Shigellosis

• Reporting criteria
• The disease and its epidemiology
• Case definition

• Laboratory testing
• Case investigation
• Disease control measures

• References
• Contact

What and how to report to the Colorado Department of Public Health and Environment (CDPHE) or local public health agency  

• All specimens with a positive test for Shigella (regardless of specimen source) by culture, polymerase chain reaction (PCR), or other form of testing should be reported to public health within four (4) days of the positive test result.
  • All positive Shigella laboratory tests should be reported to public health, regardless of symptoms. Public health will make the determination of whether the case meets the case definition.
• Cases should be reported using EpiTrax Reportal, fax, or telephone to CDPHE or local health departments (telephone and fax numbers are listed at the end of this document).
• All potential foodborne, waterborne, and enteric disease outbreaks should be reported immediately to CDPHE or local health departments and entered into EpiTrax, even if the causative agent is not yet known.
  • In general, an “outbreak” is defined as an increase in the number of illnesses above what is normally expected among a specific population, within a given area, over a certain period of time.
  • Specifically, a foodborne disease outbreak occurs when two or more people get the same illness from the same contaminated food or drink.

Purpose of surveillance and reporting

• To identify cases for investigation and potential outbreaks
• To monitor trends in disease incidence

Back to top

Etiologic agent

Shigellosis refers to disease caused by any bacteria in the genus Shigella. There are four Shigella species (or serogroups): S. dysenteriae, S. flexneri, S. boydii, and S. sonnei.

Clinical description

The most common symptoms of shigellosis are diarrhea (sometimes bloody), fever, nausea, vomiting and stomach cramps, and tenesmus (constant feeling of needing to have a bowel movement even when the bowels are empty). Dehydration may be severe, especially among infants and the elderly. Asymptomatic infections may occur. The disease is usually self-limiting, with symptoms usually lasting 5 to 7 days, but some people may experience symptoms up to four or more weeks. S. dysenteriae is usually associated with more severe disease and complications, and can lead to death. 

Reservoirs

Humans are the only significant reservoir of Shigella bacteria.

Modes of transmission

Shigella bacteria are transmitted via the fecal-oral route through direct person-to-person contact or ingestion of contaminated food, drinking water, or recreational water. A very small dose of Shigella is needed to cause illness (probably 10 to 100 organisms). The most common mode of transmission is person-to-person spread, often occurring in settings where maintaining personal hygiene is challenging, such as preschools, daycare facilities, residential care facilities, and among people experiencing homelessness. Transmission can also occur person to person through sexual contact (e.g., oral-anal contact), and outbreaks have been reported among men who have sex with men (MSM). Individuals shedding the bacteria may also contaminate food by failing to properly wash their hands before handling food, potentially causing large numbers of people to become ill. Recreational water venues, such as lakes and ponds, can be a source of infection when they are contaminated with human sewage or where people ill with Shigella are swimming. The risk of transmission may be elevated during international travel, especially to regions where the bacteria is endemic.

Incubation period

The average incubation period is about 1–3 days but can range from 12 to 96 hours. It can be up to a week for S. dysenteriae.

Infectious period

The disease is communicable for as long as the infected person excretes Shigella bacteria in their stool. This usually lasts for less than four weeks after onset of illness. Effective antibiotic treatment has been shown to decrease the shedding period; antibiotic susceptibility testing, often completed by a patient’s doctor, can help determine which antibiotics are considered effective for an individual’s infection. Prolonged carriage is uncommon. As is the case with most enteric illnesses, people are most infectious when they have diarrhea and are usually more infectious than those who are asymptomatic.

Epidemiology

During 2023, 468 cases were reported in Colorado, with a five-year average of 312 cases per year (2019-2023). S. sonnei was the most common Shigella species reported in Colorado. Outbreaks in the U.S. have occurred in child care centers, in recreational water settings, among men who have sex with men, among people experiencing homelessness, and in correctional facilities. Outbreaks have also been caused by contaminated food, such as raw produce. 

In 2022, there were 14,744 shigellosis cases reported in the United States, with a five-year average of 13,752 cases per year (2018-2022). During this time period, 30% of shigellosis cases in the FoodNet catchment area were hospitalized and < 1% of cases died. Five percent of cases were outbreak-associated, and approximately 20% were acquired internationally.

For more data, see Colorado reportable disease data (Colorado data), CDC WONDER and CDC BEAM Dashboard (national data), and CDC FoodNet Fast (FoodNet catchment area data).

