Volume 20, Number 6—June 2014
Research
Rapid Spread and Diversification of Respiratory Syncytial Virus Genotype ON1, Kenya
Table 1
Occurrence of RSV group A and B viruses and of genotype ON1 in Kilifi, Kenya, 2012*
Month | No. RSV strains detected |
RSV group A sequencing result |
||||||
---|---|---|---|---|---|---|---|---|
Group A | Group B | Co-infected (A+B) | Total | No. (%) ON1 strains† | Non-ON1 | Not sequenced | ||
First wave | ||||||||
Jan | 0 | 18 | 0 | 18 | 0 | 0 | 0 | |
Feb | 6 | 23 | 0 | 29 | 1 (20.0) | 4 | 1 | |
Mar | 15 | 26 | 1 | 42 | 8 (53.3) | 7 | 1 | |
Apr | 14 | 16 | 1 | 31 | 5 (41.7) | 7 | 3 | |
May | 4 | 6 | 0 | 10 | 3 (100.0) | 0 | 1 | |
Jun | 11 | 2 | 0 | 13 | 9 (81.8) | 2 | 0 | |
Jul | 3 | 0 | 0 | 3 | 3 (100.0) | 0 | 0 | |
Aug |
2 |
0 |
0 |
2 |
2 (100.0) |
0 |
0 |
|
Non-wave period | ||||||||
Sep |
0 |
1 |
0 |
1 |
0 |
0 |
0 |
|
Second wave | ||||||||
Oct | 7 | 1 | 0 | 8 | 4 (66.7) | 2 | 1 | |
Nov | 38 | 16 | 1 | 55 | 31 (91.2) | 3 | 5 | |
Dec‡ |
23 |
5 |
0 |
28 |
11 (84.6) |
2 |
10 |
|
Total | 123 | 114 | 3 | 240 | 77 (74.0) | 27 | 21 |
*The calendar year 2012 spans parts of 2 epidemics: the 2011–12 epidemic, which occurred during October 2011–August 2012 (peak March 2012), and the 2012–13 epidemic, which occurred during October 2012–July 2013 (peak November 2012). Group B RSVs predominated during the 2011–12 epidemic (65.0%), and group A RSVs predominated during the 2012–13 epidemic (79.28%). RSV, respiratory syncytial virus.
†Percentages represent the proportion of ON1 viruses among RSV A sequenced samples from each month.
‡Because of local logistics problems, samples were not collected from all the subjects that were eligible in December.