Department of Preventive Medicine, Dongguk University College of Medicine, Gyeongju, Korea.
Copyright © 2013 The Korean Society for Preventive Medicine
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n |
Initial test on 25 July (n=81) |
Until the end of epidemic1 (n=81) |
Subjects with immunity2 | No. of susceptible person3 | No. of cases | Attack rate (95% confidence interval)4 | ||
---|---|---|---|---|---|---|---|---|
IgG anti-HAV positive (%) | IgM anti-HAV positive (%) | IgM anti-HAV positive (%) | ||||||
Residents | 51 | 15 (29.4) | 4 (7.8) | 16 (31.4) | 11 | 40 | 15 | 37.5 (24.2, 53.0) |
Sex | ||||||||
Male | 40 | 12 (30.0) | 3 (7.5) | 15 (37.5) | 9 | 31 | 14 | 45.2 (29.2, 62.2) |
Female | 11 | 3 (27.3) | 1 (9.1) | 1 (9.1) | 2 | 9 | 1 | 11.1 (2.0, 43.5) |
Age (y) | ||||||||
10-19 | 12 | 1 (8.3) | 1 (8.3) | 7 (58.3) | 0 | 12 | 7 | 58.3 (32.0, 80.7) |
20-29 | 18 | 1 (5.6) | 1 (5.6) | 4 (22.2) | 0 | 18 | 4 | 22.2 (9.0, 45.2) |
30-39 | 11 | 4 (36.4) | 1 (9.1) | 4 (36.4) | 3 | 8 | 4 | 50.0 (21.5, 78.5) |
40-49 | 5 | 4 (80.0) | 1 (20.0) | 1 (20.0) | 3 | 2 | 0 | 0.0 (0.0, 65.8) |
≥50 | 5 | 5 (100.0) | 0 (0.0) | 0 (0.0) | 5 | 0 | 0 | - |
Living unit | ||||||||
Unit A5 | 8 | 3 (37.5) | 0 (0.0) | 0 (0.0) | 3 | 5 | 0 | 0.0* (0.0, 43.4) |
Unit B5 | 8 | 3 (37.5) | 3 (37.5) | 6 (75.0) | 0 | 8 | 5 | 62.5 (30.6, 86.3) |
Unit C5 | 8 | 1 (12.5) | 0 (0.0) | 6 (75.0) | 1 | 7 | 6 | 85.7 (48.7, 97.4) |
Unit D5 | 8 | 4 (50.0) | 0 (0.0) | 1 (12.5) | 4 | 4 | 1 | 25.0 (4.6, 69.9) |
Unit E5 | 7 | 1 (14.3) | 0 (0.0) | 2 (28.6) | 1 | 6 | 2 | 33.3 (9.7, 70.0) |
Unit F6 | 6 | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 | 6 | 0 | 0.0 (0.0, 39.0) |
Unit G6 | 6 | 3 (50.0) | 1 (16.7) | 1 (16.7) | 2 | 4 | 1 | 25.0 (4.6, 69.9) |
Teachers/staff | 31 | 14 (46.7) | 0 (0.0) | 1 (3.3) | 15 | 16 | 1 | 6.3 (1.1, 28.3) |
Sex | ||||||||
Male | 13 | 3 (25.0) | 0 (0.0) | 1 (8.3) | 4 | 9 | 1 | 11.1 (2.0, 43.5) |
Female | 18 | 11 (61.1) | 0 (0.0) | 0 (0.0) | 11 | 7 | 0 | 0 (0.0, 35.4) |
Age (y) | ||||||||
20-29 | 11 | 0 (0.0) | 0 (0.0) | 1 (9.1) | 0 | 11 | 1 | 9.1 (1.6, 37.7) |
30-39 | 7 | 2 (33.3) | 0 (0.0) | 0 (0.0) | 3 | 4 | 0 | 0 (0.0, 49.0) |
40-49 | 6 | 5 (83.3) | 0 (0.0) | 0 (0.0) | 5 | 1 | 0 | 0 (0.0, 79.3) |
≥50 | 7 | 7 (100.0) | 0 (0.0) | 0 (0.0) | 7 | 0 | 0 | - |
Total | 82 | 29 (35.8) | 4 (4.9) | 17 (21.0) | 26 | 56 | 16 | 28.6 (18.4, 41.5) |
Sex | ||||||||
Male | 53 | 15 (28.8) | 3 (5.8) | 16 (30.8) | 13 | 40 | 15 | 37.5† (24.2, 53.0) |
Female | 29 | 14 (48.3) | 1 (3.4) | 1 (3.4) | 13 | 16 | 1 | 6.3 (1.1, 28.3) |
Age (y) | ||||||||
10-19 | 12 | 1 (8.3) | 1 (8.3) | 7 (58.3) | 0 | 12 | 7 | 58.3* (32.0, 80.7) |
20-29 | 29 | 1 (3.4) | 1 (3.4) | 5 (17.2) | 0 | 29 | 5 | 17.2 (7.6, 34.5) |
30-39 | 18 | 6 (35.3) | 1 (5.9) | 4 (23.5) | 6 | 12 | 4 | 33.3 (13.8, 60.9) |
40-49 | 11 | 9 (81.8) | 1 (9.1) | 1 (9.1) | 8 | 3 | 0 | 0.0 (0.0, 56.1) |
≥50 | 12 | 12 (100.0) | 0 (0.0) | 0 (0.0) | 12 | 0 | 0 | - |
Subjects | ||||||||
Residents | 51 | 15 (29.4) | 4 (7.8) | 16 (31.4) | 11 | 40 | 15 | 37.5* (24.2, 53.0) |
Teachers | 18 | 6 (35.3) | 0 (0.0) | 1 (5.9) | 7 | 11 | 1 | 9.1 (1.6, 37.7) |
Staff members | 13 | 8 (61.5) | 0 (0.0) | 0 (0.0) | 8 | 5 | 0 | 0.0 (0.0, 43.4) |
HAV, hepatitis A virus.