Back to top

Clinical criteria

An illness of variable severity commonly manifested by diarrhea, fever, nausea, cramps, and tenesmus (constant feeling of needing to have a bowel movement). Asymptomatic infections may occur.

Laboratory criteria for diagnosis

Confirmatory laboratory evidence:

• Isolation of Shigella spp. from a clinical specimen (i.e., culture)

Supportive laboratory evidence:

• Detection of Shigella spp. or Shigella/Enteroinvasive Escherichia coli (EIEC) in a clinical specimen using a culture-independent diagnostic test (CIDT).

Note: Results that read “Shigella/EIEC” should be reported as shigellosis cases into EpiTrax.

Epidemiologic linkage

A clinically compatible case that is epidemiologically linked to a case that meets the supportive or confirmatory laboratory criteria for diagnosis.

Criteria to distinguish a new case from an existing case

A case should not be counted as a new case if laboratory results were reported within 90 days of a previously reported infection in the same individual. When two or more different serotypes are identified in one or more specimens from the same individual, each should be reported as a separate case.

Case classification

Confirmed

• A case that meets the confirmed laboratory criteria for diagnosis.

Probable

• A case that meets the supportive laboratory criteria for diagnosis; OR
• A clinically compatible case that is epidemiologically linked to a case that meets the supportive or confirmatory laboratory criteria for diagnosis.

Interpretation note: Epi-linked probable cases can be epi-linked to either a confirmed or probable case, as long as the index case has a positive test result (see laboratory criteria, above). Additionally, confirmed or laboratory-confirmed probable cases can include asymptomatic infections and infections at sites other than the gastrointestinal tract that are laboratory-confirmed (rare).

Back to top

• The Colorado State Public Health Laboratory (“State Lab”) provides testing services to support public health investigations.
• The State Lab may test clinical and/or environmental samples when determined to be necessary for public health investigations. These services vary by pathogen but may include:
  • Testing for individuals who have been restricted or excluded from work or child care by public health
  • Testing for outbreak investigations, with prior approval from CDPHE
  • Other testing services as discussed with CDPHE
• The State Lab maintains a test directory, guidance for submitting samples, and other helpful resources on their webpage.
  • Additional questions can be directed to the Lab Coordinators by email (cdphe_labcoordinators@state.co.us; preferred method) or phone 303-692-3069.
• Clinical and commercial laboratories are required to submit Shigella isolates or clinical material to the State Lab for confirmation and whole genome sequencing (WGS; i.e., molecular subtyping). While these submissions do not require prior approval from CDPHE, a complete lab requisition form is required for each isolate/clinical material submission to the State Lab.
  • WGS results are used for public health surveillance only and cannot be released to clinical providers or used for clinical decision-making.
  • The State Lab does not perform routine antimicrobial susceptibility testing (AST); providers interested in AST should order it from a clinical or commercial laboratory.

Back to top

Interview all confirmed and probable (including epi-linked probable) cases of shigellosis to determine:

• Potential source of infection, and implement disease control measures as appropriate
• If others are ill (i.e., could this be an outbreak?)
• If the case may be a source of infection for others (e.g., a high-risk worker or a diapered child); and if so, prevent further transmission

Local health departments have primary responsibility for interviews of sporadic cases in their jurisdictions. CDPHE is available to assist with case investigations upon request through CDPHE’s Enteric Disease Interview Team (EDIT). Interviews should be conducted and appropriate disease control measures implemented as soon as reasonably possible after the case is reported. Interviews should not be delayed until confirmatory laboratory testing is completed at the State Lab.

Forms 

For single cases, use the CDPHE Shigellosis case investigation form for your interview and enter the information into the case’s morbidity record (CMR) in EpiTrax. Interview all cases, regardless of specimen source (stool, blood, wound, urine, etc.). 

For surveillance purposes, collect exposure histories for the seven days before symptom onset. Determining the exposure period can be difficult for cases who do not have an acute onset of gastrointestinal symptoms. It’s important to do a complete assessment for GI illness, even when the specimen was collected from a source other than stool, to determine if any GI symptoms were present, even if mild. Use the following criteria to determine the case’s exposure period:

1. If the case reports diarrhea or vomiting, then use the onset date of diarrhea/vomiting to determine exposure period.
2. If the case does not report diarrhea or vomiting but reports other clinically relevant symptoms (see Clinical description section above), then use the onset date of other symptoms to determine exposure period.
3. If the case does not report onset of any clinically relevant symptoms (see Clinical description section above), then use the specimen collection date to determine exposure period.*

*Do not enter specimen collection date as “onset date” in EpiTrax (clinical tab); use this date to determine exposure period only. “Onset date” in EpiTrax only applies if the case experienced symptoms of illness. Otherwise, leave this field blank.

