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Disease Implications of Water

Naegleria Fowleri

by Meredith Roberts

Chlorovirus: A Brief

By Nicole Kraatz

Recently, a virus normally known to only infect plants, such as algae, has been found in a the throats and mouths of a specific population in Baltimore in a study being conducted by researchers at the University of Nebraska and Johns Hopkins. Chlorovirus is a large DNA virus, typically found in fresh water that can infect endosymbiotic strains of the unicellular green alga Chlorella. The virus can form plaques on lawns of the green algae. Until this unexpected discovery, the virus was found to solely infect plants and not humans. The virus has never been able to transfer from different kingdoms before, let alone transferring from plants to humans.

The original purpose of the study being performed by the researchers was to try and figure out the biological effects of certain microorganisms that are known to live in the human body. They were performing multiple assessments, some of which were cognitive tests. Along with the assessments, researchers of the study swabbed the throats of the participants to perform genetic analysis. When testing the original 33 people in the study, it was noted that 40% of the population in the study had the chlorovirus living in either their mouths or throats. After this alarming discovery, researchers compared cognitive data in those that had the virus in their mucous membranes to the data of those that did not have the virus. Analysis showed that those that had the virus processed visual information about 10% slower than those that did not. The researchers could not attribute the slower visual procession to any other outside factor, such as socioeconomic status, smoking habits or race.

In order to continue studying the prevalence of the chlorovirus in the population, the researchers of the study added an additional 59 participants. Out of the total 92 participants in the study that were tested, 40 were found to have the virus. A very similar percentage as the initial group. In addition to adding more human participants, the researchers also tested the affect of the virus in mice and found that mice containing chlorovirus navigated mazes 10% slower than those that did not and also also spent 20% less time exploring new surroundings. 

Because of the small number of people in the study, researchers have yet to discover if the virus transferring to humans is contained in the specific population or if it is a common occurrence in other parts of the world. However, with these findings, scientists may be able to work on ways to try and improve normal cognitive function and behavior in humans by changing the composition of organisms around them.

Birth Defects Associated with Impaired Water and Water-borne Pathogens in the U.S.

by Saima Hedrick

According to the CDC, birth defects are the leading cause of infant mortality in the United States. Studies show that these birth defects are caused by consumption of impaired water.

Municipal water in the U.S. is disinfected with chlorine to before it is piped to the populous for consumption. The chlorine can react with natural organic compounds and create disinfection by-products (DBPs), which can cause birth defects. A study conducted by the California Department of Health Services showed that consumption of chlorinated drinking water could result in spontaneous abortion. The study focused on the effects of trihalomethanes (a class of DBPs). A similar study of Norwegian births over a period of 6 years, showed that exposure to chlorinated water high in natural organic compounds increased the risk of birth defects. In Chesapeake, VA, 214 women filed a lawsuit against the city due to the high levels of trihalomethanes in the water. This was the first time residents had taken legal action against a city for water-related grievances. Several chlorine studies ensued, but the EPA did not set any limits for these compounds because there are over 500 possible DBPs. In order to determine which compounds cause illness and where they occur in high concentrations, the EPA is currently conducting a nationwide study.

Another problematic compound is perchloroethylene (PCE) which is a solvent used in dry cleaning products and the textile industry. PCE readily evaporates into the air, but can also seep into the ground, where the soil is unable to neutralize it, and ultimately into the groundwater. A study of birth defects in Massachusetts revealed that any prenatal PCE exposure can increase the risk of neural tube defects or oral clefts three-fold. The risk was also higher in women that were exposed around the time of conception. The EPA’s maximum contaminant level (MCL) for this compound is 5 g/L. However, in areas where the main water source is groundwater, PCE contamination is unchecked. According to the EPA’s Cleanup Sites list, there are 106 sites of PCE contamination in New England alone.

Atrazine, a corn herbicide, has already been banned in Europe but is still used in the U.S. A USGS survey showed that 75% of stream water and approximately 40% of groundwater in agricultural areas contain atrazine. A comparison of the USGS data with U.S. birth defect rates revealed that there is a correlation. The ethical restrictions of doing a human study of atrazine, and most other suspected teratogens, make it impossible to get conclusive data. However, animal studies have shown definite birth defects associated with atrazine exposure.

Arsenic is used in the wood preservation industry and can contaminate groundwater. In 2000, the USGS released results of a nationwide arsenic sampling study that showed that 25% of groundwater in each county contained arsenic. Animal studies of arsenic have shown that high concentrations can cause birth defects. Retroactive human studies have not yet been conducted.

