UCSF Osher Center for Integrative Medicine

Mini Medical School for the Public

FALL 2013 – Tuesday Course Series VACCINES, ANTIBIOTICS, AND INFECTIONS:

GETTING YOUR QUESTIONS ANSWERED Date: Tuesday, October 22, 2013, 7:00 pm – 8:45 pm Topic: THE INFLUENCE OF INFLUENZA– EPIDEMICS, PANDEMICS AND EVERYTHING IN-BETWEEN Speaker: Janice K. Louie, MD, MPH, Public Health Medical Offi cer, California Department of Public Health; Assistant Clinical Professor Janice Louie MD, MPH received her medical degree and completed residency training in Internal Medicine at UC San Diego, followed by a fellowship in infectious diseases at UCSF, and a Master’s in Public Health at UC Berkeley. She currently serves as a Public Health Medical Officer in the Immunization Branch of the California Department of Public Health, and is Assistant Professor of Clinical Medicine at UCSF. Her main focus over the past 13 years has been on the influenza virus, at both the individual and public health level. She has overseen statewide surveillance for influenza, tracking which, when and where influenza viruses are circulating each winter season and who they are affecting. As a clinician, she has led research to identify risk factors that make persons more likely to become severely ill with influenza, and how antiviral medications can help treat influenza disease, with over 35 peer-reviewed publications on these topics. She has worked with the Centers for Disease Control and Prevention on national policy recommendations for preparing for influenza pandemics and strategies for targeting and prioritizing influenza vaccine and antiviral medications. She is a recent recipient of The Wolinsky Award for the best original research article published in 2011 by the editors of the journal Clinical Infectious Diseases. She also has an interest in working on health disparities in vulnerable populations, and regularly volunteers at a primary care clinic in Honduras

Bibliography:

Centers for Disease Control and Prevention. Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the ACIP — United States, 2013–2014. MMWR; September 20, 2013 / 62(RR07);1-43

UCSF Osher Center for Integrative Medicine

Mini Medical School for the Public

Louie JK, Yang S, Acosta M, et al. Treatment with neuraminidase inhibitors for critically ill patients with influenza A(H1N1)pdm09. Clin Infect Dis 2012 Nov;55(9):1198-204.

Louie JK, Acosta M, Samuel MC, et al. A novel risk factor for a novel virus: obesity and 2009 pandemic influenza A (H1N1). Clin Infect Dis. 2011 Feb;52(3):301-12.

Louie JK, Gavali S, Acosta M, et al. Children Hospitalized With 2009 Novel Influenza A(H1N1) in California. Arch Pediatr Adolesc Med. 2010 Nov;164(11):1023-1031.

Louie JK, Acosta M, Jamieson DJ, Honein MA; California Pandemic (H1N1) Working Group. Severe 2009 H1N1 influenza in pregnant and postpartum women in California. N Engl J Med. 2010 Jan 7;362 (1):27-35.

Louie JK, Acosta M, Winter K, et al. Factors Associated With Death or Hospitalization Due to Pandemic 2009 Influenza A(H1N1) Infection in California. JAMA. 2009 Nov 4;302(17):1896-1902

Louie JK, Schnurr DP, Guevara HF, et al. Creating a Model Program for Influenza Surveillance in California: Results from the 2005-06 Influenza Season. Am J Prev Med. 2007 Oct;33 (4):353-7

Louie JK, Schechter R, Honarmand S, et al. Severe Pediatric Influenza in California, 2003–2005: Implications for Immunization Recommendations. Pediatrics 2006; 117: e610-e618.

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The Influenza of Influenza:Epidemics, Pandemics and Everything in‐Between

Janice Louie, MD, MPHCalifornia Department of Public Health

Definitions

• Bacteria– Single celled organisms that divide by fission

– Can exist anywhere

– Respond to antibiotic therapy

• Viruses– Smaller organisms

– Live within host cells

– Do not respond to antibiotic therapy

• Yeasts/Mold

• Parasites

Influenza type Hemagglutinin subtype

Geographic source

A/California/7/04 (H3N2)

Year of isolation

Isolate number Neuraminidase subtype

Influenza virus

Adapted from Levine AJ. Viruses. 1992;165, with permission.

