for Sick Persons
If you are sick, youIf you are sick, youshould stay home andshould stay home andavoid contact withavoid contact withother people as muchother people as muchas possible.as possible.
If you get sick and If you get sick and experience any of experience any of these warning signs,these warning signs,seek emergency seek emergency medical care.medical care.
Warning Signs in Children:Warning Signs in Children:• Fast breathing or trouble breathing Fast breathing or trouble breathing • Bluish skin color Bluish skin color • Not drinking enough fluids Not drinking enough fluids • Not waking up or not interacting Not waking up or not interacting • Irritable, the child does not want to be held Irritable, the child does not want to be held • Flu-like symptoms improve but then return Flu-like symptoms improve but then return with fever and worse cough with fever and worse cough • Fever with a rash Fever with a rash
Warning Signs in Adults: Warning Signs in Adults: • Difficulty breathing or shortness of breath Difficulty breathing or shortness of breath • Pain or pressure in the chest or abdomen Pain or pressure in the chest or abdomen • Sudden dizziness Sudden dizziness • Confusion Confusion • Severe or persistent vomitingSevere or persistent vomiting
Interim CDC Guidance for Institutions of Higher Interim CDC Guidance for Institutions of Higher Education (May 11, 2009)Education (May 11, 2009)
CDC is not currently recommending that institutions cancel or dismiss classes or CDC is not currently recommending that institutions cancel or dismiss classes or other large gatheringsother large gatherings
If confirmed cases of novel influenza A (H1N1) virus infection or a large number If confirmed cases of novel influenza A (H1N1) virus infection or a large number of cases of influenza like illness (ILI) (i.e. fever with either cough or sore throat) of cases of influenza like illness (ILI) (i.e. fever with either cough or sore throat) occur among students, faculty, or staff or in the community, institutions officials occur among students, faculty, or staff or in the community, institutions officials should consult with state and local health officials regarding an appropriate should consult with state and local health officials regarding an appropriate responseresponse
Because the spread of novel influenza A (H1N1) within a health professions Because the spread of novel influenza A (H1N1) within a health professions school may pose special concerns, school administrators are strongly school may pose special concerns, school administrators are strongly encouraged to contact their state and local public health authorities if they encouraged to contact their state and local public health authorities if they suspect that cases of ILI are present on their campusessuspect that cases of ILI are present on their campuses
Students, faculty or staff who live either on or off campus and who have ILI Students, faculty or staff who live either on or off campus and who have ILI should self-isolate (i.e., stay away from others) in their dorm room or home for 7 should self-isolate (i.e., stay away from others) in their dorm room or home for 7 days after the onset of illness or at least 24 hours after symptoms have resolved, days after the onset of illness or at least 24 hours after symptoms have resolved, whichever is longerwhichever is longer
If possible, persons with ILI who wish to seek medical care should contact their If possible, persons with ILI who wish to seek medical care should contact their health care provider or campus health services to report illness by telephone or health care provider or campus health services to report illness by telephone or other remote means before seeking care. Institutions should assure that all other remote means before seeking care. Institutions should assure that all students, faculty and staff receive messages about what they should do if they students, faculty and staff receive messages about what they should do if they become ill with ILI, including reporting ILI to health servicesbecome ill with ILI, including reporting ILI to health services
Interim CDC Guidance for Institutions of Higher Interim CDC Guidance for Institutions of Higher Education (May 11, 2009)Education (May 11, 2009)
If persons with ILI must leave their home or dorm room (for example, to seek If persons with ILI must leave their home or dorm room (for example, to seek medical care or other necessities) they should cover their nose and mouth when medical care or other necessities) they should cover their nose and mouth when coughing or sneezing. A surgical loose-fitting mask can be helpful for persons who coughing or sneezing. A surgical loose-fitting mask can be helpful for persons who have access to these, but a tissue or other covering is appropriate as well. (See have access to these, but a tissue or other covering is appropriate as well. (See Interim Guidance for H1N1 Flu (Swine Flu): Taking Care of a Sick Person in Your Interim Guidance for H1N1 Flu (Swine Flu): Taking Care of a Sick Person in Your Home)Home)
Roommates, household members, or those caring for an ill person should follow Roommates, household members, or those caring for an ill person should follow guidance developed for caring for sick persons at home. (See Interim Guidance for guidance developed for caring for sick persons at home. (See Interim Guidance for H1N1 Flu (Swine Flu): Taking Care of a Sick Person in Your Home)H1N1 Flu (Swine Flu): Taking Care of a Sick Person in Your Home)
Persons who are at high risk of complications from novel influenza A (H1N1) Persons who are at high risk of complications from novel influenza A (H1N1) infection (for example, persons with certain chronic medical conditions, children infection (for example, persons with certain chronic medical conditions, children less than 5 years, persons 65 years or older, and pregnant women) should less than 5 years, persons 65 years or older, and pregnant women) should consider their risk of exposure to novel influenza if they attend public gatherings in consider their risk of exposure to novel influenza if they attend public gatherings in communities where novel influenza A virus is circulating. In communities with communities where novel influenza A virus is circulating. In communities with several reported cases of novel influenza A (H1N1) virus infection, persons who several reported cases of novel influenza A (H1N1) virus infection, persons who are at risk of complications from influenza should consider staying away from are at risk of complications from influenza should consider staying away from public gatheringspublic gatherings
Groups at Higher Risk for Severe Illness from Groups at Higher Risk for Severe Illness from Novel Influenza A (H1N1) Infection Novel Influenza A (H1N1) Infection
Children younger than 5 years old Children younger than 5 years old Persons aged 65 years or older Persons aged 65 years or older Children and adolescents (younger than 18 years) who are receiving Children and adolescents (younger than 18 years) who are receiving
long-term aspirin therapy and who might be at risk for experiencing Reye long-term aspirin therapy and who might be at risk for experiencing Reye syndrome after influenza virus infection syndrome after influenza virus infection
Pregnant women Pregnant women Adults and children who have pulmonary, including asthma, Adults and children who have pulmonary, including asthma,
cardiovascular, hepatic, hematological, neurologic, neuromuscular, or cardiovascular, hepatic, hematological, neurologic, neuromuscular, or metabolic disorders such as diabetesmetabolic disorders such as diabetes
Adults and children who have immunosuppression (including Adults and children who have immunosuppression (including immunosuppression caused by medications or by HIV) immunosuppression caused by medications or by HIV)
Residents of nursing homes and other chronic-care facilities Residents of nursing homes and other chronic-care facilities
Interim CDC Guidance for Institutions of Higher Interim CDC Guidance for Institutions of Higher Education: Large GatheringsEducation: Large Gatherings
Institutions should encourage persons with ILI to Institutions should encourage persons with ILI to stay home and away from large gatherings stay home and away from large gatherings
Persons who are sick should be instructed to:Persons who are sick should be instructed to: limit their contact with other people as much as limit their contact with other people as much as
possible and to stay home for 7 days after their possible and to stay home for 7 days after their symptoms begin or until they have been symptoms begin or until they have been symptom-free for 24 hours, whichever is longersymptom-free for 24 hours, whichever is longer
use appropriate respiratory and hand hygiene use appropriate respiratory and hand hygiene
CDC Interim Guidance for Institutions of Higher CDC Interim Guidance for Institutions of Higher Learning (cont.)Learning (cont.)
