H1N1 Global Pandemic Kevin Sherin, MD, MPH, FACPM, FAAFP Director Orange County Health Department

Transcription

1 H1N1 Global Pandemic 2009 Kevin Sherin, MD, MPH, FACPM, FAAFP Director Orange County Health Department

2 What is H1N1 Swine Flu? It s not like other recent human H1N1 s. Pieces come from birds, pigs, and people.

3 Pandemic H1N1/09 Virus First Cases: -Mexico early March, California early April Spread: -This virus has spread 4 x as fast as 1918 pandemic influenza Severity: -WHO classified as Moderate - 1/3 of lethal cases may have had no determined underlying disease had 1-2% mortality Strain: -8 strands, 5 porcine, 1 human, 2 avian -Recombination, 12 Countries including the U.S.

4 Flow of H1N1 Info

5 Containment to Mitigation The virus is widespread in the community Individual case investigation, contact quarantine & contact tracing is no longer feasible or effective Voluntary measures to reduce person-to-person spread Self-isolation of the sick Encourage good respiratory hygiene, handwashing Sensible, practical methods to reduce transmission in public and private settings Help treatment facilities provide appropriate care Reduce healthcare amplify of infection Make best use of available treatment drugs and equipment to reduce morbidity and mortality Coordinate public health and healthcare responses Health Department Measures Investigation of critical cases and deaths Outbreak investigations Influenza Surveillance Provide public and medical community with accurate information and guidelines 5

6 What Can We Hope to Accomplish? Reduce total number of cases Reduce number of deaths Spread out cases over a longer period Delay cases until vaccine is available Protect the Public s Health! 6

7 H1N1 Statistics (Sept. 4) U.S. 593 Deaths 9,079 Hospitalizations World 2,837 Deaths (WHO) 254,206 Cases (WHO) 68,222 Confirmed Cases in 50 states and 4 territories (unofficial count) The WHO and the CDC are no longer counting individual cases. CDC will report hospitalizations and deaths weekly and as well as data from traditional influenza surveillance systems. Unofficial counts are based on media reports\.

8 International Co-circulation of 2009 H1N1 and Seasonal Influenza As of September 2

9 U.S. Influenza Activity Note the widespread activity in Southeastern states

10 Current Surveillance by FL DOH State public health laboratory 100 sentinel providers ESSENCE syndromic surveillance system (Hospital ED s) County health departments Weekly count of deaths Outbreak investigations Local systems (e.g. school absenteeism)

11 Florida Statistics- September 2 Florida 644 hospitalizations 70 deaths 51 cases in pregnant women Numerous outbreaks in daycares, camps, correctional facilities, workplaces, and schools. 11

12 County Influenza Activity based on Surveillance Reports Based on number of outbreaks reported, ILI activity detected through local surveillance systems and lab evidence of influenza in the community.

13 ESSENCE: ED visits for ILI The percent of emergency department visits associated with influenza-like illness is greatest in the <1-19 age group, and now exceeds the percent observed during the initial increase in May Increases since June are mostly occurring in the younger and middle age groups.

14 Laboratory Surveillance FIGURE 4. The Bureau of Laboratories is now reporting that 50% of the specimens submitted to them are positive for influenza. Of those positive for influenza, 98% were novel H1N1 influenza. The remaining 2% were seasonal influenza B.

15 Clinical Presentation

16 Transmission Seasonal human influenza viruses- are thought to spread from person to person primarily through large-particle respiratory droplet transmission (e.g., when an infected person coughs or sneezes near a susceptible person). Transmission via large-particle droplets requires close contact between source and recipient persons because droplets do not remain suspended in the air and generally travel only a short distance (< 6 feet). Contact with contaminated surfaces is another possible source of transmission and transmission via droplet nuclei (also called airborne transmission). Because data on the transmission of novel H1N1 viruses are limited, the potential for ocular, conjunctival, or gastrointestinal infection is unknown. Since this is a novel influenza A virus in humans, transmission from infected persons to close contacts may be common. All respiratory secretions and bodily fluids (diarrheal stool/vomitus) of novel influenza A (H1N1) cases should be considered potentially infectious.