Hemagglutinin Subtypes of Influenza A Virus

Subtype Human Swine Horse Bird

H1H2H3H4H5H6H7H8H9H10H11H12H13H14H15H16

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Adapted from Levine AJ. Viruses. 1992;165, with permission.

Neuraminidase Subtypes of Influenza A Virus

Subtype Human Swine Horse BirdN1N2N3N4N5N6N7N8N9

• Structure of hemagglutinin (H) and neuraminidase (N) periodically change

• Drift: Minor change, same subtypePoint mutations in geneMay result in epidemic

• Shift: Major change, novel subtypeExchange of gene segmentMay result in pandemic

Influenza Antigenic Changes

Humanvirus

Reassortantvirus

Non-humanvirus

Mechanisms of Influenza Virus Antigenic “Shift”

16 HAs9 NAs

Years Flu Virus Mortality

1918-1919 “Spanish” Type A (H1N1) 20 million worldwide550,000 US

1957-1958 “Asian” Type A (H2N2) 70,000 US

1968-1969 “Hong Kong” Type A (H3N2) 34,000 US

2009-2010 “Swine H1N1” Type A (swine H1N1) ~13,000 US

Glezen WP. Epidemiol Rev. 1996;18:65.Centers for Disease Control and Prevention. Influenza Prevention and Control. Influenza. Available at:http://www.cdc.gov/ncidod/diseases/flu/fluinfo.htm.

History of Influenza Pandemics

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Infectious Disease Mortality, U.S.20th Century

Armstrong, et al. JAMA 1999;281:61-66.

Impact of Seasonal Influenza-US

• ~ 82 million infected annually• ~ 36,000 (range 8000-68,000) excess deaths per year• ~ 226,000 (range 55,000-431,000) excess

hospitalizations per year• Higher mortality during seasons when influenza type A

(H3N2) viruses predominate• 90% of influenza-related deaths occur among persons

>65 years

Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP), 2008. MMWR Recomm Rep. 2008 Aug 8;57(RR-7):1-60.

Age High Risk Not High Risk0-11 months 1900 496-10381-2 years 800 1863-4 years 320 865-14 years 92 4115-44 yrs 56-110 23-2545-64 yrs 392-635 13-2365 yrs 399-518 125-228

Data from multiple studies 1972-1995.

US Influenza-Related Hospitalization Rates (per 100,000), 1972-1995

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National Institute of Allergy and Infectious Diseases, 12/97.

Community

Family/Household

School-age children infected

School absenteeism

Increased visits for medical care

Employee absenteeismHospitalization

(esp. elderly)

Employee absenteeismHospitalization (esp. elderly)

Influenza Epidemic in the Community Influenza is highly contagious

• Infectivity is relatively high• The incubation period is short (1-4 days)• Adults infectious from 1 day before onset of

symptoms to 5-7 days after onset.• Young children can shed virus several days

before onset of symptoms and up to 10-14 days after onset.

• Severely immunocompromised persons can shed for weeks or months.

MMWR July 13, 2007 / 56(RR06);1-54

Influenza Routes of Transmission

Poorly characterized• Common: large droplets (sneezing, coughing,

contact with saliva)• Probably common: contact

– Direct– Fomite

• Rare: airborne • Attack rate

estimates:5-50%

Respiratory Etiquette

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Influenza on Surfaces

• Influenza viruses can live:– Up to 48 hours on hard nonporous 

surfaces (e.g. stainless steel/plastic, doorknobs, keyboards)

– Up to 12 hours on cloth and tissues

– Up to one week at human body temperatures

– Up to 30 days at freezing temperatures

– Indefinitely at temperatures below freezing

Adapted from Mandell GL, Bennett JE, Dolin R, eds. Mandell, Douglas and Bennett’s Principlesand Practice of Infectious Disease. 5th ed. 2000:1831.

