What are the other Names for this Condition? (Also known as/Synonyms)

• Abdominal Actinomycosis
• Actinomycosis of Abdominal Wall
• Gastric Actinomycosis

What is Digestive Tract Actinomycosis? (Definition/Background Information)

• Digestive Tract Actinomycosis is a rare, chronic bacterial infection of the abdominal wall and/or organs of the digestive tract, caused predominantly by the bacterium Actinomyces israelii, and to a lesser extent by other Actinomyces species
• They exist naturally in the mucous lining of the nose, throat, mouth, digestive tract, and female reproductive tract, and are not normally harmful. These anaerobic bacteria have the ability to grow in the absence of oxygen, or in reduced concentrations of oxygen
• However, any injury, trauma, or surgical procedure can cause the bacterial cells to enter deeper tissues, where they are not normally found. Since these bacteria can grow without oxygen, they can thrive in such environments, resulting in infection
• Digestive Tract Actinomycosis can occur as a consequence of infections, surgery, or ingestion of a foreign object, causing chronic pain, nausea, loss of appetite, and weight loss. This type is more common in adult men than women and children, and constitutes approximately 20% of all reported cases (of actinomycosis)
• The bacteria are slow-growing and the infection leads to the formation of hard, pus-filled abscess in the affected tissue. The abscess may drain and this can be accompanied by pain and fever
• The diagnosis of Digestive Tract Actinomycosis may involve imaging studies to ascertain areas of infection, as well as surgical removal of tissue sample for analysis and culture. The drainage from the abscess may be observed under the microscope to check for “sulfur granules”
• Prolonged treatment with antibiotics is necessary to remove the infection. In some cases, the abscess may need to be surgically drained or removed
• With prompt diagnosis and sustained treatment, Actinomycosis of Digestive Tract is curable. However, if the infection becomes generalized via spread of bacteria through the bloodstream, it can spread to other organs and tissues. In such cases, the recovery can be prolonged 

Who gets Digestive Tract Actinomycosis? (Age and Sex Distribution)

• Digestive Tract Actinomycosis is a very rare infection affecting the organs of the abdomen and the abdominal wall
• Approximately, one-fifth of all reported cases of actinomycosis affect the tissues and organs of the digestive tract
• The infection occurs worldwide in all age groups. However, adult men are more susceptible to the infection when compared to women and children

What are the Risk Factors for Digestive Tract Actinomycosis? (Predisposing Factors)

The risk factors for Digestive Tract Actinomycosis are as follow:

• Infection of an abdominal organ (such as appendicitis)
• Perforation of the appendix
• Surgery involving the abdominal organs
• Ingestion of foreign object(s)
• Compromised immunity owing to HIV/AIDS, organ transplantation, chemotherapy or radiation therapy

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s 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 Digestive Tract Actinomycosis? (Etiology)

Digestive Tract Actinomycosis is caused by anaerobic bacteria, belonging to the family Actinomycetaceae. These bacteria are gram-positive and can survive in very low concentrations of oxygen. The following are some bacterial species known to cause actinomycosis:

• Actinomyces israelii, which is responsible for majority of infections
• Actinomyces gerencseriae
• Actinomyces viscosus
• Actinomyces meyeri
• Actinomyces naeslundii

Under normal circumstances, the bacteria are present in the mucous lining of the mouth, throat, digestive system, and the female reproductive tract, without causing harm. However, the lining of the organs or walls of the abdomen may get damaged due to the following factors:

• Infection such as appendicitis
• Perforation of appendix, releasing its contents into the abdominal cavity
• Surgery such as to remove an inflamed appendix
• Ingestion of foreign objects such as chicken bone

Under such conditions, the bacteria enter the inner/deeper tissues:

• Being anaerobic, they can survive and multiply in the low oxygen conditions of deep tissue, causing the development of scar tissue and fistula (or abnormal tracts)
• Abscess formation can take place with the accumulation of pus, which may drain when the tracts reach the surface of skin. This process may take months to years
• The infection can occur in the esophagus, pancreas, liver, colon, cecum, and appendix

Note: Digestive Tract Actinomycosis is not a contagious infection, since the anaerobic bacteria are unable to survive outside the human body.