Similarly, hexavalent chromium has been shown to cause birth defects in animals and there is no conclusive data in humans. However, the EPA warns that chromium can be transferred to the fetus and must be avoided.

Toxiphene, a pesticide banned in 1990, is still being detected in waterways near agricultural areas. This is because the compound persists in the soil and runs off into the water with sediment. It has also been shown to cause birth defects in animals.

Volatile organic compounds (VOCs) are another class of compounds that have been proven to cause spina bifida, anencephaly and cleft lip and palate. According to the EPA, one-fifth of U.S. water contains these dangerous compounds.

Water-borne pathogens can also cause birth defects. Salmonella enterica, a bacterium that is normally spread by food, can be found in the water. In 2008, the Colorado Department of Public Health and Environment had to deal with a 33 confirmed cases of salmonella due to contaminated tap water. Although the Salmonella bacterium itself does not cause birth defects, the fluoroquinolones used to treat the infection do. This broad-spectrum antibiotic is often used for genitourinary infections and as a second line of defense after the fist antibiotic does not clear the infection. Although clearly contraindicated in pregnant women, exposure does happen when the infection occurs before the mother and doctor are aware of the pregnancy.

Toxoplasma gondii, a parasite that lives in cats, can get into water and food and infect the human consuming it. An estimated 1.5 million people in the U.S. are infected with this parasite every year. Pregnant women are tested, as part of routine prenatal care, for blood antigen levels for this parasite to make sure that the mother does not pass the infection to the fetus. Toxoplasmosis has been proven to cause serious brain damage to the fetus.

Campylobacter jejuni, is another bacterium that lives in animals that causes campylobacteriosis, a diarrheal disease that is common in the US. C. jejuni is typically found in runoff from chicken farming industry which gets into local waterways. Ingestion of this untreated water can fever, diarrhea, and vomiting. In pregnant women, the bacteria can get into the placenta and cause stillbirth.

Cryptosporidium parvum is an intestinal parasite that causes an estimated 748,000 infections in the U.S. each year. Transmission usually occurs from consumption of contaminated water. Due to the weakened immune state of pregnant women, the sustained diarrhea that can result from this infection can be harmful to the fetus.

Overall, the CDC recommends that pregnant women should not consume any food or water that has not been properly disinfected. In the case of water, this is very difficult as the vast majority of the population does not have water testing kits readily available to make sure that their water is not contaminated. The women involved in the case in Chesapeake, VA simply stopped drinking the tap water and had healthy babies. However, that is not always possible as the contaminated water may be the only source of fluid for the pregnant mother.

Therefore, the EPA and local governments need to increase monitoring and community education efforts so that risks are known and infections are prevented.


Cholera, Dengue Fever, and Malaria:

The Unquestionable Link to Water

by Lori Lewis

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

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.

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.

Battling H1N1

Life during an epidemic

By Rebecca Shore

All over the world epidemics and disease are a part of everyday life. People who live with these problems face serious consequences with health, fear for sick family members and overall concern for what the future holds. However, epidemics, such as malaria, cholera, dengue and typhoid do not occur solely in developing nations, recently an epidemic of H1N1 struck the United States. All of these illnesses are extremely serious and have caused countless deaths in many countries. However, they are also very treatable, but without proper care or education, they can both become quite serious and deadly.

Malaria is one of the leading causes of death in Africa and Asia. In 2008, the World Health Organization estimated that 190 to 311 million cases of malaria were reported and 708,000 to 1,003,000 people died of malaria, most of them children in Africa. Malaria is a serious and often fatal sickness caused by a parasite that lives in some female mosquitoes. When a person is bit by an infected mosquito, it transmits the parasite through its saliva into the red blood cells. Within a couple of weeks the person begins to feel flu-like symptoms, including joint pain, headache, chills, and sometimes anemia. If he or she is not treated, then the infection will progress to kidney failure, confusion, coma, and death. However, if treated with medication, malaria is very easily treated. For people traveling outside of the United States, to areas with high prevalence of malaria, there are pills that can be taken to help reduce the risks of contracting the infection.

Two years ago, while volunteering in Bagamoyo, Tanzania, I was infected with malaria. One night I was outside with some friends and I was bitten several times by a mosquito; one week later I woke up sick. Although I can laugh about it now, the morning I woke up feeling sick was the worst feeling I have ever experienced. At that moment, I knew what it felt like to be dying. My muscles and joints hurt, I had no appetite, I was very fatigued, and I felt extremely feverish. Luckily for me, I was treated very quickly at the local clinic and I had the five dollars it cost to buy medication. My experience with malaria, although scary, is not comparable to the stories of the locals who contract the disease. Often times, they have to walk hours or even days to reach the closest hospital or clinic, and once they get there they have to wait several more hours until they can be seen. Then they have to have enough money to buy the medication. For them, malaria means death unless they can find somewhere to get the money for medicine. Unfortunately people can contract malaria over and over again, which makes it difficult with families with lots of children to always have the funds available for healthcare. As a result, thousands of people die yearly, mostly children who do not have access to help.