Onset of Influenza A

Days After Inoculation

Temp °F

Illness

Headache, Malaise, Myalgia

Nasal Obstruction and Discharge,Throat Pain, Cough

-1 0 1 2 3 4 5 6 7 8 23

100

99

97

Type of Symptoms Children <5 yrs Adults ElderlyRespiratory Rhinitis Nonproductive cough Nasal obstruction

Sore throat Sore throatConstitutional or Fever Rapid onset Fever >99.0°Fsystemic Vomiting of symptoms Lassitude

Diarrhea Fever, usually >100°F Confusion Chills/sweats Headache Myalgia Potentially severe,

persistent malaise Substernal soreness,

photophobia and ocular problems

Signs and Symptoms of Influenza Laboratory Diagnosis

• Commercial rapid tests (ELISA)• Direct fluorescent antibody (DFA)• Viral culture

• Polymerase chain reaction (PCR)

• Serology (HIA and neut)

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Antivirals:Adamantanes and Neuraminidase Inhibitors

NA

inhi

bito

rs

HA

blo

cker

s

Adamantanes

• Inexpensive– Amantadine ~ $0.60/pill– Rimantidine ~ $2.20/pill

• Not effective against influenza B• Resistance due to a single point S31N

substitution in the M2 protein• Usefulness for seasonal influenza now

unclear

Treatment with Neuraminidase Inhibitors

• Oseltamivir: 75 mg po bid x 5 days• Zanamivir (>5 yrs):10 mg inhaled bid

– Evidence for effectiveness based on studies of outpatients with uncomplicated influenza

– If treatment begun within 48 hours of onset of symptoms, reduction in symptoms by ~1 day

– Likely reduces viral sheddingEmergency Use Authorization: • IV Peramivir (EUA expired June 23, 2010)

• IV Zanamivir (EUA expired June 23, 2010)

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Toronto Invasive Bacterial NetworkProspective Cohort Study

• Significant reduction in mortality in highly vaccinated population (71%) of adults and children with laboratory confirmed influenza (odds ratio 0.21, CI 0.06‐0.80).  Benefit seen even when oseltamivirstarted >48 hr after onset.

• Significant reduction in mortality in small number of adults admitted to ICU for laboratory‐confirmed influenza (none treated within 48 hours of onset) 

McGeer et al, Clin Infect Dis 2007;45:1568, ICAAC 2007.

Antiviral ResistanceConcern: an untreatable influenza virus• H275Y mutation results in resistance to oseltamivir and peramivir (not zanamavir)• Mostly mild illness• Common themes: young children, immunosuppressed persons on treatment, long-term prophylaxis• No sustained transmission, but clusters reported

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Influenza VaccineContent Updated yearly to protect against

anticipated strains, consists of type A (2) and type B (1)

Process Grown in embryonated chicken eggs and formalin inactivated

Timetable for interpandemic vaccine production

Live Attenuated Influenza Vaccine (FluMist)

www.flumist.com/

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http://healthland.time.com/2013/01/11/flu-vaccine-is-62-effective-say-health-officials/

What does effective mean?

It depends on what you are looking at:

• Prevent infection with the virus

• Prevent illness

• Prevent severe complications

• Prevent death

Vaccine efficacy depends on many factors, such as circulating virus type, virulence, age, underlying comorbidities and what outcome is being measured.

Ref: Osterhom MT et al. Lancet Infectious Diseases. 2012; 12: 36-44.

HOW EFFECTIVE IS INFLUENZA VACCINE?

