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The Médecins sans frontières experience in measles outbreak response

The Médecins sans frontières experience in measles outbreak response. Rebecca Freeman Grais March 16, 2011. Outline. Brief background Guidelines Three recent examples, three different experiences Maroua, Cameroon N’djamena, Chad Malawi Ways forward. Background (I).

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The Médecins sans frontières experience in measles outbreak response

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  1. The Médecins sans frontières experience in measles outbreak response Rebecca Freeman Grais March 16, 2011

  2. Outline • Brief background • Guidelines • Three recent examples, three different experiences • Maroua, Cameroon • N’djamena, Chad • Malawi • Ways forward

  3. Background (I) • Missions in 32 African countries • Vaccination • Support in primary care when relevant • Outbreak response • Case management • MSF vaccinated against measles • 1.5 million persons in 2009 • > 4.5 million persons in 2010 • Frustrating field reality

  4. Backgound (II): Duration of epidemics, reported cases and timing of interventions Reported cases Place Year Duration (months) 1 12+ 6 Niamey, Niger 10880 2003 Adamawa, Nigeria 2505 2004 Kinshasa, DRC 2005 40857 N’Djamena, Tchad 2005 8015 2009 Burkina Faso 53000 +

  5. Background (III): Burden of disease in pockets of high endemicity • Difficult to reach populations • High birthrates • Insufficient vaccination coverage • Morbidity and mortality burden • CFR of 7% in rural areas

  6. Proportion cases prevented by intervention coverage and time: 6 to 59m, Niamey, Niger 100 2 months 3 months 90 4 months + 6 months 80 70 60 50 Proportion of Cases Prevented (%) 40 30 20 10 0 30 40 50 60 70 80 90 100 Intervention Coverage (%) Source: Grais et al, 2007

  7. Proportion cases prevented by intervention coverage and time: 6 to 15y, Niamey, Niger 100 90 80 70 60 Proportion of cases prevented(%) 50 40 2 months 3 months 30 4 months 20 10 0 30 40 50 60 70 80 90 100 Intervention Coverage (%) Source: Grais et al, 2007

  8. New WHO guidelines (March 2009) • There is time and benefit to intervening • Vaccination • Immediate selective vaccination (6m to 5y) • District level outbreak management team • decision about whether non-selective mass campaign needed

  9. Next step is to evaluate and further improve on recent gains and prevent them from slipping

  10. Jan – May 2008 39 cases Renforce EPI 1.Maroua, Cameroun 2008-2009 (872 cases) • 29 Jan. – 4 Feb. 2009 • MoH mass campaign • 6 mo to 15 years • Free treatment (MSF) 100 • October 2008 • Increase in cases • Campaign 6 to 59 months for certain wards 80 60 cases 40 20 0 0 5 10 15 20 25 30 35 40 45 50 2 7 12 17 week

  11. 1. Vaccine coverage survey, Maroua, Cameroon, April 2009 (n=3,025) Vaccination coverage of mass campaign estimated at 90% Number of doses received among children 6-59 months 7% unvaccinated 25% 1 dose 47% 2 doses 21% 3 doses Source: Luquero et al, JID, in press

  12. 1. Lessons learned from Maroua outbreak • Risk-assessment and interventions followed the guidelines • Close cooperation between MoH, WHO and MSF • Cases subsided but strategy still missed children

  13. 2. Measles epidemics in Ndjamena, Chad • Rare context of subsequent interventions in the same city (2005, 2010) • LQAS surveys to estimate coverage, before and after interventions • 2005 non-selective mass campaign (6-59m) • 2010 non-selective mass campaign (6m – 15y)

  14. 2. Reported cases, Ndjamena, Chad, 2005 and 2010 Campaign Campaign survey survey N=7822, AR = 64.6 per 10,000 N=8481, AR = 54.5 per 10,000

  15. 2. Vaccination coverage before and after campaign (6-59 m), Ndjamena, Chad Source: Guerrier et al, Trop Med Int’l Health, in press

  16. 2. Lessons learned, N’djamena, Chad • Intervention earlier, but still late • Chronically low vaccine coverage • Failure to reach older children through routine services • Measles-susceptibles built up and led to the 2010 epidemic • 18% received their first dose in 2010 • previously vaccinated children were easier to reach during the outbreak than unvaccinated children

  17. SIA’s 3. Measles cases and coverage 1997 -2009, Malawi Source: Malawi MoH Next SIA planned for 2011 for 6-59 months old

  18. 3. Weekly distribution of measles cases in Malawi, week 1 to week 35, 2010N=118.173, AR=847 per 100.000, CFR=0.2% Only ~250 deaths reported, 28/28 districts NB: 25% of districts with no report for week 32, 50% for week 34

  19. 3. Weekly incidence in districts vaccinated by MSF, Malawi 2010 93.1 [90.9-95.2] 98.0 [97.4-98.6] 96.6 [95.6-97.6] 96.4 [95.0-97.9]

  20. Reported measles cases & attack rates by region, sex and age group, Malawi 2010

  21. 3. Lessons learned from Malawi • Accumulation of susceptible individuals • No large outbreak in 12 years • Outbreaks in the nineties of smaller scale • Vaccine effectiveness study found under 90% for EPI • High routine coverage but likely under 95% • Reduction immunity over time • Apostolic communities • Under estimation of the epidemic risk Source: Minetti et al, in press

  22. Ways forward • EPI • possibility for catch up > 11 months • SIA • Strategies to adapt the changing epidemiology of measles • Flexible age range • Interval between campaigns • Outbreak response • Increased communication about new guidelines and importance of prompt response • Need for planning for outbreak response in budget • Evaluations

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