Prevention of communicable diseases after disaster: A review

Abstract

Natural disasters are tragic incidents originating from atmospheric, geologic and hydrologic changes. In recent decades, millions of people have been killed by natural disasters, resulting in economic damages.

Natural and complex disasters dramatically increase the mortality and morbidity due to communicable diseases. The major causes of communicable disease in disasters are categorized into four sections: Infections due to contaminated food and water, respiratory infections, vector and insect-borne diseases, and infections due to wounds and injuries. With appropriate intervention, high morbidity and mortality resulting from communicable diseases can be avoided to a great deal.

This review article tries to provide the best recommendations for planning and preparing to prevent communicable disease after disaster in two phases: before disaster and after disaster.

Disasters can be seen as sudden and terrible events causing great damage, loss or destruction. Disasters have been defined as ecologic troubles or severe and high-magnitude emergencies resulting in deaths, injuries, illnesses, and profound damages that cannot be successfully managed using ordinary procedures or resources and require external support.¹ Disasters include earthquakes, floods, volcanic eruptions, tsunamis, drought and landslides. These disasters may begin acutely or insidiously with dramatic health, social, and economic sequels.² In recent decades, millions of people have been killed by natural disasters, adversely influenced the lives of more than one billion people, and caused significant economic compensations. Due to the latest report of International Federation of Red Cross and Red Crescent Society in the last decade (1999-2008), over 7100 disasters happened in the world that caused 1,243,480 deaths and over one billion US dollars damage.³ In 2005, 246 (42%) out of 650 severe natural hazard events recorded globally occurred in Asia killing over 97,000 (90% of the global total of 110,000 individuals) and affecting more than 150 million people. In 2006, 174 disasters affected 28 million people in Asia and the Pacific.

In 2008, from top 10 countries with the highest amount of disaster-related deaths in the world, 9 of them were in Asia. In fact, it is estimated the average $39.5 billion physical losses from disasters throughout Asia annually.⁴ Terrific earthquake in Marmara region in Turkey that caused more than 17,000 deaths in 1999 or the devastating flood in Central Europe occurred in 2002, resulted in economic damages estimated more than $15 billion are only some examples.⁵

The Bam earthquake was the most catastrophic event in the last decade in Iran. On 26 December 2003, a tragic earthquake measured 5.6 on the Richter scale, struck the ancient and agricultural city of Bam in the south-east of Iran. In this devastating event more than 30,000 people were killed, around 80 percent of the houses in the area were ruined and more than 100,000 became homeless.⁶

Natural and complex disasters such as earthquakes dramatically increase the mortality and morbidity resulting from communicable diseases.⁷ Although the epidemics of infectious diseases after the natural disaster are rare,^8–10 63% of the morbidity among Nicaraguan refugees in Costa Rica in 1989 was due to acute respiratory infections.¹¹ In 1993, acute respiratory infections caused 30% of deaths in dwellers of Kabul, Afghanistan and 23% of deaths in unsettled people.¹² In addition, after the earthquakes in El Salvador in 2001, 30% of infections were upper respiratory infections.¹³,¹⁴ The top five causes of death in emergencies and disasters include diarrhea, acute respiratory infection, measles, malnutrition and, in endemic zones, malaria.¹⁵ With appropriate intervention, high morbidity and mortality resulting from communicable diseases can be avoided to a great deal.¹⁶

Communicable disease after disaster

The major causes of communicable disease in disasters can be categorized into four areas: Infections due to contaminated food and water, respiratory infections, vector and insectborne diseases, and infections due to wounds and injuries.¹⁷ The most common causes of morbidity and mortality in this situation are diarrheal disease and acute respiratory infections.¹⁸