When the vaccine strain matches the strain circulating in the community, vaccination reduces disease 70%.  Even when the match is poor, vaccination has been shown to reduce death due to influenza.Medical Letter, v.52, 10/4/10

Influenza vaccination, even with moderate effectiveness, can reduce illness, antibiotic use, doctor visits, time lost from work, hospitalizations, and deaths. MMWR.  January 18, 2013 / Vol. 62 / No. 2 / Pg. 17 ‐ 40; ND 16 ‐ 29

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http://summaries.cochrane.org/CD004876/vaccines-for-preventing-seasonal-influenza-and-its-complications-in-people-aged-65-or-older

• Elderly persons have diminished immune response (lower post-vaccination titers)

• Most studies of elderly have been observational cohort studies that have varied greatly in conclusions

• Advantages of this study:- Large dataset: 18 HMO cohorts and 713,872 person-seasons- Over 10 flu seasons, including mismatch years- Multiple sites (MN, WI, WA, NYC)- Multiple attempts to control for bias

• Conclusions: influenza vaccination reduced the risk of hospitalization by 27% and death by 48%

2011-12: ~47% of pregnant women vaccinated

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• Randomized blinded trial of 340 healthy women vaccinated in the 3rd trimester

• Mothers and infants followed for 24 weeks after birth

• Results showed:- lower risk of laboratory-confirmed influenza in infants by 63%

- lower risk of any febrile respiratory illness in infants (20%) and mothers (36%)

• Limitation: conducted in a tropical country where influenza circulates year-round

Worldwide Child Mortality(WHO/UNICEF/UNDP/World Bank 2010)

2005 World Health Report: Make Every Mother and Child Count (WHO) and The Lancet’s Newborn Survival Series (2005) and UNICEF (2008)

Move to Universal Vaccination

• Recognition of suboptimal vaccine effectiveness among groups at highest risk for influenza complications (e.g. elderly, persons with chronic illness)

• Potential for reducing community transmission through vaccinating school children and healthy adults if high coverage can be achieved

• Lessened concerns about vaccine supply• Increased concern about an influenza pandemic‐need to lean 

how to vaccinate an entire population against influenza.• Belief that current low coverage for most recommended 

groups might be improved by a simple universal recommendation

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2007-08 INFLUENZA PREVENTION & CONTROL RECOMMENDATIONS

Persons for Whom Annual Vaccination is Recommended

• All persons aged 6 months and older;

• Chronic pulmonary disease (including asthma)• Chronic cardiovascular disease (except hypertension)• Chronic metabolic disease (renal, hepatic, diabetes mellitus); • Immunosuppression • Neurologic condition (e.g., cognitive dysfunction, spinal cord injuries,

seizure disorders, or other neuromuscular disorders);• Women who will be pregnant during the influenza season; • Persons receiving long-term aspirin therapy; • Health-care personnel; • Residents of nursing homes and other chronic-care facilities; • Healthy household contacts and caregivers of children aged <6 months and

persons with medical conditions that put them at higher risk for severe complications from influenza.

U.S. Influenza Vaccine, 2013‐2014 SeasonLicensed only for adults

Ages Trade Name Mfr Presentation

≥18 yrs Flucelvax® Novartis 0.5 mL single‐dose syringe

≥18 yrs FluLaval® ID Biomedical 5.0 mL multidose vial 

18‐49 yrs FluBlok® (Recombinant) Protein Sciences 0.5 mL single‐dose syringe

18‐64 yrs Fluzone® Intradermal sanofi pasteur 0.1 mL prefilled microinjection system

≥65 yrs Fluzone® High‐Dose sanofi pasteur 0.5 mL single‐dose syringe

What are the side effects of the influenza vaccine (IM)?

