The accidental or hostile exposure of individuals to ionizing irradiation is of great public and military concern. Radiation sickness (acute radiation syndrome, or ARS) occurs when the body is exposed to a high dose of penetrating radiation within a short period of time. Systemic infection is one of the serious consequences of ARS. There is a direct relation between the magnitude of radiation exposure and the risk of developing infection. The risk of systemic infection is higher whenever there is a combined injury such as burn or trauma. Ionizing radiation enhances infection by allowing translocation of oral and gastrointestinal flora, and reducing the threshold of sepsis due to endogenous and exogenous microorganisms. The potential for concomitant accidental or terrorism-related exposure to bio-terrorism agents such as anthrax and radiation also exists.

This site is made of a home page that presents new developments and updates on the management of acute radiation syndrome including concomitant exposure to radiation and anthrax. Separate pages are dedicated to the treatment modalities.

Prevention of Infections in Humans

           

Nuclear War. Painted by Itzhak Brook in 1957


 Initial care of medical casualties with moderate and severe radiation exposure should include early institution of measures to reduce pathogen acquisition from the environment, with emphasis on food with low microbial content, clean water supplies, frequent hand washing (or wearing of gloves), and air filtration. ( Bland SA. Mass casualty management for radiological and nuclear incidents. J R Army Med Corps. 2004;150 (3 Suppl 1):27)

          
   Prophylactic use of selective gut decontamination with antibiotics that suppress aerobes but preserve ordinarily commensal anaerobes is recommended. Antibiotic prophylaxis should be considered only in afebrile patients who are at the highest risk for infection because of exposure to a high dose of radiation over 1.5 Gy. The quinolones (e.g., ciprofloxacin, levofloxacin) are used for selective decontamination. However, the use of pefloxacin for selective decontamination or therapy of post-irradiation sepsis is not recommended because its use in irradiated mice increases their mortality rate due to suppression of granulocyte-macrophage progenitor cells. ( Patchen et al. Adverse effects of pefloxacin in irradiated C3H/HeN mice: correction with glucan therapy. Antimicrob Agents Chemother; 37:1882, 1993).
               The disadvantage of using quinolones for selective decontamination is that they are absorbed and distributed throughout the body. This may generate systemic side effects and promote antimicrobial resistance.  ( Ng et al. Fluoroquinolone prophylaxis against febrile neutropenia in areas with high fluoroquinolone resistance--an Asian perspective. J Formos Med Assoc
. 2010 ;109:624).
The development of such resistance may interfere with the potential use of the quinolones if a systemic infection develops. An alternative approach is the use of non-absorbable antibiotics such as polymyxin, neomycin, and bacitracin. Because these agents are not used for therapy, their use for prophylaxis does not generate resistance.
Measures that help prevent infections of an alimentary tract source (mouth, esophagus, and intestines) following exposure to irradiation include the maintenance of gastric acidity (avoidance of antacids and H2 blockers). This measure may prevent bacteria from colonizing and invading the gastric mucosa and may reduce the frequency of nosocomial pneumonia due to their aspiration. The use of sucralfate or prostaglandin analogues can prevent gastric hemorrhage without decreasing gastric activity.
To maintain the immunologic and physiologic integrity of the gut, an early oral immunoincompetent diet is preferred to intravenous feeding. A subcutaneously tunneled central venous catheter may be needed to allow frequent venous access, but meticulous attention to proper care is necessary to reduce catheter-associated infections, which could become life-threatening.
 Wounds and burns ( including irradiation burn ) should be treated by debridedment and cleaning and  covered by a clean, dry dressing as soon as possible to prevent infection. Application of topical antimicrobials may be useful in preventing local and systemic infections.