National Enteric Disease Surveillance: Shigella Annual...
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CS247172 April 2014 National Center for Emerging and Zoonotic Infectious Diseases Division of Foodborne Waterborne, and Environmental Diseases National Enteric Disease Surveillance: Shigella Annual Report, 2012 An overview of surveillance methods and systems for Shigella infections is available online at http://www.cdc.gov/ncezid/dfwed/PDFs/Shigella-Overview-508.pdf (1). Human Surveillance Data: Laboratory-based Enteric Disease Surveillance (LEDS) The Laboratory-based Enteric Disease Surveillance (LEDS) system collects reports of isolates of laboratory- confirmed human Shigella infections from state public health laboratories. Reporting to LEDS is voluntary, and the number of states submitting reports varies somewhat from year to year, although almost all states report every year. Occasionally, more than one isolate is reported from a single episode of infection in a person; this report includes only one isolate of a given Shigella species per person within a 30-day period. In this report, we summarize the number of infections reported, and also report incidence rates (cases per 100,000 population), which are calculated as the number of Shigella infections in humans reported for a given year divided by the state population for that year. Data were received from 50 of 51 reporting jurisdictions (49 states plus the District of Columbia) in 2012. Data in this report current as of 1/21/2014. Photograph depicting the colonial morphology displayed by Shigella boydii bacteria cultivated on a Hektoen enteric (HE) agar surface.
Transcript of National Enteric Disease Surveillance: Shigella Annual...
CS247172 April 2014
National Center for Emerging and Zoonotic Infectious DiseasesDivision of Foodborne Waterborne, and Environmental Diseases
National Enteric Disease Surveillance: Shigella Annual Report, 2012
An overview of surveillance methods and systems for Shigella infections is available online at http://www.cdc.gov/ncezid/dfwed/PDFs/Shigella-Overview-508.pdf (1).
Human Surveillance Data: Laboratory-based Enteric Disease Surveillance (LEDS)The Laboratory-based Enteric Disease Surveillance (LEDS) system collects reports of isolates of laboratory-confirmed human Shigella infections from state public health laboratories. Reporting to LEDS is voluntary, and the number of states submitting reports varies somewhat from year to year, although almost all states report every year. Occasionally, more than one isolate is reported from a single episode of infection in a person; this report includes only one isolate of a given Shigella species per person within a 30-day period.
In this report, we summarize the number of infections reported, and also report incidence rates (cases per 100,000 population), which are calculated as the number of Shigella infections in humans reported for a given year divided by the state population for that year. Data were received from 50 of 51 reporting jurisdictions (49 states plus the District of Columbia) in 2012.
Data in this report current as of 1/21/2014.
Photograph depicting the colonial morphology displayed by Shigella boydii bacteria cultivated on a Hektoen enteric (HE) agar surface.
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Table 1. Laboratory-confirmed Shigella infections reported to CDC, by species, United States, 2012
Rank Serotype Number Reported Percent
1 S. sonnei 5824 75.2
2 S. flexneri 957 12.4
3 S. boydii 60 0.8
4 S. dysenteriae 26 0.3
Sub Total 6867 88.7
Unknown 879 11.3
Total 7746 100
State public health laboratories reported 7,746 laboratory-confirmed Shigella infections to CDC through LEDS
• Of the 7,746 isolates, 6,867 (89%) were identified to species level.
• Distribution by species was similar to previous years, with Shigella sonnei accounting for the largest percentage of infections (75%), followed by Shigella flexneri (12%), Shigella boydii (0.8%), and Shigella dysenteriae (0.3%).
Table 2. Median age (years) of persons with laboratory-confirmed Shigella infections reported to CDC, by species and year, United States, 2002-2012
Species 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012
S. sonnei 7 7 7 7 7 6 6 6 6 6 7
S. flexneri 21 23 20 20 18 15 17 22 25 26 28
S. boydii 21 17 21 25 10 26 16 17 22 24 28
S. dysenteriae 29 22 9 25 20 8 15 31 28 26 27
Unknown 6 6 7 8 8 9 7 22 8 9 10
In 2012, the median age of persons with S. sonnei was 7 years, slightly higher than in each of the previous 5 years. The median age of persons with S. flexneri and of persons with S. boydii in 2012 (28 years for both) was higher than in any of the previous 10 years.
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Figure 1. Incidence rate of laboratory-confirmed Shigella infection reported to CDC (all species), United States, 1970-2012
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Shigella dysenteriae Shigella unknownShigella boydiiShigella flexneri
Shigella Shigella sonnei
The top panel of this graph shows the incidence rates of infection with Shigella (all species) and Shigella sonnei from 1970 to 2012.
• Since 1970, the incidence rate of infection with Shigella (all species) has been driven by the incidence rate of infection with Shigella sonnei.
• The incidence rate of infection with Shigella sonnei decreased from 2008 through 2011, but increased in 2012.
The bottom panel of this graph shows the incidence rate of infection with Shigella species other than Shigella sonnei and includes infections with an unknown species.
• The incidence rate of infection with Shigella flexneri has decreased since the 1970s, but has remained relatively stable since 2007.
• Since the mid-1980s, the incidence rate of infection with an unknown species of Shigella has fluctuated, likely representing at least to some extent outbreak situations where public health laboratories did not characterize outbreak-associated Shigella isolates to the species level. Peaks in incidence of these isolates are generally parallel to peak in incidence of S. sonnei.