If the case reports international travel for even one day during their exposure period, it is fine to complete the travel section then skip to the “School, work, and volunteer information” section. No other additional exposure information needs to be collected.

After completing the case interview, enter the information into the case’s morbidity record (CMR) in EpiTrax, including the investigation form, and conduct any necessary disease control activities. If an outbreak is suspected, create a new outbreak in EpiTrax and contact CDPHE if assistance is needed; this includes requests for additional testing at the State Lab.

Identify and evaluate contacts

Symptomatic contacts

• Contacts of a case with a positive lab test who have clinically compatible symptoms are epi-linked probable cases and are treated the same as cases with a positive lab test for disease control purposes. See Disease control measures below.
  • Complete a case interview with all epidemiologically linked probable cases.
  • Epi-linked probable cases who have been interviewed should be entered into EpiTrax as a new, probable shigellosis morbidity record (CMR). Link this newly created CMR to the laboratory-confirmed case’s CMR under the “contacts” tab in EpiTrax.
• Refer symptomatic individuals who have not previously been tested (especially if they are high-risk workers) to their health care provider for stool testing and appropriate medical care.
• If a common source of exposure is suspected (e.g., a shared meal or social event), create an outbreak record in EpiTrax and notify CDPHE as soon as possible.  

Asymptomatic contacts 

• Ask about high-risk occupations, including food handling, health care, community residential programs, and child care/ school attendance.
• Provide information on symptom monitoring and next steps if symptoms develop.
  • Stress the importance of good handwashing, personal hygiene, excluding themselves from work, and notifying their supervisor whenever they have a diarrheal illness.
• If an asymptomatic contact develops diarrhea, follow the steps outlined above under symptomatic contacts. If the contact works in a high-risk setting, exclude them from work per the Managing special situations section below, even in the absence of a positive lab test.

Reported incidence is higher than usual/outbreak suspected

If the number of reported cases of shigellosis in your jurisdiction is higher than usual, or if an outbreak is suspected, investigate the situation to determine the source of infection and mode of transmission. Notify CDPHE as soon as possible to discuss potential stool testing of untested, symptomatic contacts, and enter the outbreak into EpiTrax. CDPHE staff can assist local public health agencies to investigate outbreaks and determine disease control recommendations to prevent further cases, as well as coordinate surveillance of cases that cross county lines.

Back to top

Shigella (Shigellosis) | CDC

Treatment

Most infections with Shigella are self-limiting and do not require antimicrobial therapy. However, antimicrobial therapy may be effective in slightly shortening the duration of diarrhea and eradicating organisms from feces. Treatment is recommended for patients with severe disease, dysentery, or underlying immunosuppressive conditions. In mild disease, the primary indication for treatment is to prevent spread of the organism. Because antimicrobial resistance is common in Shigella, including substantial multidrug resistance, it is important to obtain the antimicrobial susceptibility pattern of the isolate from the clinical microbiology laboratory. Antimicrobial resistant, including extensively drug resistant (XDR), Shigella has been increasing in Colorado and the United States.

In general, individuals experiencing diarrhea are at risk of dehydration due to loss of fluids. If symptoms persist, worsen, or are severe, cases should promptly seek medical care.

Prophylaxis

No prophylactic treatment of close contacts is recommended.

Education

Encourage the case to:

• Avoid preparing food for other individuals until diarrhea has resolved.
• Avoid sex (vaginal, anal, and oral) or use a barrier (condom, dental dam) for two weeks after resolution of diarrhea.
• Avoid swimming while symptomatic with diarrhea.
• Always wash hands thoroughly with soap and water for at least 20 seconds before eating or preparing food, after using the toilet, and after changing diapers.
• After changing diapers, wash your hands and the child’s hands for at least 20 seconds. Clean and sanitize diaper changing stations/areas often.
  • In child care and other institutional settings, dispose of stool and soiled diapers/linens in a sanitary manner.
• Avoid fecal contact, including sexual practices that may involve direct contact with feces. Latex barrier protection should be emphasized as a way to prevent the spread of Shigella to case’s sexual partners, as well as being a way to prevent the exposure to and transmission of other pathogens.

