Volume 22, Number 12—December 2016
Dispatch
Digital PCR for Quantifying Norovirus in Oysters Implicated in Outbreaks, France
Table
Characteristics of outbreaks of norovirus infection associated with consumption of oysters, analyzed oyster samples, and virus concentrations obtained by digital PCR*
Outbreak no. |
Epidemiology information | Sample no. |
Samples analyzed | Viral RNA copies/oyster | |||||
---|---|---|---|---|---|---|---|---|---|
Date of consumption |
No. sick/
no. exposed |
Days to illness onset† |
Days to sampling‡ |
Sample location§ |
Genogroup GI |
Genogroup GII |
|||
1 | 2014 Feb 23 | 7/16 | 0.5 | 3486 | 4 | Same batch | ND | 1.09 × 102 | |
3488 | 7 | Prod area | ND | ND | |||||
3489 |
7 |
Prod area |
ND |
2.96 × 102 |
|||||
2 |
2014 Feb 27 |
3/4 |
2 |
3498 |
5 |
Same batch |
ND |
3.72 × 102 |
|
3 | 2014 Mar 16 | 4/4 | 1 | 3519 | 2 | Prod area | ND | 2.02 × 102 | |
3517 | 5 | Prod area | ND | 6.81 × 102 | |||||
3518 | 2 | Prod area | 3.80 × 102 | 6.15 × 102 | |||||
3531 | 15 | Prod area | 1.08 × 103 | ND | |||||
3532 |
15 |
Prod area |
3.88 × 102 |
ND |
|||||
4 | 2014 Dec 12 | 3/3 | No data | 3703 | 6 | Same batch | 1.18 × 102 | ND | |
3694 |
–4 |
Prod area |
ND |
1.70 × 102 |
|||||
5 | 2014 Dec 14 | 2/2 | 1.5 | 3704 | 3 | Same batch | ND | 1.21 × 102 | |
3705 | 3 | Same batch | 2.74 × 102 | 44.1 | |||||
3695 | –6 | Prod area | ND | 43.2 | |||||
3698 | –6 | Prod area | 1.18 × 102 | ND | |||||
3700 |
–6 |
Prod area |
1.1 × 103 |
9.50 × 102 |
|||||
6 |
2014 Dec 27 |
3/6 |
0.5 |
3733 |
6 |
Same batch |
ND |
1.26 × 102 |
|
7 | 2015 Jan 9 | 3/4 | 1.5 | 3740 | 3 | Same batch | 9.20 × 102 | ND | |
3738 | –3 | Prod area | 1.17 × 103 | ND | |||||
3739 |
–3 |
Prod area |
6.38 × 102 |
53.4 |
|||||
8 | 2015 Mar 29 | 16/36 | 2 | 3816 | 3 | Consumed | ND | 82.1 | |
3817 | 3 | Same batch | 1.85 × 102 | ND | |||||
3791 | –19 | Prod area | ND | 1.87 × 102 | |||||
3792 | –19 | Prod area | 8.28 × 102 | ND | |||||
3822 | 10 | Prod area | 1.28 × 102 | ND |
*ND, not detected; Prod, production.
†Median days to onset of vomiting or diarrhea.
‡Days from date of consumption to sample collection.
§Same batch = samples from batch of oysters consumed.