Measles in W and C Africa - HumanitarianResponse · 2020. 5. 1. · Common reasons for measles...
Transcript of Measles in W and C Africa - HumanitarianResponse · 2020. 5. 1. · Common reasons for measles...
Measles in W and C Africa
B Masresha
June 2019
Background
• Measles – highly contagious, preventable
• WHO recommends a 2-dose vaccination policy
• 85% seroconversion when given at 9 months
• Unprotected young children (unvaccinated PLUS those vaccinated but not seroconverting) accumulate with time
• Once the number of unprotected children reaches the size of a birth cohort, the risk of large outbreaks of measles increases• This happens once every 2 – 4 years in most countries (based on
the vaccination coverage rates)
• This explains why SIAs are done every 2 – 4 years, before the peak measles transmission season
Seasonality of measles transmission
• In the Sahel, incidence of all causes of febrile rash are clustered in first half of year
• This pattern is consistent throughout region
• Transmission peaking in the months after the end of the rainy season!
African Regional goal: Measles elimination by 2020
• >95% MCV1 coverage at national and district level
• > 95% SIAs coverage
• incidence of < 1 case / million population /year (excluding imported cases).
• Achieve the surveillance performance targets:• > 80% districts investigating one or more suspected measles
cases /year,
• a non measles febrile rash illness rate of > 2 per 100 000 population at national level.
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DPT3, MCV1 and MCV2 coverage. WUENIC. African Region. 2000 - 2017
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Number of countries by MCV1 coverage grouping. WUENIC. 2010 - 2017
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M/ MR SIAs admin and survey coverage. 2017 - 2018
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Measles cases and coverage. AFR. 1990 – 2017
• Measles control – elimination goal• Periodic SIAs
• Case based surveillance
Examples from Nigeria
Suspected Measles cases per week . Nigeria. 2016 – 2019 ( data as at week 18 of 2019)
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Weeks
2016' 2017' 2018' 2019*
March/April 2019 OBR Borno
Trends of Measles cases. Nigeria. Jan 2016 - Apr 2019
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Lab-Confirmed EPI-LINK Compatible Discarded Pending
IMC Jan’2016 (South)
MVC Dec 2017 (Phase 1-S1 & 2 North)
MVC Apr 2018(Phase 2 South)
Jan 2017 OBR in Adamawa, Borno
and Yobe
March/April 2019 OBR Borno
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Weekly trends of confirmed measles cases. Nigeria. Jan. 2015 - Nov. 2018
Northern States Southern States
• Nigeria has 42% - 44% MCV1 coverage (WUENIC) for the last 5 years!
L+E+C = Lab-confirmed + EpiLink + Clinical
Nigeria: Distribution of confirmed (L+E+C) Measles cases by age & vaccination status, Jan - Apr 2019
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Examples from DRC
Evolution hebdomadaire de la notification des cas suspects de rougeole en RDC, 2010-2019 (sem.23)
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1 1019283746 3 1221303948 5 1423324150 7 1625344352 9 18273645 2 1120293847 4 1322314049 6 1524334251 8 17263544 1 101928
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
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Semaine epidémiologique par Anné
SUD-KIVUORIENTALENORD-KIVUMANIEMAKINSHASAKATANGAKASAI ORIENTALKASAI OCCIDENTEQUATEURBAS CONGOBANDUNDU
Classification des cas de Rougeole IgM+ par statut vaccinal et par groupe d’âge S1-23, 2019
894 cas IgM Positives Rougeole dont 69% des enfants ont moins de 5 ans.Statut vaccinal : 36% vaccinés, 15% non vaccinés et 49% inconnu.
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Common reasons for measles outbreaks
• Very low measles vaccination coverage (routine immunization and/ OR SIAs coverage)
• Sudden disruptions of vaccination services • EVD outbreak in W Africa 2014 - 2015
• Population displacement• Civil disturbances – eg., S Sudan, CAR
• Long term accumulation of susceptibles into older age groups ( eg Mauritania, Madagascar)
• Delays in the scheduled preventive SIAs• Recent examples: Chad, Burkina Faso, Benin, Cameroon
Relationship of measles outbreaks to the timing of SIAs
Trends in confirmed measles case reports in countries supported by MR catch-up SIAs – pre and post SIAs
Trends in confirmed measles case reports in countries supported by MR catch-up SIAs – pre and post SIAs
Trends in confirmed measles case reports in countries supported by M follow-up SIAs – pre and post SIAs
Trends in confirmed measles case reports in countries supported by M follow-up SIAs – pre and post SIAs
Incidence of confirmed measles and rubella per million population. AFR. 2010 - 2018
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The challenges
• Routine immunization coverage plateauing
• Wide drop out rates between MCV1 and MCV2
• Delays and gaps in quality of SIAs
• Multiple public health priorities – inadequate attention/ funding for measles elimination
• Dependence on polio funding and staffing
• Inadequate resources for surveillance and lab support
• Inadequate preparedness to respond to outbreaks
The opportunities
• Regional elimination goal
• African countries that have attained near elimination status ( Ghana, Rwanda, Senegal, Eritrea, Zimbabwe, etc)
• Global and regional sensitivity to measles outbreaks – WHE involvement
• GAVI funding for SIAs
• Engagement of AU and Regional economic bodies
Way forward
• Support countries to improve routine immunisation (2 doses of measles vaccination)
• Timely periodic supplemental immunisationactivities (SIAs)
• Funded outbreak preparedness and response plans
• Early and aggressive outbreak response activities
• Use outbreaks as an opportunity to advocate for better leadership and ownership of vaccination programs