The symptoms and signs of chronic schistosomiasis are mostly the body's reaction to the eggs retained in the tissues. S. mansoni or S. japonicum can cause mucosal ulcerations, bloody diarrhea, focal fibrosis, strictures, fistulas and papillomatuous growths. Ulcerations in the bladder by S. haematobium may bring on dysuria, hematuria, frequent urination, and chronic cystitis. Secondary bacterial infections in the genitor-urinary tract may also develop. S. mansoni can induce persistent Salmonella septicemia. S. haematorium may cause genital disease or infertility. Their eggs can cause fibrosis and cirrhosis, portal or pulmonary hypertension in the liver or transverse myelitis and seizure in the central nervous system (Pearson). Diagnosis and Treatment

Schistosomiasis is diagnosed through a urine or stool test for parasites (DHPE, 2010;

DPDx, 2010). The Centers for Disease and Control uses a blood test on a sample taken 6-

8 weeks after exposure. It can be cured with praziquantel taken for 1 or 2 days. If praziquantel is not effective in some areas, oxamniquine is prescribed. Prompt treatment is required to avoid complications. Chronic schistosomiasis is often difficult to cure. By then, damage to the liver, lungs, intestines, or the bladder may be life-long. Complications are, however, rare in those who are only briefly exposed or are not re-infected (DHPE, DPDx).

Epidemiology

Recent statistics reveal that approximately 200 million have been afflicted with schistosomiasis worldwide (DPHE, 2010; DPDx, 2010, Kogulan & Lucey, 2007; Pearson, 2009). Extensive incidence in a given country indicates serious problems with sanitary waste disposal and treatment. The resulting chronic illnesses caused by the disease can significantly impact the socio-economic development of that country. It is prevalent in the regions earlier mentioned and does not respect race. It is more common among males, probably because of their greater exposure to contaminated water through their economic activities. Prevalence is highest among those aged 10-14, although exposure can begin right after birth. Adults are lower

Water from canals, lakes, rivers, streams or springs should not be drunk unless previously and adequately boiled or filtered. No vaccines or prophylactic chemotherapy has been developed for schisostomiasis. Artemether may, however, be used as a prophylactic every 2-4 weeks. Those exposed should be promptly diagnosed and treated. The World Health Organization recommends preventive chemotherapy, safe water supply, health education and snail control in endemic areas (DPHE, DPDx, Kogulan & Lucey, Pearson).
Significance

Schistosomiasis is considered an emerging infectious disease worldwide with newer agricultural and water resources in countries, resulting in increased exposure (DPHE, 2010; Ross et al., 2002). Moreover, there have been reports of resistance to the major mode of treatment, praziquantel. Despite successful control measure, schisostomiasis continues to spread and afflict populations on account of increased water resources and migration (DPHE, Ross et al.).

BIBLIOGRAPHY

DHPE (2010). Schistosomiasis fact sheet. Infectious Facts: Directors of Health Promotion

and Education. Retrieved on November 5, 2010 from http://www.dhpe.org/infect/schisto.html

DPDx (2010). Schistosomiasis. Division of Parasitic Diseases and Malaria: Centers of Disease Control and Prevention. Retrieved November 5, 2010 from http://www.dpd.cdc.gov/dpdx/html/schistosomiasis.htm

Kogulan, P. And Lucey, D.R. (2010). Schistosomiasis. eMedicine Specialties: Infections.

Medscape. Retrieved on November 5, 2010 from http://www.medscape.com/viewarticle/228392

Pearson, R. (2009). Schistosomiasis. Section 14 Chapter 183. Merck Medical Library:

Merck & Co., Inc. Retrieved on November 5, 2010 from http://www.merck.com/mmpe/sec14/ch183/ch183h.htm

Ross, A.G.P., et al. (2002). Schistosomiasis. 346: 1212-1220 New England Journal of Medicine: Massachusetts Medical Society. Retrieved on November 5, 2010 from http://www.nejm.org/doi/full/10.1056/NEJMra012396