By: Lori Lewis (Guest Writer)
Cholera, Malaria, and Dengue Fever have been plaguing humans for centuries, and although scientific breakthroughs have brought about cholera vaccines and malaria prophylactics, these three diseases continue to be a source of illness and death for millions of people in today's world. The common link for these three very different diseases is their relationship with water. Cholera, a bacterial illness, can be acquired when sources of drinking water have been contaminated. Malaria is caused by a parasite, and a virus causes Dengue Fever. Both malaria and Dengue fever are carried by mosquitoes, which lay their larvae in still water. All three diseases are becoming more prevalent as the effects of climate change are emerging.
The incidence of Dengue Fever is on the rise, and one reason behind this is the rapid urbanization of tropical areas (Chandra, Kashyap, & Singh 2010). When population growth outpaces the existing infrastructure, wastewater treatment systems are unable to cope with the influx, garbage and sanitation facilities cannot contain the increased refuse, and access to clean, treated drinking water may not be available. All of these conditions contribute to the possibility of excess water pooling, which creates the perfect environment for disease causing mosquitoes to breed (Sergo 2007). When drinking water is unavailable through a community system (either wells or through a home tap), it must be carried and stored near the home. Uncovered containers of stored drinking water are also the perfect habitat for breeding mosquitoes.
Malaria, a disease caused by parasites that enter the blood through the bite of a mosquito, causes fever, anemia, and can lead to severe complications and even death. Malaria is being found more frequently in areas where it was never prevalent before. Some scientists think this might be due to rising global temperatures, which allow mosquitoes to thrive where it was once too cool for them to live (Barclay 2008). The same factors that promote the spread of Dengue fever also apply to the spread of malaria. The use of pesticides and treated mosquito nets, along with neighborhood cleanup of garbage and debris, can help to reduce exposure to the mosquitoes. However, the toughest issues to control are those that contribute the most to increasing the incidence of mosquito-born illnesses: population growth, insufficient infrastructure and civil services, and changing weather patterns.
Epidemics of cholera, a bacterial illness that causes severe watery diarrhea and vomiting, are seen more often during times of disaster, when community infrastructure has been destroyed or compromised. Floods, earthquakes, and civil unrest can lead to the breakdown of community services. Lack of access to improved sanitation facilities can cause the bacteria to leak into the water supply, thus having the potential to infect all who drink the water. This bacterium spreads very easily from person to person, and in times when fresh, clean water is not available for drinking and hand washing, caretakers of the sick can infect themselves and others very easily (Falco and Smith 2010). The recent outbreak of cholera in Haiti is a prime example of the need for sanitation facilities to be erected immediately after a disaster. With hundreds of thousands of people without access to clean, running water or toilet facilities, many people have no choice other than to defecate in the open, which further complicates the ability to keep the spread of the cholera epidemic under control (Falco, et al. 2010).
According to Hamlin (2009), "'Cholera forcing' - the idea that cholera 'forces' beneficial changes in public health - is probably the best-known case of the myth of the good epidemic: public health infrastructure is inadequate; sooner or later an epidemic arrives and flourishes in these foul conditions; then, technological changes that had not seemed possible become imperative." One common theme emerges when discussing these three diseases. The areas that are most prone to epidemics of cholera, dengue fever, and malaria are areas of the world that are home to some of the world's poorest people. In order to control these and other infectious diseases, it is imperative that people in these regions have access to clean, safe drinking water and improved sanitation. Building wells and latrines before a disaster or an epidemic strikes would provide the basic human rights these citizens need to protect themselves against three of the world's most dangerous diseases.
Barclay, E. (January 9, 2008). Climate change fueling malaria in Kenya, experts say. Retrieved from http://news.nationalgeographic.com/news/2008/01/080109-malaria-warming.html
Chandra, S., Kashyap, S., & Singh, A. (2010). Dengue syndrome: an emerging zoonotic disease. North-East Veterinarian, 9(4), 21-22. Retrieved from Global Health database.
Falco, M., Smith, M. (November 18, 2010). Poor sanitation could worsen Haiti cholera outbreak, CDC says. Retrieved from http://www.cnn.com/2010/HEALTH/11/18/haiti.cholera.sanitation/
Hamlin, C. (2009). "Cholera forcing": the myth of the good epidemic and the coming of good water. American Journal of Public Health, 99(11), 1946-1954. doi:10.2105/AJPH.2009.165688.
Sergo, P. (August 10, 2007). Dengue fever warming up to human habits. Retrieved from http://www.scienceline.org/2007/08/environment-sergo-denguefever/