What are the Signs and Symptoms of Digestive Tract Actinomycosis?

The signs and symptoms of Digestive Tract Actinomycosis may vary depending on the site and severity of infection, and may include:

• Formation of an abscess in different sites of the abdomen, such as in the cecum, colon, appendix, liver, and pancreas
• Long-term pain in the abdomen
• Diarrhea or constipation
• Nausea and vomiting
• Weight loss, which can be severe

How is Digestive Tract Actinomycosis Diagnosed?

Digestive Tract Actinomycosis is diagnosed on the basis of the following test and exams:

• A thorough physical examination and assessment of symptoms
• Evaluation of the affected individual’s medical history
• Microscopic observation of drainage or tissue samples, to check for the presence of sulfur granules (which are round and yellow, and thus, named for their characteristic appearance and not because they contain sulfur). The tissue samples may have to be obtained surgically
• Culture of fluid or tissue from infected area: These bacteria are slow to grow in culture, and it may take over 3 weeks to obtain a (positive) culture result
• X-ray or computed tomography (CT) imaging to ascertain location and number of abscesses, as well as differentiate inflammatory masses due to infection from the tumors

Note: Digestive Tract Actinomycosis may mimic some malignant conditions, and therefore, ruling out other health conditions may be necessary to arrive at a final diagnosis.

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 Digestive Tract Actinomycosis?

The following are some potential complications from Digestive Tract Actinomycosis:

• Formation of large lesions
• The infection spreading to other organs away from the primary site of infection (such as resulting in meningitis, when the brain is affected)
• Jaundice

How is Digestive Tract Actinomycosis Treated?

Digestive Tract Actinomycosis may treated in the following manner:

• Through prolonged use of antibiotics (anywhere from 2 months to over 12 months); typically, β-lactam (such as penicillin, amoxicillin) or tetracycline family of antibiotics are used
• Surgical drainage of abscess; draining the abscess by inserting a needle
• Surgical removal of infected tissue:
  • Surgery is sometimes necessary for cases in which large abscesses have developed, the infection has spread to organs and bones, and antibiotics alone are unsatisfactory
  • Surgery creates an aerobic environment, which is detrimental to bacterial growth. It also allows for the excision of lesions, drainage of sinuses, as well as containment and elimination of the disease
• Hyperoxygen therapy to eliminate bacteria:
  • This therapy helps increase the concentration of oxygen in the infected tissues
  • The presence of oxygen results in higher amounts of oxygen-derived radicals that harm, and are specifically drawn to anaerobic organisms, such as Actinomyces
  • This method has only been approved as an adjunct to other forms of treatment

How can Digestive Tract Actinomycosis be Prevented?

Digestive Tract Actinomycosis can be prevented through adherence to the following factors:

• Educating oneself or monitoring self for any signs of discomfort following a surgery, and promptly reporting to the attending healthcare provider, so that infections may be detected early and treated appropriately
• Avoiding ingestion of foreign objects

Completing the full course of prescribed antibiotics regimen, to eliminate the infection causing bacteria from deep tissue, as well as to prevent relapse of infection and development of drug-resistant bacterial species.

What is the Prognosis of Digestive Tract Actinomycosis? (Outcomes/Resolutions)

If Digestive Tract Actinomycosis is diagnosed in a timely manner and treated promptly, the prognosis is positive, provided the overall health of the affected individual is generally good.

• However, the outcomes may be influenced by underlying medical conditions and/or compromised immunity
• Additionally, a lack of treatment may allow the infection to spread to other organs and tissues, which may prolong the treatment and recovery process

Additional and Relevant Useful Information for Digestive Tract Actinomycosis:

Actinomycosis commonly occurs in animals (mostly cattle) and rarely in humans. In cattle, the bacteria target areas around the head, especially the jaw, which gives rise to the name “big/lumpy jaw”.