| An infection is defined as the presence and growth of a microorganism that produces tissue damage. Such microorganisms are called pathogens. The pathogen can be bacterial, viral, or fungal in nature. The extent of infection varies depending on the number of microorganisms, their ability to cause illness (virulence), and the body's ability to defend against them. Tissue damage can occur directly or from substances produced by the organism (e.g., toxins and enzymes). Localized infections affect one particular tissue or area of the body, whereas systemic infections affect the whole body.
Infections can be acquired in many different ways. Pathogens can be consumed (clostridium botulism, Salmonella) or inhaled (influenza virus, mycobacterium tuberculosis). In addition, some pathogens acquire access to the body by penetrating the skin or mucous membranes (Neisseria gonorrhoeae, HIV, bacteria that cause conjunctivitis). Sometimes organisms not usually harmful move from a part of the body where they normally exist to another part of the body where they can cause damage. For example, the bacteria E. coli is a normal inhabitant of the intestinal tract but causes serious illness if ingested or located in the urinary tract.
Many infections can spread from individual to individual in several ways. Airborne pathogens are discharged into the air from the respiratory tract of an infected individual through coughing or sneezing. They may be inhaled or settle on another individual, clothing, walls, or floors and then be transmitted by direct contact, which includes kissing and sharing utensils. Other pathogens can live on or in the bodies of individuals who do not experience symptoms but transmit the pathogens to others (carriers). Prenatal infection occurs when the mother passes an infection to her baby during pregnancy, either through the placenta or from contact with maternal membranes. Infections can also spread through insect vectors (such as mosquitoes or ticks), through animal carriers (by direct or indirect contact), on food (due to bacteria from the soil or from fertilizer), when soil enters the body through wounds (tetanus, gangrene), or through a contaminated water supply (typhoid, dysentery, or cholera).
Certain factors increase the risk of acquiring an infection, including injury (trauma), surgery, a defect in the body's natural defense system (immune compromise), and age.Risk: The very young and the elderly are at increased risk, compared to the rest of the population. |
Source: Medical Disability Advisor
| History: Symptoms of an infection vary greatly, depending on the primary site of infection. For example, meningitis is associated with headache, stiffness, and pain in the neck and involves difficulty turning and bending the head, whereas appendicitis is associated with pain in the lower abdomen and involves nausea and vomiting. Symptoms of an upper respiratory infection may include headache, cough, and nasal discharge. Symptoms of a gastrointestinal infection may include nausea, vomiting, and diarrhea. The common cold is a systemic viral infection with symptoms that may include fever, aching muscles (myalgias), and a vague feeling of discomfort or illness (malaise). Physical exam: Physical examination findings depend on where the infection is located. When examined by touch (palpated), the area around a local infection may feel warm. Touching the area may elicit pain. In general, the affected area may be red, warm, and/or tender. Discharge from an abscess may be present. A systemic infection may not cause any specific physical abnormalities. Diagnosis may rely on history, symptoms, and testing. Vital signs, including pulse, blood pressure, respiration, and temperature, may be affected. Tests: A complete blood count (CBC) with differential or an erythrocyte sedimentation rate can indicate the presence of an infection irrespective of its site. Examining the stool for white blood cells may indicate an infectious process if it involves the gastrointestinal tract. A microbial culture of an infected site often identifies the organism responsible for the infection.
Based on the location of an infection, tests that assess the extent of the infection include chest x-ray, abdominal ultrasound, sinus films, CT, spinal tap, or MRI. Fluid from an infected site should be obtained whenever possible for culture and sensitivity, especially before antibiotics are started, to optimize the opportunity for a positive culture. This may involve removal (aspiration) of the fluid with a needle and syringe. |
Source: Medical Disability Advisor
| Rest and adequate fluid intake are important factors in the recovery from any infection. Individuals with pain or muscle aches may need pain-relieving medicine (analgesics). Those with fever may require fever-reducing medicine (antipyretics). Other treatments vary, depending on the responsible pathogen and the tissues or organ systems involved.
A bacterial infection is treated with an antibiotic. The specific antibiotic used is either chosen based on experience (empirically) or on the sensitivity of the organism to different antibiotics used in the bacteriology laboratory. If the infection has become walled off (abscess), it is usually cut open (incised) and allowed to drain. Severe bacterial infections (e.g., meningitis) may require intravenous antibiotic administration.
