question: Why is radiation poisoning contagious?
comment: Radiation poisoning isn't contagious--but it *does* destroy one's immune system, in severe cases. The reason they must be kept in isolation is because they'd die from the germs others brought to them.
passages: Section::::Cause of infection.
  
  Infections caused by ionizing radiation can be endogenous, originating from the oral and gastrointestinal bacterial flora, and exogenous, originating from breached skin following trauma. 
  
  The organisms causing endogenous infections are generally gram negative bacilli such as Enterobacteriaceae (i.e. "Escherichia coli, Klebsiella pneumoniae, Proteus" spp. ), and "Pseudomonas aeruginosa."
  
  Exposure to higher doses of radiation is associated with systemic anaerobic infections due to gram negative bacilli and gram positive cocci. Fungal infections can also emerge in those that fail antimicrobial therapy and stay febrile for over 7–10 days.
   Exogenous infections can be caused by organisms that colonize the skin such as "Staphylococcus aureus" or "Streptococcus" spp. and organisms that are acquired from the environment such as "Pseudomonas" spp. 
  
  Organisms causing sepsis following exposure to ionizing radiation:
  
  Section::::Principles of treatment.
   Infections caused by exposure to ionizing radiation can be extremely dangerous, and are of public and government concern. Numerous studies have demonstrated that the susceptibility of organisms to systemic infection increased following exposure to ionizing radiation. The risk of systemic infection is higher when the organism has a combined injury, such as a conventional blast, thermal burn, or radiation burn. There is a direct quantitative relationship between the magnitude of the neutropenia that develops after exposure to radiation and the increased risk of developing infection. Because no controlled studies of therapeutic intervention in humans are available, almost all of the current information is based on animal research.
   BULLET::::3. Neurovascular. This syndrome typically occurs at absorbed doses greater than , though it may occur at . It presents with neurological symptoms such as dizziness, headache, or decreased level of consciousness, occurring within minutes to a few hours, and with an absence of vomiting. It is invariably fatal.
  
  Early symptoms of ARS typically includes nausea and vomiting, headaches, fatigue, fever, and a short period of skin reddening. These symptoms may occur at radiation doses as low as . These symptoms are common to many illnesses, and may not, by themselves, indicate acute radiation sickness.
  
  Section::::Signs and symptoms.:Skin changes.
   BULLET::::1. Hematopoietic. This syndrome is marked by a drop in the number of blood cells, called aplastic anemia. This may result in infections due to a low amount of white blood cells, bleeding due to a lack of platelets, and anemia due to too few red blood cells in the circulation. These changes can be detected by blood tests after receiving a whole-body acute dose as low as , though they might never be felt by the patient if the dose is below . Conventional trauma and burns resulting from a bomb blast are complicated by the poor wound healing caused by hematopoietic syndrome, increasing mortality.
   Another cause is infection with Influenza A virus subtype H1N1 (and other subtypes of the Influenza A virus) and is then often associated with Monocytosis; H1N1 was responsible for the Spanish flu, the 2009 flu pandemic and in 2016 for the Influenza-epidemic in Brazil.
  
  Large doses of radiation, such as those involved with nuclear accidents or medical whole body radiation, may cause lymphocytopenia.
  
  Section::::Diagnosis.
  
  Lymphocytopenia is diagnosed when the complete blood count shows a lymphocyte count lower than the age-appropriate reference interval (for example, below 1.0 x 10(9)/L in an adult).
  
  Section::::Prognosis.
   Section::::Prevention.:Distance.
  
  Increasing distance from the radiation source reduces the dose according to the inverse-square law for a point source. Distance can sometimes be effectively increased by means as simple as handling a source with forceps rather than fingers. This could reduce erythema to the fingers, but the extra few centimeters distance from the body will give little protection from acute radiation syndrome.
  
  Section::::Prevention.:Shielding.
   The amount of time between exposure to radiation and the onset of the initial symptoms may be an indicator of how much radiation was absorbed. Symptoms appear sooner with higher doses of exposure. The symptoms of radiation sickness become more serious (and the chance of survival decreases) as the dosage of radiation increases. A few symptom-free days may pass between the appearance of the initial symptoms and the onset of symptoms of more severe illness associated with higher doses of radiation.
  
