Disaster Epidemiology: Frequently Asked Questions (FAQs)

Disaster Epidemiology

1. What is a disaster?
   From the standpoint of public health, a disaster is defined on the basis of its consequences on health and health services. A disaster is a serious disruption of the functioning of society, causing widespread human, material or environmental losses, that exceeds the local capacity to respond, and calls for external assistance. Based on this definition, disasters could be any emergency (man-made or natural) that exceed local capacity to respond; so what may be a disaster in one jurisdiction might not be in another.

2. Why should we collect data during a disaster?
   Collecting health and needs information during a disaster helps to provide situational awareness. We need to know what is happening to understand what the needs are, plan the response, and gather the appropriate resources. We want to prevent further morbidity and mortality by addressing both immediate and long-term needs, adjusting priorities, allocating resources, and projecting and planning for future needs. We also use data to identify risk factors and improve prevention and mitigation strategies for future disasters.

3. What is disaster epidemiology?
   Disaster epidemiology is the use of epidemiology to assess the short- and long-term adverse health effects of disasters and to predict consequences of future disasters. Typically, the main objectives of disaster epidemiology are to

   • prevent or reduce the number of deaths, illnesses, and injuries caused by disasters,
   • provide timely and accurate health information for decision-makers, and
   • improve prevention and mitigation strategies for future disasters by gaining information for future response preparation.

4. What tools are available for local and state health department use during disaster response?
   State health departments should look first at the tools they are using in non-disaster settings to assess their applicability for adaption to a disaster response. However, CDC provides various tools for public health disaster response including template forms for morbidity surveillance, mortality surveillance, shelter assessments, and a Community Assessment for Public Health Emergency Response CASPER toolkit [PDF - 2.56 MB] .
5. How do state and local health departments request CDC assistance?
   The CDC Health Studies Branch (HSB) provides scientific consultation, technical assistance, and disaster epidemiology training to local, state/territorial, federal and international public health partners to help them respond to natural and man-made disasters. There are various mechanisms with which you can request CDC assistance. If you would like more information on CDC HSB consultation, technical assistance, or disaster epidemiology training, please click HERE.

Public Health Surveillance during a Disaster

1. What is public health surveillance?
   Public health surveillance is the systematic collection, analysis, and interpretation of deaths, injuries, and illnesses in order to provide information about any adverse health effects related to a disaster event in a community. It allows us to assess the human health impacts of a disaster and evaluate potential problems related to planning and prevention.
2. Why conduct public health surveillance during disaster response?
   Public health morbidity surveillance allows us to detect disease outbreaks and track disease trends. A common myth is that epidemics are inevitable during a disaster. Early detection and response, however, can mitigate the likelihood for outbreaks. Additionally, conducting health surveillance allows for the ability to make informed decisions about action items such as allocating resources, targeting interventions to meet specific needs, and planning for future disasters. In addition to public health morbidity surveillance, mortality surveillance can provide information that can prevent excess death. The number of deaths is a strong indicator of the impact of the disaster. Disasters can overwhelm local medical examiners and emergency systems, disrupting typical reporting methods. Most mortality surveillance data (such as Vital Statistics) are collected in a way that is not timely or detailed enough to be useful for disaster response. Thus, implementing active mortality surveillance following a disaster provides a critical aspect to response.
3. What tools are available to assist in conducting surveillance during a disaster?
   The CDC has developed multiple ready-to-use templates for mortality and morbidity surveillance. These tools can be used to supplement existing surveillance systems or replace surveillance systems that have been hindered or destroyed due to a disaster.
4. How do we create a surveillance system during a disaster?
   During disasters, several steps may need to be conducted simultaneously when planning a surveillance system. Just as purpose and objective should be clear in any disaster response effort, the surveillance system should have well-defined objectives. Additionally, data sources need to be identified and selected. Facility-based surveillance of hospitals and emergency medical operations can provide information on those seeking care during a disaster, yet there is often the need to use additional nontraditional sources of information (such as a shelters, pharmacies, or physician offices) as well. Ideally, data collection instruments for surveillance should be developed, tested, and distributed before the disaster occurs (e.g., CDC-developed surveillance tools). However, these instruments will need to be modified for each disaster and location. The data collection instrument should collect only the most essential information and should have easy data entry. For information to be useful, it must be disseminated in a timely fashion through appropriate channels (e.g., public health and other government officials, relief workers, the affected community, and the media).

Community Assessment for Public Health Emergency Response (CASPER)

1. What is CDC’s Community Assessment for Public Health Emergency Response (CASPER)?
   The CDC’s Division of Environmental Hazards and Health Effects (EHHE), Health Studies Branch (HSB) has developed the Community Assessment for Public Health Emergency Response (CASPER) toolkit to assist personnel from any local, state/territorial, regional, or federal public health departments in conducting a community needs assessment. CASPER is an epidemiologic technique designed to provide quickly and at low cost, household-based information about an affected community’s needs after a disaster in a simple format to decision-makers. To learn more information about CASPER, please visit the Health Studies Branch CASPER website.
2. Is the CASPER a rapid needs assessment?
   In short, yes. The CDC Community Assessment for Public Health Emergency Response (CASPER) is a type of rapid needs assessment. CASPER is designed to provide accurate and timely data through precise analysis and interpretation for decision-makers. Gathering health and basic needs information using valid statistical methods allows public health and emergency managers to prioritize their responses and to make informed decisions regarding the distribution of resources.

3. What are the objectives of CASPER?
   The primary goals of the CASPER are to rapidly obtain information about the needs of an affected community and to assess changes in needs during the recovery period. The main objectives of CASPER are to

   • produce household-based population estimates of needs for decision-makers,
   • determine the critical health needs and assess the impact of the disaster on the community,
   • characterize the population residing in the disaster area including any ongoing health effects, and
   • evaluate the effectiveness of relief efforts using follow-up CASPER.

   CASPER is not intended to deliver food, medicine, medical services or other resources to the affected area or to provide direct services to residents such as cleanup or home repair.

4. When should you conduct a CASPER?
   During a disaster, the local, state, or regional emergency managers or health department officers may decide to initiate a CASPER when at least one of the following conditions occurs:

   • the effect of the disaster on the population is unknown,
   • the health status and basics needs of the affected population are unknown, or
   • when response and recovery efforts need to be evaluated.

   Although the CDC’s Health Studies Branch typically provides technical assistance during a disaster response, CASPER methodology can be used in both a disaster and non-disaster setting. CASPER methodology has been used to assess public health perceptions, and estimate needs of a community during a non-disaster setting. Regardless of the setting and objectives, once the decision to conduct the CASPER has been made, it should be initiated as soon as possible.

5. How do I learn more information about using CASPER?
   The CDC’s Division of Environmental Hazards and Health Effects (EHHE), Health Studies Branch (HSB) has developed the CASPER toolkit to assist personnel from any local, state/territorial, regional, or federal public health departments in conducting a CASPER during a disaster. The toolkit was developed to standardize the assessment procedures. While it is focused on United States disaster response, it may also be adapted for use in a non-disaster. The CASPER toolkit provides guidelines on questionnaire development, methodology, sample selection, training, data collection, analysis, and report writing and is available at the Health Studies Branch CASPER website.
6. How do I request a CASPER in my jurisdiction?
   If you would like CDC technical assistance in conducting a CASPER in your jurisdiction, please visit the CDC Health Studies Branch Disaster Training and Response webpage.