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Emergence of a virulent new meningococcal W sequence type 11 in
South America: experience, control measures and impact
Marco Aurélio P. Sáfadi, MD, PhDFCM da Santa Casa de São Paulo
Outline • A brief overview of the current epidemiology
of MD in Brazil, Argentina and Chile.• The emergence of the serogroup W ST-11 cc
(“South American” strain).• Control measures implemented and lessons
learned
Annual number of cases and Incidence of Invasive Meningococcal Disease: Latin America, 2008-2011.
Notified incidence rates/100,000
persons
Safadi M. et al. Epidemiol and Infect, 2012
Not reported<0.3
> 10.3 to 1
0
500
1000
1500
2000
2500
3000
Argentina Brazil Chile Uruguay Mexico Colombia Venezuela
Annual number of cases
0,9
0,4
0,4
1,5
0,33
4
Year
Fonte: A. Lutz/SINAN
%70%
19%
7,5%3%
Meningococcal Disease: Distribution by Serogroup. Brazil, 1990 - 2014
ST-103cc
Brazil started MenC conjugate vaccination of all children <2 years of age in 2010.
• Infant immunisation (3 and 5 months) with booster dose at 12 months.
• Children between 12 and 23 months: 1 dose• No catch up campaign in older age groups
Safadi M, et al. JPIDS. 2014;3:91-93.
Incidence rates before and after routine Men C vaccination. Brazil, 2008-2014
Cases/100,000
Early impact on incidence rates of meningococcal disease observed only in the age groups targeted for vaccination.
Safadi M, et al. JPIDS. 2014;3:91-93.
Prevalence of carriage by serogroup
High carriage rates for serogroup C among adolescents of all age groups
Moraes JC; et al. Ped Infect Dis J, 2015
9.2 8.9
12.9
0
2
4
6
8
10
12
14
11- 13 years 14 - 16 years 17 - 19 years
Prevalence of carriage. N=1,200 adolescents
N=45/487 N=40/450 N=35/271
8
J Infect, 2008Journal of Infection, 2008
North
Southeast
South
WestCenter
Northeast
Case Fatality Rates of MD. Brazil 2001-2014
MCC
MM + MCC
MM
• Unacceptably high CFR for serogroup W cases (26%)
0
10
20
30
40
50
60
70
80
90
100B C Y W135
%
Year
%
49%
47%
3%
1%
Epidemiology of Meningococcal Disease in Argentina.
Servicio Bacteriología Clínica. INEI-ANLIS C.G. Malbrán /SIREVA 2015
Incidence rates of MD, Argentina, 2006-2014
in 2006, there were only four invasive MenW isolates detected in Argentina, increasing to 63 in 2010, 73 in 2011 and 96 isolates in 2012
Age group distribution of MD cases. Argentina.• Only 6% of the MenB cases occurred
in adults older than 30 years of age vs. 21% of the MenW cases.
Debbag R et al . ESPID, 2015
Epidemiology analysis of MD in Argentina. 2012 - 2014
• 848 cases. Incidence rate of 0.7 /100,000 hab.• 43.3% (368) < 2 years, 78.8% < 1 year.• I.R. in infants: 14.7/100.000; 1-4 y: 2.8/100,000. • serogroup W 50% and serogroup B 41%.• Argentina decided to implement ACWY-CRM
vaccine in infants (3,5 and 15 months). Adolescents with 11 years will receive one dose
Rancano C et al. SADI, 2015
Incidence rates and CFR of Meningococcal Disease in Chile. 1990-2012
Increased incidence of MD in 2012 (from 0.4 to 0.8), associated to emergence of serogroup W (3 cases in 2010, 20 in 2012 and 60 in 2012).
http://epi.minsal.cl/epi/html/bolets/reportes/Meningitis/meningitis.pdf
CFR
(%)
Inci
denc
e ra
tes
(per
100
,000
hab
)
2008
%
0
15
30
45
60
75
90
2000 2002 2004 2006
24%
2%
Meningococcal Disease: Distribution by Serogroup. Chile, 1999 - 2014
73%
Serogroup BSerogroup CSerogroup W
Fuente : Instituto de Salud Publica Lab. Referencia Fuente : Instituto de Salud Publica Lab. Referencia Neisseria Neisseria Chile week 42, 2014.Chile week 42, 2014.