• ■Waterborne diseases:
  • Diarrheal disease: Diarrheal disease outbreaks can arise subsequent to drinking-water contamination, and have been reported after flooding and related movement. Vibrio cholera (O1 Ogawa and O1 Inaba) and enterotoxigenic Escherichia coli are the major causes of this type.^19–22
  • Hepatitis A and E: Hepatitis A and E have also fecal-oral transmission, especially in poor water sanitation.²³,²⁴
  • Leptospirosis: Leptospirosis is a bacterial zoonosis transmitted through contact of mucous membranes and skin with water, moist vegetation, or dirt contaminated with rodent urine.^25–28
• ■Diseases associated with crowding: Acute respiratory infections (ARI) as the main cause of morbidity and mortality among unsettled people are seen predominantly in children less than 5 years old.2 Furthermore, meningitis and measles are transmitted from person to person, especially in crowded circumstances.²⁹
• ■Vector-borne diseases: Malaria, cutaneous leishmaniasis³⁰ and rabies¹⁷ are transmitted by vectors. In 1991, an earthquake in Costa Rica's Atlantic region was accompanied with1a high increase in malaria cases.³¹ Furthermore, intermittent flooding associated with El Niño–Southern Oscillation has been correlated with malaria epidemics in Peru.³²
• ■Infections due to wounds and injuries: The potentially significant threats to persons suffering a wound are tetanus, staphylococci and streptococci.³³

This review article tries to provide the best recommendations for planning and preparing to prevent communicable disease after disaster in two phases: before disaster and after disaster.

Strategies for prevention of communicable disease

Before Disaster

The first phase of disaster policy making is to clarify our needs. For primary prevention, the most important risk factors of communicable diseases should be determined. The most significant risk factors in disasters are population movement and displacement.² Additionally, overpopulation, economic and environmental devastation, poverty, lack of sanitary water, poor waste management, lack of shelter, malnutrition as a consequence of food shortages, and poor access to health care cause a dramatic increase in the rates of communicable diseases after disaster.¹⁶,^34–37

Furthermore the breakdown or overwhelming of public health organizations and deficiency of health services obstruct prevention and control programs.³⁸ With emphasizing on these risk factors, preparing and policy making before disasters are a critical need. The response to the disaster is a multifaceted operation requiring persistent review and modification of preparedness missions at the local, nationwide, and global level.³⁹

The Aim of this phase is to decrease vulnerability to communicable diseases through reducing causalities and exposure to risk factors that provide passive protection during disaster. It needs some national regulations that reduce hazard exposure through constructing evidence-based guidelines for protecting individuals.⁴⁰ Emergency response plans before disasters should include training in identifying and management of specific potentially threatening diseases; preparing needed equipment, supplies and materials, making local backups of supplies and tools for diagnosis and treatment, and environmental health measures for disease outbreaks.

Furthermore, reinforcement of health-surveillance systems and practicing guidelines for managing information on specific diseases; increasing the awareness of potentially affected population about communicable diseases and the prerequisites for quick referral to a health facility are critical.¹⁵,^40–42 Prepositioning of emergency supplies is one mechanism of increasing preparedness for natural disasters.⁴³ Additionally, in countries with potential threat of disasters, providing fully operational field hospitals providing effective and efficient health care services to the damaged people in the probable forthcoming disasters, seems critical; this plan has an important role to reduce mortality and morbidity of communicable diseases.⁴⁴ Such strategies are significantly facilitated by continuing support of government, academic and private organizations in terms of assigning programs designed to offer up-to-date education and training.

Post disaster Phase

In this phase, the emergency response for controlling communicable disease includes: Emergency medical care, provision of shelter and site planning, water and sanitation, safe food preparation, nutrition, case management, medical supplies and vector control. Moreover, health education and providing the health of humanitarian workers is a critical point.

• Select and plan sites

providing appropriate shelters and site planning at the start of an emergency can decrease the incidence of communicable disease especially diarrheal diseases, acute respiratory infections, meningitis, tuberculosis, measles and vector-borne diseases.⁴⁷ Shelters should have sufficient space according to the needs of victims. Furthermore, access to the water, fuel, and transport, solid waste management, and safety of food stores are essential.¹⁶,⁴⁸ The new methods of GIS (Geographic Information System) application is useful for finding the proper place for shelter settlement.⁴⁹

• Ensure adequate water and sanitation facilities.

As mentioned before, water borne diseases are a main cause of communicable disease after disaster. Ensuring constant delivery of safe drinking-water is the major preventive measure to be applied after a natural disaster.