17 Novel H1N1 vs. Seasonal H1N1 In vitro and in vivo characterization of new swine-origin H1N1 influenza viruses. Nature, Yasushi et al,13 July 2009 Novel H1N1 was found to replicate more efficiently in mice, ferret, and non-human primate models than seasonal H1N1. Novel H1N1 was found to cause more severe pathological lesions in mice vs. seasonal H1N1. Novel H1N1 was found to have a similar transmission pattern to seasonal H1N1 viruses. High transmissibility that we are currently seeing likely due to lack of pre-existing immunity among majority of the population. We are not seeing increased severity but are seeing severe illness in atypical age group for influenza.

18 Incubation Period Incubation period The estimated incubation period is unknown and could range from 1-7 days, but more likely 1-4 days.

19 Infectious period The duration of shedding of H1N1 virus is unknown. Estimated is based on data for seasonal influenza infection. Seasonal Flu Shedding: one day before onset until resolution of symptoms; typically 1 day before to 7 days after illness onset. Children, especially younger children, might be infectious for up to 10 days. New Self-Isolation Guidelines from CDC : Self-isolation (no school or work) should be recommended for all patients presenting with ILI until 24 hours after fever resolves (<100 F) without the use of a fever reducer. Isolation guidelines remain the same for healthcare workers: 7 days from onset or until symptoms resolve, whichever is longer.

20 Seasonal Flu High Risk Groups Children less than 5 years old and adults aged 65 yrs or older Children and adolescents (< 18 years) receiving longterm aspirin therapy (Reye s syndrome) Pregnant women Adults and children who have chronic pulmonary, cardiovascular, hepatic, hematological, neurologic, neuromuscular, or metabolic disorders Persons who have immunosuppression (including immunosuppression caused by medications or by HIV) Residents of nursing homes and other chronic-care facilities

21 Children CDC MMWR on Pediatric Deaths Associated w/ H1N1-Sept.4 67% of H1N1 deaths in kids less than 18yrs had underlying medical conditions, 92% of which were neurodevelopmental (developmental delay or cerebral palsy). 41% had both neurodevelopmental and chronic pulmonary conditions. In children w/ cultures done, 43% had bacterial co-infection; co-infection was found in all cases less than 5 yrs old. Almost 50% of H1N1 cases in FL are in children 18 and under, who are less than 25% of the population. Most H1N1 outbreaks were associated with daycares or camps this summer in FL. 13% of H1N1 deaths are in persons <24 yrs in FL. They include: 1 death in a child less than 4 yrs, 9 deaths in persons 5-24 yrs, 6 with underlying medical conditions.

22 Pregnancy H1N influenza virus infection during pregnancy in the USA, The Lancet, Jamieson et al, 29 July 2009 From April 15 to July 16, 13% of H1N1 associated deaths are in pregnant women Pregnant women are at increased risk for H1N1 complications Pregnant women have a higher rate of hospitalization than the general public Per CDC data, pregnant women are 4 times as likely to be hospitalized for H1N1 than the general population. Pregnant women with influenza-like illness should be treated promptly with antiviral medications. Pregnancy should not be considered a contraindication to oseltamivir or zanamivir use. The benefits outweigh the risks. Oseltamivir is preferred to zanamivir in pregnant women.

23 Antiviral Medications Oseltamivir (Tamiflu) Prophylaxis: once a day for 10 days Treatment: twice a day for 5 days Dosage: based on weight/age EUA for prophy in children less than 1 yr old Zanamivir (Relenza) Prophylaxis: two 5mg inhalations once a day for 10 days Treatment: two 5mg inhalations twice a day for 5 days Only treat those who are high risk!

24 Complications Clinicians should expect complications to be similar to seasonal influenza: exacerbation of underlying chronic medical conditions upper respiratory tract disease (sinusitis, otitis media, croup) lower respiratory tract disease (pneumonia, bronchiolitis, status asthmaticus) cardiac (myocarditis, pericarditis) musculoskeletal (myositis, rhabdomyolysis) neurologic (acute and post-infectious encephalopathy, encephalitis, febrile seizures, status epilepticus) toxic shock syndrome and secondary bacterial pneumonia with or without sepsis Critically ill 25 year old H1N1 patient tle_with_swine_flu_ends_wednesday.html

25 How Does Influenza Kill? Primary pneumonia viral Secondary pneumonia bacterial Both congest airways and make breathing impossible Contribute to deaths from heart attack, stroke, cancer, etc.

