Disaster Epidemiology

Introduction

Disasters and unfortunate events are part of life. No one plans for them and no one wishes or intends them to happen to him or her or anyone they care for. This has made it to be an acceptable feature of life as disaster varies from acts of God to sheer human negligence. In medical terms and public health practice, cannot be allowed to happen, as there are a responsibility and duty of those trained as professionals in this particular field to ensure the health and safety of the public is not at risk. They have therefore come up with elaborate plans and procedures to mitigate disasters from being catastrophic. They have to learn and understand from their past experiences and catastrophes that disasters can be prevented or reduced by acting and planning first to counter its effect. This is the same principles when it comes to disaster emergency management.

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For example, a slight computer problem in a city can disrupt electrical power supply in a region cutting off the power supply. This may cause a total shutdown of all computerized systems in all that area spanning from manufacturing to communications (traffic, airports control and rail systems). At the end of it such, an occurrence would interfere with emergency control centers such as police and fire brigade lines. Coming to think of it, the effects would be magnanimous yet it all began with a small computer hitch. To increase emergency preparedness against such incidences as power outages; Emergeo (2013) has developed digital imagery, emergency response plans, and descriptive data e.g. of building dimensions or evacuation routes that curb the effects of disaster. However, natural disasters have created a turnaround in relation to disaster epidemiology and crisis management. It has caused chronic and acute health effects on both man and beast. 

In fact, the major aim of disaster epidemiology is to develop and implement strategies that are crucial in the prevention of chronic and acute health effects. Disasters may either be natural or fabricated. In the case of a natural disaster such as a hurricane landfall like Hurricane Sandy; evacuation of residents is necessary and should be done as fast as possible. Evacuation is a primary deterrence or prevention mechanism that seeks to avoid deaths, injuries or illnesses (medscape.com, 2005). Consequently, when the hurricane happens fast and sweeps people, then secondary prevention measures are quickly adopted. They seek to educate victims of controlling injury and initiate fast recovery. The last mechanism induced is tertiary prevention.

This is the epitome of a natural disaster and its health causes. The tertiary mechanism involves the establishment of evaluation units that assess health (disease and disability) of the patients or victims of a disaster.  Victims with chronic illness (e.g. heart disease or kidney failure) can get short-term pharmaceuticals when the common source has been destroyed by the disaster (Medscape.com, 2013).  Victims with acute severe illnesses may be unlucky as the disease may be onset very fast and if proper medication is not available on time, then the worst could happen (death).  According to Medscape.com (2013), strategies established by disaster epidemiology include “rapids needs assessment, disease control strategies, health services use and availability, surveillance systems for both descriptive and analytic investigations of disease and injury, and research on risk factors contributing to disease, injury, or death.” These strategies are used in EDM practices.

These practices are referred to as competency domains (royalroads.ca, 2013). They include “emergency mitigation, preparedness, and emergency response; recovery and disaster management.” They are important in “analytical thinking, strategic planning, decision making, problem-solving; conflict and crisis management” (Ibid).  An information system has to be established to collect, manipulate, store and retrieve data based on a natural disaster.  Productivity is mostly disrupted in the case of a disaster. This necessitates a surveillance team to collect, analyze problem-based data. Data collected is in relation to health and how it has been robbed of the general public. Information is based on incidence, prevalence, and severity of illness or injury due to ecological changes, alterations in endemic changes of disease, displacement of people, loss of health care, overcrowding, sanitation breakdowns and loss of public utilities” (Medscape.com). These practices coincide with those carried out by CIP.

CIP’s practices include “information sharing, research and development and risk assessment” (Phe.gov, 2013). Infrastructures that are credited for offering health care support in cases of disasters include medical, nursing and public health institutions. Hospitals also provide vital information for morbidity in relation to natural disasters. Community clinicians also play a crucial role in “educating patients about infectious infections, reporting cases and preventing the spread of infections” (Medscape.com, 2013).  In emergencies, portable computers from hospitals, clinics, and other health departments can be used in reporting patient data in event of a disaster. An epidemiologist in a CIP situation has to analyze public health situation and the association between exposure and outcome relative to the population. For example, a cyclone causes a high wind exposure that in turn leads to injury if the winds blow buildings away. A volcanic eruption on its part may release ash particulates that may cause silicosis- a respiratory infection.   This helps in understanding the information of disaster incidents.

This information includes: “demographic characteristics of affected areas, numbers and characteristics of displaced people, health care personnel needed, management of the health care infrastructure, relief material (food, water and medical) supplies needed and public information”  (Medscape.com, 2013). These approaches relate to EDM and CIP (emergency and the infrastructural impact), especially in a post-impact disaster situation. A disaster assessment team uses quick methods (simple and flexible) to assemble victim information. They also use uncouth or forged methods to give immediate responses such as roughly estimating the numerator or denominator data when giving quick needed response. This may be subject to bias but it is the most favored. For instance, an emergency response team may not have an accurate estimate of a town affected by an earthquake. The methods described above may readily come in handy. However, a critical look at the situation on the ground shows that lack of preparedness may be the causes of lack of instant information in the event of a disaster.

