The Parasites of Poverty

Cultural affects of Schistosomes and Soil-transmitted Helminths

• This presentation will discuss two types of parasites and why they are prevalent in less developed countries.

Intestinal Parasites• Parasites are either:

– Helminths• Worms with many cells• I’ve chosen to focus on

Hookworm, a type of Soil-transmitted helminth because it is prevalent in areas of extreme poverty.

• I’ve chosen Schsitosomes, often known as flukes and are also prevalent in areas of extreme poverty.

Parasites live in or on a host organism and damages the host by using its nutrients for energy to live.

_ Protozoa• Worms with only one cell

Intestinal parasites infect 23 times more people than

HIV/AIDS today.

• The World Health Organization estimates that 1 billion people are chronically infected with soil-transmitted helminths and over 250 million are infected with schistosomiasis.

Species of Schistosomes

There are hundreds of species of schistosomes.

I’ve chosen to focus on the three of the most prevalent.

Three main species of Schistosomes

• Schistosoma mansoni (aka bilharzia, manson’s blood fluke, and swamp fever)

-Live in small veins near the intestines.

- Found in Africa, Middle East,

South America

• Schistosoma japonicum (aka oriental blood fluke)

– Found in the far East

– Live in small veins near the intestine.

– Common in the far east.

• Schistosoma haematobium (blood flukes, snail fever)

– Live in blood vessels in the pelvic regions close to the bladder.

– Prevalent in Africa, Middle East, Portugal

Schistosome Life Cycle

• Eggs leave the host in feces and urine.

• Eggs hatch in water and penetrate the vector-Fresh water snail.– Specific snail species

differ between each species of Schistosoma.

• Hundreds of infectious larvae leave the snail and travel through the water.

• Penetrate the skin of the victim and enter the blood stream.

• Travel through blood to the liver where there is the most nutrients and the adult can mature.

Schistosome Life Cycle Continued

• The females lay their eggs in tiny blood vessels.

• S. mansoni and S. japonicum eggs end up in the intestine and are passed through feces.

• S. haematobium eggs break into the urinary bladder and are released through urine.

• The adult worms can live up to 30 years inside human intestines.

Initial Signs and Symptoms of Schistosomiasis

• Similar to “swimmer’s itch,” the first sign of a Schistosome infection is itching at the site of entry where the bug entered.

Signs and Symptoms of Schistosomiasis

• Long term infection:– Bloated abdomen– Liver and spleen enlarge because

the tissue grows from increased infection of more worms.

– 2/3 of the eggs do not leave via urine but stay in the liver and spleen.

– Remaining eggs burrow in the tissue and create pockets that block blood flow and cause the organ to decay.

• Beginning stage of infection: – Diarrhea, chronic hunger, fever,

chills, sweating, cough, blood in the urine (S. hemaetobium)

• Associated with bladder cancer (S. hemaetobium)

Signs and Symptoms Schistosomiasis Continued

• S. japonicum eggs are sometimes carried to the central nervous system and cause headache, disorientation, amnesia and coma.

Helminths

• Soil-transmitted Helminths– Many types,

Hookworms burrow through the soles of the feet.

• Snail-Mediated• Ingested Helminths• Nematodes

Soil-transmitted Helminths(Hookworms)

• Infected individual contaminates soil with feces containing helminth eggs.

• Eggs develop in the soil.• Other individuals infected

by ingestion through food, dirty hands, or by larvae penetrating the skin.

Hookworm Infection Continued– After penetrating the skin, the larvae travel to

the lungs via the blood stream.– Larvae are coughed up, swallowed, and taken

to the stomach and intestines.– Mature into adult worms in the intestines

where eggs are laid and excreted in the feces.

Initial Signs and Symptoms of Hookworm Infection

• Itching and a rash at the site of where skin touched soil or sand is usually the first sign of infection.

• These symptoms occur when the larvae penetrate the skin.

Signs and Symptoms of a Chronic Hookworm Infection

• Chronic= Light amount of worms

• Abdominal pain, loss of appetite, weight loss, distended abdomen– Hookworms live and

accumulate in the walls of the intestines.

Acute Hookworm Infection

• Acute= large amounts of adult worms

• Abdominal pain and swelling

• Anemia and protein deficiency– The worms live off of the

hosts blood, causing blood loss and iron deficiency. Which leads to weakness and loss of strength.

• Stunted growth and delayed puberty in children, mental dullness.– Caused by iron and protein

deficiencies.

• Craving to eat soil, dry skin and hair.

Mortality rates

• There are no real accurate estimates of mortality rates of parasitic infections today.

• Studies have been done in some areas of the world, but they are not representative of the actual prevalence of the disease.

