Presentation on theme: "Seasonal Influenza versus Avian Flu and Public Health’s Role:"— Presentation transcript:
1Seasonal Influenza versus Avian Flu and Public Health’s Role: Content adapted for BugLine from presentation by :Cassandra D. Youmans, MD, MPH, MS-HCM, FAAPDistrict Health DirectorEast Central Health District VI
2Epi Terms (www.healthyamericans.org) Endemic – expected or usual occurrence of diseaseEpidemic – unexpected or unusual occurrence of diseasePandemic – epidemic, but wider geographic area and larger population affectedShift – big change in a virus strain due to mutationPrevalence – existing disease in a given population at a given timeIncidence – rate of occurrence of new cases of disease in a populationTransmission – any means of spreading infectious disease to or among peopleAntigen – protein, usually foreign, that elicits a specific immune responseAntibody – protein in the blood produced after exposure to an antigenParasite/pathogen/germ – any organism causing diseaseImmunity – not susceptible to infection or diseaseVaccine - a drug intended to induce active artificial immunity against a pathogen. It can be live or dead
3Active Immunization (www.swinton.net) Attenuated (weakened) versions or strains of the pathogenOne dose typically induces a full antibody response or memoryExample: MMR vaccine from wild strains of measles/mumps/rubella viruses that are repeatedly passed through cell lines until non-pathogenicKilled (dead) versions or strains of the pathogenWhole pathogen; examples: Salk polio strain and pertussis vaccineHighly immunogenic part of the pathogen (toxoid vaccines)These do not multiply in the host; multiple doses are typically given to induce a full antibody response.
4Passive Immunization (www.swinton.net) Passive immunization is differentConcentrated pathogen specific antibodies (not weak or dead virus) are given to lesson the signs and symptoms of an infection or to provide short-term protection for several monthsDoes not induce memory needed for long term protection
5Influenza Virus (Red Book 2003) 3 virus/antigen types (A,B,C)Each has subtypesOnly three subtypes known to be currently circulating among humans: H1N1, H1N2, H3N2 (www.bt.cdc.gov)Epidemics are caused by types A and BAntigenic shift has occurred only with Influenza AAntigenic shift - Major changes in these antigens lead to the emergence of new strains of the virus (the body cannot recognize or respond to the virus from past years)Influenza B is slower to change and has no subtypesAntigenic drift – Minor changes cause seasonal epidemics (the body can still recognize and respond to the virus based on past years)
7Seasonal Influenza Spread in Humans Person to person spread via secretions or direct contact with contaminated surfacesMost infectious 24 hours prior to symptoms1–3 day incubation periodAttack rate depends on immunity within the community
8Higher Risk Groups Cancer Diabetes Asthma COPD Cystic fibrosis Infant BPD (Bronchopulmonary dysplasia)Congenital heart diseaseSickle cell and other red cell shape abnormalities
9Diagnostic Tests (Red Book 2003) Nasopharyngeal (NP) swab/aspirateRapid screening test is reliable (sensitivity 45-90%, specificity 60-95%).Can culture in the first 72 hours of illnessVirus concentration decreases after 72 hoursEgg or cell culture isolates virus within 2–6 daysCan get 2 antibody titersA 4-fold increase in titer from acute to convalescent stages of illness is diagnostic
10Current Treatment Recommendations For Type A and B Influenza (Tarascon Pocket Pharmacopoeia 2005) For treatment of Type A and B infectionsBegin within 2 days (48 hrs) of symptom onsetOseltamivir (Tamiflu)For prophylaxis, not 100% effectiveIndiscriminate use may cause viral resistanceZanamivir (Relenza)Not for prophylaxis, not for young children
11Pandemics (Pandemic Flu: What you should know Pandemics (Pandemic Flu: What you should know. Q & A Volume I Winter 2006)An average of 3 occur every centuryFive in the last 120 years1889, 1900, 1918, 1957, 19581918 (Spanish Flu, million died, 500,000 in US1957 (Asian Flu, 4 million died)1958 (6 million died)Lower mortality because antibiotics available to treat secondary bacterial infections
121957 Pandemic: Asian Flu (Pandemic Flu: What you should know 1957 Pandemic: Asian Flu (Pandemic Flu: What you should know. Q & A Volume I Winter 2006)April 1957, a strain of influenza infected 250,000 people in Hong KongUS researcher, Maurice Hillerman, predicted the start of the Hong Kong outbreak signaled the next pandemicDuring the next 5 months, he persuaded 6 drug companies to produce influenza vaccine against the strain circulating in Hong KongThe virus entered the US in September 1957, 20 million people infected, 70,000 diedLesson learned: If enough vaccine is made in advance of a pandemic, lives will be saved
13Pandemics (Pandemic Flu: What you should know Pandemics (Pandemic Flu: What you should know. Q & A Volume I Winter 2006)The best way to protect against a pandemic is a vaccineThe vaccine will have to contain the strain of influenza virus that is causing the problemAn effective vaccine can’t be developed until the pandemic begins4 companies make influenza vaccineSanofi Pasteur, GlaxoSmithKline, Chiron, and MedImmuneThere is limited infrastructure to produce large quantities of vaccine, therefore the vaccine would be rationedDepartment of Health and Human services is developing a plan (www.pandemicflu.gov/plan)
14Avian Influenza or Bird Flu (www.bt.cdc.gov)(www.healthyforums.com) Type A Influenza Virus principally found in, and occurs naturally among birdsSeasonal flu among birdsH5N1 spreads rapidly among birds, but rarely in humansWild birds carry the virus in their intestines, but rarely get sickDomestic birds - chickens, ducks, turkeys can get very sick and die1997, Public Health Officials detected the strain in Southeast Asia, 170 people infected, 50% (85) diedIn affected countries, the virus has spread to other mammals like pigs, cats, and tigers.