Managing special situations 

Food handlers 

When a known or suspected case of shigellosis occurs in a food handler, immediate involvement of public health authorities is critical.

• Definitions
  • "Exclude" means to prevent a person from working as an employee in a food establishment or entering a food establishment as an employee.
  • “Highly Susceptible Population” means people who are more likely than other people in the general population to experience foodborne disease — because they are immunocompromised, preschool-age children, or older adults — and they obtain food at a facility that provides services such as custodial care, health care, assisted living, child or adult day care center, kidney dialysis center, hospital, long-term care facility or nursing home, or nutritional or socialization services such as a senior center.
  • “Restricted duties" means to limit the activities of an employee so that there is no risk of transmitting a disease that is transmissible through food, and the food employee does not work with exposed food, clean equipment, utensils, linens, or unwrapped single-service or single-use articles.
• Food handlers who work in a food establishment predominantly serving a highly susceptible population must remain excluded until:
  • (A) Diarrhea has resolved for at least 24 hours without the use of anti-diarrheal medications 
    AND
  • (B) Adequate hygiene can be maintained, ideally as verified by environmental health 
    AND
  • (C) They have two consecutive negative stool tests collected at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given.
• Include your local environmental health specialist to determine if a facility is serving a highly susceptible population.
• Food handlers who work in an establishment not predominantly serving a highly susceptible population may return to work for restricted duties while doing return to work/child care testing if:
  • (A) At least 24 hours has passed since diarrhea resolved without the use of anti-diarrheal medications 
    AND
  • (B) Environmental health specialists and the case’s employer believe working with restricted duties is feasible.
    • If either Environmental Health or the employer do not believe working with restricted duties is feasible, follow the instructions for food handlers who work in a food establishment predominantly serving a highly susceptible population (above).
• The case may only return to regular (non-restricted duties) once they have two consecutive negative stool tests collected at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given.
• Additional details:
  • If the case’s confirmatory culture at the State Lab is negative, that negative counts as the first negative test to return to work.
  • A letter or memo should be sent to the food service facility documenting the requirements for the infected food handler (e.g., restricted duties, exclusion from facility). Letter templates can be requested from CDPHE.
  • Return to work testing is required even if the case was asymptomatic, or symptoms have since resolved.
  • During an outbreak, exclusion periods may be extended, additional testing may be required, and/or restricted duties may not be permitted.
• The Colorado Retail Food Establishment Regulations may require additional restrictions or disease control measures for the case, their close contacts, and/or their employer.
  • Consult with environmental health to determine if the case’s place of employment should enact additional disease control measures to be in compliance with the regulations.

Child care centers/preschools

When a case of shigellosis occurs in a child care center attendee or worker, immediate involvement of public health authorities is critical. Shigella spreads very quickly through child care centers, though it can be controlled if appropriate action is taken. 

Refer child care providers to the CDPHE Infectious Diseases in Child Care and School Settings for an overview of Shigella infections.

Children

• Children with shigellosis must be excluded from the child care center until the following criteria have been met:
  • (A) At least 24 hours after diarrhea has resolved without the use of anti-diarrheal medications 
    AND 
  • (B) Either the child has been treated with an effective antibiotic for 3 days OR they have two consecutive negative stool tests collected at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given.
    • It is important to obtain the antibiotic susceptibility pattern for the isolate from the physician or the clinical laboratory that performed the test in order to determine if a child has been treated with an effective antibiotic. If an antibiotic susceptibility test was not performed, the child must have two consecutive negative stool tests to return.
• Return to child care testing is required (as described above), even if the case was asymptomatic or symptoms have since resolved.
  • If the case’s confirmatory culture at the State Lab is negative, that negative counts as the first negative test to return to child care.
• Parents of cases should be counseled not to take their children to another child care center during this period of exclusion in order to avoid possible transmission of shigellosis at a new location.
• Determine whether additional children or staff are (or have recently been) ill with diarrheal illness.
• Other children or staff with diarrhea must be excluded and referred to their health care provider for stool testing and appropriate medical care.
• If others in the facility are identified with Shigella-like symptoms, refer to the Shigellosis Outbreak Investigation and Control in Child Care Centers/Preschools guidelines, and contact CDPHE for assistance.
  • If other cases in the center are identified, initiate an outbreak investigation, and consider sending a letter home to parents.
• If the case is the only person in the classroom or facility who has been ill, no further action is indicated for other children/staff in that classroom or center.
• Reinforce the importance of meticulous handwashing, proper sanitizing and disinfection, and proper diaper-changing technique with child care center staff. If possible, this should be verified by environmental health.
• Consult with CDPHE for instances in which children attend drop-in style care at gyms, churches, etc.

