The Vermont Health Department is investigating an outbreak of gastrointestinal illness at Wake Robin, a retirement community in Shelburne. Specimens from seven individuals have tested positive forShigella sonnei. More than 50 individuals associated with the facility, or with someone who lives or works at the facility, have reported symptoms consistent with shigellosis.
Consider Shigellosis When Evaluating Clinically Compatible Illnesses
Clinical manifestations of shigellosis range from watery or loose stools with minimal symptoms to more severe illness including high fever, abdominal cramps or tenderness, tenesmus, and mucoid stools with or without blood. Symptoms usually resolve in five to seven days but sometimes last for four or more weeks. Asymptomatic infection is possible.
Shigella bacteria are present in the stools of infected people while they have diarrhea, and for up to four weeks after symptoms resolve. The primary mode of transmission is fecal-oral, although transmission can also occur via contact with a contaminated fomite, ingesting contaminated food or water, or sexual contact. The incubation period is one to seven days, but is usually less than four days.
Report all suspected and confirmed cases to the Health Department’s Infectious Disease – Epidemiology program at 802-863-7240.
Test for Shigella
Clinicians who see patients with symptoms of shigellosis are encouraged to collect a stool specimen and have it tested for Shigella. Antibiotic resistance is relatively common, so susceptibility testing of clinical isolates is indicated to guide appropriate therapy. To date, testing of isolates associated with this outbreak has indicated susceptibility to Ciprofloxacin and resistance to Ampicillin and Trimethoprim-Sulfa. Hospital or reference laboratories in Vermont should forward Shigella isolates or original specimens to the Health Department Laboratory for further testing such as molecular subtyping (performed at no charge).
Submit specimens through the existing hospital courier service for receipt at Health Department Laboratory within 48 hours. Stool specimens should be collected and preserved in Cary-Blair medium. VDHL Kit #1 (which may be obtained at no charge by contacting theLaboratory’s Customer Service at 802-338-4724), or an appropriate culture specimen container (available from hospital laboratories) should be used for the collection and transport.
Treatment
Shigellosis is usually self-limited and treatment with antibiotics is not generally recommended in otherwise healthy adults with mild illness. However, antibiotics may be prescribed when warranted by the severity of the illness, underlying health conditions, or patient’s occupation. Anti-diarrheal medication that inhibits peristalsis, such as loperamide (e.g. Imodium) or diphenoxylate with atropine (e.g. Lomotil) are contraindicated and may prolong illness and increase the rate of complications.
Prevent New Cases
Strict attention to hand hygiene is essential to limit spread. Symptomatic children who attendday care should stay home until the Health Department says it’s safe to return. People with confirmed shigellosis who work as health care providers, child care workers or food handlers should be excluded from work until two consecutive negative stool cultures (collected 24 hours apart and at least 48 hours after discontinuation of antibiotics) have been documented.
Symptomatic people should not prepare food or share food with others. They should not swim and should not have sex (vaginal, anal, and oral) for one week after diarrhea has resolved.
Shigellosis Information for Clinicians
Resources for clinicians are available on the Health Department’s website:
http://www.healthvermont.gov/immunizations-infectious-disease/food-waterborne- diseases/shigellosis.
If you have questions, contact the Vermont Department of Health, Infectious Disease – Epidemiology program at 802-863-7240.