Dengue fever is an infection also transmitted through mosquitoes. It is estimated that there are over 100 million cases of dengue worldwide each year. When a person contracts dengue, they experience fevers, headaches, pain behind the eyes, rash, and bleeding such as nose bleeds. In its most severe cases dengue fever causes failure of the circulatory system leading to death. Although there is no specific treatment for dengue, rest, hydration and pain relievers can help reduce the risks of death. The best way to avoid contracting dengue is to properly cover any still water, so water jugs must be covered to avoid mosquitoes laying their eggs in them.

Recently, there have been several small outbreaks of dengue in Queensland, Australia. The three most recent outbreaks took place in January and February 2011 when 8 people, 42 people, and 9 people got sick. Queensland Health has developed a Dengue Fever Management Plan to help the government properly control the outbreaks. The DFMP focuses on three major aspects, disease surveillance, mosquito control and surveillance, and education. People living in Queensland face the fear of having another outbreak pop up at any time. Therefore, many families have begun to focus on prevention, such as mosquito repellent, mosquito zappers, and getting rid of mosquito breeding grounds to help alleviate the problem. Although dengue is usually not a serious infection, it still affects families all over the world.

The third global epidemic is cholera. An estimated 3 to 5 million cases and over 100,000 deaths occur each year around the world. Cholera is found in water or food sources that have been contaminated with feces from an already infected person. Most commonly, it is found in areas with poor water sanitation and inadequate hygiene. In most cases of cholera the symptoms are often mild or even none existent. However, one out of every 20 people who contract the infection will have severe symptoms, such as profuse, watery diarrhea, vomiting and leg cramps. In these cases, rapid dehydration and shock occurs, and death can occur within hours. If caught early, cholera can be treated by rehydration and replacement of salts. Severe cases also require intravenous fluid replacement. With prompt rehydration, less than one percent of cholera patients die.

In October 2010 a cholera outbreak was confirmed in Haiti after the January earthquake that hit the country. Since cholera had not been documented in Haiti for many years, it was considered unlikely that an epidemic would occur, however only months after the earthquake, people started getting sick.

Since then, the CDC has been working to control the spread of the disease and treat those already sick. They are increasing access to oral rehydration formulas as well as improving access to sanitation and clean water. They are also holding sessions for families, communities, and health care providers on the causes, symptoms, and treatments for cholera. Living in an area infected with cholera is extremely difficult but manageable. People must make a conscious effort to drink, cook with, and wash in clean water. They must also be knowledgeable about the food they are eating and where it comes from, to make sure that it is not contaminated. Cholera is a very controllable infection if people have the information to protect themselves and their families.

Typhoid fever is a life threatening illness found both in the United States and developing nations. Each year, about 400 people are diagnosed with it in the US, while almost 21.5 million people are diagnosed in developing nations. Typhoid presents with a high fever, weakness, stomach pains, headache or loss of appetite. It is contracted by people who eat food or drink beverages that are contaminated with Salmonella, or if Salmonella gets into the water people use for drinking or washing food. Consequently, it is more commonly found in countries where hand washing is used less frequently and water is contaminated with sewage. However, there are two simple methods for preventing typhoid fever. First of all, avoid eating foods or drinking beverages that could be contaminated. A good way to do this is to only eat foods that have been thoroughly cooked and fruits that can be peeled, and to only drink from sealed bottles and avoid drinks with ice cubes.

Ryan Bishop, an American who traveled to Mexico contracted typhoid from drinking out of a contaminated bottle, “I got it by drinking from a dirty beer bottle my first night in Mexico. It was a brand new bottle but they washed the bottles with dirty city water.” In this situation, although Bishop followed the suggestions as to avoid typhoid, he unfortunately still contracted it. In communities where people are not educated about how to prevent typhoid, the chances of contracting it are still high. The second way to avoid typhoid is to get vaccinated against it. The vaccination takes a couple weeks to begin working, but it lasts up to a couple of years. By following these two steps, typhoid fever is extremely preventable.