Staff

• Since many child care center staff assist with food preparation and/or feeding children, those with Shigella infection must be excluded from work until
  • (A) At least 24 hours after diarrhea has resolved without the use of anti-diarrheal medications 
    AND
  • (B) They have two consecutive negative stool tests collected at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given.
• In this situation, it is important for Environmental Health staff to work closely with the center to ensure that affected staff are excluded until cleared by public health. See section Food handlers above.
• Return to work testing is required, even if the case was asymptomatic or symptoms have since resolved.
  • If the case’s confirmatory culture at the State Lab is negative, that negative counts as the first negative test to return to work.
• Staff with no role in food preparation or feeding (e.g., office staff) may return to work after diarrhea has been resolved for at least 24 hours without the use of anti-diarrheal medications. Return to work testing is not required for these workers.
• Determine whether additional children or staff are (or have recently been) ill with diarrheal illness.
• Other children or staff with diarrhea must be excluded and referred to their health care provider for stool testing and appropriate medical care.
• If others in the facility are identified with Shigella-like symptoms, refer to the Shigellosis Outbreak Investigation and Control in Child Care Centers/Preschools guidelines, and contact CDPHE for assistance.
  • If other cases in the center are identified, initiate an outbreak investigation, and consider sending a letter home to parents.
• If the case is the only person in the classroom or facility who has been ill, no further action is indicated for other children/staff in that classroom or center.
• Reinforce the importance of meticulous handwashing, proper sanitizing and disinfection, and proper diaper-changing technique with child care center staff. If possible, this should be verified by environmental health.

Schools 

Refer school personnel to the CDPHE Infectious Diseases in Child Care and School Settings for an overview of Shigella infections. 

• Students or staff with shigellosis must be excluded until at least 24 hours after their diarrhea has resolved without the use of anti-diarrheal medications.
• Nursing staff or other school staff that provide medical care or administer medications must be excluded until
  • (A) At least 24 hours after their diarrhea has resolved without the use of anti-diarrheal medications 
    AND
  • (B) They have two consecutive negative stool tests collected at least 24 hours apart at least 48 hours after completion of antibiotics, if antibiotics are given. See section Patients and staff in health care facilities below.
• Students or staff who handle/prepare food for others must not prepare food until
  • (A) At least 24 hours after their diarrhea has resolved without the use of anti-diarrheal medications 
    AND
  • (B) They have two consecutive negative stool tests obtained at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given. See section Food handlers above.
• In the above two scenarios, return to work/school testing is required even if the case was asymptomatic, or symptoms have since resolved.
• If there are concerns about the case’s hygiene (e.g., the case has developmental disabilities and wears diapers) consider obtaining two consecutive negative stool tests collected at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given, before a case returns to school.
• During an outbreak, exclusion may be lengthened and additional testing may be required.

Community residential programs (including facilities serving the developmentally disabled)

Actions taken in response to a case of shigellosis in a community residential program will depend on the type of program and the level of functioning of the residents. In general: 

• Residents with shigellosis must be placed on contact precautions until
  • (A) At least 24 hours after their diarrhea has resolved without the use of anti-diarrheal medications 
    AND
  • (B) They have two consecutive negative stool tests collected at least 24 hours apart at least 48 hours after completion of antibiotics, if antibiotics are given.
• Residents and staff with shigellosis must be excluded from handling or preparing food for other residents until
  • (A) At least 24 hours after their diarrhea has resolved without the use of anti-diarrheal medications 
    AND
  • (B) They have two consecutive negative stool tests collected at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given.
• For staff members who provide direct patient care (e.g., feed patients, give mouth or denture care, or give medications) follow guidelines for staff in health care facilities below.
• In these scenarios, return to work testing is required even if the case was asymptomatic, or symptoms have since resolved.
• Staff members with Shigella infection who are not food handlers and do not provide direct patient care must be excluded from work until at least 24 hours after their diarrhea has resolved without the use of anti-diarrheal medications. Return to work testing is not required for these workers.
• During an outbreak, exclusion may be lengthened and additional testing may be required.