Establishing a relationship with their state and local health departmentsEstablishing a relationship with their state and local health departments Keeping informed regarding the evolving situation through regular visits Keeping informed regarding the evolving situation through regular visits
to the CDC's H1N1 Flu web siteto the CDC's H1N1 Flu web site Developing educational messages in a variety of formats regarding the Developing educational messages in a variety of formats regarding the
illness and how to reduce the spread of influenza. (See H1N1 Flu and illness and how to reduce the spread of influenza. (See H1N1 Flu and You)You)
Alternative educational delivery such as distance learning, web-based Alternative educational delivery such as distance learning, web-based learning, or other ways to increase social distancinglearning, or other ways to increase social distancing
Planning for assistance for students with ILI, including provision for Planning for assistance for students with ILI, including provision for meals, medications, and other caremeals, medications, and other care
Developing contingency plans for how to reduce exposure of non-ill Developing contingency plans for how to reduce exposure of non-ill students, staff and faculty to ill students, staff and facultystudents, staff and faculty to ill students, staff and faculty
Institutions should consider the following in preparation for possible outbreaks Institutions should consider the following in preparation for possible outbreaks of novel influenza A (H1N1):of novel influenza A (H1N1):
Recommendations for Treatment with Recommendations for Treatment with Anti-viral MedicationsAnti-viral Medications
All hospitalized patients with confirmed, probable or All hospitalized patients with confirmed, probable or suspected novel influenza (H1N1) suspected novel influenza (H1N1)
Patients who are at higher risk for seasonal Patients who are at higher risk for seasonal influenza complications influenza complications
Note: SNS deployed antiviral medications to all states Note: SNS deployed antiviral medications to all states
Recommendations for Post-exposure Recommendations for Post-exposure Antiviral ProphylaxisAntiviral Prophylaxis
Close contacts of cases (confirmed, probable, or suspected) Close contacts of cases (confirmed, probable, or suspected) who are at high-risk for complications of influenza who are at high-risk for complications of influenza
Health care personnel, public health workers, or first Health care personnel, public health workers, or first responders who have had a recognized, unprotected close responders who have had a recognized, unprotected close contact exposure to a person with novel (H1N1) influenza contact exposure to a person with novel (H1N1) influenza virus infection (confirmed, probable, or suspected) during virus infection (confirmed, probable, or suspected) during that person’s infectious period that person’s infectious period
Recommendations for Outbreak ControlRecommendations for Outbreak Control
Steps for preparing for potential commercial scale Steps for preparing for potential commercial scale production of a pandemic vaccineproduction of a pandemic vaccine
Under pandemic flu preparedness contracts, HHS Under pandemic flu preparedness contracts, HHS has allocated $1 billion for clinical vaccine studies, has allocated $1 billion for clinical vaccine studies, and supplies of bulk vaccine antigen and adjuvantand supplies of bulk vaccine antigen and adjuvant
Decisions pending on possible useDecisions pending on possible use
Anticipated that vaccine production will proceed as Anticipated that vaccine production will proceed as planned using the 3 vaccine strains recommended planned using the 3 vaccine strains recommended by WHO by WHO
What May Lie Ahead?What May Lie Ahead?
Miller MA et al., NEJM 2009:361 (May 7)
SummarySummary
A novel influenza A H1N1 virus emerged in the U.S. A novel influenza A H1N1 virus emerged in the U.S. and globally in spring 2009and globally in spring 2009
CDC, WHO and public health officials worldwide are CDC, WHO and public health officials worldwide are carefully monitoring the situationcarefully monitoring the situation
Recommendations should be followed for slowing Recommendations should be followed for slowing the spread of influenzathe spread of influenza
For the most current information on the novel H1N1 For the most current information on the novel H1N1 influenza outbreak: http://www.cdc.gov/h1n1flu/influenza outbreak: http://www.cdc.gov/h1n1flu/
* Current and archived MMWR publications are available at: * Current and archived MMWR publications are available at: http://www.cdc.gov/mmwr/http://www.cdc.gov/mmwr/