Hurricane Katrina that hit New Orleans and Louisiana affected tens of thousands of people (King, 2005). This information though vague, it represents a substantial amount that may be used to build up the case. King (2005) continues to state, “Data from the 2000 U.S census long-form survey indicate that 20.2% of the population, roughly 275,000 people aged 5 years an older in the 10 parishes in the greater New Orleans metropolitan area had a disability of some type.” This number looks much but it shows that the assessment would have an easy time in undertaking evacuation. Hurricane Katrina caused an exacerbation of chronic illnesses. This is because it depreciated the amount of food, clean water, exaggerated heat and cold; physical and mental stress (Molded et al, 2005).  However, there are those who are at greater risk in the event of a natural disaster.

Pregnant women, their unborn fetuses, and the elderly who suffer from multiple chronic conditions or those under critical treatment suffer the most (Bierman and Clancy, 2001). Economically challenged people, mentally ill; the disabled and those without health insurance covers are also among the most vulnerable (Mokdad et al, 2005). An economically damaging earthquake or a cyclone such as Katrina easily shook stroke patients and especially those under anticoagulants. High mortality could have been cited on “diabetic patients whose status is controlled by insulin, heart attack survivors taking clot preventing medications, lung disease patients taking home oxygen therapy, people with hereditary blood disorders and patients under hemodialysis for kidney failure” (Fernandez et al, 2002). With data in hospitals pertaining to the patients under the above category, it becomes a bit simpler to ascertain the right move of action in the event of an unexpected natural disaster.  Nevertheless, inadequate access to routine health services after a disaster is the leading cause of mortality for both acute and chronic infections (Centers for Disease Control and Prevention, 2005).

Cases such as power outages cause extremes of heat and cold. This may also “interrupt supplemental oxygen supplies” (Mokdad et al, 2005). Disabled personalities are as well at a loss when they are forced to live without routine health services.  Women in their early pregnancy stage are in worse conditions due to their “exposure during organogenesis to toxins or infectious agents” (Ibid). Fewer studies have been made on the problems faced by vulnerable persons in the event of both natural and man-made disasters. However, a look at the horrible disaster caused by Hurricane Katrina shows that there is urgent need to recommend control measures against chronic and acute illnesses.

According to CDC (2005), 5 of the top 6 reported conditions were all chronic diseases (1 acute), and that other than injuries, the majority of medical and health visits were for medical refills, oral and other chronic health issues. The top 10 conditions that led the list of chronic diseases after the hurricane were “hypertension, cardiovascular diseases, diabetes and psychiatric disorders (new and existing)” (Ibid). Of the 41% Hurricane Katrina evacuees, there was at least one chronic health condition such as “heart diseases, hypertension, diabetes or asthma” (Kaiser, 2005). A year back (2004) saw the occurrence of Hurricane Charley in Florida. A survey report of this disaster showed that six deaths reported were from “exacerbation of existing cardiac or pulmonary infections” (MMWR, 2004). This report sought to “strengthen local disaster plans and public health messages for vulnerable populations who are likely to have chronic medical conditions that may require medical supplies that depend on electricity to operate” (MMWR, 2004). There should be proper guidance that addresses patient triage, clinical evaluations, and medications that consider chronic health conditions during such preparations (Mokdad et al., 2005).

Prevention and control of chronic and acute diseases in the event of a disaster should be guided by four major aspects. “1).Pre-disaster rates of adverse health outcomes and disease burden. 2). Awareness of the immediate needs of people with chronic illnesses (including a plan for providing appropriate medication). 3). Knowledge of the basic and surge capacity of health care delivery systems of the affected and surrounding areas to treat and manage chronic diseases, and 4) the affected areas’ ability to rebuild the basic infrastructure needed to support care” (Mokdad et al, 2005). The above guidelines reveal the need to have risk reduction mechanisms and not just an evacuation plan or emergency treatment measures. The theories of evacuation plans and how emergency treatment is vital for both EDM and CIP are important but, risk reduction processes and community resilience activities should be considered first. This is because they benefit patients with chronic and acute illness. Consequently, essential medications that support such patients in the event of a disaster should be developed.

Mokdad et al (2005) recommend the development of surveillance tools by the Centers for Disease Control and Prevention (CDC) in conjunction with the public health community. These tools are to address issues on disaster planning that consider vulnerable populations such as pregnant women and those living with disabilities. Such a surveillance tool should have three major components. They should be able to do the following: “1) establish a baseline of the size, functional status, and needs of the vulnerable populations in areas susceptible to predictable disasters (e.g. hurricanes), 2) able to assess the needs and levels of actual response during disasters; and 3) be able to monitor the long-term effects of the emergency” (Ibid). In this regard, EDM and CIP teams can map out disaster surveillance activities into a timeline that shows before (pre), during and after (post) events of a disaster (Ibid). These surveillance tools and components will pave way for the use of EDM and CIP models.