26 Deaths associated with novel H1N1 75% have underlying chronic disease Age distribution is different from that for all confirmed cases In many cases there was late initiation of antiviral treatment due to delayed medical evaluation or misdiagnosis as bacteria illness Important for high risk individuals to seek medical attention early in illness to avoid complications Emergency Symptoms : has difficulty breathing or chest pain has purple or blue discoloration of the lips is vomiting and unable to keep liquids down has signs of dehydration such as dizziness when standing, absence of urination, or in infants, a lack of tears when they cry has seizures (for example, uncontrolled convulsions) is less responsive than normal or becomes confused 26

27 Cases and Deaths by Age Group Deaths are occurring in older age groups than cases Number of Deaths Age Group Newly reported Year-to-date 27

28 Influenza Rapid Test

29 H1N1 Confirmatory Testing Since July 13, the DOH Bureau of Laboratories has only test for the novel 2009 H1N1 virus specimens from: Patients with life-threatening illnesses, Patients from county health departments investigating suspected influenza outbreaks Patients from the Florida network of sentinel surveillance practices. RT-PCR testing to detect the novel H1N1 virus is now also available through at least one commercial laboratory (Quest), and some local hospital systems. Specimen- nasopharyngeal swab or aspirate, nasal swab plus a throat swab or nasal wash, or tracheal aspirate should be collected. (Nasopharyngeal swabs are preferred) Wear appropriate PPE when collecting the specimen Not all people with suspected novel influenza (H1N1) infection need to have the diagnosis confirmed, especially if the illness is mild. Remember 99% of current circulating flu is H1N1!

30 Infection Control Patients with ILI who present for care at a healthcare facilities should be placed directly into individual rooms and the door should be kept closed The ill person should wear a surgical mask to contain secretions when outside of the patient room Healthcare personnel entering the room of a patient in isolation should be limited to those performing direct patient care.

31 Infection Control All healthcare personnel who enter the rooms of suspect H1N1 patients should wear a fit-tested disposable N95 respirator or better (CDC/IOM). FL DOH recommends the use of surgical masks for routine contact. In a Healthcare setting- Isolation precautions for 7 days from symptom onset or until symptoms resolve, whichever longer. Asymptomatic healthcare personnel who have unprotected exposure to novel H1N1 may continue to work if they are started on antiviral prophylaxis.

32 Intervention Strategy: H1N1 Swine Flu Vaccine Initial doses will be made available when received from CDC- tentatively mid-october The H1N1 shot will be separate from the seasonal flu shot- it is unknown whether the H1N1 and seasonal shots can be administered at the same time Shots will be VOLUNTARY and FREE Will likely involve 2 doses separated by 21 to 28 days. Drive-Thru Vaccine POD

33 Vaccine Initial Target Groups Pregnant women Health care workers and emergency services personnel People caring for infants under 6 months of age Children and young adults from 6 months to 24 years People aged 25 to 64 years with underlying medical conditions (e.g. asthma, diabetes, respiratory or cardiac illness) Resource: ** Older people may have protection against H1N1 **

34 Subset of Target Groups During Limited Vaccine Availability Same groups as previous slide with following 2 caveats children aged 6 months--4 years children and adolescents aged years who have medical conditions that put them at higher risk for influenzarelated complications

35 Prevention Messages Wash your hands Cough or sneeze into your sleeve or elbow, when a tissue is not available. Try to stay in good general health by getting plenty of sleep, drink plenty of fluids, and eat nutritious food. STAY HOME IF SICK- at least 24 hours after fever is gone for the general public; 7 days after symptoms begin or until all symptoms are gone, whichever is longer, for all health care workers Get vaccinated as soon as vaccines become available (for seasonal flu) and if you are in the target group (for H1N1 swine flu). For more flu information, visit:

36 Public Education Efforts Press releases Numerous media interviews Articles in Medical Society newsletter Blast s to local providers Contact with public and private schools, universities, major employers, daycares, hospitals, clinics, etc. Education material provided to schools, daycares created by Orange CHD. Protect! Don t Infect! (PDI)

37 Questions?