Alerts and Notices
SynopsisShigellosis, or bacillary dysentery, is an infectious disease caused by the Gram-negative bacteria Shigella, a member of the Enterobacteriaceae family.
Shigella is transmitted through fecal-to-oral contact or by ingestion of contaminated food or water. Contamination occurs when an infected person prepares food without washing their hands or when food or water is exposed to other contaminated foods, sewage, or infected flies. A very small inoculum of 50-100 bacilli can cause infection.
One to three days after exposure, the patient will present with fever, crampy abdominal pain, and voluminous watery diarrhea. Dehydration may occur. This may proceed to dysentery with bloody diarrhea, tenesmus, rectal ulcerations, and constitutional symptoms. Without treatment, the illness can last up to 30 days, although the average is 7 days.
In the United States, an estimated 500 000 cases occur annually. Two-thirds of the cases of shigellosis in the United States are caused by Shigella sonnei and the remainder by Shigella flexneri. Infection with S flexneri may result in reactive arthritis (Reiter syndrome), a chronic autoimmune condition producing arthralgia, eye problems, and dysuria.
International travelers are at increased risk for infection with multidrug-resistant Enterobacteriaceae, and the US Centers for Disease Control and Prevention (CDC) reports that, due to repeated importation by travelers, ciprofloxacin-resistant S sonnei is now circulating domestically in the United States. There have been reports of strains with reduced susceptibility to azithromycin in New York City. In 2022, 5% of Shigella infections reported to the CDC were classified as extensively drug resistant (XDR) to all commonly recommended empiric and alternative antibiotics (azithromycin, ciprofloxacin, ceftriaxone, trimethoprim-sulfamethoxazole [TMP-SMX], and ampicillin); an increase from 0% in 2015.
There is no vaccine against shigellosis. The CDC has designated it a possible bioterrorism agent (food safety threat).
People at higher risk for contracting shigellosis are residents of dormitories, nursing homes, reservations, and military camps, as well as children in day care centers. Other specific populations at risk include Orthodox Jews, international travelers, HIV-infected patients, and men who have sex with men.
A03.9 – Shigellosis, unspecified
36188001 – Shigellosis
Differential Diagnosis & PitfallsInfectious causes of diarrhea:
- Bacterial – Vibrio cholera, Salmonella, Campylobacter, Yersinia, Shiga toxin-producing E coli, Clostridioides difficile
- Parasitic – Giardia, Cryptosporidium, Entamoeba histolytica
- Viral – norovirus, rotavirus
- Inflammatory bowel disease (eg, Crohn disease, ulcerative colitis)
- Celiac sprue
- Ischemic bowel disease
- Ricin poisoning
Patient Information for Shigellosis
OverviewShigellosis is an infectious disease in the intestines that is caused by the bacteria Shigella. This infection results in bloody diarrhea and can be passed to others through contact with infected fecal matter. This can happen when an infected person prepares food without hand washing.
Who’s At RiskToddlers have a high risk of contracting the disease. Also, crowded spaces such as day care centers, schools, nursing homes, and hospitals increase the chances for the disease to spread. In addition, traveling to areas with poor sanitation increases the risk of contracting this disease. Men who have sex with men have a higher risk of exposure due to oral-anal contact.
Signs & SymptomsThe symptoms of shigellosis typically begin 1-2 days after initial exposure. These symptoms include diarrhea that is often bloody, abdominal pain, and fever.
Self-Care GuidelinesThere is no vaccination for shigellosis. However, there are steps you can take to limit your chances of contracting this disease. Carefully wash your hands prior to eating, cooking, and after changing diapers. Avoid swallowing water from untreated bodies of water such as ponds and lakes. In addition, always follow safety precautions for water when traveling internationally.
When to Seek Medical CareSeek medical care if you cannot drink enough fluids to replace the lost fluids from diarrhea. Children with shigellosis may have convulsions. If your child has a seizure, seek medical care for them immediately.
TreatmentsTreatment focuses on replacing fluids and electrolytes. Children can be given an oral rehydration solution such as Pedialyte. If you are extremely dehydrated, hospitalization with IV fluids may be necessary. For severe cases of shigellosis, antibiotics may shorten the duration of the virus.