neisseria meningitides outbreak-harenabuluk district, ethiopia,2011 yembo gole ejeta 1, fikire bulti...
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Neisseria meningitides outbreak-Harenabuluk District, Ethiopia,2011 Yembo Gole Ejeta1, Fikire Bulti2 an Kebabe Tolasa3
1Addis Ababa University, 2Oromia Health Bureaus,3Madawalabu University
Introduction
Acknowledgements
Results
Ethiopia •Within the "meningitis belt" of Sub-Saharan Africa•Neisseria meningitides(NM) outbreaks occur yearly• with >3000 cases/year and 1.4-8.5% case fatality rate
•February 2011, a cluster of suspected meningitis cases in Harenabuluk; outside the classical meningitis belt areas
• Investigated to confirm the outbreak, identify etiologic agent, determine risk factors, and establish control measures
FETPEthiopia
Methods
• Descriptive study followed by case-control study• Introduced identical structured questionnaires to both patients and controls
•Case was a person from Harenabuluk in which NM was isolated by bacterial culture from cerebrospinal fluid between 02/02/-17/03/2011
• Selected age and sex matched controls from the neighbor of patients in the ratio of 1:1
•Adjusted odds ratios (AOR) with 95% of confidence interval (CI)
•Bivariate and multivariate analysis logistic regression • Collected laboratory specimens from 49 patients•Collected meteorological data
Results• Forty-nine cases identified in the outbreak •Median age of 12 years(range,1-60years)•Sixty (62%) were female •Observed highest attack rate ( 115/10,000) among 20-29 years old (Table1)
•This was NM outbreak caused by serogroup A•The outbreak showed two unusual characteristics•Geographical location outside the meningitis belt and high age specific AR among 20-29 years
•The occurrence of the outbreak and the identified meningitis risk factors, demonstrate that meningitis outbreaks are possible in all situations once the NM has been introduced
•Our recommendations led to start vaccination (1-30 age groups) and active surveillance with monthly community health education on meningitis and its risk factors.
Conclusions
Map 1: Site of Meningitis outbreak-Harenabuluk, Ethiopia,2011
•Laboratory analysis showed that all 49 patients were positive for NM serogroup A
•Harenabuluk District experienced extended drought
27 28 29 30 31 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Jan-11 Feb-11 Mar-11
02468
10121416
Date of onset
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Pre
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case
We would like to thank the staff from the Oromia Regional Health Bureau, Madawalabu University and Bale Zone Health Department who participated in this investigation
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Table2: Bivaiate analysis results-Harenabuluk,Ethiopia,2011
Dat
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Figure 1: Meningitis case by date of onset, Harenabuluk, Ethiopia, 2011
Table1: Meningitis attack rate and case fatality rate by age group-Harenabuluk, Ethiopia,2011
Age
group
s
Populati
on
Number of cases
(%) of the total
cases (N=49)
Attack
rate /
10,000
Deaths Case
fatality
rate / 100
0-4 2317 14(29.17) 60.42 0 0
5-14 1951 18(37) 92.29 2 11.11
15-29 1210 14(27.08) 115.7 4 29
30+ 2541 3(6.25) 11.8 0 0
Total 8019 49(100) 61.1 6 8.16
Exposure Proportion exposedOdd
ratio
95%
confidence
interval
Cases (n %)Control (n
(%)
Having no ventilation 31(63.3) 10(24.4) 8.3 3.2-10.6
Attendance at Koran teaching 39(79.6) 19(38.8) 7.2 4.1-13.2
Having kitchen in the living room 42(85.7)
26(5.3)
6.3 1.9-1-12.1
Living in one house with more than 4 peoples 40(81.6) 26(53.1) 5.9 1.6-12
Sharing bedroom with more than two people 37(75.5) 19(38.8) 4.8 2.0-11.6
Exposure to dusty environment 34(69.4) 26(53.1) 4 1.1-4.5
Contact history with case-patient 30(62.5) 18(67.5) 2.7 1.2-6.3
Sharing house with animals 44(89.8) 43(87.8) 1.9 2.1-7
Travel history 14(28.6) 9(18.4) 1.8 2-4-12
• Bivariate analysis identified nine risk factors (Table2)• Four risk factors remained associated in logistic regression (Table3)
Exposure Proportion exposed
Odd
ratio
95%confide
nce interval
Cases (n %))
Control (n
(%))
Having no ventilation 31(63.3) 10(24.4) 6.7 2.7-16.6
Attendance at Koran teaching 39(79.6) 19(38.8) 6.1 2.5-15.2
Having kitchen in the living room 42(85.7)26(5.3)
5.3 2-13
Living in one house with more than 4 peoples 40(81.6) 26(53.1) 3.9 1.6-11
Table3. Logistic regression analysis results-Harenabuluk, Ethiopia, 2011