• Shigella boydii and Shigella dysenteriae infections are rare in the United States.
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Figure 2a. Incidence rate of laboratory-confirmed Shigella infection reported to CDC (all species) by reporting jurisdiction, United States, 2012*
0.04–0.57
LegendRate per 100,000 population
0.58–1.161.17–1.821.83–3.413.42–13.20
* Unshaded reporting jurisdictions are those for which the reporting jurisdiction reported no Shigella isolates (i.e., no infections were diagnosed or the reporting jurisdiction did not report to CDC).
Fifty reporting jurisdictions reported a total of 7,746 Shigella infections corresponding to an overall incidence rate (cases per 100,000 population) of 2.5. The reporting jurisdictions with the highest incidence rates were Nebraska (13.2), New Jersey (7.6), and Minnesota (7.1).
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Figure 2b. Incidence rate of laboratory-confirmed human Shigella sonnei infection reported to CDC, by reporting jurisdiction, United States, 2012*
0.01–0.22
LegendRate per 100,000 population
0.23–0.630.64–1.401.41–2.592.60–7.49
* Unshaded reporting jurisdictions are those for which the reporting jurisdiction reported no Shigella isolates (i.e., no infections were diagnosed or the reporting jurisdiction did not report to CDC).
Fifty reporting jurisdictions reported a total of 5,824 Shigella sonnei infections, corresponding to an overall incidence rate (cases per 100,000 population) of 1.9. The reporting jurisdictions with the highest incidence rates were Nebraska (7.5), New Jersey (7.1), and Mississippi (6.9).
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Figure 2c. Incidence rate of laboratory-confirmed Shigella flexneri infection reported to CDC, by reporting jurisdiction, United States, 2012*
0.01–0.13
LegendRate per 100,000 population
0.14–0.230.24–0.360.37–0.600.61–1.10
* Unshaded reporting jurisdictions are those for which the reporting jurisdiction reported no Shigella isolates (i.e., no infections were diagnosed or the reporting jurisdiction did not report to CDC).
Forty-five reporting jurisdictions reported a total of 957 Shigella flexneri infections, corresponding to an overall incidence rate (cases per 100,000 population) of 0.3. The reporting jurisdictions with the highest incidence rates were New Mexico (1.1), Hawaii (1.1), and Georgia (1.0).
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Figure 3. Incidence rate of laboratory-confirmed Shigella infection reported to CDC, by age group and sex, United States, 2012 (n=7,294 with age and sex information reported)
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5–9 10–19 20–29 30–39 40–49 50–59 60–69 70–79 80+
During 2012, the highest incidence rate of Shigella infection was in children under 5 years old. Among ages 0 to 4 and 40 to 49 years, males had a higher incidence rate of Shigella infection than females. Among ages 5 to 29 and ≥80 years, females had a higher incidence rate of Shigella infection than males. In the remaining age groups (30–39 and 50–79), incidence rates were relatively similar (i.e., ≤10% difference) among both males and females.
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Figure 4. Percentage of laboratory-confirmed Shigella infections reported to CDC, by month of specimen collection, United States, 2012 and mean percentage during 2002 to 2011
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Compared with the previous 10 years (2002–2011), a larger portion of Shigella infections in 2012 were reported from January through March.
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Human Surveillance Data: National Notifiable Diseases Surveillance System (NNDSS)The National Notifiable Disease Surveillance System (NNDSS) collects and compiles reports of nationally notifiable infectious diseases, including Shigella. This system includes reports of laboratory-confirmed cases and probable cases (clinically compatible cases with an epidemiological link to a confirmed case).
The report for 2012 was not yet available when this report was written. Reports are available at http://www.cdc.gov/mmwr/mmwr_nd/index.html.
Human Antimicrobial Resistance Data: National Antimicrobial Resistance Monitoring System (NARMS)The National Antimicrobial Resistance Monitoring System (NARMS) monitors antimicrobial resistance among enteric bacteria (including Shigella) isolated from humans.
The report for 2012 was not yet available when this report was written. Reports are available at http://www.cdc.gov/narms/reports.html.
Human Outbreak Data: Foodborne Disease Outbreak Surveillance System (FDOSS) and Waterborne Disease Outbreak Surveillance System (WBDOSS)The Foodborne Disease Outbreak Surveillance System (FDOSS) collects reports of foodborne disease outbreaks from local, state, tribal, and territorial public health agencies.
The report for 2012 was not yet available when this report was written. Reports are available at http://www.cdc.gov/foodsafety/fdoss/data/annual-summaries/index.html.
The Waterborne Disease and Outbreak Surveillance System (WBDOSS) collects reports of waterborne disease outbreaks associated with drinking water and recreational water from local, state, and territorial public health agencies.
The report for 2012 was not yet available when this report was written. Reports are available at http://www.cdc.gov/healthywater/surveillance/surveillance-reports.html.
References1. Centers for Disease Control and Prevention (CDC). National Shigella Surveillance Overview. Atlanta, Georgia: US Department of
Health and Human Services, CDC, 2011.
Recommended Citation:
Centers for Disease Control and Prevention (CDC). National Shigella Surveillance Annual Report, 2012. Atlanta, Georgia: US Department of Health and Human Services, CDC, 2014.
NCEZID Atlanta: For more information please contact Centers for Disease Control and Prevention 1600 Clifton Road NE, Atlanta, GA 30333 MS C-09 Telephone: 1-404-639-2206 Email: [email protected]
