Cholera is an acute, diarrheal illness caused by infection of the intestine with the bacterium Vibrio cholerae. One in 20 infected persons has severe disease characterized by profuse watery diarrhea, vomiting, and leg cramps. In these persons, rapid loss of body fluids leads to dehydration and shock. Without treatment, death can occur within hours.
Typhoid Fever is a life-threatening illness caused by the bacterium Salmonella Typhi. In the developing world, typhoid affects 21.5 million persons each year. A person gets typhoid fever from eating or drinking beverages contaminated with sewage. Many people in the developing world do not have access to clean water to wash their hands. Therefore, typhoid fever is more common in areas of the world where hand washing is less frequent and water is likely to be contaminated with sewage. Persons with typhoid fever usually have a sustained fever as high as 103° to 104° F. They may also feel weak or have stomach pains, headache, or loss of appetite. In some cases patients have a rash of flat, rose-colored spots. Persons who do not get treatment may continue to have fever for weeks or months, and as many as 20% die from complications of the infection.
Malaria is a mosquito-borne disease caused by a parasite. People with malaria often experience fever, chills, and flu-like illness. Left untreated, they may develop severe complications and die. Each year 350-500 million cases of malaria occur worldwide, and over one million people die, most of them young children in Africa south of the Sahara.
Yellow fever is a viral disease that is transmitted to humans through the bite of infected mosquitoes. Yellow fever can cause severe, life-threatening illness. Symptoms of severe infection are high fever, chills, headache, muscle aches, vomiting, and backache. After a brief recovery period, the infection can lead to shock, bleeding, and kidney and liver failure. Liver failure causes jaundice (skin and whites of the eyes), which gives yellow fever its name.
Onchocerciasis or river blindness, is an infection caused by the parasite Onchocerca volvulus worm, spread by the bite of an infected blackfly. When the blackfly bites an infected person, the microscopic worm in the infected person infects the blackfly. The bite of the infected blackfly infects other human beings, thus the disease spreads. Infected persons will have dermatitis, eye lesions, and or nodules under the skin. Skin biopsies will identify the parasite. Globally an estimated 17.7 million have the disease, 270,000 of these are blind and another 500,000 have visual impairment. About 99% of the disease is in Africa.
West African Trypanosomiasis, also called Gambian sleeping sickness, is transmitted by the bite of an infected tsetse fly. It is caused by the parasite Trypanosoma brucei gamiense. Symptoms include fever, rash, swelling of the face and hands, headaches, fatigue, aching muscles and joints, itching skin, and swollen lymph nodes. Weight loss occurs as the disease progresses. Other symptoms include personality change, confusion, and daytime sleepiness with nighttime sleep disturbances. Symptoms become worse as the illness progresses. About 12,000 new cases of West African sleeping sickness occur each year. It is a serious illness which is fatal after several years of infection if left untreated.
Dracunculiasis or Guinea Worm Disease, is caused by a parasite Dracunculus medinensis. Infected persons do not usually have symptoms until about one year after they become infected. A few days to hours before the worm emerges the person may develop a fever, swelling and pain in the area. More than 90% of the worms appear on the legs and feet, but may emerge anywhere on the body. Affected people in rural areas of Africa typically do not have access to medical care. The disease affects poor communities in remote parts of Africa that do not have safe drinking water. There is no treatment for Guinea worm disease. The worm must be removed by a trained doctor as it emerges from the infected person’s skin. Frequently the skin lesions caused by the worm develop secondary bacterial infections which can cause incapacitation for weeks or months, sometimes permanent disability of joints occurs. In 2007, Sudan and Ghana reported 9,173 cases of the Guinea worm disease. At risk is anyone who drinks standing pond water contaminated by persons with guinea worm disease.
Bilharzias or schistosomiasis is caused by a parasite, blood trematodes. Various animals serve as carriers of the parasite. Eggs are eliminated into water with feces or urine. These penetrate the skin of a human host and mature to become worms in humans, capable of moving between sites in the human body. Symptoms may occur weeks after the initial infection, including fever, cough, abdominal pain, and occasionally, bloody diarrhea. The parasite eventually causes damage in the human’s brain or spinal cord leading to central nervous system lesions. Human contact with infected water is necessary for infection by schistosomes.