1 Sum of all the IgM anti-HAV test results received over the surveillance period.
2 People who were IgM anti-HAV negative and IgG positive in the serology test on July 25. One person (teacher) who was vaccinated before was included.
3 Initial 3 cases and 1 asymptomatic infection were regarded as the susceptible persons although they were IgG anti-HAV positive.
4 95% confidence intervals of attack rate are the value (π) of the following quadratic equation ‘χ2 = (p-π)2/[π(1-π)/n] (χ2 = 3.84, p= proportion of sample, n=number of sample).’
5 Males’ living unit.
6 Females’ living unit.
* p<0.05 calculated by log likelihood test,
† p<0.05 calculated by Fisher’s exact test.
Sample | Items exceeding the standard |
---|---|
Cooking utensils1 | |
Kitchen knife | Not detected |
Cutting board | Not detected |
Dishcloths | Not detected |
Water2 | |
Underground water | Color, turbidity |
For cooking | Color, turbidity |
Water purifier | Not detected |
1 Tests included Salmonella species, Shigella species, Vibrio species, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Campylobacter jejuni, Clostridium perfrigens, Bacillus cereus, and Yersinia enterocolitica.
2 Tested items were color, turbidity, odor, taste, NHn-N, NO3-N, total colony counts, total coliforms, fecal coliforms, KMnO4 consumption, total solids, pH, Cl-, Al, Mn, and F.
n | Initial test on 25 July (n=81) |
Until the end of epidemic |
Subjects with immunity |
No. of susceptible person |
No. of cases | Attack rate (95% confidence interval) |
||
---|---|---|---|---|---|---|---|---|
IgG anti-HAV positive (%) | IgM anti-HAV positive (%) | IgM anti-HAV positive (%) | ||||||
Residents | 51 | 15 (29.4) | 4 (7.8) | 16 (31.4) | 11 | 40 | 15 | 37.5 (24.2, 53.0) |
Sex | ||||||||
Male | 40 | 12 (30.0) | 3 (7.5) | 15 (37.5) | 9 | 31 | 14 | 45.2 (29.2, 62.2) |
Female | 11 | 3 (27.3) | 1 (9.1) | 1 (9.1) | 2 | 9 | 1 | 11.1 (2.0, 43.5) |
Age (y) | ||||||||
10-19 | 12 | 1 (8.3) | 1 (8.3) | 7 (58.3) | 0 | 12 | 7 | 58.3 (32.0, 80.7) |
20-29 | 18 | 1 (5.6) | 1 (5.6) | 4 (22.2) | 0 | 18 | 4 | 22.2 (9.0, 45.2) |
30-39 | 11 | 4 (36.4) | 1 (9.1) | 4 (36.4) | 3 | 8 | 4 | 50.0 (21.5, 78.5) |
40-49 | 5 | 4 (80.0) | 1 (20.0) | 1 (20.0) | 3 | 2 | 0 | 0.0 (0.0, 65.8) |
≥50 | 5 | 5 (100.0) | 0 (0.0) | 0 (0.0) | 5 | 0 | 0 | - |
Living unit | ||||||||
Unit A |
8 | 3 (37.5) | 0 (0.0) | 0 (0.0) | 3 | 5 | 0 | 0.0* (0.0, 43.4) |
Unit B |
8 | 3 (37.5) | 3 (37.5) | 6 (75.0) | 0 | 8 | 5 | 62.5 (30.6, 86.3) |
Unit C |
8 | 1 (12.5) | 0 (0.0) | 6 (75.0) | 1 | 7 | 6 | 85.7 (48.7, 97.4) |
Unit D |
8 | 4 (50.0) | 0 (0.0) | 1 (12.5) | 4 | 4 | 1 | 25.0 (4.6, 69.9) |
Unit E |