H1N1 is another illness which has affected people here in the United States. In the spring of 2009, the first cases of H1N1 flu were detected, ultimately infecting thousands of people, ranging from small children and babies to the elderly. Also called "swine flu", it was a new virus which had not been introduced to the public, and ultimately became a pandemic, spreading all over the world. Consequently, many more people became sick with influenza than normal. Bua Bishop (pictured above), now a young mother, contracted H1N1 before she got pregnant. “It was the worst flu I ever had,” said Bishop, “I felt tired and I didn’t want to do anything but sleep. My body’s temperature went high all the time even though I just got out from the shower.” Bishop presented with all of the typical symptoms, including fever, cough, chills, sore throat, body aches, headaches, and fatigue. After going to the hospital and getting tested to confirm the diagnosis, she was immediately put on antibiotics. After three days in the hospital receiving shots, she was released and feeling better. Bishop was extremely lucky that her case was not ultimately life-threatening; however several people lost their lives that year to H1N1. H1N1 is both treatable and preventable. By getting a flu shot before flu season begins and staying well hydrated and eating right throughout the winter, lowering the chances of getting influenza are good.

In the end, epidemics are serious threats to people all over the world. They occur in places other than just developing nations and can affect people living in Western nations. With the proper medicine and education, we can help prevent the spread of these epidemics and lessen the death they cause.

Wastewater Pathogens

By Shannyn Snyder

Bacterium in water, also known as pathogens, is a public health hazard with risk factors in nearly all parts of the world. Waterborne pathogens can occur in all types of water sources and are particularly rampant in areas where there are large amounts of untreated wastewater.

Wastewater is defined as any water that has been used, such as for domestic or industrial use and contains waste products. These waste products are most often liquid or solids and they can be biological, chemical or radioactive. In addition to having adverse health implications, wastewater contamination can also have natural and ecological affects. These may include the degradation of ecosystems such as a decrease in important aquatic plants that help preserve the condition of waterways or biodiversity loss such as loss of aquatic life like fish and crustaceans that are an important part of both animal and human diet.

In a large waterway, such as a river or stream that has a continuous flow and a renewable source of fresh water, a small amount of contaminant may not make a considerable impact as there is a natural process of bacteria breakdown if water temperature, dilution and solar radiation are optimal. Streams and rivers, which wind through rocks, pebbles, gravel and sand also have a natural filtration system that can help to break down contaminants. In addition, a certain amount of nutrients is actually helpful in the growth process of aquatic plants, but excessive nutrients can also hasten algae growth which then leads to a decrease in dissolved oxygen. This overgrowth of algae clouds the water and prevents sunlight from permeating, leading to the destruction of important organisms, plant and animal life. Nearly half of the U.S. fresh water resources currently show a disturbance of aquatic species. (Source: 2008, EPA’s Report on the Environment: Highlight of National Trends)

Waterway filled with “sludge.” Source

Heavy, slow-moving, degraded water, filled with an excess of contaminants can also create a sludge, which may contain pathogens such as fungi, worms and toxins. Sludge can also contain fecal bacteria and bloodborne viruses. Examples of viruses commonly found in wastewater are Hepatitis and Norwalk virus and a common fungus is Candida. Common bacteria, such as Salmonella can cause food poisoning where as Vibrio cholerae is the pathogen that causes cholera. Parasites such as Cryptosporidium and Schistomsoma can cause diarrhea, and just about all wastewater pathogens can lead to serious gastrointestinal illness in addition to other, more specific implications, which is significant cause of death worldwide. (Source: 2005, Wastewater Pathogens by Michael H. Gerardi and Mel C. Zimmerman and Rehydration Project: Focus on Diarrhoea, Dehydration and Rehydration)

Even water that looks clear can contain pathogens, as raw waste and pollutants are sometimes discharged into relatively pristine waterways from point and non-point sources. In addition, 60% of shallow wells in U.S. agricultural areas have tested positive for pesticides, and 21% of groundwater wells exceed the federal allowance for nitrates. Public pools, lakes and waterparks are also at risk for E. coli and Cryptosporidium pathogens.

Although many laws, such as the Federal Water Pollution Control Act, the Clean Water Act and the Safe Drinking Water Act are in place to protect the public from waterborne health hazards by controlling the amount of contaminants allowed in a particular water source, it is important that all persons are knowledgeable about good sanitation habits. Paying attention to boil water alerts and not drinking or swallowing water being swam in or used by others are effective ways of limiting a possibility of infection. By dumping refuse into only approved receptacles and holding individuals and entities responsible for unsafe practices, it is possible that the degradation of U.S. waterways can be slowed, and ideally, reversed. This reversal can ultimately reduce the overall occurrences of gastrointestinal illnesses associated with water contamination and may help to prevent nationwide waterborne health epidemics.

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