Wednesday, July 28, 2010

Waterborne Diseases


With ever so massive population growth, the scarcity of food, lack of shelter and non-availability of clean water to all is becoming one major global issue for humankind. The water shortage alone, has become life-threatening. People are left with no choice but to consume water from whichever source they can, be it wells, natural rain water reservoirs, offshoots of river banks, man-made wells. The picture turns more pathetic when as is a common observation made in rural areas that human population is consuming water from the same source as being used by domestic as well by wild animals. Add to this, the industrial wastage being dumped so casually into water reservoirs, which can become a source of human as well as animal consumption.

The hazards which can result from such a compromise, are so devastating that widespread epidemics of life-threatening diseases can engulf a massive area of population. It can either result from drinking untreated water or using dirty water for cooking and bathing. One can easily conclude from the situation prevailing, the heavy burden the health facilities have to bear in order to combat situations for which they have not been prepared to handle. This poses much greater concerns in third world countries as compared to developed ones, where not only the authorities make it possible for all the residents a clean supply of water, but also educate people on avoiding exposing themselves from unhygienic water.

International monitoring of situation

- Data of general concerns.

1.1 billion people globally don’t have access to clean drinking water.
2.4 billion people globally are not provided with proper sanitation facility.
2.2 billion people die each year due to water-sanitation and hygiene related diseases.
82 million disability adjusted years are lost annually (DALYS) (R Bos, 2004)

- Data related to specific diseases.

2 billion people are infected with schistosome and soil helmithes,300 millions of these have serious illness resulting from such infestations (WHO report)

1 million people die of malaria each year (largest group being children under 5 years of age) mainly in south Sahara in Africa.

365 million cases/year of acute illness is caused only by malaria alone (pregnant woman are the major group effected)

42 million DALYS by malaria are lost each year as estimated in year 2001

Diarrhea due to multiple causes accounts for 4% of all deaths and 5% of DALYS each year.
In some regions ,specific toxins creat health situations, e.g. in Bangladesh 35 million people are exposed daily to elevated levels of Arsenic, which not only is a health hazard but also shortens life expectancy.

Sources of water pollution

- Contamination by sewage and water treatment residue.

Both surface of land and water sources meant for human consumption get contaminated, when raw sewage overflows, if there is excessive storm water flow, which in urban areas run parallel to sanitary sewer system, resulting in overflow contamination. The grave consequence of such an event is bacteria and viruses like vibrio cholera, salmonella typhi, E.coli, Giardia, Hepatitis, cryptosporidium and helminthes as well as chemical toxins like nitrates, metals etc. polluting the water meant for human consumption, giving rise to epidemics of cholera, typhoid and hepatitis etc.

- Septic tanks overflow.

These are enclosed storage spaces, where sewer is treated before dumping takes place, and it is mostly adopted in rural areas where there is no proper sewer system. This system can fail, resulting in premature entering of untreated sewer into main water reservoirs, which can be future sources of human consumption.

- Sewer lines leakages.

From industrial or domestic sewer, waste water can contaminate drinking water source if the delivery pipes are damaged and leakage goes on unabated. The damage to living being in such situation can be enormous, such as chlorides, micro-organism, organic and trace metals, and other chemicals causing life threatening diseases getting mixed in otherwise safe water sources.

- Contamination from agricultural lands.

In agricultural sector, pesticides are being extensively used, to protect the valuable crops from weeds, rodents, insects harmful to cotton fields, and moulds. They are mostly alachlor, atrazine, cyanazine, metlachlor -- all being potential cancer forming substances in human beings. They easily get into drinkable water source as runoff from lands used for growing crops, especially when the crops are young and can not reduce the concentration of these toxic substances by consuming more and more water and hence the pesticide runoff too.

Specific Disease Condition From Contamination of Water

Water born diseases can be caused by:

- Viruses
- Bacteria
- Protozoa
- Intestinal parasites

a) Viral infections through contaminated water

Adenovirus flu is caused by adenovirus which spreads through improperly treated
water. Symptoms of sneezing, coughing, body aches with moderate to high degree fever are usual present but complication of croup and bronchitis to -- as severe as -- pneumonia can develop.

Treatment: Complete bed rest, increase in fluid intake, steam inhalations, antipyretics to control fever, and in case bacterial pneumonia complicates as
is usually happens, then proper antibiotics to prescribed.

b) Viral gastro-enteritis

Caused by Parvo, enteric, Adeno and Astro viruses, manifest with symptoms of vomiting, loose motions, malaise, abdominal cramps with or without fever.

Treatment: Because there is a greater risk of dehydration, the basic aim of management is quick replacement of fluids, and electrolytes, that can either be done by intravenous route or oral route after control of vomiting.

c) Hepatitis A

This is the result of infection caused by hepatitis A virus in contaminating water for human consumption. It effects human liver acutely, giving rise to symptoms of loss of appetite, nausea, weakness, pain abdomen, vomiting, itching, yellow coloration of eyes(jaundice), with or without fever.

Treatment: Complete bed rest, high caloric, protein and a low fat diet is all that is required. It is a self-limiting condition like most of the viral infections.

In addition to above mentioned common diseases, there are less common ones which can be spread via contamination of water meant for human consumption, such as polio myelitis, caused by polio virus and spreading when feces of infected person contaminate drinking water sources. SARS (Severe Acute Respiratory Syndrome) caused by corona virus when improperly treated water is supplied to population.


d) Bacterial infection through contaminated water

Typhoid fever is caused by salmonella typhi when feces of infected person contaminates water reservoir and when the infected person handles food for human consumption. The main feature of typhoid fever is the stepladder pattern of high grade fever, which is sustained, and never touches the baseline unless infection is controlled by proper antibiotics. Other features include profuse sweating and abdominal pain, with or without loose motions. Rash may be seen specially on trunk.

With the availability of laboratory facility, early diagnosis and prompt treatment, fatality due to typhoid fever is rare.

Treatment: Complete bed rest, high calorie diet, intravenous or oral fluids to compensate for any electrolytes /calorie deficiency, symptomatic treatment with specific antibiotics to control bacterial infection. As part of preventive measures, patient should be nursed in isolation, strict hygiene must be followed, whether the patient is hospitalized or cared at home environment. Washing hands after attending the infected person under treatment.

Dysentery is also caused by different strains of salmonella and shigella group of organisms, when drinking water gets contaminated by sewage water or persons handling food are infected by causative bacteria. Predominant symptoms are frequent passage of stools with or without cramps, mixed with blood or mucus, in some severe cases vomiting of blood.

Treatment: Soft, easily palatable diet, fruit juices, and soups should be given at frequent
intervals to combat the generalized weakness resulting from illness, if there are any signs of
dehydration.