Table 2.
Meningococcal Carriage and Serogroups
| Meningococcal Carriage | Round 1: February 2015, N (%) | Round 2: April 2015, N (%) | Round 3: September 2015, N (%) | Round 4: March 2016, N (%) |
|---|---|---|---|---|
| Total participants | 717 | 878 | 622 | 626 |
| Neisseria meningitidis carriage | 175 (24) | 211 (24) | 123 (20) | 130 (21) |
| Meningococcal serogroup | ||||
| By real-time polymerase chain reactiona | ||||
| A | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| B | 31 (4) | 36 (4) | 26 (4) | 22 (4) |
| C | 8 (1) | 3 (0.3) | 0 (0) | 0 (0) |
| W | 0 (0) | 0 (0) | 1 (0.2) | 1 (0.2) |
| X | 1 (0.1) | 2 (0.2) | 0 (0) | 5 (1) |
| Y | 3 (0.4) | 4 (0.5) | 1 (0.2) | 2 (0.3) |
| Nongroupable | 132 (18) | 166 (19) | 95 (15) | 100 (16) |
| By slide agglutinationb | ||||
| A | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| B | 9 (1) | 12 (1) | 7 (1) | 6 (1) |
| C | 1 (0.1) | 0 (0) | 0 (0) | 0 (0) |
| Ec | 4 (1) | 4 (0.5) | 6 (1) | 8 (1) |
| W | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| X | 3 (0.4) | 2 (0.2) | 0 (0) | 0 (0) |
| Y | 2 (0.3) | 2 (0.2) | 0 (0) | 0 (0) |
| Zc | 0 (0) | 0 (0) | 1 (0.2) | 0 (0) |
| Nongroupable | 156 (22) | 191 (22) | 109 (18) | 116 (19) |
In round 1, 18% of 175 isolates were serogroup B, 5% were serogroup C, 1% were serogroup X, 2% were serogroup Y, and 75% were nongroupable by real-time polymerase chain reaction. Similarly, round 2 isolates were 17% B, 1% C, 1% X, 2% Y, and 79% nongroupable; round 3 isolates were 21% B, 1% W, 1% Y, and 77% nongroupable; and round 4 isolates were 17% B, 1% W, 4% X, 2% Y, and 77% nongroupable.
In round 1, 5% of 175 isolates were serogroup B, 1% were serogroup C, 2% were serogroup E, 2% were serogroup X, 1% were serogroup Y, and 89% were nongroupable by slide agglutination. Similarly, round 2 isolates were 6% B, 2% E, 1% X, 1% Y, and 91% nongroupable; round 3 isolates were 6% B, 5% E, 1% Z, and 89% nongroupable; and round 4 isolates were 5% B, 6% E, and 89% nongroupable.
Serogroups E and Z were only assessed via slide agglutination, not by real-time polymerase chain reaction.