15Domestic Birds (www.bt.cdc.gov) Low virulence form - mild symptoms like ruffled feathers or drop in egg productionHigh virulence form– spreads rapidly through flocks of poultry with mortality rates 90 to 100% in 48 hours
16Transmission in Birds (www.healthforums.com) Infected birds shed virus in their saliva, nasal secretions, and fecesOther birds are infected via direct contact with these secretions or excretions, or contaminated surfaces (cages, water, or feed)
17Avian Flu Spread in Humans (www.healthforums.com) Direct contact with infected poultry or contaminated surfacesRisk factor – poultry worker, hand butchering infected foulRare reports of the virus spreading from one person to another, and these cases have not been seen to continue beyond one person
18US Department of Agriculture Guidelines - Common Sense At Home (www US Department of Agriculture Guidelines - Common Sense At Home (www.healthforums.com)Wash hands with warm water and soap for at least 20 seconds before and after handling foodKeep raw poultry and its juices away from other foodsKeep hands, utensils and surfaces such as cutting boards cleanUses a food thermometer to ensure poultry has been fully cooked
19Bird Flu and Humans (www.bt.cdc.gov) Prior to 1997, no human death associatedNo evidence that properly cooked poultry or eggs is a source of infectionNo human infections from eating poultry in affected countriesH5N1 has not been detected in the USThere have been no cases of infected poultry in the USIn 2004, the US banned import of poultry from countries affected by Avian Influenza
20District VI Public Health Department Focuses on Health and Wellness Emergency PreparednessPromote3P’sProtectMedical ServicesEnvironmental HealthProvide
21Public Health’s Principle Role in Disaster Mitigation To assure access to Special Needs Shelters (SNS) when neededTo directly administer or provide for administration of agent specific prophylactic and/or therapeutic pharmacologys to mass populationsTo support local and district EOC emergency preparedness efforts
22Pre Event: Is ALL about education! Preparation begins with education prior to a disasterSeek information about potential hazards within your community.Then you can:Secure your safetySecure your family and homeEncourage friends, peers, community to do the samePlan for two-way communication with emergency personnel and family, and have contingencies built inBe flexibleBe prepared
23Public Health Challenge Risk of a shift: H5N1 virus might exchange genes with a human virus strain or mutate into a form that is easily spread to and among humansRare in humans, therefore our immune systems have not been exposed to be able to develop enough of an immune response to fight it, an influenza pandemic could beginThe seasonal human influenza vaccine will not provide protectionH5N1 specific vaccines have been in development since April 2005Clinical trials are underwayAntiviral drugs are being studied for efficacy
24Estimated population is 9.1 million Pandemic Flu Impact Assumptions (Pandemic Flu Response Standard Operating Guide (SOG)Assuming Georgia makes up approximately 3 % of the US Population,Estimated population is 9.1 million
25Consider the expected impact on area finances and infrastructure due to flu illness, absentees, deaths!
26Disasters vary, but planning questions remain the same Who?What?Where?When?How?Why?Drills Offer Opportunities to Exercise Plans, Modify, and Adjust.
27Successful Disaster Management Requires Partnership & Integration Volunteer Medical Reserve corpsLocal emergency operations centersAcademic medical centersCommunity health centersFederally Qualified Health CentersFaith based organizationsNursing schoolsESF8
28Contacts:Georgia Department of Human Resources, Division of Public Health;East Central Health District Emergency Preparedness ;East Central Health District,Centers for Disease Control and Prevention; ;East Central Health District Collaborators:Melba McNorrill, RN Child Health CoordinatorGary Zgutowicz, Emergency Preparedness CoordinatorDonna Scott, Clinical Services CoordinatorSadie Stockton, TUPS/Chronic Disease Prevention CoordinatorJodie Reece, IT DirectorHelen Smith, Administrative Assistant to the District Health DirectorCounty Facility Managers and staff