There are two reasons for this:

– Parasitic infections are usually secondary infections in the developing world where they are most prevalent.

• Infections exaggerate other health problems and cause death to come more rapidly.

• Malnutrition: Intestinal parasites eat up to 20% of a child’s nutritional intake each day. This is the difference between life and death in an already malnourished person.

– There hasn’t been much research and development in the past. Parasitic infections are considered one of the world’s many neglected tropical diseases.

• While there are tests for Schistosomes and Hookworms, testing for parasites are only available for about 5% of the known varieties with 20% accuracy.

• “90% of global disease burden occurs in the tropics where only 5% of research and development is being done.” –Godal

Polyparastic Infections

• To be infected with more than one parasite.

• An infection with one parasite weakens the immune system and makes the victim more likely to be infected with another parasite.

It’s estimated that 20,000 people died from Polyparasitic Infections last year.

Case Study in Ivory Coast 2006

• Epidemiologists wanted to find out who was at most risk of co-infections of S. mansoni and hookworm.

Predicted Prevalence

• High risk group:– Boys 11-16 years in

the poorest households.

• Less likely to have a latrine and access to healthcare and clean water.

• “Recent epidemiologic studies confirmed that polyparasitism remains a predominant problem in the developing world.”

Intestinal parasitic infections are most prevalent in tropical climates where healthcare and sanitation are

chronically neglected.

http://www.case.edu/med/epidbio/mphp439/Schistosomiasis_files/image002.gif

Epidemiology

_ Chronic parasitic infections infect the poorest people of the poorest countries.

_Where proper bathing stalls,

shoes, and

clean water

are luxuries

that do not exist.

http://www.oneinamillion.co.ke/photos/women.jpg

Imagine…

• By an accident of latitude, you were born into a region of extreme poverty.

• Where would you take a bathe if you didn’t have a shower?

• Where would you get water if there wasn’t a system to obtain it?

• You would bathe in the nearest body of water, with everyone else.

• You would go to the nearest water source and fetch it, like everyone else.

• While bathing you of course, like most people in the developed world do also, you urinate where you bathe. Not realizing that your urine releases eggs of a parasite that will potentially reinfect you and your friends who wade in the very same water.

• It isn’t your fault though. You’ve never heard Schistosomiasis or worms that live in your stomach. In fact, you’ve never even been past the first grade.

Culture• Poverty is directly related to

parasitic infections because the factors that put someone at risk are poverty related factors.

Poverty Related Factors of Parasitic Infections

• Sanitation• Clean Water• Soil• Climate• Hygiene and health

awareness– education, religion

Religion and Parasites in Haiti

• Like many religions in the world today, those who practice voodoo do not believe in the powers of antibiotics and Western medicine.

• Haiti’s national religion is Catholicism, however it is believed that over half of the population practices Voodoo.

•It’s estimated that 8 million residents in Haiti are infected with intestinal parasites. •In some areas, over 40% of children are infected with worms.

Voodoo • Voodoo practitioners can make a diagnosis

by using cards, shells, or trances.

• Treatment by voodoo practitioners usually consists of dancing, incantations, herbal preparations, prayer, and calling on spirits.

Some voodoo rituals include bathing in streamsInfested with sewage.Those who practice voodoo will seek healing from a voodoo priest In the community.

Voodoo in Haiti

A Vodou priest treats an ill woman with mud from the sacred pool in Haiti, during the annual festival honoring the spirit Ogou.

Voodoo believers possessed by spirits at the sacred pool at Sucry near Gonaives, Haiti.

Knowledge

• It’s highly unlikely that people are going to receive proper treatment if they don’t understand what is making them sick.

• Knowledge about how to prevent parasitic infections is the best way to control the parasites.

Health Awareness and Prevention

• Wearing shoes• Cooking food

thoroughly, you can’t always see the eggs you are ingesting

• Clean water systems• Improved hygiene

and sanitation

• This may seem obvious to us, but imagine if you or your parents had never been to school?

• Would know how important these things are to your health?

• What if you didn’t have shoes, or an oven, or running water?

Treatment

• Ridding the world of parasites isn’t the answer.

• But preventing and treating current infections is a reasonable task.

Treatment

• De-worming 250 children costs less than a pack of cigarettes

Conclusion

• Funding for research and development for treatment, vaccines, and widespread drug programs to eradicate the infections.

• Outreach programs to educate the community against reinfection needs to be made a priority if the occurrence of parasitic infections is going to be reduced.

CNN Heroes Video

• http://www.cnn.com/2007/WORLD/americas/09/11/jackson.heroes/index.html#cnnSTCVideo

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Schistosomiasis at Community Level.” WHO/CTD/SID. 98.1 (1998): 3-36.

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