1 / 24

Diphtheria and Pertussis: The Forgotten VPDs

Diphtheria and Pertussis: The Forgotten VPDs. Presented by: Dr Esteghamati National EPI Manager. Challenge. In the context of polio eradication, MMR, MNTE, new vaccines introduction: difficult to raise awareness about old forgotten diseases.

Thomas
Télécharger la présentation

Diphtheria and Pertussis: The Forgotten VPDs

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Diphtheria and Pertussis: The Forgotten VPDs Presented by: Dr Esteghamati National EPI Manager

  2. Challenge In the context of polio eradication, MMR, MNTE, new vaccines introduction: difficult to raise awareness about old forgotten diseases

  3. Current high DTP3(4-5) coverage: changes in epidemiology: shift in age distribution • Low DTP3 coverage countries: outbreaks of diphtheria and pertussis

  4. Diphtheria outbreak IDP camp near Kandahar July – September 2003 Tot Pop: 40,000 10 settlements approx 3000/each 80 cases, 3 deaths CFR 3.8% Since 2002 Number cases Index case 7 24 3 15 6 7 (?) outside cases in neighboring districts 2 deaths (1 in other IDP camp) CFR 29% A 6yo case: wedding in Zare Dasht then infected neighbor x x 9 6 2 5 3

  5. Diphtheria outbreaksEMRO • Yemen 1981-82 • Jordan 1982 • Sudan 1978/1988 • Iraq: suspected outbreak in Sept 2003 • Afghanistan 2002, 2003 • Sporadic cases 1998-2002 in all countries.

  6. Characteristics of NIS epidemic (Newly Independent States of former Soviet Union) • Largest epidemic in recent years: >150,000 cases and 4500 deaths during 1990-1995 • High proportion of infected adults • Spread from outbreaks in groups with high rates of close contacts (military troops, hospitals, schools,) to a more generalized epidemic, specifically in socio-economically disadvantaged groups

  7. Pakistan: diphtheria fatal case • March 98: 9 yo, resident student of religious school died of diphtheria • School in Islamabad: 400 students 9-20, males • Rapid response: Td vaccination + prophylaxis, and throat swabs from contacts

  8. NIS “scenario” • Large pool of susceptible adults (waning immunity + lack of exposure), coupled with susceptible children, + previous good coverage: potential for epidemic • NIS 0-4 5-9+10-15 >15 (Ukraine) 8% 12% 80% • Iraq (2001-4) 18% 16% 66%

  9. Estimated DTP3 coverage among under one children, EMR, 2002 Palestine 0 0 2 0 33 854 0 10 0 22 2 0 0 0 9 0 0 Bahrain 26 - 90% or more () - 70% - 89% (2) Diphtheria cases reported to WHO, 2002, aggregates 50% - 69% (3) Less than 50% (2)

  10. Pertussis: a challenge! • Major cause of morbidity and mortality: high CFR in dev countries • Highly contagious: rates 2nd transmission in households: 90%, schools 50-80% • Clinical and lab confirmation of B. pertussis is still one of the most difficult challenges facing clinicians • Poor surveillance: disease burden largely unrecognized

  11. Pertussis changing epidemiology in countries with high DTP coverage • In developed countries, with high DTP3 coverage and good surveillance: increase in reported pertussis. • Increase in part due to better recognized cases of pertussis in older adults • In well-immunized populations: shift to older age groups • Older children and adults responsible for transmission of disease to infants and young children

  12. Pertussis in Adults • Accounts for up to 7% of cough illnesses per year • Disease often milder than in infants and children • Adults often source of infection for children

  13. Pertussis Complications Condition Pneumonia SeizuresEncephalopathy Death Hospitalization Percent reported 5.2 0.8 0.1 0.2 20

  14. Clinical case definition A case diagnosed as pertusis by a physician OR A person with a cough lasting at least 2 weeks with at least one of the following • Paroxysm of cough • Inspiratory whooping • Post tussive vomiting

  15. Criteria for lab confirmation • Isolation of bordetella pertusis • Detection of genome sequences by PCR • Rising titer

  16. Reported global DTP3 vaccine coverage and pertussis cases, 1974-2002

  17. Denmark, Finland, UK 2003: Recommendations for preschool aP booster Austria 2003: Recommendation for aP boosters in school-children, adolescents and adults Canada 2003: NACI and CPS recommend aP boosters for adolescents and adults Australia 2003:· Removal of 18-month DTaP dose; switch from Td to TdaP vaccine for 15- to 19-year-olds   Some Recent Changes in National Pertussis Immunization Schedules

  18. TdaP Vaccine for Adolescents and Adults: Unanswered Questions • What is the duration of protection? • Will vaccination of adolescents result in decreases in infant pertussis? • Is it necessary to vaccinate additional age groups? If so, how can we do that? • Will pertussis incidence increase in older age groups?

  19. Pertussis surveillance • Difficult clinical diagnosis • Difficult laboratory diagnosis • Poor awareness, poor notification

  20. Estimated DTP3 coverage among under one children, EMR, 2002 Palestine 1 476 1 1439 -(2922) 51 21 27 2 - 233 21 0 8 42 18 96 Bahrain 0 - 213 2 90% or more () - 70% - 89% (2) Pertussis cases reported to WHO, 2002, aggregates 50% - 69% (3) Less than 50% (2)

  21. Disease burden • In most countries, pertussis surveillance inadequate for accurate estimates of cases and deaths • Increased burden of pertussis.

  22. Pertussis (WHO 2000 meeting): Recommendations • Better data for estimating disease burden • Good quality surveillance (case def, age, vacc status, plans for pertussis surveillance) • Outbreaks investigated, reported and documented (guidelines to be developed). • Lab standardization (guidelines for specimen collection, transport, etc) • Monitoring of booster dose policies • Research: develop better understanding of adult disease • Training material to be developed

More Related