According to WHO guidelines, Chlorine is broadly obtainable, low-cost, easily used and effective against almost all waterborne pathogens.¹⁵ The sphere project proposes the following minimum standards for the water supply in disasters: (1) sufficient access to safe water, (2) water quality should be maintained based on international guidelines, and (3) water consumption facilities and goods should be safe. People should have sufficient facilities and provisions to collect, save and use adequate quantities of water for drinking, cooking and personal hygiene, and to certify that drinking water remains safe until consumption.⁴⁵,^50–52

Additionally, personal hygiene is an important issue in health promotion during disasters. Personal hygiene habits will influence the general health status of the population. The importance of soap and hand washing as a protection against fecal-oral disease should be emphasized in educational programs. Soap and water should be provided to all disaster victims and rescue personnel.^53–55

• Ensure safety of food:

Food safety is crucial for disease prevention in natural disasters. The World Health Organization recommends five keys for ensuring the safety of food supplements following a disaster event;

Key 1: Preserve clean - (prevents the growth and spread of hazardous microorganisms)

Key 2: Separate cooked and raw food (microorganisms transfer prevention)

Key 3: Cook thoroughly (kills dangerous microorganisms)

Key 4: Preserve food at harmless temperatures (microorganisms growth prevention)

Key 5: Consuming safe water and raw materials (contamination prevention)⁵⁶

• Control vectors

Natural disasters can influence transmission of vector-borne disease. The crowding of infected and vulnerable hosts, a debilitated public health infrastructure and disruptions of ongoing control processes are entirely risk factors for transmission of vector-borne disease.⁵⁷ Major diseases frequently spread by vectors are malaria, dengue, Japanese encephalitis, yellow fever, typhus, and trypanosomiasis. For prevention, vector control interventions based on the local context and epidemiology of diseases are essential. Examples of some useful interventions are indoor residual spraying for malaria, insecticide-treated nets, and traps for tsetse flies as the vectors of trypanosomiasis.⁵⁸

• Implement vaccination campaigns (e.g. measles)

Campaigns for measles immunization are one of the most cost-effective interventions in public health.¹⁶ Mass measles immunization, as well as vitamin A supplementation is an immediate health priority after natural disasters in regions with poor coverage levels. Mass immunization should be fulfilled as soon as possible in areas with baseline coverage rates below 90% among individuals under 15 years old.

Furthermore, immediate provision of Tetanus Diphtheria (TD) vaccine and tetanus antitoxin to persons injured during the earthquake and those undergoing emergency surgeries, is essential.⁵⁹

• Provide essential clinical services

Access to the primary care services is critical to prevention, early diagnosis and treatment of a variety of diseases, as well as providing secondary and tertiary care.⁶⁰ Effective diagnosis and treatment of communicable diseases, prevents excess mortality and morbidity.⁶¹

Furthermore, standardized guidelines for diagnosis and treatment of the most common infectious diseases are needed. The Inter-agency Emergency Health Kit 2006 (IEHK 2006) which is designed by world health organization to meet the initial primary health care needs of a displaced population is useful in disaster scene. It can be set in immediate aftermath of a natural disaster or during an emergency and includes essential medicines, medical facilities and also clinical protocols needed in the context of emergency situations.⁶²

• Provide basic laboratory facilities

Establishing a clinical laboratory is not a priority during the initial phase of most disasters. The diagnosis of most common communicable diseases can usually be done by clinical diagnosis. Laboratory testing is remained useful for confirming during a supposed epidemic event for which mass immunization may be indicated (e.g. meningococcal meningitis) or where culture and antibiotic sensitivity testing is effective in clinical decisions (e.g. dysentery).⁶³

Consclusion

An important key to diminish adverse health effects due to natural disasters is a multidisciplinary approach with a wide range of proficiency which is useful in prevention and also immediate treatment of communicable diseases.

The establishment, implementation, and continuous monitoring of minimum standards for water safety security, sanitation, shelter, and personal hygiene is critical for health promotion after disasters. Awareness of the emergence of water and food born disease is of importance to the health of the victims. Furthermore by establishment of a surveillance system and monitoring the trend of disease carefully, the threat of outbreaks will be assessed. In addition, some strategic guidelines for controlling outbreaks are needed.

This approach needs extensive continuing preparation, planning, education and also policy development. The ultimate goal is better awareness and response for natural disaster or other complex emergency circumstances to minimize the morbidity and mortality of such ominous events.

Author's Contributions

NJ conceived and designed the experiment. NJ, AS, MM and AL developed the review protocol. AS and MM conducted the literature review and did the initial screening based on titles and abstracts. Data extraction and quality appraisal was conducted by either NJ and AS or MM and AL. The first draft of the paper was produced by NJ and AL, with subsequent drafts developed by all four authors. All authors have read and approved the manuscript