• Pain 24%• Redness 11%• Swelling 6%• Muscle ache 18%• Malaise 14%• Headache 14%• Fever 2%

All transient

undoubtedly an overestimate, as no placebo group

2010-11 Northern Hemisphere Influenza Vaccine Recommendations

• A/California/7/2009 (H1N1)pdm09• A/Victoria/361/2011 (H3N2)• B/Massachusetts/2/2012 (Yamagata lineage)• For quadrivalent vaccines: Brisbane/60/2008 (Victoria

lineage)

ACIP Recommends Universal Annual Influenza Vaccination for everyone 6 months of age and older

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Influenza B virus lineage mismatch

Season Vaccine B Lineage

% of type B influenza from opposite strain

% of all US influenza from opposite strain 

1999‐2000 Yamagata <1% <1%

2000‐2001 Yamagata <1% <1%

2001‐2002 Yamagata 77% 10%

2002‐2003 Victoria <1% <1%

2003‐2004 Victoria 93% <1%

2004‐2005 Yamagata 26% 7%

2005‐2006 Yamagata 78% 15%

2006‐2007 Victoria 24% 5%

2007‐2008 Victoria 98% 28%

2008‐2009 Yamagata 83% 27%

Reed C, et al. ACIP 10/2012; Vaccine (2012)

Reasons given for not getting vaccinated

• I’m not at risk for influenza, 39%

• People around me are not at risk of getting influenza, 29%

• Influenza isn’t a serious threat to my health, 66%

• Influenza isn’t a serious threat to the health of people around me, 40%

• Vaccination can’t protect me from getting influenza, 46%

• If I get vaccinated, people around me won’t be better protected, 55%

• Influenza vaccination isn’t safe, 34% 

• The flu vaccine will give me influenza, 9% • MMWR 60:1073, ICT 15:12

The Facts

• Of all vaccine‐preventable diseases,  seasonal influenza is the number one cause of hospitalizations and deaths. 

• The goal of influenza vaccination is NOT to prevent influenza infection.  The goal is primarily to prevent severe complications from influenza, including in those most vulnerable (e.g., your grandson, your aunt with heart disease, your elderly neighbor).

Putting Flu Surveillance Data to Work

• Detect emergence and spread of a novel influenza virus (or other respiratory pathogen) that is causing disease

• Characterize population being affected

• Characterize risk factors and clinical features of infected cases

• Provide data for targeting of educational campaigns and interventions (e.g. vaccine and antiviral allocation)

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Typical influenza illness-like in 2 children

CDPH notified April 14, 2009• Case Patient A, San Diego county. March 30, 2009

– Previously healthy 10 year old boy with fever, cough, vomiting x 1 week– No exposure to pigs– Mother and brother had respiratory illness preceding case patient– Flew to Dallas, Texas on April 3rd while febrile

• Case Patient B, Imperial county. March 28, 2009– Previously healthy 9 year old girl with fever to 104°F and cough x 1 week – No direct exposure to pigs– Attended state fair where pigs exhibited but never saw pigs– Traveled to Mexicali, Mexico 2 weeks prior– 13 year old brother and 13 year old cousin with respiratory symptoms

Typical influenza‐like illness in 2 children

• Cases occurred 80 miles apart

• Samples collected by different people at different times

• Samples never went through the same lab

• Both cases positive for influenza A by PCR but untypeable for human H1 or H3

• Reference testing at CDC: swine flu A/H1N1

Early Confirmed Cases of SIV

0

1

2

3

4

3/26/2

009

3/29/2

009

4/1/20

09

4/4/20

09

4/7/20

09

4/10/2

009

4/13/2

009

4/16/2

009

Date

Texas CasesCalifornia Cases

Num

ber o

f Con

firm

ed C

ases

Case Patient A Flew to Dallas,

Texas

No known epidemiologic link between the Texas and California cases

Mexicali

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April 24, 2009

US Hospitalizations and Deaths due to H1N1

• California cumulative totals:  – Hospitalizations:  8959

– Deaths:  597

• Estimated cumulative US totals (lab‐confirmed): – Hospitalizations:  41,821

– Deaths:  2117

• Adjusted cumulative US estimates– Total cases:  61 million

– Hospitalizations:  274,000

– Deaths:  12,470

Available at URL: http://www.cdc.gov/h1n1flu/estimates_2009_h1n1.htm

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Age‐specific mortality rate (per 100,000 population) of 2009 H1N1 influenza in California, reported April 23, 2009 – May 1, 2010