7 | 1 (14.3) | 0 (0.0) | 2 (28.6) | 1 | 6 | 2 | 33.3 (9.7, 70.0) |
Unit F |
6 | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 | 6 | 0 | 0.0 (0.0, 39.0) |
Unit G |
6 | 3 (50.0) | 1 (16.7) | 1 (16.7) | 2 | 4 | 1 | 25.0 (4.6, 69.9) |
Teachers/staff | 31 | 14 (46.7) | 0 (0.0) | 1 (3.3) | 15 | 16 | 1 | 6.3 (1.1, 28.3) |
Sex | ||||||||
Male | 13 | 3 (25.0) | 0 (0.0) | 1 (8.3) | 4 | 9 | 1 | 11.1 (2.0, 43.5) |
Female | 18 | 11 (61.1) | 0 (0.0) | 0 (0.0) | 11 | 7 | 0 | 0 (0.0, 35.4) |
Age (y) | ||||||||
20-29 | 11 | 0 (0.0) | 0 (0.0) | 1 (9.1) | 0 | 11 | 1 | 9.1 (1.6, 37.7) |
30-39 | 7 | 2 (33.3) | 0 (0.0) | 0 (0.0) | 3 | 4 | 0 | 0 (0.0, 49.0) |
40-49 | 6 | 5 (83.3) | 0 (0.0) | 0 (0.0) | 5 | 1 | 0 | 0 (0.0, 79.3) |
≥50 | 7 | 7 (100.0) | 0 (0.0) | 0 (0.0) | 7 | 0 | 0 | - |
Total | 82 | 29 (35.8) | 4 (4.9) | 17 (21.0) | 26 | 56 | 16 | 28.6 (18.4, 41.5) |
Sex | ||||||||
Male | 53 | 15 (28.8) | 3 (5.8) | 16 (30.8) | 13 | 40 | 15 | 37.5 |
Female | 29 | 14 (48.3) | 1 (3.4) | 1 (3.4) | 13 | 16 | 1 | 6.3 (1.1, 28.3) |
Age (y) | ||||||||
10-19 | 12 | 1 (8.3) | 1 (8.3) | 7 (58.3) | 0 | 12 | 7 | 58.3 |
20-29 | 29 | 1 (3.4) | 1 (3.4) | 5 (17.2) | 0 | 29 | 5 | 17.2 (7.6, 34.5) |
30-39 | 18 | 6 (35.3) | 1 (5.9) | 4 (23.5) | 6 | 12 | 4 | 33.3 (13.8, 60.9) |
40-49 | 11 | 9 (81.8) | 1 (9.1) | 1 (9.1) | 8 | 3 | 0 | 0.0 (0.0, 56.1) |
≥50 | 12 | 12 (100.0) | 0 (0.0) | 0 (0.0) | 12 | 0 | 0 | - |
Subjects | ||||||||
Residents | 51 | 15 (29.4) | 4 (7.8) | 16 (31.4) | 11 | 40 | 15 | 37.5 |
Teachers | 18 | 6 (35.3) | 0 (0.0) | 1 (5.9) | 7 | 11 | 1 | 9.1 (1.6, 37.7) |
Staff members | 13 | 8 (61.5) | 0 (0.0) | 0 (0.0) | 8 | 5 | 0 | 0.0 (0.0, 43.4) |
Sample | Items exceeding the standard |
---|---|
Cooking utensils |
|
Kitchen knife | Not detected |
Cutting board | Not detected |
Dishcloths | Not detected |
Water |
|
Underground water | Color, turbidity |
For cooking | Color, turbidity |
Water purifier | Not detected |
HAV, hepatitis A virus. Sum of all the IgM anti-HAV test results received over the surveillance period. People who were IgM anti-HAV negative and IgG positive in the serology test on July 25. One person (teacher) who was vaccinated before was included. Initial 3 cases and 1 asymptomatic infection were regarded as the susceptible persons although they were IgG anti-HAV positive. 95% confidence intervals of attack rate are the value (π) of the following quadratic equation ‘χ2 = (p-π)2/[π(1-π)/n] (χ2 = 3.84, Males’ living unit. Females’ living unit.
Tests included Tested items were color, turbidity, odor, taste, NHn-N, NO3-N, total colony counts, total coliforms, fecal coliforms, KMnO4 consumption, total solids, pH, Cl-, Al, Mn, and F.