Hazards should be mapped and vulnerability assessments performed. Certain information systems applications or models can be used to facilitate these maps. Geographical information system (GIS) is one such software. According to Col.org (2008) GIS is used in forward planning as it gives spatial data using computer-based maps. This spatial representation is used in mitigating structural and non-structural (disease) effects of a disaster. For example when an area is mapped as vulnerable, GIS identifies areas that are at risk. To show how GIS is related to chronic and acute diseases, the software gives the human resources within a particular region that has been identified as risky. This helps in accentuating preparedness, especially of health resources.

The people needed most in the event of a disaster are prepared by this model. Moreover, it also helps the CIP. Roads and other infrastructure such as communication that may not handle the effects of a disaster are identified. If a particular building that is meant to house chronic and acute health resources is wrongly placed, then the model maps out a different location that may serve the same purpose. A man-made disaster such as a chlorine explosion may require a quick response. Rescue or emergency disaster management (EDM) team will use EDM to locate the unsafe area (Col.org, 2013). The CIP team will use the same model to map out the closest and the safest alternative area upon which to relocate the victims and establish a health center. Apart from that, it gives evacuation areas, safe routes, assembly points (Ibid). Recovery will also be facilitated by GIS.         

GIS shows the exact places, routes and institutions (all with the number of people) that have been affected. This information is necessary to establish where to begin when rebuilding the towns. Another vital model is the global positioning system. This system was developed by the United States Department of Defense. Its rightful name is the Navigation System with Timing and Ranging Global Positioning System (NAVSTAR GPS) (Col.org, 2008). It is used in EDM to “track emergency vehicles and supplies” (Ibid). The receiver itself is attached to this vehicle and any other supply system and its location is represented or overlaid on a map. A vehicle unit to be used to supply chronic and acute patients with medical supply will be in dire need of this system so that it does not disappear on the radar. 

Tsunamis or sea surges can also be measured using a GPS system as it measures wave heights when attached to buoys. It also infers volcanic activity by locating any deformities in the ground. This information is very important to the health of individuals. Prior information is needed to prepare health mechanisms that will be appropriate in the event of a disaster. The last tool is remote sensing.

It can be applied in the event of floods, hurricanes, volcanic eruptions; landslides and earthquakes. Remote sensing is known for its use of high-resolution technology. It scales geographical areas and identifies storm surges, flooding levels. For example; LandSat imagery is used to view an earthquake and gives guidelines on the planning process. Remote sensing maps out on-the-spot seismic activity in the event of volcanic eruptions. EDM team uses this information to evacuate residents and gather health relief supplies that will be needed. At this point, it is important to see the disease risks associated with disaster epidemiology.

According to Cdc.gov (2013), the risk of infectious diseases among travelers, moving in a disaster-stricken area can only be facilitated by a causative agent. In addition, the disease has to be “endemic before the disaster occurs” (Ibid). Endemic diseases such as cholera and leptospirosis have often been prompted by floods. Such occurrences disrupt water and sewerage systems and have contaminated drinking water as well as food supplies. It is only by preventing the damage and contamination of these systems that a community can actualize ways of avoiding enteric disease transmission. Further, afield, “travelers who are injured during a natural disaster should have a medical evaluation to determine what additional care is needed for wounds potentially contaminated with feces, soil or saliva. The wound may also be exposed to fresh or sea water that may have parasites or bacteria” (Ibid). Such an occurrence necessitates a “tetanus booster status to be kept current always” (Ibid).  Disaster managers should be wary of spreading harmful diseases.

The team that is offering relief aid to disaster-stricken areas should be protected from disease outbreaks. This ensures they do not reintroduce the infections and lower immunity of victims suffering from chronic or acute illness. Developing countries have almost eliminated vaccine-preventable diseases. However, a disease such as measles could be reintroduced in that country by a disaster manager who unknowingly has contracted that infection in the event of offering aid. Chronic pulmonary patients who are “immuno-compromised” should be wary as they are most susceptible to environmental risks such as release of chemical or biological contaminants.  Lastly, infectious diseases are not the major causes of deaths in the event of a natural or man-made disaster. Victims succumb to blunt trauma, crash-related injuries or drowning.

Conclusion

To recapitulate, two approaches of disaster epidemiology have been identified in this paper. The first approach studies the causes of a natural and man-made disaster. It focuses on the event itself such as hurricane, earthquake and the mortality or morbidity that is linked to it. It is impossible to prevent a similar case without identifying the underlying factors. The second approach uses these epidemiological findings to alleviate the trouble. It has identified both acute and chronic infections as the most common results of disasters. This helps in mapping out surveillance systems that can be used to track areas that can facilitate transmission of communicable disasters. This is a very direct application of disaster epidemiology especially as it strengthens the use of EDM and CIP models. Three prevention mechanisms have been identified in the paper. They include primary, secondary and tertiary.  Theories and practices used in disaster epidemiology have a major impact on EDM and CIP. They include evacuation, emergency preparedness (understanding of hazards) and victim protection. These theories and others have been strengthened by the introduction of risk reduction measures, community resilience activities and sustainable communities to accentuate recovery. It is by these practices that an EDM and CIP can manipulate disaster epidemiology to develop strategies that can manage chronic and acute illnesses.   

References

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