0.2

0.5

1.0

1.8

3.1

1.6

1.4

1.2

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

<1 1-4 5-18 19-24 25-35 36-49 50-64 65+

Age group

Influ

enza

mor

talit

y ra

te

All ages = 1.5

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High fatality in the elderly once in the ICU

• In persons ≥60 years, case fatality rate due to 2009 H1N1 decreases with increasing age.

• This same population has a high prevalence (90%) of co‐morbidities associated with risk for severe influenza.  

• Once admitted to intensive care, all adults had high case‐fatality ratios; persons 70‐79 years of age were most likely (45%) to die. 

• Older age groups may be somewhat spared due to pre‐existing relative immunity to 2009 H1N1; however, once infected and hospitalized in intensive care, case‐fatality ratios can be high for all adults, especially the elderly.

BMI and case fatality proportion due to H1N1

17.4

15.5

11.8

15.7

17.5

27.2

0

5

10

15

20

25

30

35

40

<18.5 18.5-24 25-29 30-34 35-39 40+

Body mass index category

Perc

ent f

atal

2009 H1N1 among US pregnant women

• Pregnant women ~1% of the general population

• Pandemic (H1N1) 2009 influenza in pregnant women

– ~7‐10% of hospitalizations 

– ~6‐9% ICU cases and 

– ~6‐10% of deaths

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Pregnancy and H1N1, CaliforniaApril‐August 11, 2009

• 94 cases (10% of all hospitalized cases)

• 95% in the second or third trimester

• One‐third had other underlying risk factors.   

• 20% with rapid clinical deterioration requiring  intensive care; one‐quarter intubated at admission.  

• Six deliveries in ICU, including 4 stat C‐sections

• Six deaths, due to ARDS

• Eight cases were 2 weeks postpartum, 4 admitted to intensive care and two died.

* California total: 586 hospitalizations, 16 deaths (CFR 2.7%)

News quotes

9.29.09 “Maybe this year we can change that culture. It’s not supposed to happen that you, when you are pregnant, are fighting for your lifeon a respirator”- Dr. Anne Schuchat, CDC

New concerns:  Postpartum RiskNumber of Days from Delivery to Symptom Onset (n=14*)

0

1

2

3

4

5

6

7

8

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44

Number of Days

Num

ber o

f Adm

issi

ons

ICU Admissions Resulting in DeathICU AdmissionsHospital Admissions

* Timing of delivery date to symptom onset w as unknow n in one ICU admission. ICU: intensive care unit

Continued Vigilance

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Avian Influenza 

Surveillance Worldwide

US wild bird surveillance: dead birds only

www.aphis.usda.gov

World Organization for Animal Health (OIE)

Notifiable avian influenza (NAI) is defined as an infection of poultry caused by any influenza A virus of the H5 or H7 subtypes or by any AI virus with an intravenous pathogenicity index (IVPI) greater than 1.2 (or as an alternative at least 75 percent mortality). 

http://www.oie.int/animal-health-in-the-world/update-on-avian-influenza/2013/

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H5N1 Outbreak – Hong Kong 1997

• Seminal event– Provided direct evidence that avian

influenza viruses can infect people– Provided epidemiological link between

avian influenza infections in poultry with disease in humans

– Demonstrated unusual lethality of H5N1; 18 cases, 6 deaths.

– Contained only when entire poultry population of HK culled in 3 days (1.5 million birds)

– Precursor to the H5N1 virus circulating today

Influenza A H5N1 facts

• Since November 2003, 566 human H5N1 cases reported from 15 countries in Asia, Africa, the Pacific, Europe and the Near East.  Indonesia, Vietnam and Egypt have reported the highest number to date.

