Africa: Infectious diseases and prevention (1)

Did you know that diarrheal disease accounts for an estimated 4.1% of the total global burden of desease and is responsible for deaths of 1.8 million people every year, all over the world?

In 88% of all these cases, the development of diarrhea is due to usage of insufficiently purified water, often contaminated with feces, urin or other agents.

Second problem are bad water supply systems, and also poore hygiene of people. This is very common in developing countries of Africa, and unfortunately most of victims are children.

Water filtering systems

Investing in new, more efficient systems for transport of water, in units for filtering smaller quantities of water for villages in remote regions is infrastructural base for rising the awarenes in the minds of people about importance of using the pure, filtered water as a basic "tool" for prevention of deadly diseases.

Infectious diseases are caused by pathogenic microorganisms. Pathogenicity stands for a potential of certain microorganism to induce the development of desease in it`s host (humans, animals).

Types of infections:

• Protosoal infections: Amebiasis (Entamoeba hystolitica) - infectious amoeba that can cause diarrhea. Source: dirth (ground), unfiltered water. Transmission: fecal-oral route. This amoeba is responsible for 70 000 deaths every year. Location: western and southern Africa. Prevention: good hygiene and usage of pure water.

Contamination of water with sewage

• Parasitic infections:Schistosomiasis (cl. Trematoda) - infectious fluke. Although it has a low mortality rate, schistosomiasis often is a chronic illness that can damage internal organs and, in children, impair growth and cognitive develompment. Source: contaminated water with urin and feces. Transmission: penetration trough the skin of host during swimming in contaminated water. Facts: Schistosomiasis is the second most socioeconomically devastating parasitic disease after malaria - 100 million people infected every year. Location: tropical countries of Africa, western-central Africa.Prevention: Castor oil (oral) - antipenetration agent.

One of characteristic signs of schistosomiasis - destended belly.

• Parasitic infections: Dracunculiasis - (Dracunculus medinensis) - more commonly known as Guinea worm disease is parasitic infection caused by nematode worm D. medinensis. Source, Transmission: usage (drinking) of water contaminated with Copepodes (small water crustaceans that host larvae of D. medinensis). That enables larvae to enter the body (when copepodes are desolved in the stomach), and then to leave the stomach and finde a mate in abdominal cavity. After copulation females attache themselves to connective tissues or long bones. After almost one year after initial infection, worm starts to move towards skin(lower extremities) in attempt to leave the body. When it reaches the skin it forms a blister; that causes a very painful burning sensation as the worm emerges.Within 72 hours the blister ruptures, exposing one end of the emergent worm. When that happens, painfull burning sensation force people to immerse the affected limb in water to relieve this burning sensation - that enables the worm to release hundreds of thousands of worm larvae. Treatment: Mechanical removal of the worm.Mechanical removal of the mature worm

Prevention: usage of pure water (filtering), usage of chemicals for killing the Copepodes.

Risks: Secondary bacterial infections (tetanus) - poore health care in developing countries.

Facts: 200 million (worldwide) every year, 200 000 deaths.

Location: Sudan, Ghana, Mali, Ethopia (endemic countries). Total eridication (destruction) of worms is possible (trough behaviour change) because every generation of worms need a human host for development every year, and there is no known animal or enviromental reservoir of worms.

Sudanese boys using pipe filters to prevent Guinea worm disease

Summary: Infectious diseases are caused by infectious microorganisms or worms. Source of these pathogens are dirth and with feces and urin contaminated water (sewer). Prevention is building efficient water filetring systems and usage of chemicals for desinfection of water. Usage of available vaccines and infection preventive drugs. Education of people about general hygiene.