Epidemiological Characteristics of Meningococcal Meningitis (2016 to 2018) Four Years after the Introduction of Serogroup A Meningococcal Conjugate Vaccine in Benin

Table 1

Frequencies of N. meningitidis serogroups stratified by the geographic region, age, appearance of CSF samples, and sex in the Benin republic, 2016–2018.

Characteristics	Number of CSF samples (%)	Number of pathogens identified (%)	Number of N. meningitidis strain identified (%)	Number of ungrouped N. meningitidis strain	Number of N. meningitidis serogroups (%)
					C	A	W	X
Total	2928 (100)	899 (30.7)	219 (24.4)	156 (71.2)	15 (6.8)	1 (0.5)	43 (19.6)	4 (1.8)
Appearance of CSF samples
Clear	1594 (54.4)	129 (14.3)	24 (11.0)	14 (9.0)	3 (20.0)	0 (0.0)	6 (14.0)	1 (25.0)
Turbid	875 (29.9)	674 (75.0)	182 (83.1)	131 (84.0)	11 (73.3)	1 (100.0)	36 (83.7)	3 (75.0)
Hemorragic	199 (6.8)	38 (4.2)	1 (0.4)	1 (0.6)	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)
Xanthochromic	112 (3.8)	52 (5.8)	10 (4.6)	8 (5.1)	1 (6.7)	0 (0.0)	1 (2.3)	0 (0.0)
Unknown	148 (5.1)	6 (0.7)	2 (0.9)	2 (1.3)	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)
Sex
Male	1639 (56.0)	531 (59.1)	131 (59.8)	92 (59.0)	11 (73.3)	1 (100.0)	24 (55.8)	3 (75.0)
Female	1285 (43.9)	366 (40.7)	87 (39.7)	63 (40.4)	4 (26.7)	—	19 (44.2)	1 (25.0)
Unknown	4 (0.1)	2 (0.2)	1 (0.5)	1 (0.6)	—	—	—	—
Region
Northern	2907 (99.3)	889 (98.9)	203 (92.7)	145 (92.9)	12 (80.0)	1 (100.0)	42 (97.7)	3 (75.0)
Center	6 (0.2)	3 (0.3)	9 (4.1)	6 (3.8)	2 (13.3)	—	—	1 (25.0)
Southern	15 (0.5)	7 (0.8)	7 (3.2)	5 (3.2)	1 (6.7)	—	1 (2.3)	—
Age (years)	n = 1965	n = 591	n = 150	n = 87	n = 15	n = 1	n = 43	n = 4
Median (IQR)	4 (1–90)	4 (1–90)	4 (1–13)	6 (4–43)	15 (2–25)	—	9 (2–36)	6 (4.5–7.75)
Age category (Years)
0–4	892 (45.4)	143 (24.2)	34 (22.7)	14 (16.1)	05 (33.3)	—	14 (32.6)	1 (25.0)
5–9	355 (18.1)	112 (19.0)	28 (18.7)	14 (16.1)	03 (20.0)	—	09 (20.9)	02 (50.0)
10–14	184 (9.4)	77 (13.0)	26 (17.3)	17 (19.5)	04 (26.7)	01 (100.0)	03 (7.0)	01 (25.0)
15–19	106 (5.4)	58 (9.8)	16 (10.7)	14 (16.1)	—	—	02 (4.7)	—
20–24	56 (2.8)	23 (3.9)	03 (2.0)	—	—	—	03 (7.0)	—
25–29	65 (3.3)	35 (6.0)	09 (6.0)	5 (5.7)	—	—	04 (9.3)	—
30–34	57 (2.9)	28 (4.7)	05 (3.3)	—	—	—	05 (11.6)	—
35–39	64 (3.3)	34 (5.8)	05 (3.3)	02 (2.3)	—	—	03 (7.0)	—
40–44	30 (1.5)	13 (2.2)	03 (2.0)	03 (3.4)	—	—	—	—
45–49	47 (2.4)	19 (3.2)	05 (3.3)	05 (5.7)	—	—	—	—
50–54	20 (1.0)	10 (1.7)	05 (3.3)	02 (2.3)	03 (20.0)	—	—	—
55–59	39 (2.0)	21 (3.6)	06 (4.0)	06 (6.9)	—	—	—	—
60–64	13 (0.6)	02 (0.3)	01 (0.7)	01 (1.2)	—	—	—	—
65–69	23 (1.2)	07 (1.2)	03 (2.0)	03 (3.4)	—	—	—	—
≥70	14 (0.7)	09 (1.5)	01 (0.7)	01 (1.2)	—	—	—	—