Patients and staff in health care facilities (including hospitals, medical and dental clinics, skilled nursing and long-term care facilities)

Hospitals and skilled nursing and long-term care facilities may have written infection control policies and procedures for handling cases of communicable disease among patients and staff members. 

If a facility’s policies are more strict than the guidance below, they can follow those. Otherwise:

• Patients with shigellosis must be placed on contact precautions until
  • (A) At least 24 hours after their diarrhea resolves
    AND
  • (B) They have two consecutive negative stool tests collected at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given.
• Health care workers who provide direct patient care or handle medications (e.g., pharmacists) must be excluded from work until
  • (A) At least 24 hours after their diarrhea has resolved without the use of anti-diarrheal medications 
    AND
  • (B) They have two consecutive negative stool tests collected at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given.
• Return to work testing is required, even if the case was asymptomatic or symptoms have since resolved.
• If the case’s confirmatory culture at the State Lab is negative, that negative counts as the first negative test to return to providing direct patient care.
• Health care workers who do not provide direct patient care can return at least 24 hours after their diarrhea has resolved without the use of anti-diarrheal medications. Return to work testing is not required for these workers.
• Depending on the type of health care facility, it may be possible for a health care worker who normally does direct patient care to return to work for restricted duties while doing return to work testing if
  • (A) At least 24 hours has passed since after diarrhea has resolved without the use of anti-diarrheal medications
    AND
  • (B) The case’s employer believes working with restricted duties is feasible.
• They may only return to regular (non-restricted duties) once they have two consecutive negative stool tests collected at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given.
  • “Restricted duties" means to limit the activities of the health care worker so that there is no risk of passing on a disease that is transmissible through direct patient care or the handling of medications. Specifically, the health care worker does not put hands directly on a patient, including but not limited to: taking vitals, performing an exam, or administering vaccinations or handling medications or clean equipment that will be used by staff or patients.
  • Examples of restricted duties may include:
    • Checking patients in at the front desk
    • Calling patients to share lab results
    • A pharmacist handling only sealed packaged/bottled medications, but not compounding medication/administering vaccines/counting pills
• A letter or memo should be sent to the health care facility documenting the requirements for the infected health care worker (e.g., restricted duties, exclusion from facility). Letter templates can be requested from CDPHE.

Environmental measures

• Food items prepared by cases must be removed from the environment.
• A decision about testing suspect/implicated food items must be made in consultation with CDPHE.
  • The general policy of the State Lab and the Communicable Disease Branch is only to test food samples associated with outbreaks, not in single cases. 

Back to top

American Academy of Pediatrics. Red Book: 2024-2027 Report of the Committee on Infectious Diseases, 33rd Edition. Illinois, Academy of Pediatrics, 2024.  

CDC Website: www.cdc.gov (click on “Diseases and Conditions”) 

Centers for Disease Control and Prevention (CDC). FoodNet Fast: Pathogen Surveillance Tool. Atlanta, Georgia: U.S. Department of Health and Human Services. Available from URL: http://wwwn.cdc.gov/foodnetfast. Accessed May 21, 2025.

Centers for Disease Control and Prevention. National Notifiable Diseases Surveillance System (NNDSS) Annual Summary Data for years 2016-2022, United States, CDC WONDER online database. Accessed at http://wonder.cdc.gov/nndss-annual-summary.html on May 22, 2025.

Heymann DL, ed. Control of Communicable Diseases Manual, 21st Edition. Washington, DC, American Public Health Association, 2022.

Hoffman RE, Shillam PJ. The use of hygiene, cohorting, and antimicrobial therapy to control an outbreak of shigellosis. Am J Diseases Children. 1990;144:219-221.

Nelson JD, Kusmiesz, H, Jackson LH, Woodman E. Trimethoprim-sulfamethoxazole therapy for shigellosis. JAMA. 1976;235:1239-1243.

Shigellosis (Shigella spp.) 2017 Case Definition | CDC. (n.d.). https://ndc.services.cdc.gov/case-definitions/shigellosis-2017/

Back to top

CDPHE Communicable Disease Branch

• Phone: 303-692-2700 or 800-866-2759
• Fax: 303-782-0338
• After hours: 303-370-9395

CDPHE Lab Coordinators: 

• Email (preferred): cdphe_labcoordinators@state.co.us  
• Phone: 303-692-3069

Back to top