2010 20121998 2014
Age group distribution of MD cases. Chile, 2011 - 2014
The proportion of MenW cases in older adults is significantly higher when compared to the MenB cases
Serogroup B casesSerogroup W cases
Boletín ISP, Vol 4, N° 9, September 2014
Case fatality rates of serogroup W MD by age group. Chile, 2010 - 2013
Moreno G. Rev Chilena Infect 2013
Increasing CFR according to age and overall CFR as high as 28% associated to serogroup W (compared to 14% for serogroup B and C cases).
Reactive MenW Immunisation action in Chile
http://epi.minsal.cl/epi/html/bolets/reportes/Meningitis/meningitis.pdf
• An immunisation campaign started in 2012 with the tetravalent conjugate vaccine (Men ACWY), initially targeting children aged 9 months to < 5 years.
• 9 m to < 2 y: 2 doses (MenACWY-DT) and > 2 y: 1 dose (MenACWY-CRM).
• Approximately 1 million children vaccinated (Coverage >95%).
• From 2014: 1 dose (MenACWY-TT) in toddlers at 12 months.
Vaccine effectiveness of MenACWY-D: Case-Control Study in US Adolescents*
Cases (N=157)*Controls (N=180) VE (95% CI)
Vaccinated <1 year 82% (54%-93%)
Vaccinated 1-2 years 80% (52%-92%)
Vaccinated ≥3-6 years 59% (5%-83%)
McNeil J et al. IPNC, 2012
Impact of the Impact of the MenACWY immunisation campaign in Chile, 2012-2014Chile, 2012-2014
Inci
denc
e ra
tes
(cas
es/1
000)
ISP, Chile]
58% reduction
• Reduction of 58% in the incidence rates of MD in children aged 1- 5 years• No impact on incidence rates of other age groups
Age (years)http://epi.minsal.cl/epi/html/bolets/reportes/Meningitis/meningitis.pdf
Pre-vaccine
Post-vaccine
Number of cases of MD. Chile, 2010 - 2014
0
20
40
60
80
100
120
140
160
2010 2011 2012 2013 2014
W
Others
Vaccination
Number of cases of serogroup W MD. Chile, 2010 - 2014
0
20
40
60
80
100
120
2010 2011 2012 2013 2014
W
Vaccination
Incidence rates of Meningococcal Disease in Chile. 2014
http://epi.minsal.cl/epi/html/bolets/reportes/Meningitis/meningitis.pdf
Incidence (2014): 0.8 /100,000 hab. Santiago – 1.1/100,000Number of cases of W in 2014: 99CFR: 19%
Gobierno de Chile / Ministerio de Salud 23
Carriage study – Chile, 2013
N= 4,217 adolescents, 10-19 years
Strains (N)
Prevalence (%)
24
What do you, in UK, have to do with the South-American situation?
Jay Lucidarme et al. Journal of Infection 2015An expanding South American/UK MenW strain was distinct from the ‘Hajj outbreak’ strain.
Mustapha M et al. Ebio Medicine, 2015:These data also demonstrate the co-circulation of W ST-11 strains in South America, UK and other regions that are phylogenetically and antigenically distinct from the Hajj clone
25
Laboratory-confirmed cases of invasive meningococcal disease by capsular group in UK, 2000 – 2014.
Ladhani S et al. CID, 2015
• A quarter of cases occurred in children aged <5 years, and half the cases in adults aged ≥45 years.
• 49% of the cases presenting with septicemia• CFR of 13%
26
UK decision
• In the light of the rapidly increasing W (cc11) disease from 2009/10 to 2014/15, ACWY conjugate vaccine will be used from August 2015 in 14-18 years teenagers and university freshers and is intended to induce herd protection.
27
• A hypervirulent MenW cc11 strain that became endemic in South America is now expanding in UK
• The experience in Chile showed that no early impact was observed in unvaccinated age groups with the reactive ACWY vaccination program including only young children.
• We have to acknowledge that unlike serogroups A, C and Y we do not have available data showing impact of serogroup W conjugate vacines on carriage to predict the magnitude of indirect effects of vaccination programs.
Key Points
28
The South American-UK connection is now elucidated!
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