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Dr Joan O’Donnell April 3 rd 2008. Influenza and TB: Challenges in 21 st Century Ireland. Influenza Seasonal Influenza-Epidemiology Challenges National influenza and pneumococcal vaccine uptake telephone survey Avian and Pandemic Influenza Challenges Tuberculosis
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Dr Joan O’DonnellApril 3rd 2008 Influenza and TB: Challenges in 21st Century Ireland
Influenza Seasonal Influenza-Epidemiology Challenges National influenza and pneumococcal vaccine uptake telephone survey Avian and Pandemic Influenza Challenges Tuberculosis Context and epidemiology Challenges Future Directions Overview
An RNA virus of the orthomyxovirus family Three types: Type A that causes moderate to severe illness Human and animal reservoirs Unstable - antigenic shift likely (epidemics likely) Type B causes milder epidemics-Humans only reservoir Primarily affects children, relatively stable, immunogenic Type C: Humans only reservoir, Not associated with epidemics (Sub clinical infection) Serious illness and mortality in those with co-morbidity and older people Influenza Virus
Sources of Influenza Data ICGP NVRL Departments of Public Health Other Sentinel GP ILI consultations Hospital admissions GRO-Mortality data School absenteeism Sentinel specimens HSE-Influenza vaccine uptake Enhanced influenza surveillance Non-sentinel specimens GP Co-Ops ILI outbreaks International-EISS, HPA, etc Influenza notifications HPSC EISS HPA Dept Public Health Weekly surveillance report
ILI rate per 100,000 population and the number of positive influenza specimens detected by the NVRL during the 2000/2001, 2001/2002, 2002/2003, 2003/2004, 2004/2005, 2005/2006 & 2006/2007, 2007/2008 seasons
Number of sentinel GPs increased Aim 5% population coverage 2004/2005: 2.7% 2005/2006: 3.8% 2006/2007: 4.0% 2007/2008: 4.8% Sentinel General Practices
Maintain sentinel surveillance network Exploring surveillance using GP co-ops (NHS Direct) Enhanced surveillance of hospitalised children aged 0-14 years Guide influenza vaccine policy for 0-4 year olds Measurement of influenza vaccine uptake ILI/influenza outbreak surveillance and management protocol Influenza baseline estimation Public health action re antiviral use in high risk groups Mortality Project –EU MoMo Early warning system for influenza epidemic and pandemic and other public health emergencies Current Challenges
The uptake of Influenza and Pneumococcal Vaccine in Ireland 2005/2006
Influenza vaccine annually Recommended for risk groups Influenza vaccine recommended for all healthcare workers (HCWs) Pneumococcal vaccine once usually Recommended for risk groups Limited influenza vaccine uptake data available No pneumococcal vaccine uptake data available Population aged <65 years with health risk unknown Influenza and pneumococcal vaccination policy in Ireland
To estimate The proportion of the population aged 18-64 years in at-risk groups for influenza or pneumococcal infection Uptake of influenza and pneumococcal vaccine in all risk groups in order to provide baseline information, to improve targeted immunisation programmes and to prevent morbidity and mortality Study Objective
Study design Cross-sectional retrospective telephone survey Study population Over 18 years Age and sex Resident in Ireland Landline telephone Sample size 1500 respondents Data collection Standardised questionnaire Interviews June 2006 Methods and Materials
Vaccine uptake For those over 65 years Meets national target for influenza (69%) Low for pneumococal vaccine (41%) For those aged 18-64 years with health risk Low (28% influenza, 11% pneumococcal) For influenza among HCWs Very low (20%) First national estimate of health risk groups (11%) Conclusions
Selection bias 88% have a fixed line phone Persons with limited mobility Excluded Non-English speakers Institutional settings, non-private dwellings Recall bias Questions cover quite a long period of time Self reported information Not validated Study Limitations
Continue to promote influenza vaccination among those aged 65 years and over Endeavour to increase vaccine uptake In risk groups aged 18-64 years for both vaccines HCWs Telephone surveys are feasible options during a pandemic to determine morbidity, vaccine uptake and absenteeism in the population National Information system for vaccine uptake statistics Chronic Disease Registers Recommendations
Avian influenza (AI) -identified in the early 1900s. Usually affects only birds, and pigs, but rarely can cross the species barrier to infect humans Vast majority of AI viruses found in birds do not infect humans Current strain of concern, AH5N1 has infected humans Avian influenza (bird flu)
H5N1 has caused the largest outbreak in birds on record, since late 2003 Despite culling >200 million birds, it has become endemic in parts of SE Asia, Africa Why is there concern about avian influenza A/H5N1?