• Majority of cases are among children and adults < 40 years old. 332 (58%) of the cases have died.

• Almost all cases infected after direct or close contact with sick or dead infected poultry.

• Other risk factors include visiting a live poultry market and prolonged, unprotected close contact with a sick H5N1 patient. 

• Currently, H5N1 virus does not transmit efficiently from person to person. Some cases of limited, non‐sustained human‐to‐human transmission have been reported in family clusters.

Influenza A H5N1 facts

• H5N1 is a highly pathogenic virus which causes illness in birds.

• Over 400 million birds have been culled in an effort to prevent spread, causing an estimated $20 billion in economic damage. 

• The number of outbreaks in domestic poultry and wild bird populations shrank steadily from an annual peak of 4000 to 800 in 2010‐2011

• Currently, H5N1 virus is considered endemic in poultry in six countries (Bangladesh, China, Egypt, India, Indonesia, and Vietnam).

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Influenza A H7N9 facts

• Between April 1 and April 29, 126 cases had been reported, including 24 deaths.  Most severely ill cases reported in elderly males with underlying medical conditions.  Some, but not all, report poultry exposure.

• Virus has mutations that convey ability to easily infect human respiratory mucosa.

• No evidence of sustained person‐to‐person transmission: testing 20,739 patients with ILIs revealed only six cases of H7N9 infection, a rate of .03%.

• Reports of new cases dropped in May;    current case count:  136 cases, 45 deaths (33%)

Influenza A H7N9 facts

• The virus has been found in a small number of chickens, ducks, and captive‐bred pigeons at live bird markets; many thousands have been tested.

• Low pathogenicity virus means infected birds can shed virus, but do not have symptoms.

• The drop‐off in newly reported H7N9 cases in China over the summer may be the result of containment measures including closing live bird markets, as well as seasonal factors like warmer weather, higher humidity.

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• N=82

• Median age ‐ 63 years (range, 2 to 89); 46% in persons > 65 years of age

• 73% male

• 87% had ACIP risk factors

• 77%) reported recent exposure to animals at live bird markets:

• 45 (76%) to chickens, 12 (20%) to ducks, and 4 (7%) to swine

• Median time from exposure to illness was 6 days

• 21% mortality

• 1251 contacts monitored, 19 developed ILI and tested negative for influenza

• Three family clusters identified with likely person‐to‐person transmission

Live bird markets in California

Southern CA live bird markets (n=29): 200-1000 birds sold daily

Don’t forget us!

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3

• 379 cases of mostly mild ILI, 16 hospitalizations, one death. • Almost all cases associated with swine exposure at agriculture fairs• Hotspots: Indiana, Ohio during fair season• Most cases in children; <10 years appear to be non-immune

Swine Influenza is not reportable

• As in people, influenza frequently circulates in swine. Symptoms include fever, cough and nasal discharge.

• USDA has a voluntary surveillance program. The goal is to” identify viruses that may be circulating in swine, and gain knowledge to contribute to improved animal health diagnostics and vaccines”, NOT to determine prevalence.

• Specimens submitted anonymously

• 2010‐2012: 12,662 samples from 3,766 swine collected. 1,488 were positive for Influenza A infection. 

– 73 H3N2 positive in 2011 

– 138 H3N2 positive in 2012

California: Flu by the Numbers

During a single flu season– Sentinel providers report ~40,000 ILI visits and ~1.5 million clinic visits

– Sentinel laboratories test  ~50,000 specimens

– Local public laboratories test and subtype ~4500 specimens

– Estimated number of influenza deaths in all ages:  ~3500. 

– Estimated number of influenza deaths <age 65:  ~300. 

– Estimated number of LTCF with potential for respiratory outbreaks with high morbidity and mortality:  1400 with ~102,000‐300,000 residents

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Questions