  Section::::Immediate effects.
   Note that the "bystander effect" is not the same as the "abscopal effect". The abscopal effect is a phenomenon where the response to radiation is seen in an organ/site distant to the irradiated organ/area, that is, the responding cells are not juxtaposed with the irradiated cells. T-cells and dendritic cells have been implicated to be part of the mechanism.
  
  In suicide gene therapy, the "bystander effect" is the ability of the transfected cells to transfer death signals to neighboring tumor cells.
   Signs and symptoms of radiation poisoning
  
  The symptoms of radiation poisoning includes a phenomenon where, following a dose of ionizing radiation, a person may have a period of apparent health, lasting for days or weeks, despite a terminal illness. The lag time of the effects of even severe radiation poisoning are a result of many biological processes, manifesting damage in different ways.
   The radiation generally occurs from a source outside the body, is applied over minutes with most of the body being exposed, and involves a total dose of greater than 0.7 Gy (70 rads). It is generally divided into three types: i) bone marrow syndrome (0.7 to 10 Gy); ii) gastrointestinal syndrome (10 to 50 Gy); and iii) neurovascular syndrome (50 Gy). Sources of such radiation may include nuclear reactors, cyclotrons, and certain devices used in cancer therapy. The cells that are most affected are generally those that are rapidly dividing. Diagnosis is based on a history of exposure and symptoms. Repeated complete blood counts (CBCs) can indicate the severity of exposure.
   Section::::"Walking Ghost phase".
   The “prodromal syndrome” is not a diagnosis, but the technical term used by health professionals to describe a specific group of symptoms that may precede the onset of an illness. For example, a fever is “prodromal” to measles, which means that a fever may be a risk factor for developing this illness.
  
  Section::::Radiation poisoning.:Bone marrow death.
   BULLET::::2. Gastrointestinal. This syndrome often follows absorbed doses of . The signs and symptoms of this form of radiation injury include nausea, vomiting, loss of appetite, and abdominal pain. Vomiting in this time-frame is a marker for whole body exposures that are in the fatal range above . Without exotic treatment such as bone marrow transplant, death with this dose is common. The death is generally more due to infection than gastrointestinal dysfunction.
   High radiation doses can cause DNA damage. If left unrepaired, this damage can create serious and even lethal chromosomal aberrations. Ionizing radiation can produce reactive oxygen species, which are very damaging to DNA.
   Section::::Diagnosis.
  
  Gastrointestinal symptoms occurring in a person who has had exposure to radiation need appropriate investigations to diagnose the nature and the extent of involvement. Symptoms such as diarrhea and painful defecation need to be systematically investigated and the underlying causes each carefully treated. 
  
  Proctitis is usually recognized by the macroscopic appearances on endoscopy (sigmoidoscopy or colonoscopy) and mucosal biopsy is not needed. Telangiectasia are characteristic and prone to bleeding.
  
  Section::::Treatment.
   Treatment is supportive with the possible use of antibiotics, blood products, colony stimulating factors, and stem cell transplant. Symptomatic measures may also be employed.
  
  Section::::Management.:Antimicrobials.
  
