MENINGITIS EPIDEMIC TRENDS in AFRICA

Mamoudou H. DJINGAREY, MD/MPHWHO-IST/WEST AFRICAOUAGADOUGOU

WHO/IST/WA - Meningitis Vaccine Project (MVP) |2|

Background

� Epidemic Meningococcal meningitis = a challenging public health threat in Africa.

� 1996: Devastating meningococcal group A epidemic: > 250 000 cases and 25 000 deaths.

� NmA = main cause of major epidemics, despite emergence of NmW135 (Burkina F 2002) & NmX (Niger 2006).

� MVP’s new conjugate A vaccine to be introduced progressively starting 2009.

� What approach during the transition period and beyond?

WHO/IST/WA - Meningitis Vaccine Project (MVP) |3|

Meningitis Surveillance/Control in

the Belt�Early detection = Weekly Attack Rates (alert/epid. Districts)

�Target population = Attack Rates/ Age groups

�Lab Identification = Confirmation/ serogroups/ serotypes

Enhanced surveillance

(epidemiologic + lab)

Early detection for

Efficient Vaccination

WHO/IST/WA - Meningitis Vaccine Project (MVP) |4|

Trends of epidemic meningitis disease

in the African belt, 1970-2008

50 000

100 000

150 000

200 0001

97

01

97

21

97

41

97

61

97

81

98

01

98

21

98

41

98

61

98

81

99

01

99

21

99

41

99

61

99

82

00

02

00

22

00

42

00

62

00

8

Years

Ca

se

s

WHO/IST/WA - Meningitis Vaccine Project (MVP) |5|

Meningitis epidemic weekly trends in Niger (1986-2008),

Mali (1992-2008) and Burkina Faso (1996-2008)

0

1000

2000

3000

4000

5000

6000

1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

Weeks

Ca

se

s

Niger Mali Burkina Faso

WHO/IST/WA - Meningitis Vaccine Project (MVP) |6|

Meningitis: Geographic distribution of epidemic districts (red) and alert districts (yellow) in Africa in 2008

WHO/IST/WA - Meningitis Vaccine Project (MVP) |7|

Meningitis: Geographic distribution of epidemic districts (red) and alert districts (yellow) in Africa in 2009 (Week 1 – 4)

2009 DATA at WEEK 6 :Burkina: 3 alert districtsNiger : 3 districts in alert and 1 in epidemic phaseNigeria : 9 LGAs in alert and 11 in epidemic phase (600 cases & 40 deaths in 10 States)

WHO/IST/WA - Meningitis Vaccine Project (MVP) |8|

Nigeria CSM Surveillance: LGAs ever in Alert/Epidemic Threshold Week 01-06,

2009

(Week 6: 11 LGAs crossed epidemic threshold and 9 in alert

Week 1-6: 18 epidemic LGAs)

LGAs in Alert: (5.00 < AR < 10.00)

LGAs in Epidemic: (AR > 10.00)

WHO/IST/WA - Meningitis Vaccine Project (MVP) |9|

Distribution of meningitis by CSF isolates and age group (651 positive cases from Burkina Faso, Mali, Niger

and Togo in 2007)

0,0

5,0

10,0

15,0

20,0

25,0

30,0

35,0

40,0

< 1 year 1 - 4 years 5 - 14 years 15 - 29 years 30 and more

Pe

rce

nt

N. meningitidis

S. pneumoniae

Hib

Other pathogens

The under 30 years old represents 91.4 % of confirmed cases

WHO/IST/WA - Meningitis Vaccine Project (MVP) |10|

Distribution of CSF isolates from

countries during the epidemic seasons

(2003 to 2008, Week 1 to week 26)

52%

6%

8%

24%

7%3%

Nm A

W135

Other Nm

Pneumo

Hib

Other pathogens

WHO/IST/WA - Meningitis Vaccine Project (MVP) |11|

A, W135 X, W135

A

X

Geographical distribution of Nm serogroups

responsible for epidemics, 2007

WHO/IST/WA - Meningitis Vaccine Project (MVP) |12|

The Beginning of a new epidemic

wave?

� Spread of a new menA strain (ST-2859)

� Intense activity in hyper endemic countries since 2006

2009 DATA at WEEK 6 :

� Burkina: 3 alert districts

� Niger : 3 districts in alert and 1 in epidemic phase

� Nigeria : 9 LGAs in alert and 11 crossed epidemic threshold

(10 States recorded 600 cases and 40 deaths)

WHO/IST/WA - Meningitis Vaccine Project (MVP) |13|

Ensuring epidemic response during the transition period before Men A introduction

2008 2009 2010 2011 2012 2013 2014 2015

Men A conjugate

introduction begins

Population at risk

in the belt covered

Risk of large

epidemics persists

Large stockpile of

vaccine needed for

outbreak control

Low risk of A epidemics

Risk of epidemics by other

serogroups remains

Small stockpile of vaccine

for outbreak control

WHO/IST/WA - Meningitis Vaccine Project (MVP) |14|

Funds received for Epidemic Response

� US$55.2 million approved by the GAVI Board in June 2008

� Availability of adequate quantities of Men Ps vaccines (AC, ACW) by:

� Establishing epidemic-response stockpiles

(WHO-UNICEF)

� Improving timeliness of response (ICG).

WHO/IST/WA - Meningitis Vaccine Project (MVP) |15|

CONCLUSION

� Monitoring of epidemic trends through Enhanced surveillance has dramatically improved the quality of surveillance data and laboratory identification of pathogens.

� Risk of major outbreak next 1-3 years.

� 45 million doses of stockpile available for the next 5 years for epidemic response (transition period).

� Support to surveillance /epidemic response through country capacity strengthening.

WHO/IST/WA - Meningitis Vaccine Project (MVP) |16|