H5N1 is now present in birds in over 60 countries – migratory birds spreading it to Europe Virus has crossed species barrier on multiple occasions to infect 376 persons in 14 countries It causes severe disseminated disease affecting multiple organs and systems with death in 63% of those affected Most cases have occurred in previously healthy children and young adults As no virus of H5 subtype has ever circulated widely in humans, all will be susceptible to infection Current Situation-H5N1
Strategy is: Prevention of introduction to poultry via: bio security measures ban on import of poultry from infected areas Early detection via surveillance and rapid diagnosis If AI outbreak occurs, stamp out via culling Joint working response plan with public health to protect contacts of avian influenza source and workers at risk Available at http://www.ndsc.ie/hpsc/A-Z/Respiratory/AvianInfluenza/ Guidance/ AI control strategy in Ireland
The risk of a pandemic is great The risk will persist Evolution of the threat cannot be predicted The early warning system is weak Preventable intervention is possible, but untested Reduction of morbidity and mortality globally will be impeded by inadequate medical supplies Although AH5N1 is the current strain of concern, the next pandemic might not come from AH5N1 The threat posed by avian influenza: WHO assessment (2005)
Pandemic flu is a global epidemic of a newly emerged strain of flu (a new influenza A subtype) Three pandemics in the last century 1918 ‘Spanish flu’ 1957 ‘Asian flu’ 1968 ‘Hong Kong flu’ What is pandemic flu? • Worst killed 40+ million worldwide
Can occur at any time of year - not only in winter In each pandemic you can have very different Death rates, severity and patterns of illness, age most severely affected You get a rapid surge in number of cases over brief period of time, often measured in weeks Tend to occur in waves - subsequent waves may be more or less severe Key lesson – unpredictability Lessons from past pandemics
How pandemic flu may affect Ireland • Impossible to predict when it will begin • Difficult to predict impact with any accuracy • Great deal of uncertainty over estimates of scale of illness, death rates and those most likely to have severe illness • Will also depend on the availability and effectiveness of antiviral drugs and vaccines
25% of the workforce will take 5-8 working days off over a three-month period Likely to spread rapidly in schools and other closed communities leading to potential closure Impact on all services including gardai, fire, the army, fuel supply, food production, distribution and transport, prisons, education and business Impact on Business, Schools, Services
Surveillance Diagnosis Antiviral drugs Vaccines (once they become available) Public health interventions Reduce impact through
Surveillance systems and early warning system Alternative e.g. GP OOH, cluster surveillance, internet Health Service Response Clinical management, human resources, infection control Anti-virals Emergence of Oseltamivir resistance Supply Vaccines Availability Implementation of public health measures Multidisciplinary, intersectoral approach Out of hours Challenges
Tuberculosis:An old and new problem… • In Giacomo Puccini's 1896 opera, La Bohème, Mimi dies from consumption • 100 years later, in John Larson’s musical remake, RENT, the bohemians suffer from AIDS
Case-based surveillance since 1998 Marked decline in the number of cases since 1950s Lowest rate in 2001 (9.7/100,000) HOWEVER Still a Problem Decline not sustained with slow increase since: 2005: 10.6/100,000 (450 cases) 2006: 10.8/100,000 (458 cases) 2007:474 cases Inner city pockets of high incidence HSE-East (North Inner City):24.5/100,000 HSE-South (North Inner City):21.5/100,000 Current Situation (1)
National Notifications in IrelandDept. of Health Statistics 1952-1998
National TB notifications, rate & 3 year moving average 1991-2006* *2006 provisional data only
Outcome data, 2005 • Outcomes reported for 392 (87.1%) of the 450 cases notified in 2005