  There is a direct relationship between the degree of the neutropenia that emerges after exposure to radiation and the increased risk of developing infection. Since there are no controlled studies of therapeutic intervention in humans, most of the current recommendations are based on animal research.
   The treatment of established or suspected infection following exposure to radiation (characterized by neutropenia and fever) is similar to the one used for other febrile neutropenic patients. However, important differences between the two conditions exist. Individuals that develop neutropenia after exposure to radiation are also susceptible to irradiation damage in other tissues, such as the gastrointestinal tract, lungs and central nervous system. These patients may require therapeutic interventions not needed in other types of neutropenic patients. The response of irradiated animals to antimicrobial therapy can be unpredictable, as was evident in experimental studies where metronidazole and pefloxacin therapies were detrimental.
   Classically acute radiation syndrome is divided into three main presentations: hematopoietic, gastrointestinal, and neurological/vascular. These syndromes may or may not be preceded by a prodrome. The speed of onset of symptoms is related to radiation exposure, with greater doses resulting in a shorter delay in symptom onset. These presentations presume whole-body exposure and many of them are markers that are not valid if the entire body has not been exposed. Each syndrome requires that the tissue showing the syndrome itself be exposed. The gastrointestinal syndrome is not seen if the stomach and intestines are not exposed to radiation. Some areas affected are:
   Exposure to fungal species that secrete gliotoxin is common because airborne "Aspergillus" fungal spores are ubiquitous in many environments. Regular environmental exposure does not typically cause illness, but can cause serious infections in immunosuppressed individuals or those suffering from chronic respiratory illnesses. Infections caused by "Aspergillus" fungus are called aspergillosis. There are many types of aspergillosis, but infections typically affect the lungs or the sinuses.
   Section::::Diagnosis.
  
  Diagnosis is typically made based on a history of significant radiation exposure and suitable clinical findings. An absolute lymphocyte count can give a rough estimate of radiation exposure. Time from exposure to vomiting can also give estimates of exposure levels if they are less than 10 Gray (1000 rad).
  
  Section::::Prevention.
  
  Section::::Prevention.:Time.
   As the name implies, molluscum contagiosum is extremely contagious. Transmission of the molluscum contagiosum virus can occur many different ways including direct skin contact (e.g., contact sports or sexual activity), contact with an infected surface (fomite), or autoinoculation (self-infection) by scratching or picking molluscum lesions and then touching other parts of the skin not previously affected by the virus. Children are particularly susceptible to autoinoculation and may have widespread clusters of lesions.
   While usually caused by Epstein–Barr virus, also known as human herpesvirus 4, which is a member of the herpes virus family, a few other viruses may also cause the disease. It is primarily spread through saliva but can rarely be spread through semen or blood. Spread may occur by objects such as drinking glasses or toothbrushes. Those who are infected can spread the disease weeks before symptoms develop. Mono is primarily diagnosed based on the symptoms and can be confirmed with blood tests for specific antibodies. Another typical finding is increased blood lymphocytes of which more than 10% are atypical. The monospot test is not recommended for general use due to poor accuracy.
   Section::::Causes.:Radiation enteritis.
  
  Inflammation of the gastrointestinal tract is common after treatment with radiation therapy to the abdomen or pelvis. It is classified as early if it manifests within the first 3 months, and delayed if it manifests 3 months after treatment. Early radiation enteritis is caused by cell death of the crypt epithelium and subsequent mucosal inflammation, however usually subsides after the course of radiation therapy is completed. Delayed radiation enteritis is a chronic disease which has a complex pathogenesis involving changes in the majority of the intestinal wall.
  
  Section::::Diagnosis.
   The management of established or suspected infection following exposure to radiation (characterized by neutropenia and fever) is similar to that used for other febrile neutropenic patients. However, important differences between the two conditions exist. The patient that develops neutropenia after radiation is susceptible to irradiation damage to other tissues, such as the gastrointestinal tract, lungs and the central nervous system. These patients may require therapeutic interventions not needed in other types of neutropenic infections. The response of irradiated animals to antimicrobial therapy is sometimes unpredictable, as was evident in experimental studies where metronidazole and pefloxacin therapies were detrimental. 
  
presuppositions: Radiation poisoning is contagious because patients need to be kept in isolation. Radiation poisoning is contagious.
corrections: Radiation poisoning is not contagious, but the reason the patients need to be kept in isolation is that they would die from germs from others. Radiation poisoning is not contagious.
raw_presuppositions: Radiation poisoning is contagious because patients need to be kept in isolation. Radiation poisoning is contagious.
raw_corrections: Radiation poisoning is not contagious, but the reason the patients need to be kept in isolation is that they would die from germs from others. Radiation poisoning is not contagious.