Table 5.
Temporal clusters of CGF40 subtypes, case onset dates within 30 days, Nova Scotia, January 2012–March 2015 (n = 82)
| Year | CGF40 | No. of cases | Episode date range | Cluster noted by Public Health | Significant association detected for subtype* |
|---|---|---|---|---|---|
| 2012 | 0922·001·002 | 4 | 3 July–4 Aug. | Yes, 3 cases from outbreak with 6 laboratory-confirmed cases and 12 probable cases | No |
| 0018·001·002 | 3 | 9–17 Nov. | No | Unpasteurized milk | |
| 0253·004·001 | 3 | 21 Sept.–21 Oct. | No | Acquired in NS | |
| 0269·004·001 | 2 | 19–23 July | No | n.a. | |
| 0044·003·001 | 2 | 20 Aug.–8 Sept. | No | Acquired in NS | |
| 0891·001·001 | 2 | 20–27 Aug. | No | n.a. | |
| 2013 | 0083·001·002 | 9 | 16 June–10 Oct. | No | Acquired in NS, pet dog or cat |
| 0117·001·001 | 2 | 13–21 Sept. | No | No | |
| 0169·001·002 | 2 | 12 July–1 Aug. | No | No | |
| 0173·010·002 | 2 | 18 May–16 June | No | n.a. | |
| 0027·006·001 | 2 | 26 June –July 10 | Yes, 2 cases | n.a. | |
| 2014 | 0017·001·004 | 3 | 18 May–23 | No | n.a. |
| 0253·004·001 | 3 | 24 July–Aug. 28 | No | Acquired in NS | |
| 0633·004·002 | 3 | 2 Nov.–Dec. 13 | No | No | |
| 0926·002·001 | 3 | 22 June–July 10 | No | Rural residence | |
| 0952·003·002 | 3 | 7 July–Aug. 9 | No | n.a. | |
| 0120·001·007 | 2 | 21–26 Feb. | No | n.a. | |
| 0129·001·002 | 2 | 27–30 May | Yes, 2 cases | Rural residence, contact with chickens | |
| 0129·001·002 | 2 | 1–8 Sept. | No | Rural residence, contact with chickens | |
| 0173·002·004 | 2 | 4–19 Nov. | No | Acquired in NS | |
| 0173·008·002 | 2 | 3–8 Aug. | No | n.a. | |
| 0018·001·002 | 2 | 6–8 June | No | Unpasteurized milk | |
| 0018·001·002 | 2 | 7–12 Aug. | No | Unpasteurized milk | |
| 0253·004·001 | 2 | 5–23 May | No | Acquired in NS | |
| 0044·003·001 | 2 | 19 Nov.–15 Dec. | No | Acquired in NS | |
| 0611·003·001 | 2 | 27 Apr.–5 May | No | n.a. | |
| 0082·001·001 | 2 | 13–29 Nov. | No | n.a. | |
| 0083·007·001 | 2 | 12 Apr.–2 May | No | No | |
| 0882·005·001 | 2 | 8–18 Aug. | No | Contact with chickens | |
| 0904·005·004 | 2 | 16–21 June | No | n.a. | |
| 0933·008·001 | 2 | 16–22 June | No | n.a. | |
| 0960·007·001 | 2 | 18–21 July | No | No | |
| 2015 | 0018·001·002 | 2 | 6–10 Mar. | Yes, 2 cases from cluster of 3 laboratory-confirmed cases in same setting† | Unpasteurized milk |
NS, Nova Scotia; n.a., not applicable.
CGF40 clusters with ⩾5 cases were tested for associations with the following risk factors: urban residence, acquisition of illness in Nova Scotia, age, sex, work in chicken or mink farming/processing, contact with chickens through owning or visiting a farm or working in chicken farming/processing, unpasteurized milk, contact with pet dog and/or cat, recreational water, farm/zoo/wildlife animals (see Table 4). These sources may provide leading hypotheses for investigation.
Third outbreak case differed in one PCR result, CGF40 subtype was 0018·001·003; however, this single locus difference was found to be a spurious result upon retesting.