FETP Ethiopia Neisseria meningitides outbreakHarenabuluk District Ethiopia 2011

FETP Ethiopia Neisseria meningitides outbreak-Harenabuluk District, Ethiopia, 2011 Yembo Gole Ejeta 1, Fikire Bulti 2 an Kebabe Tolasa 3 1 Addis Ababa University, 2 Oromia Health Bureaus, 3 Madawalabu University Results Introduction Date investigation began 16 14 12 10 8 6 4 2 0 Presumed index case 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 Number of cases Figure 1: Meningitis case by date of onset, Harenabuluk, Ethiopia, 2011 27 29 31 03 05 07 09 11 13 15 17 19 21 23 25 27 01 03 05 07 09 11 13 15 17 19 21 23 Jan-11 Feb-11 Mar-11 Date of onset Methods • Bivariate analysis identified nine risk factors (Table 2) • Four risk factors remained associated in logistic regression (Table 3) Map 1: Site of Meningitis outbreak-Harenabuluk, Ethiopia, 2011 Table 2: Bivaiate analysis results-Harenabuluk, Ethiopia, 2011 Exposure Proportion exposed Cases (n %) • 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 -60 years) • Sixty (62%) were female • Observed highest attack rate ( 115/10, 000) among 20 -29 years old (Table 1) Table 1: Meningitis attack rate and case fatality rate by age group-Harenabuluk, Ethiopia, 2011 Age Populati Number of cases Attack Deaths group on s Case (%) of the total rate / fatality cases (N=49) 10, 000 rate / 100 0 -4 2317 14(29. 17) 60. 42 0 0 5 -14 1951 18(37) 92. 29 2 11. 11 14(27. 08) 115. 7 4 29 15 -29 1210 30+ 2541 3(6. 25) 11. 8 0 0 Total 8019 49(100) 61. 1 6 8. 16 Odd ratio 95% confidence interval 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 Table 3. Logistic regression analysis results-Harenabuluk, Ethiopia, 2011 Exposure Proportion exposed Odd 95%confide ratio nce interval Control (n Cases (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 • Laboratory analysis showed that all 49 patients were positive for NM o serogroup A • Harenabuluk District experienced extended drought Conclusions • 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. Acknowledgements 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