Medical Countermeasures for Children in Radiation and Nuclear Disasters: Current Capabilities and Key Gaps.

OBJECTIVE: Despite children's unique vulnerability, clinical guidance and resources are lacking around the use of radiation medical countermeasures (MCMs) available commercially and in the Strategic National Stockpile to support immediate dispensing to pediatric populations. To better understand the current capabilities and shortfalls, a literature review and gap analysis were performed. METHODS: A comprehensive review of the medical literature, Food and Drug Administration (FDA)-approved labeling, FDA summary reviews, medical references, and educational resources related to pediatric radiation MCMs was performed from May 2016 to February 2017. RESULTS: Fifteen gaps related to the use of radiation MCMs in children were identified. The need to address these gaps was prioritized based upon the potential to decrease morbidity and mortality, improve clinical management, strengthen caregiver education, and increase the relevant evidence base. CONCLUSIONS: Key gaps exist in information to support the safe and successful use of MCMs in children during radiation emergencies; failure to address these gaps could have negative consequences for families and communities. There is a clear need for pediatric-specific guidance to ensure clinicians can appropriately identify, triage, and treat children who have been exposed to radiation, and for resources to ensure accurate communication about the safety and utility of radiation MCMs for children. (Disaster Med Public Health Preparedness. 2019;13:639-646).

US CENTERS FOR DISEASE CONTROL AND PREVENTION EXPERIENCE IN THE JOINT EXTERNAL EVALUATION PROCESS-RADIATION EMERGENCIES TECHNICAL AREA.

In 2015-16, the US Department of Health and Human Services led 23 US Government (USG) agencies including the Centers for Disease Control and Prevention (CDC), and more than 120 subject matter experts in conducting an in-depth review of the US core public health capacities and evaluation of the country's compliance with the International Health Regulations using the Joint External Evaluation (JEE) methodology. This two-part process began with a detailed 'self-assessment' followed by a comprehensive independent, external evaluation conducted by 15 foreign assessors. In the Radiation Emergencies Technical Area, on a scale from 1-lowest to 5-highest, the assessors concurred with the USG self-assessed score of 3 in both of the relevant indicators. The report identified five priority actions recommended to improve the USG capacity to handle large-scale radiation emergencies. CDC is working to implement a post-JEE roadmap to address these priority actions in partnership with national and international partners.

A public health perspective on the U.S. response to the Fukushima radiological emergency.

On 11 March 2011, northern Japan was struck by first a magnitude 9.0 earthquake off the eastern coast and then by an ensuing tsunami. At the Fukushima Dai-ichi Nuclear Power Plant (NPP), these twin disasters initiated a cascade of events that led to radionuclide releases. Radioactive material from Japan was subsequently transported to locations around the globe, including the U.S. The levels of radioactive material that arrived in the U.S. were never large enough to cause health effects, but the presence of this material in the environment was enough to require a response from the public health community. Events during the response illustrated some U.S. preparedness challenges that previously had been anticipated and others that were newly identified. Some of these challenges include the following: (1) Capacity, including radiation health experts, for monitoring potentially exposed people for radioactive contamination are limited and may not be adequate at the time of a large-scale radiological incident; (2) there is no public health authority to detain people contaminated with radioactive materials; (3) public health and medical capacities for response to radiation emergencies are limited; (4) public health communications regarding radiation emergencies can be improved to enhance public health response; (5) national and international exposure standards for radiation measurements (and units) and protective action guides lack uniformity; (6) access to radiation emergency monitoring data can be limited; and (7) the Strategic National Stockpile may not be currently prepared to meet the public health need for KI in the case of a surge in demand from a large-scale radiation emergency. Members of the public health community can draw on this experience to improve public health preparedness.

Emergency department management of patients internally contaminated with radioactive material.

After a radiation emergency that involves the dispersal of radioactive material, patients can become externally and internally contaminated with 1 or more radionuclides. Internal contamination can lead to the delivery of harmful ionizing radiation doses to various organs and tissues or the whole body. The clinical consequences can range from acute radiation syndrome to the long-term development of cancer. Estimating the amount of radioactive material absorbed into the body can guide the management of patients. Treatment includes, in addition to supportive care and long term monitoring, certain medical countermeasures like Prussian blue, calcium diethylenetriamine pentaacetic acid (DTPA) and zinc DTPA.

2011 investigation of internal contamination with radioactive strontium following rubidium Rb 82 cardiac PET scan.

During routine screening in 2011, US Customs and Border Protection (CBP) identified 2 persons with elevated radioactivity. CBP, in collaboration with Los Alamos National Laboratory, informed the Food and Drug Administration (FDA) that these people could have increased radiation exposure as a result of undergoing cardiac Positron Emission Tomography (PET) scans several months earlier with rubidium Rb 82 chloride injection from CardioGen-82. We conducted a multistate investigation to assess the potential extent and magnitude of radioactive strontium overexposure among patients who had undergone Rb 82 PET scans. We selected a convenience sample of clinical sites in 4 states and reviewed records to identify eligible study participants, defined as people who had had an Rb 82 PET scan between February and July 2011. All participants received direct radiation screening using a radioisotope identifier able to detect the gamma energy specific for strontium-85 (514 keV) and urine bioassay for excreted radioactive strontium. We referred a subset of participants with direct radiation screening counts above background readings for whole body counting (WBC) using a rank ordering of direct radiation screening. The rank order list, from highest to lowest, was used to contact and offer voluntary enrollment for WBC. Of 308 participants, 292 (95%) had direct radiation screening results indistinguishable from background radiation measurements; 261 of 265 (98%) participants with sufficient urine for analysis had radioactive strontium results below minimum detectable activity. None of the 23 participants who underwent WBC demonstrated elevated strontium activity above levels associated with routine use of the rubidium Rb 82 generator. Among investigation participants, we did not identify evidence of strontium internal contamination above permissible levels. This investigation might serve as a model for future investigations of radioactive internal contamination incidents.

Use of epidemiological data and direct bioassay for prioritization of affected populations in a large-scale radiation emergency.

Following a radiation emergency, evacuated, sheltered or other members of the public would require monitoring for external and/or internal contamination and, if indicated, decontamination. In addition, the potentially-impacted population would be identified for biodosimetry/bioassay or needed medical treatment (chelation therapy, cytokine treatment, etc.) and prioritized for follow-up. Expeditious implementation of these activities presents many challenges, especially when a large population is affected. Furthermore, experience from previous radiation incidents has demonstrated that the number of people seeking monitoring for radioactive contamination (both external and internal) could be much higher than the actual number of contaminated individuals. In the United States, the Department of Health and Human Services is the lead agency to coordinate federal support for population monitoring activities. Population monitoring includes (1) monitoring people for external contamination; (2) monitoring people for internal contamination; (3) population decontamination; (4) collecting epidemiologic data regarding potentially exposed and/or contaminated individuals to prioritize the affected population for limited medical resources; (5) administering available pharmaceuticals for internal decontamination as deemed necessary by appropriate health officials; (6) performing dose reconstruction; and (7) establishing a registry to conduct long-term monitoring of this population for potential long-term health effects. This paper will focus on screening for internal contamination and will describe the use of early epidemiologic data as well as direct bioassay techniques to rapidly identify and prioritize the affected population for further analysis and medical attention.