b型流感嗜血杆菌英文ppt课件

,Click to edit Master title style,Click to edit Master text styles,Haemophilus influenzae type b,Using vaccines to measure,disease,b,urden: A Tale of Two Studies,Presentation to,PABIO 550,Diseases of Public Health Importance and Their Control,David Mercer, Ph.D.,Haemophilus influenzae type b,Hib - characteristics,Gram negative cocco-bacilli,carried by 3% to 15% of young children in the world,causes disease in young children,meningitis,pneumonia,epiglottitis,septic arthritis,Hib - characteristicsGram nega,Hib disease,Industrialized countries,median age 1-2 years,most meningitis then epiglottitis?,meningitis mortality under 5%,affects 1-2/1000 children,Developing countries (Africa),median age 6-9 months,most pneumonia, then meningitis,meningitis mortality 20-50%,affects 10/1000 children?,Hib diseaseIndustrialized coun,b型流感嗜血杆菌英文ppt课件,Gambian PRP-T trial,42,000 infants randomized to receive PRP-T or placebo at 2, 3 and 4 months of age,population studied for:,Hib meningitis,Hib pneumonia,all pneumonia,Hib carriage,Gambia slides courtesy of Kim Mulholland, MD,University of Melbourne,Gambian PRP-T trial42,000 infa,Study design,individually randomized, double blind study,major effort to detect Hib pneumonia,randomization in 10 groups numbered 0 through 9:,DTP + PRP-T,DTP + placebo,at 2, 3 and 4 months of age,5 numbers,5 numbers,Study designindividually rando,Final results, March 199642,848 infants enrolled,PRP-T group,21,490 infants,1272 possible Hib disease,616 chest radiographs,173 lumbar punctures,71 lung aspirates,Control group,21,358 infants,1342 possible Hib disease,653 chest radiographs,192 lumbar punctures,75 lung aspirates,Final results, March 199642,8,Did the vaccine actually prevent pneumonia?,*cough + fast breathing or lower chest wall indrawing,Did the vaccine actually preve,What did the Gambia trial tell us about the epidemiology of Hib pneumonia in West Africa?,Hib is responsible for about 20% of radiological pneumonia in Gambian infants,Previous studies had suggested 5-10% of pneumonia due to Hib,Very little “WHO pneumonia” which is not radiologically obvious is due to Hib,What did the Gambia trial tell,Conclusions,PRP-T effectively prevented meningitis and pneumonia due to Hib in The Gambia,Hib vaccines have been proven in Finland, USA, UK, Chile and other countries,Why arent Hib vaccines used everywhere?,ConclusionsPRP-T effectively p,b型流感嗜血杆菌英文ppt课件,Why are Hib vaccines not used all over the world?,cost,varies, currently $2 per dose,affordable for most Asian countries,understanding of burden of disease is the major problem in Asia,Why are Hib vaccines not used,Asia,Many Asian countries can afford Hib vaccine,Hib was known to be an important cause of bacterial meningitis in Asia,But:,Microbiologically confirmed Hib incidence lower than elsewhere ( one color vaccine,Average age at enrollment (i.e., first vaccine plus 2 week delay): 13 weeks,Vaccination of childrenVaccina,All incidences are per 100,000 child-years,Pneumonia Outcomes,All incidences are per 100,000,All incidences are per 100,000 child-years,Pneumonia Outcomes,All incidences are per 100,000,All incidences are per 100,000 child-years,Meningitis Outcomes,All incidences are per 100,000,All incidences are per 100,000 child-years,Meningitis Outcomes,All incidences are per 100,000,Published rates of Hib meningitis,(Children under 5 years per 100K person-years),Published rates of Hib meningi,b型流感嗜血杆菌英文ppt课件,Mortality rates are per 100,000 child-years,Mortality after at least 1 dose,Mortality rates are per 100,00,Mortality rates are per 100,000 child-years,Mortality after 3 doses,Mortality rates are per 100,00,Conclusions,Hib vaccine,not,an effective intervention against ALRI (pneumonia) in Lombok,Hib meningitis burden underestimated by microbiology true burden 10X greater,Hib vaccine may significantly reduce meningitis mortality,1 in 33 unvaccinated children on Lombok develop invasive Hib disease before age 2.,ConclusionsHib vaccine not an,Comparison of Gambia and Lombok Results,Hib vaccine prevents about 20% of radiological pneumonia in Gambian infants,Very little “WHO pneumonia” which is not radiologically obvious is due to Hib,Protection conferred after 3,rd,dose,Hib vaccine prevents little to no radiological pneumonia in Lombok infants,The predominant pneumonia prevented by Hib vaccine is non-severe WHO pneumonia.,Protection conferred after first dose.,For every case of laboratory-diagnosed Hib disease on Lombok, there were 10 cases of Hib meningitis, and 100 cases of Hib pneumonia.,Gambia,Lombok,Comparison of Gambia and Lombo,