Shigella outbreak in Fond du Lac

Parents of children who attend Roberts Elementary School in Fond du Lac, Wisconsin, received letters this week regarding a Shigella outbreak at the school.  At least 14 people have become ill with shigellosis since the outbreak began, and parents were warned of the symptoms of Shigella infection and were asked to keep kids home from school and daycare if they exhibit symptoms of the illness. 

According to the Fond du Lac Reporter, all cases reported so far involve children, their household contacts, or daycare and school staff. 

Symptoms of Shigellosis:

Most people who are infected with Shigella develop diarrhea, fever, and abdominal cramps. Severity of the disease ranges from mild to very severe diarrhea. Diarrhea is bloody 25-50% of the time and most often contains mucus. Rectal spasms, medically termed "tenesmus," are common. The illness starts 12 hours to 6 days, usually 1-2 days, after exposure. Dehydration is also a common symptom of Shigella infection.

Shigellosis is more severe than other forms of gastroenteritis. This is because when Shigella bacteria multiply in the human gut they invade cells and result in much tissue destruction. Also, many strains produce a toxin called "shiga toxin" which is very potent and destructive. Shiga toxin is very similar to the verotoxin of E. coli O157:H7.

Complications of shigellosis include severe dehydration, seizures in small children, rectal bleeding, and invasion of the blood stream by the bacterium.  In addition, up to 3% of persons who are infected with Shigella may later develop a syndrome that includes joint pain and swelling, irritation of the eyes, and sometimes painful urination. This is a reaction to the previous gastroenteritis and is called “reactive arthritis” or Reiter's Syndrome.

Shigella cases increase in Mississippi

The Associated Press reported that Mississippi is experiencing an increase in the number of Shigella cases reported in comparison to last year's numbers.  According to the Mississippi Department of Health, at least 103 people have been confirmed ill with Shigellosis in Harrison, Hancock, Jackson, Pearl River, Stone, and George Counties.

The spread of Shigella from an infected person can be stopped by frequent and careful hand washing with soap and water. The ill individual should practice this, as well as any contacts. Supervised hand washing of all children should be followed in day care centers and as soon as children return home. Young children with a Shigella infection, or with diarrhea of any cause, should not be in contact with uninfected children.

If a child in diapers has shigellosis, everyone who changes the child's diapers should be sure the diapers are disposed of properly in a closed-lid garbage can, and should wash his or her hands carefully with soap and warm water immediately after changing the diapers. After use, the diaper changing area should be wiped down with disinfectant, such as household bleach or bactericidal wipes.

At swimming pools, maintaining a chlorine level of at least 0.5-PPM will kill Shigella. At swimming beaches, children not yet toilet trained should be excluded from public swimming areas; stay clear if this rule is broken. Children with diarrhea should never be taken to public swimming areas.

Basic food safety precautions will also help to prevent shigellosis. Shigella organisms are killed by heat used in cooking. People who have shigellosis or any diarrhea should not prepare food for others until they have been shown to no longer be carrying the bacterium.

Drink water only if it has been chlorinated (most tap water) or treated with ozone (most bottled water) and then you know it will not contain pathogenic bacteria. Consume only pasteurized dairy products.

In the developing world, shigellosis is far more common and is present in most communities most of the time. Simple precautions taken while traveling to the developing world can also prevent getting shigellosis. Drink beverages only if they are imported (e.g. Evian), carbonated (e.g. cola - without ice), boiled (e.g. coffee) or have been in contact with alcohol for a prolonged period (e.g. wine or beer, not mixed drinks). Eat a cooked diet with the exception of fruits you peel yourself.