A viral infection may or may not be treated with an antiviral medication. It is difficult to design drugs that kill the virus without also killing the cells they live in. Therefore, treatment of viral infections depends largely on relieving the symptoms while relying on the body's own defense system to eradicate the virus. If the individual has a defective immune system (immunocompromised), more aggressive therapy may be necessary.
Fungal infections are treated with antifungals based on the location of the infection. Skin and nail fungal infections are generally treated with antifungal creams or lotions applied to the skin. Antifungal drugs are also available in tablet, lozenge, suspension, vaginal suppositories, and injection forms. Fungal infections in immunocompromised individuals may require antifungal drugs administered intravenously (IV). |
Source: Medical Disability Advisor
| Infections can usually be controlled by appropriate antibiotic therapy but can be fatal. Complications increase the risk of disability and death. The very young and the elderly are at increased risk of complications from infections. If the individual is immunocompromised, recovery is slower with an increased risk of death due to the underlying disease.
Some infections are incurable and may become chronic and controlled to a variable degree. |
Source: Medical Disability Advisor
| Infection can cause death to body tissue (necrosis), requiring removal of tissue or amputation of that body part. Infections can create life-threatening diseases, including but not limited to pneumonia, meningitis, encephalitis, botulism, tetanus, typhoid, and cholera. An infection can also spread beyond the local area of involvement and into the bloodstream, causing a potentially fatal condition known as sepsis or bacteremia. |
Source: Medical Disability Advisor
| Accommodations may include additional sick leave to allow the individual to rest and prevent transmission to coworkers. Restrictions will vary, depending on the nature of the infection and the job requirements of the individual. For example, a chef with an upper respiratory infection should not prepare food, and a nurse with the flu should avoid patient contact.
In some cases, complications may result in permanent disability (e.g., gangrene resulting in amputation). Some infections are incurable and become chronic (HIV, herpes). |
Source: Medical Disability Advisor
| If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case. Regarding diagnosis:
- Was pathogen inhaled or ingested? Did it penetrate the skin or mucous membrane or move from one part of the body to another?
-
Was an insect vector or animal carrier involved? Was the water supply contaminated?
-
Has individual recently had an injury or surgery?
-
Is individual immunocompromised?
-
Where is individual's infection? What symptoms does individual have?
-
On exam, is the area tender to palpation? Is the area warm?
-
Was the exam normal?
-
Has individual had a CBC, with differential and erythrocyte sedimentation rate? Have a culture and sensitivity of the affected area been done?
-
Depending on the location of the infection, has a chest x-ray been done? Ultrasound? Other x-rays? CT or MRI? Spinal tap?
-
Have conditions with similar symptoms been ruled out?
Regarding treatment:
- Has individual received rest, fluids, analgesics, and antipyretics, as needed?
-
Is infection bacterial? Has individual been treated with the appropriate antibiotic?
-
Is infection viral? Has individual received appropriate treatment?
-
Is infection fungal? Has individual been treated with the appropriate antifungal medication?
-
Were comorbidities appropriately managed?
-
Were preventive techniques instituted to diminish likelihood of spread of the infection?
Regarding prognosis:
- Can individual's employer accommodate any necessary restrictions?
-
Does individual have any conditions that may affect ability to recover?
-
Have any complications occurred, such as necrosis, sepsis, or bacteremia, that may affect recovery?
|
Source: Medical Disability Advisor
| Mayo Clinic Staff. "From Bacteria to Parasites: Understanding the Germs that Cause Infection." MayoClinic.com. 22 Apr. 2005. Mayo Foundation for Medical Education and Research. 20 May 2005 <http://www.mayoclinic.com/invoke.cfm?objectid=4AB9865B-F003-4EA8-8035101E82FDFF71>. |
Source: Medical Disability Advisor
| Feedback |
| Send us comments, suggestions, corrections, or anything you would like us to hear. If you are not logged in, you must
include your email address, in order for us to respond. We cannot, unfortunately, respond to every comment.
If you are seeking medical advice, please contact your physician. Thank you! |
Send this comment to:
Sales
Customer Support
Content Development
|
|
| |
|
|
|
|
|
This publication is designed to provide accurate and authoritative information in
regard to the subject matter covered. It is published with the understanding that
the author, editors, and publisher are not engaged in rendering medical, legal,
accounting or other professional service. If medical, legal, or other expert assistance
is required, the service of a competent professional should be sought. We are unable to respond to requests for advice.
Any Sales inquiries should include an email address or other means of
communication.
|