Malaria is a vector-borne infectious disease caused by a eukaryotic protist of the genus Plasmodium. It is widespread in tropical and subtropical regions, including parts of the Americas, Asia, and Africa. Each year, there are approximately 350–500 million cases of malaria,[1] killing between one and three million people, the majority of whom are young children in Sub-Saharan Africa.Ninety percent of malaria-related deaths occur in Sub-Saharan Africa. Malaria is commonly associated with poverty, but is also a cause of poverty and a major hindrance to economic development. Malaria is one of the most common infectious diseases and an enormous public health problem. Five species of the plasmodium parasite can infect humans; the most serious forms of the disease are caused by Plasmodium falciparum. Malaria caused by Plasmodium vivax, Plasmodium ovale and Plasmodium malariae causes milder disease in humans that is not generally fatal. A fifth species, Plasmodium knowlesi, causes malaria in macaques but can also infect humans. This group of human-pathogenic Plasmodium species is usually referred to as malaria parasites. Usually, people get malaria by being bitten by an infective female Anopheles mosquito. Only Anopheles mosquitoes can transmit malaria, and they must have been infected through a previous blood meal taken on an infected person. When a mosquito bites an infected person, a small amount of blood is taken, which contains microscopic malaria parasites. About one week later, when the mosquito takes its next blood meal, these parasites mix with the mosquito’s saliva and are injected into the person being bitten. The parasites multiply within red blood cells, causing symptoms that include symptoms of anemia (light-headedness, shortness of breath, tachycardia, etc.), as well as other general symptoms such as fever, chills, nausea, flu-like illness, and, in severe cases, coma, and death. Malaria transmission can be reduced by preventing mosquito bites with mosquito nets and insect repellents, or by mosquito control measures such as spraying insecticides inside houses and draining standing water where mosquitoes lay their eggs. Work has been done on malaria vaccines with limited success and more exotic controls, such as genetic manipulation of mosquitoes to make them resistant to the parasite have also been considered
Malaria November 14, 2009
Glaucoma November 14, 2009
Glaucoma is a disease that affects the optic nerve and involves loss of retinal ganglion cells in a characteristic pattern.
Haemophilia November 14, 2009
Haemophilia (also spelled hemophilia in North America, is a group of hereditary genetic disorders that impair the body’s ability to control blood clotting or coagulation, which is used to stop bleeding when a blood vessel is broken. Haemophilia A (clotting factor VIII deficiency) is the most common form of the disorder, occurring at about 1 in 5,000–10,000 male births. Haemophilia B (factor IX deficiency) occurs at about 1 in about 20,000–34,000 male births.
Similarly to most recessive sex-linked, X chromosome disorders, only males typically exhibit symptoms. This is due to the fact that females have two X chromosomes while males have only one, lacking a ‘back up’ copy for the defective gene the defective gene becomes manifest more easily in males. Because females have two X chromosomes and because haemophilia is rare, the chance of a female having two defective copies of the gene is very low, thus females are almost exclusivelyasymptomatic carriers of the disorder. Female carriers may inherit the defective gene from either their mother, father, or it may be a new mutation. Only under rare circumstances do females actually have haemophilia. Affected males typically inherit the defective gene from their mother, or it can be a new mutation. Haemophilia has featured prominently in European royalty and thus is sometimes known as “the royal disease”.Causes
Japanese encephalitis November 5, 2009
Japanese encephalitis (Japanese: 日本脳炎, Nihon-nōen; previously known as Japanese B encephalitis to distinguish it from von Economo‘s A encephalitis is a disease caused by the mosquito-borne Japanese encephalitis virus. The Japanese encephalitis virus is a virus from the family Flaviviridae.
Mumps November 4, 2009
Mumps or epidemic parotitis is a viral disease of the human species, caused by the mumps virus. Prior to the development of vaccination and the introduction of avaccine, it was a common childhood disease worldwide, and is still a significant threat to health in the third world
Dumdum fever November 4, 2009
Visceral leishmaniasis (VL), also known as kala-azar, black fever, and Dumdum fever,[1]:426 is the most severe form of leishmaniasis. Leishmaniasis is a diseasecaused by protozoan parasites of the Leishmania genus. It is the second-largest parasitic killer in the world (after malaria), responsible for an estimated 500,000 cases each year worldwide.[2] The parasite migrates to the internal organs such as liver, spleen (hence ‘visceral)’ and bone marrow and if left untreated will almost always result in the death of the host. Signs and symptoms include fever, weight loss, mucosal ulcers, fatigue, anemia and substantial swelling of the liver and spleen. Of particular concern, according to the World Health Organization (WHO), is the emerging problem of HIV/VL co-infection
TB October 29, 2009
In the past, tuberculosis has been called consumption, because it seemed to consume people from within, with a bloody cough, fever, pallor, and long relentless wasting. Other names included phthisis (Greek for consumption) and phthisis pulmonalis; scrofula (in adults), affecting the lymphatic system and resulting in swollen neck glands; tabes mesenterica, TB of the abdomen and lupus vulgaris, TB of the skin; wasting disease; white plague, because sufferers appear markedly pale; king’s evil, because it was believed that a king’s touch would heal scrofula; and Pott’s disease, or gibbus of the spine and joints. Dr. Robert Koch discovered the tuberculosis bacillus. Miliary tuberculosis—now commonly known as disseminated TB—occurs when the infection invades the circulatory system, resulting in lesions which have the appearance of milletseeds on X-ray.[96][98] TB is also called Koch’s disease, after the scientist Robert Koch
