What are the other Names for this Condition? (Also known as/Synonyms)
- Bacillary Dysentery
- Japanese Dysentery
- Shigella Gastroenteritis
What is Shigellosis? (Definition/Background Information)
- Shigellosis is an acute, foodborne, gastrointestinal illness caused by a group of bacteria called shigella
- Infected people suffer from mild abdominal discomfort, or have a full-blown dysentery
Who gets Shigellosis? (Age and Sex Distribution)
- Shigellosis is an infectious disease that spreads when people come into close contact with each other
- Any individual is likely to be infected by Shigellosis, but infants and children have a higher risk
What are the Risk Factors for Shigellosis? (Predisposing Factors)
The following are the risk factors for Shigellosis:
- Group housing or group activities: Shigellosis spreads faster when people are in close contact with each other while working or residing together. Hence, children in childcare centers, individuals at nursing homes, jails, and military barracks have a high risk
- International travelers to certain countries, where the sanitation facilities are poor
It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.
Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.
What are the Causes of Shigellosis? (Etiology)
Shigellosis is an acute, foodborne, gastrointestinal illness caused by a group of bacteria called shigella. The bacteria can spread from an infected person, or through contaminated water and food, directly to another person. This may also happen:
- When hands are not properly washed after changing the diaper of an infected child
- Through hand-to-mouth infection
- Shigellosis is transmitted through fomites (inanimate objects that are capable of spreading infection) and mechanical vectors like houseflies
What are the Signs and Symptoms of Shigellosis?
Onset of symptoms occurs between 1-7 days after coming in contact with the bacteria. The signs and symptoms of Shigellosis include:
- Sudden onset of abdominal pain (with stomach cramps) or cramping rectal pain
- Diarrhea containing blood or mucus
- Nausea and vomiting
How is Shigellosis Diagnosed?
Diagnosis of Shigellosis is established through:
- Physical examination with evaluation of medical history
- A stool sample is taken to the laboratory for testing and confirming the presence of Shigella bacteria or their toxins
Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.
What are the possible Complications of Shigellosis?
In most cases, Shigellosis resolves without any treatment. Symptomatic treatment with replacement of lost fluids and electrolytes are necessary. Complications from the disease may include:
- Dehydration: Continuous diarrhea may lead to dehydration characterized by lightheadedness, dizziness, lack of tears in children, sunken eyes, and dry diapers. Severe dehydration may result in shock and death
- Seizures: Some children who have very high fever during a Shigella Infection can have seizures (febrile)
- Rectal prolapse: Straining during bowel movement may cause the mucus membrane/lining of the rectum, to move out through the anus
- Hemolytic uremic syndrome: This rare complication may lead to low red blood cell count (hemolytic anemia), low platelet count (thrombocytopenia), and acute kidney failure
- Toxic megacolon: The colon gets paralyzed resulting in bowel disturbances. The patient experiences abdominal pain, distension, fever, and weakness. If left unattended, the colon may rupture causing peritonitis; a serious complication which might require surgical resolution
- Reactive arthritis: This complication involves the joints, eyes, and urinary tract. The patient may have joint inflammation and pain (arthritis); redness, itching, and discharge from the eyes (conjunctivitis); and painful urination (urethritis)
How is Shigellosis Treated?
The main treatment course involves replacing the fluids lost due to fever and diarrhea. The following points are vital with respect to treating Shigellosis:
- Fluid replacement is mainstay of the treatment. Drinking lots of fluids is usually sufficient for healthy adults, to minimize dehydration and diarrhea effects
- Oral rehydration solutions (Pedia-lyte) are recommended for children
- Fluid replacement should be made intravenously (rather than orally)to dehydrated children and adults, on an emergency basis
- Over the counter anti-diarrheal medications like loperamide (Imodium) and prescription medications like diphenoxylate with atropine, should be avoided as this may prolong the course of the disease
- Administering antibiotics reduces the duration of the illness, but it is recommended only when the infection is very severe
- Antibiotics are also recommended for infants, elderly adults, and people with weakened immune system (those suffering from HIV infection, cancer)
How can Shigellosis be Prevented?
No vaccinations are currently available to prevent the condition. However, the following preventive measures can be adopted to minimize the spread of Shigellosis infection:
- Washing hands thoroughly (as frequently as necessary); children must be taught to wash their hands properly
- Proper disposal of the soiled diapers minimizes the risk of the condition
- If a child is diagnosed with Shigellosis, cleaning and disinfecting the diaper changing stations/areas (like in public restrooms) after use, is very important
- Avoid sending infected children to schools, childcare, and public play areas
- Always drink clean and treated water; avoid drinking water from ponds, lakes, and other unverified sources
What is the Prognosis of Shigellosis? (Outcomes/Resolutions)
- In most cases, individuals with Shigellosis recover completely from the infection with no complications
- But, in those with weakened immune system or with HIV infection, the prognosis depends on how soon the treatment starts
- Diarrheal diseases have been the major cause for the death of young children in the world. When the patient develops complications, like hemolytic uremic syndrome, the prognosis depends on the support care systems (like provision of dialysis)
- Generally, the prognosis for Shigellosis depends on: Duration of the disease, fluid rehydration, strength of immune system, complications that develop, and time of treatment (meaning when it is provided)
Additional and Relevant Useful Information for Shigellosis:
According to WHO, there have been Shigellosis outbreaks in many African countries during the last decade. Many deaths have occurred and populations of several thousand affected during such outbreaks.