Do seasons have effect on e coli levels

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Escherichia coli (E.coli) is a common species of bacterium that lives harmlessly in the intestines of humans and animals. The bacterium can also found in streams and other water sources as it is passed out of the body in faeces. E.coli is a common word that is often associated with water pollution. In the Msunduzi River in Pietermaritzburg tests are conducted every day to calculate the number of E.coli present per 100 ml of water. These tests prove to be very important for prospective paddlers wanting to take part in the popular canoe marathon. However there are many settlements along the Msunduzi River that get affected by the water pollution on a daily basis. This aim of this report is to determine whether or not there is a connection between E.coli and the seasons and how the E.coli affects the people living along the Msunduzi River.

1. How E.coli enters the Msunduzi River

E.coli is found in the gastro-intestinal tract of most humans and animals shortly after birth. For this reason, E.coli is constantly being passed out of the bodies in human and animal waste. From here there are many ways in which E.coli gets into the water. Along the Msunduzi River there are many farms with cattle and feedlot. During heavy rainfall the E.coli is washed, along with the faecal matter, into rivers and streams, all entering the Msunduzi River. There are also sewage works along the Msunduzi River. When there is heavy rainfall, the sewers cannot cope with the excess water and sewage pipes overflow, thus exponentially increasing the E.coli levels in the river. Some people who live in rural settlement along the river do not have the appropriate pit latrines or toilets, and then the river is used to dispose of faecal matter. In some cases there are pit latrines but they are too close to the river and the feaces seep into the river along with the E.coli.

1.1. Use of E.coli as a water quality indicator

Coliform bacteria is not pathogenic itself, however it is a very good indicator of what other disease causing bacteria could be in the water. E.coli is a coliform bacterium that is present in both human and animal intestines and for this reason it is a good indication of other pathogens present in the water. If there is a lot of E.coli in the water, this means that there are many other types of bacteria in the water as well, of which some could be pathogenic. The accepted number of E.coli /100ml of drinking water is zero. E.coli is heat sensitive and water could be sterilized by boiling it. People living alongside or close to the Msunduzi River should sterilize their water by boiling it.

1.2. Levels of E.coli safety

For drinking: 0 E.coli/100ml, for swimming/ paddling: 5000 E.coli /100ml. Water safety is very important along the Msunduzi River as there are permanent residents living along it. Locals are badly affected by sewage-borne diseases such as cholera, diarrhoea and hepatitis as a result from poor water quality. At times the Msunduzi River is up to 3000 times higher that what is considered acceptable for in a septic tank system. The HIV has already infected many of the locals on the Msunduzi River and these poor water quality results have devastating effects on these people.


Table 1 to show current drinking water standards. (Prescott Harley Klein, 2005)


Allowable Maximum Contaminant Level Goal


0 (no faecal coliforms either)



Giardia lamblia






Table 2 to show number of E.coli and the safety of these conditions: (uMngeni Conservation Trust. (2009)

E. coli count / 100 ml

Canoe use class

0 - 2000


2001 - 5 000


5 001 - 10 000


10 001 - 25 000


25 001 - 50 000


50 000 - 150 000


>150 000


2. The Effects the seasons have on E.coli levels

From the two graphs shown in Figure 1 and 2, there is a general trend that both the average precipitation and the levels of E.coli present in the river drop during the winter months in Pietermaritzburg. Although the graph in Figure 2 is very ragged with inconsistent peaks, there is a definite downward trend from May to September, the low rainfall months. As soon at the rainfall increases again in the summer months, the E.coli once again begin to peak. This shows that the levels of E.coli and rainfall are related to one another.


Graph 1 to show average rainfall in Pietermaritzburg (South African Weather service. (2003).)

Graph 2 to show E.coli levels in Slangspruit River in 2009 (Terry, S. (2010, May 28) Personal Communication)


2.1. E.coli and Precipitation link

E.coli occur naturally in the intestines of humans; here it has the optimum opportunity for growth as it is warm, dark and hydrated. When the E.coli passes out of the body in the faeces, it is no longer in its natural environment. There are organisms such as algae and zooplankton in the water that feed on the E.coli and this bacterium is also highly sensitive to the ultra violet rays of the sun. For this reason E.coli does not survive for long. In the less rainy months of the year, there is less water flow in the Msunduzi River and E.coli settle to the bottom of the river, leaving the water relatively safe. When there is heavy rainfall, more faecal matter seeps into the water, sewage systems are put under pressure and sewage pipes end up bursting or leaking, increasing the E.coli seepage into the river. As the water is also under alloy of pressure from all the rain, the E.coli do not get a chance to settle down in the river beds.

