Signs and Symptoms of Shigella Infection

Signs and symptoms

People with Shigella infection (shigellosis) usually start experiencing symptoms 1 to 2 days after contact with the germ. These symptoms include:

• Diarrhea that can be bloody or prolonged (lasting more than 3 days)
• Fever
• Stomach pain
• Feeling the need to pass stool (poop) even when the bowels are empty

Some people will not have any symptoms.

Symptoms usually last 5 to 7 days, but some people may experience symptoms anywhere from a few days to 4 or more weeks. In some cases, it may take several months before bowel habits (for example, how often someone passes stool and the consistency of their stool) are entirely normal.

When to talk to your doctor

People with diarrhea should contact their doctor if they have any of these symptoms:

• Fever
• Bloody or prolonged diarrhea
• Severe stomach cramping or tenderness
• Dehydration

People who are in poor health or whose immune systems are weakened from diseases (such as HIV) or medical treatments (such as chemotherapy for cancer) are more likely to get sick for a longer period of time. Contact your doctor if you are in one of these groups and have symptoms of Shigella infection (shigellosis).

Learn more about treatment.

Rare risks

Reactive arthritis

About 2%^1-4 of people who are infected with certain types of Shigella, most commonly Shigella flexneri, will experience reactive arthritis after infection, which can cause joint pain, eye irritation, and painful urination. The syndrome typically occurs in people who have specific genetic makeup that puts them at risk.^1,5-7 It usually lasts for 3 to 5 months, but occasionally it can last for years and lead to chronic arthritis.^8-9 Reactive arthritis can also occur in people who get sick from Shigella sonnei,^{6-7, 9-10} but is less common in other types of Shigella called S. boydii and S. dystenteriae.¹¹

Bloodstream infections

Around 0.4% to 7.3% of people with Shigella infection (shigellosis) develop bloodstream infections caused by Shigella germs or by other germs in the gut that get into the bloodstream when Shigella damages intestinal linings.^12,15 Bloodstream infections are most common among patients with weakened immune systems, such as those with HIV, diabetes, cancer, or severe malnutrition, and are more commonly seen in children.^12-15 Bloodstream infections are most commonly seen in infections caused by S. flexneri and S. dysenteriae.¹⁵ Shigellosis patients with bloodstream infections are at a higher risk of death compared to those without bloodstream infections.¹⁵

Seizures

Generalized seizures have been reported among young children with Shigella infection (shigellosis), but usually go away without treatment. Children with Shigella infection who experience seizures typically have a high fever, low blood sugar, or abnormal blood electrolytes (salts). However, healthcare professionals have not been able to definitively explain why these seizures occur.^16-21

Hemolytic-uremic syndrome

Hemolytic-uremic syndrome (HUS) is a rare complication of Shigella infections (shigellosis) that also most commonly occurs in children.^22-25 HUS occurs when bacteria enter the digestive system and produce a toxin that destroys red blood cells, which block kidneys' filtering function and can lead to kidney failure. Patients with HUS often have bloody diarrhea, and it can be a deadly complication. In patients with shigellosis, HUS is associated with Shiga toxin-producing Shigella, most often occurring with Shigella dystenteriae.^22-25 HUS can occur when antimicrobial resistant drugs are used to treat the infection or when treatment is started after 4 days of symptoms, and it is the leading cause of death in S. dysenteriae outbreaks.²³