Preventing Infectious Disease Outbreaks Following Natural Disasters

By Kimberly A. Smith, Master’s Student, Public Health, and Dr. Jennifer Sedillo, Faculty Member, Public Health

Natural disasters generate ideal conditions for the development and outbreak of infectious diseases. For example, respiratory, diarrheal and vector-borne diseases are most common after a natural disaster.

Severe storms, flooding and other natural catastrophes affect both the physical and social environment of disease victims. Infrastructures such as homes that are compromised, for example, can lead to unsafe drinking water and unsanitary conditions.

Overcrowding in Temporary Shelters and Poor Nutrition Spread Infectious Diseases

The loss of homes leads to overcrowding in temporary shelters and a lack of nutrition, which exacerbates infectious diseases. Lack of healthcare personnel and facilities under these conditions can further exacerbate diseases.

During and after natural disaster recovery, new diseases can appear and once-controlled diseases become uncontrollable, leading to epidemics. But knowing the potential origins of disease in a community helps recovery efforts and leads to the prevention of disease outbreaks.

Prevention of Infectious Diseases Starts with Mass Vaccination Campaigns 

The coordination and execution of mass immunization campaigns during disaster recovery helps to limit infectious disease outbreaks. According to Dr. Jonathan Ameli in a 2015 article in the Turkish Journal of Emergency Medicine, common and preventable infectious diseases that occur in the wake of disasters include:

• Hepatitis A
• Japanese encephalitis
• Measles
• Meningitis
• Pertussis (whooping cough)
• Tetanus
• Diphtheria
• Typhoid
• Varicella (chicken pox)
• Yellow fever

It is vital to immunize populations that have low immunity rates or those who are more vulnerable to disease, such as children, immunocompromised individuals, the elderly or the homeless. Immunization of these groups is one of the most cost-effective ways to prevent the outbreak and spread of infectious diseases, say experts Najmeh Jafari, Armindokht Shahsanai, Mehrdad Memarzadeh and Amir Loghmani in the Journal of Research in Medical Sciences: The Official Journal of Isfahan University of Medical Sciences.

Since cholera broke out on Haiti after the 2010 earthquake, there have been other excessive cholera outbreaks on the island due to hurricanes and flooding.

In a community trial, health professionals administered a cholera vaccine to more than 800,000 Haitians to stem the most recent outbreak. The international health community now recognizes the importance of this type of mass vaccination campaign, according to medical professionals Francisco Luquero and David A. Sack, writing in The Lancet.

Water Sanitation Also Critical in Preventing Spread of Infectious Diseases

After a natural disaster, waterborne diseases are typically the primary cause of infectious outbreaks. Access to safe water sources for consumption, cooking and food preparation, and personal hygiene are paramount.

The proper treatment and disposal of human waste, however, can be compromised, leading to diarrheal diseases. After floods, standing water is a breeding ground for the transmission of infectious diseases. Both the local population and relief volunteers must wear protective attire to reduce the risk of infection.

For instance, leptospirosis (or the more severe form: Weil’s disease) is a bacterial disease caused by contact with the urine of animals. When flooding occurs in places where this disease is already endemic, such as Puerto Rico, it can lead to a new outbreak of leptospirosis. According to the Centers for Disease Control and Prevention, there were increased cases of this disease after Hurricane Maria devastated Puerto Rico this year.

Access to Necessary Healthcare Services Critical for Preventing Disease Outbreaks

Ensuring access to essential healthcare services is critical in preventing infectious diseases. Early diagnosis and confirmation, proper treatment, and secondary and tertiary preventative care can prevent deaths and limit morbidity rates.

In the event of an outbreak of an infectious disease, healthcare facilities should establish isolation rooms for patients who are infectious or suspected of being infected. The loss of healthcare facilities can result in infectious diseases being misdiagnosed or going undiagnosed, report medical experts Claude de Ville de Goyet, Ricardo Zapata Marti and Claudio Osorio.

For example, measles is a potentially severe disease that can be prevented through vaccination and patient isolation. But patients must have access to the appropriate health infrastructure to prevent measles. According to the World Health Organization, supportive therapy also can help to prevent death from measles.

Preventing Vector-Borne Disease Transmission

Excessive flooding and standing water from storms are breeding grounds for mosquitoes that transmit infectious diseases like malaria, dengue fever, West Nile fever and Zika fever. But the most effective preventive approach to control mosquito vectors is the application of anti-mosquito chemicals and the removal of standing water sources. Personal protection in the form of insecticide-treated bed nets and repellant sprays also reduce the individual risk of infection from vector-borne diseases.

World Health Organization-affiliated experts John T. Watson, Michelle Gayer and Maire A. Connolly note that both earthquakes and floods have led to malaria outbreaks in Central and South America. Similarly, recent hurricanes have increased the risk of transmission of Zika, dengue, chikungunya and malaria in the Caribbean. The risk of contracting the Zika virus prompted the CDC to recommend that women who are pregnant or planning pregnancy to avoid Caribbean travel due to the risk of congenital defects.

Overall, infectious diseases can be prevented by:

• Ensuring safe food and water sources
• Executing mass immunization campaigns
• Ensuring access to health care services
• Executing various measures to control and prevent vector-borne diseases

Implementing control measures is effective in reducing unwarranted morbidity and mortality rates in the weeks and months after a disaster. But regular surveillance, community outreach and prevention methods are also necessary to prevent the disease outbreaks that follow natural disasters.

About the Authors

Kimberly A. Smith is a veteran of the United States Air Force, where she served as a public health technician for 13 years. After practicing and applying public health principles across the world, she elected to pursue a future in public health after her separation. Upon the completion of her Bachelor of Science in Public Health degree, she ambitiously and unhesitatingly decided to continue her education journey towards a Master’s in Public Health degree. She is currently enrolled at the School of Health Sciences at American Public University System.

Dr. Jennifer Sedillo is an associate professor of public health at APUS. She has held this position since receiving her doctorate in Public Health in 2014. Her expertise is in infectious disease research and microbiology.