3. Health effects of E.coli on the local inhabitants on the Msunduzi River

Contamination of water by human and animal faeces is still the greatest danger because of the E.coli. E.coli itself is not the greatest threat as it is merely an indicator organism. Indicator organisms are used to measure how much faecal matter in present. When indicators such as E.coli are not found in the water sample, it can be assumed that the water is potable. Potable water is safe and suitable for drinking. E.coli serves an important purpose in the process of digestion and they are part of the gut that is responsible for the breaking down of some sugars and proteins. However there are certain strains of E.coli that can be harmful, producing powerful toxins that can cause both bloody and non-bloody diarrhoea and abdominal cramps. The toxins attach themselves to epithelial cells which line the intestinal walls, which eventually damage the blood cells. In older people these toxins can cause kidney failure as a result of their red blood cells being destroyed. People who have AIDS, or other long term illnesses, are at a greater risk of contracting infection from this water, and the health issues related would be more serious. Usually the body’s natural defenses overwhelm the bacteria. However in young children the defense system has not yet fully developed while in older adults this defense system may be compromised.

3.1. Symptoms of water-borne infections

3.1.1. E.coli

If a person is infected by E.coli, the symptoms do not appear straight away. They usually appear after seven days, when abdominal cramps suddenly occur. A few hours later diarrhoea causes one’s body to lose a lot of water and electrolytes which make one feel tired and sick. For the first day the diarrhea will be watery, then it changes into a bright red bloody diarrhoea. This leaves your intestines full of sores and this could last up to 5 days. Some people may have slight temperature and sometimes the dehydration could cause nausea and vomiting. Kidney problems could start as little at 2 to 14 days after the start of the diarrhea and these problems could be the cause of kidney failure. This is sometimes a long term disability for children and adults, possibly resulting in death. HUS (heamolytic uraemic syndrome) occurs when the blood vessels in the kidney are damaged, and this is a serious illness can result in many complications including blindness, strokes, paralysis and seizures.HUS is the most common reason of acute kidney failure in young children, less than the age of 3 .For these reasons, people must get medical assistance when they contract this infection. This is a problem for the locals who live along the Msunduzi River as they do not always have access to clinics or doctors and their health just continues deteriorating.


3.1.2. Dysentery

Dysentery is a disease of the large intestines that is caused by a Shigella bacterium .Dysentery is passed on by contact with infected humans and also by contaminated faeces. The lining of the intestines gets inflamed and this causes fever, abdominal pain, nausea, vomiting and a watery diarrhea that sometimes includes blood and mucous. The diarrhea causes people to lose salts and other important fluids in the body. When infected with Dysentery, constant fluid intake is essential to replace the fluids lost. People should not be in contact with others until they are symptom free for at least 48 hours.

3.1.3. Cholera

Cholera is an illness of the intestines caused by the Vibrio cholera bacterium. The infection can have minimal symptoms however if left untreated the symptoms could be severe. The symptoms include watery diarrhea and vomiting. The rapid loss of fluids in the body can cause dehydration and shock. Cholera is passed on by drinking or eating contaminated food and water. The treatment of Cholera is to replace the fluid lost by the diarrhea.

3.1.4. Typhoid Fever

Typhoid fever is contracted when people drink or eat food contaminated by the Salmonella typhi bacterium. The symptoms of Typhoid include the sudden loss of appetite, fever, constipation, nausea and severe headaches. It can sometimes cause a hoarse cough and diarrhea. Typhoid fever is dangerous as the symptoms of the fever can stop, although the person can still be a carrier of the bacterium, infecting other people.

4. Authority’s Role to improve situation

The water pollution, specifically faecal matter, needs to be dealt with very seriously, starting with the municipality. Ventilated Pit Latrines need to be installed in the rural areas along the Msunduzi River specifically along Slangspruit River and in the Edendale area where there are rural communities. The Msunduzi Municipality needs to employ more skilled staff to monitor and possibly replace and repair sewage systems along the river. Properties along the river need to be inspected for storm and waste water management. Some industries illegally disperse of their industrial wastes into the river and all these sites need to be inspected as well. There is over 1450 kilometers of sewage pipeline and there are only four sewer inspectors. Some years back there were eight. More staff will improve the problem with broken pipelines allowing faecal waste to leak into the river as there will be more frequent checkups on the pipelines and when a pipe does burst, the repair could be much faster and reliable.


The E.coli problem in the Msunduzi River is an issue that only seems to appear when it is related to paddling or the health issues of the Msunduzi canoe marathon. However these people are only affected when they use the river for recreational use. There are people who live along the Msunduzi River in settlements who rely on the water on a daily basis. This water is not potable and it can be very dangerous if they ingest it, but it is also the elderly who are forced to make use of this water as well as the small children. The local inhabitants of the Msunduzi River are at a greater risk of illness during the rainy summer seasons where sewage pipes are under pressure or when they overflow into the river. It is not the E.coli itself that the people should fear; it is all the other possible pathogenic faecal bacteria in the water. E.coli levels increase in the summer seasons as this is when the Msunduzi River receives most of its annual rainfall. This is the time that most of the water-borne infections appear as the increase of E.coli indicates an increase of other pathogenic bacteria.

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